MISC - FUNABIKI Nobuo

A Study on 3D Model Adaptation for Generating Patch-based Adversarial Perturbations

瀧脇大登, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   123 ( 332(EMM2023 80-88) )   2024

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JPEG圧縮由来の歪み信号に基づくフィルタリングを活用した敵対的事例検出手法

角森健太, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   123 ( 332(EMM2023 80-88) )   2024

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A Proposal of Two Types of Exercise Problems for TCP/IP Programming Learning by C Language

LU Xiqin, FUNABIKI Nobuo, NAING Inzali, HTOO SANDI KYAW Htoo, UEDA Kiyoshi

電子情報通信学会技術研究報告(Web)   122 ( 406(NS2022 167-251) )   2023

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An Overview of Edge Device Framework in SEMAR IoT Application Server Platform

PANDUMAN Yohanes Yohanie Fridelin, FUNABIKI Nobuo, HUSNA Radhiatul, SHWE San Hay Mar, SUKARIDHOTO Sritrusta, KAO Wen-Chung

電子情報通信学会大会講演論文集(CD-ROM)   2023   2023

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An investigation of IEEE802.11ax protocol usage to holding access-point assignment algorithm in wireless local-area networks

田島滋人, 舩曵信生

電子情報通信学会技術研究報告(Web)   122 ( 406(NS2022 167-251) )   2023

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A Throughput Drop Estimation Model with Non-Channel Bonding for Two-Link Concurrent Communications in IEEE 802.11ac WLAN

ROY Sujan Chandra, FUNABIKI Nobuo, WU Bin, SUN Yuanshuai, HTET Ei Ei, KURIBAYASHI Minoru

電子情報通信学会大会講演論文集(CD-ROM)   2023   2023

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An Extension of Answer Interface File Generator for Node.js-based Java Programming Learning Assistant System Platform

AUNG Soe Thandar, FUNABIKI Nobuo, WAI Khaing Hsu, LU Xiqin, JING Yanhui

電子情報通信学会大会講演論文集(CD-ROM)   2023   2023

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Experimental Verification of Interface Setup Optimization Method Using Throughput Estimation Model for Concurrently Communicating Three Access-Points in Wireless Local-Area Network

AKHTER Fatema, FUNABIKI Nobuo, HTET Ei Ei, KURIBAYASHI Minoru

電子情報通信学会大会講演論文集(CD-ROM)   2023   2023

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An Extension of Static Worker Assignment Algorithm to Uniform Jobs with Multiple CPU Time in User-PC Computing System

ZHOU Xudong, FUNABIKI Nobuo, AUNG Lynn Htet, XU Xiang

電子情報通信学会大会講演論文集(CD-ROM)   2023   2023

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A Proposal for Flowchart Understanding Problem (FUP) for System Design Learning

MON Khin Thet, FUNABIKI Nobuo, WAI Khaing Hsu, AUNG Soe Thandar

電子情報通信学会大会講演論文集(CD-ROM)   2023   2023

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Design and Implementation of Unit Testing Tool in Client-Side Web Programming Learning System

NAING Inzali, FUNABIKI Nobuo, WAI Khaing Hsu, HTOO SANDI KYAW Htoo, QI Huiyu, FLASMA Veronicha

電子情報通信学会技術研究報告(Web)   122 ( 406(NS2022 167-251) )   2023

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An Extension of User-PC Computing System for NS-3 Network Simulations

HTET AUNG Lynn, FUNABIKI Nobuo, KURIBAYASHI Minoru, GUNJI Haruki, KOKUBUN Yuto, UEDA Kiyoshi

電子情報通信学会技術研究報告(Web)   122 ( 406(NS2022 167-251) )   2023

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A Study of Grammar-concept Understanding Problem for Web Application Development using MEAN Architecture

KYAW Htoo Htoo Sandi, KANEKO Keiichi, AUNG Soe Thandar, NAING Inzali, FUNABIKI Nobuo

電子情報通信学会技術研究報告(Web)   122 ( 406(NS2022 167-251) )   2023

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Efficient Execution of Wireless Multi-hop Network Simulation by User-PC Computing System using Docker

郡司遥輝, 舩曵信生, HTET Hein, AUNG Lynn Htet, 三好匠, 山崎託, 山本嶺, 上田清志

電子情報通信学会技術研究報告(Web)   122 ( 406(NS2022 167-251) )   2023

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A Study of Automatic Test Data Generation Method for C Programming

LI Zhikang, FUNABIKI Nobuo, LU Xiqin, QI Huiyu

電子情報通信学会大会講演論文集(CD-ROM)   2023   2023

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Development of Web Application for Generating Design QR Code

山崎裕真, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   122 ( 337(ICM2022 31-43) )   2023

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Extensions of Air Conditioning Optimization Guidance System for Improved Ventilation Instructions

坂上暢規, 浜崎和志, 伊東翔, 永山智也, 舩曵信生, 栗林稔

電子情報通信学会技術研究報告(Web)   122 ( 329(MSS2022 44-61) )   2023

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Human Head Position Detection Using OpenPose for Privacy Protection

瀬尾亮太, 田中千奈月, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   122 ( 412(EMM2022 67-92) )   2023

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A Study on Eliminating Malicious Node in Federated Learning

赤井怜音, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   122 ( 412(EMM2022 67-92) )   2023

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Prediction of Room Temperature and Airflow Distribution in Air Conditioning Guidance Systems

ZHAO Yihan, 小島一恭, 佐藤博之, HUO Yuanzhi, 舩曵信生

日本機械学会年次大会講演論文集(CD-ROM)   2022   2022

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A Feasibility Study of Interface Setup Optimization Method Using Throughput Estimation Model for Concurrently Communicating Three Access-Points in Wireless Local-Area Network

AKHTER Fatema, FUNABIKI Nobuo, WU Bin, MARIO GULO Melki, CHANDRA ROY Sujan, KURIBAYASHI Minoru

電子情報通信学会技術研究報告(Web)   122 ( 310(NS2022 128-149) )   2022

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Two Extensions of Indoor Localization System Using IEEE802.15.4 for Detection Accuracy Improvement

濱崎和志, HUO Yuanzhi, PUSPITANINGAYU Pradini, 舩曵信生, 栗林稔

電子情報通信学会技術研究報告(Web)   122 ( 310(NS2022 128-149) )   2022

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Generating patch-wise adversarial examples for avoidance of face recognition system and verification of its robustness

瀧脇大登, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   122 ( 25(IT2022 1-14) )   2022

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A study of adversarial example detection using the correlation between adversarial noise and JPEG compression-derived distortion

角森健太, 山崎裕真, 栗林稔, 舩曵信生, 越前功

電子情報通信学会技術研究報告(Web)   122 ( 25(IT2022 1-14) )   2022

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A Study on Convergency of DNN Watermarking Without Embedding Loss Function

聴覚研究会資料 = Proceedings of the auditory research meeting   51 ( 7 )   393 - 398   2021.11

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A study of fingerprint parameter optimization method for indoor localization system using IEEE802.15.4 devices

Yuanzhi Huo, Pradini Puspitaningayu, Kazushi Hamazaki, Nobuo Funabiki, Minoru Kuribayashi, Kazuyuki Kojima

電子情報通信学会技術研究報告   LOIS2021-4   19 - 24   2021.5

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A Study of Face Detection and Its Privacy Protection in Photos Taken by Wide-Angle Surveillance Camera

中井康貴, 栗林稔, 舩曳信生, 藤井爽平, 石原洋之

電子情報通信学会技術研究報告(Web)   120 ( 418(EMM2020 67-79) )   2021

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Extensions of Answer Analysis Function for Programming Learning Assistant System

西村一輝, 岩本晃司郎, HTOO SANDI KYAW Htoo, 舩曵信生, 栗林稔

電子情報通信学会技術研究報告(Web)   121 ( 12(LOIS2021 1-11) )   2021

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An Extension of Indoor Localization System Using IEEE802.15.4 Protocol for Multiple Users

濱崎和志, PUSPITANINGAYU Pradini, 舩曵信生, 栗林稔

電子情報通信学会技術研究報告(Web)   121 ( 12(LOIS2021 1-11) )   2021

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An Implementation of Ventilation Request Function in Air-Conditioning Guidance System

坂上暢規, HUO Yuanzhi, 舩曵信生, 栗林稔

電子情報通信学会技術研究報告(Web)   121 ( 12(LOIS2021 1-11) )   2021

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A Study on Feature Extraction Suitable for Double JPEG Compression Analysis Based on Statistical Bias Observation of DCT Coefficients

竹下大地, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   121 ( 28(IT2021 1-14) )   2021

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A Study of Detecting Adversarial Examples Using Sensitivities to Multiple Auto Encoders

山崎裕真, 栗林稔, 舩曵信生, NGUYEN Huy HONG, 越前功

電子情報通信学会技術研究報告(Web)   121 ( 28(IT2021 1-14) )   2021

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Detection of Adversarial Examples in CNN Image Classifiers Using Features Extracted with Multiple Strengths of Filter

東亮憲, 栗林稔, 舩曵信生, NGUYEN Huy Hong, 越前功

電子情報通信学会技術研究報告(Web)   120 ( 418(EMM2020 67-79) )   2021

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A Study on Convergency of DNN Watermarking Without Embedding Loss Function

田中拓朗, 安井達哉, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   121 ( 246(EA2021 27-56) )   2021

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Poster Presentation : Evaluation on JPEG Image Compression History Analysis Using Histogram of DCT Coefficients with Different Block Size

聴覚研究会資料 = Proceedings of the auditory research meeting   50 ( 6 )   337 - 342   2020.11

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DM-QIM Watermarking for Fully Connected Layers of DNN Model

映像情報メディア学会技術報告 = ITE technical report   44 ( 18 )   21 - 26   2020.9

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A Database-less Implementation for Portable Server of Java Programming Learning Assistant System

岩本晃司郎, 舩曵信生, 石原信也, 栗林稔

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   71st   2020

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DM-QIM Watermarking for Weights of Deep Neural Network

田中拓朗, 安井達哉, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   119 ( 463(EMM2019 102-129)(Web) )   2020

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Study of CNN-based Analysis on Editing History of JPEG File Using Histogram of DCT Coefficients

小浦啓太郎, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   119 ( 463(EMM2019 102-129)(Web) )   2020

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Detection of Illegal Movies Captured by Video Camera from Display Device

鎌苅康大, 河田健斗, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   119 ( 463(EMM2019 102-129)(Web) )   2020

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A proposal of individual input data extraction method in Word document file

LI Yuehao, 舩曵信生, 栗林稔, 石原信也

電子情報通信学会技術研究報告   119 ( 468(ET2019 76-105)(Web) )   2020

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DM-QIM Watermarking for Fully Connected Layers of DNN Model

田中拓朗, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   120 ( 151(EMM2020 29-35) )   2020

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Detecting Adversarial Examples Based on Sensitivities to Lossy Compression Algorithms

東亮憲, 栗林稔, 舩曵信生, NGUYEN Huy Hong, 越前功

電子情報通信学会技術研究報告   119 ( 463(EMM2019 102-129)(Web) )   2020

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Evaluation on JPEG Image Compression History Analysis Using Histogram of DCT Coefficients with Different Block Size

中嶋直也, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告(Web)   120 ( 241(EA2020 21-45) )   2020

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A Calligraphy Learning Assistant System with Letter Portion Practice Function Using Projection Mapping

Huda Samsul, Funabiki Nobuo, Kuribayashi Minoru, Kao Wen-Chung

IEEE Conference Proceedings   2020 ( ICCE )   2020

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A Proposal of Air Conditioner Overuse Alarm System Using Raspberry Pi

HUDA Samsul, FUNABIKI Nobuo, KURIBAYASHI Minoru, SUDIBYO Rahardhita Widyatra, ISHIHARA Nobuya

電子情報通信学会大会講演論文集(CD-ROM)   2020   2020

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An Improvement of Air-Conditioning Guidance System with Outdoor Discomfort Index for Avoiding False Messages

HUDA Samsul, FUNABIKI Nobuo, KURIBAYASHI Minoru, WIDYATRA SUDIBYO Rahardhita, ISHIHARA Nobuya

電子情報通信学会技術研究報告(Web)   120 ( 69(NS2020 22-30) )   2020

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Extraction of Characteristic Vectors and Its Dimension Reduction for Estimating Collusion Strategy in Fingerprinting Codes

コンピュータセキュリティシンポジウム2019論文集   ( 2019 )   982 - 989   2019.10

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Detecting Adversarial Example Based on Changes of CNN Classification Results Caused by JPEG Compression

コンピュータセキュリティシンポジウム2019論文集   ( 2019 )   975 - 981   2019.10

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Analysis on Editing History of JPEG File Based on the Bias in Histogram of DCT Coefficients

コンピュータセキュリティシンポジウム2019論文集   ( 2019 )   969 - 974   2019.10

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Three Improvements of Code Correction Problem in Java Programming Learning Assistant System

情報処理学会論文誌プログラミング（PRO）   12 ( 3 )   17 - 17   2019.7

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本グループでは，Javaプログラミング教育の高度化を狙いとして，Webを用いたJavaプログラミング学習支援システムJPLASを開発している．JPLASでは，学習者の作成した解答コードに対し，テストコードを用いたソフトウェアテストによる自動採点を行っている．その際，学習者は，テストコード中の情報（クラス，メソッド，変数の名称，アクセス修飾子，データ型など）を読み取り，解答コードに反映する必要がある．そのため，テストコードと誤りのある問題コードを与え，後者の修正を求める，コード修正問題を提案している．また，問題コード生成のために，ソースコードに誤りを施すアルゴリズムを提案している．本研究では，コード修正問題において，1)問題コードの多様化のための誤り情報の追加，2)テストコードを用いた問題コードの検証による正当性検証，3)問題コードの難易度の制御機能，の3つの改良を提案する．それらをJPLASに実装し，本学科Javaプログラミング授業での利用により，本提案の有効性を検証する．
To enhance Java programming educations, we have developed the Web-based Java Programming Learning Assistant System (JPLAS). JPLAS automatically marks the answer code of a student through software test using the test code. Thus, a student has to extract the necessary information from the test code to implement the answer code. To help a novice student, we proposed the code correction problem in the previous study, where a source code with errors, called a problem code, is given to a student with a test code, and is requested to be corrected to pass the test. We also proposed the algorithm to generate the problem code by making errors in the source code. In this study, we propose three improvements in the code correction problem: 1) to allow additional code items for errors for variation of the problem code, 2) to verify the correctness of the problem code by testing it, and 3) to implement the problem difficulty control function. We verify the effectiveness through applications in the Java programing course in our department.

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Implementations of Answering Status Visualization and Problem Recommendation Functions in Java Programming Learning Assistant System

情報処理学会論文誌プログラミング（PRO）   12 ( 3 )   16 - 16   2019.7

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Javaは，可搬性，堅牢性，安全性に優れたプログラミング言語として，業務系システム，組み込みシステムなどに幅広く利用されており，そのプログラミング教育が重要である．そこで本研究室では，Webを用いたJavaプログラミング学習支援システムJPLAS（Java Programming Learning Assistant System）を開発し，授業での運用を行っている．現状のJPLASでは，教員がそれぞれの学生の問題解答状況を一覧で把握するための機能を有していない．また，全学生に同一の問題が出されており，個々の学生の学習レベルに適した問題が出題されていない．本発表では，以上の課題を解決するために，JPLASにおいて，エレメント補充問題を対象として，学生の解答状況の可視化機能，および，各学生に次に解くべき問題の推薦機能を実装する．特に後者では，これまでの学生の解答結果の分析により，各問題の難易度の算出法を提案し，各学生の解答履歴から，その学生に適した難易度の問題を次に解くべき問題として推薦する．評価として，教員に対して，解答状況可視化機能を用いたプログラミング演習を行ってもらう．また，学生に対して，問題推薦機能を用いた問題演習を行ってもらう．その後，アンケートの実施および解答結果の分析を行い，有効性を検証する．今後の課題として，問題難易度設定方法の再検討，エレメント補充問題以外の問題も対応可能な問題推薦機能への拡張があげられる．
As a portable, solid, secure programming language, Java is used widely such as business system and embedded system, thus its programming education is important. Therefore, we have developed the Web-based Java Programming Learning Assistant System (JPLAS) and used it in the Java programming course. JPLAS has no function which teacher can follow answering status of problems for each student. Additionally, it set the same problems to all of students, thus, it doesn't set the suitable problems corresponding to learning level for each student. In this presentation, we implement the answering status visualization function for each student and the recommendation function which recommend problems each student should solve the next for element fill in blank problems in JPLAS. In particular in the latter one, according to analysis of students' answering results so far, we propose the calculation method of problem difficulty and the system recommend the suitable problem to solve the next with learning level and answering history of each student. As an evaluation, we apply the answering status visualization function to the teacher in the programming exercise. Furthermore, we inspect the effectiveness by conducting a questionnaire survey and analyzing the answering results after students solve some of problems using problem recommendation function. In the future works, revision of the way to set up the problem level of difficulty and extension of problem recommendation function to follow other type of problems are some important tips.

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Estimation of Collusion Strategy for Fingerprinting Codes under Noisy Environment

安井達哉, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   118 ( 494(EMM2018 91-115)(Web) )   2019

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A Study of Patch Size for Distinguishing CGs from Real Photos Using CNN

河田健斗, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   118 ( 494(EMM2018 91-115)(Web) )   2019

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Cyclically Permutable codeとLDPC符号における同期回復と誤り訂正能力の比較

須磨尚大, 栗林稔, 舩曵信生

情報理論とその応用シンポジウム予稿集(CD-ROM)   42nd   2019

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An Implementation of Letter Portion Practice Function in Calligraphy Learning Assistant System Using Projection Mapping

HUDA Samsul, FUNABIKI Nobuo, KURIBAYASHI Minoru

情報科学技術フォーラム講演論文集   18th   2019

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An Evaluation of Calligraphy Learning Assistant System Using Projection Mapping

HUDA Samsul, FUNABIKI Nobuo, KURIBAYASHI Minoru, KYAW Htoo Htoo Sandi

電子情報通信学会大会講演論文集(CD-ROM)   2019   2019

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Implementation and Evaluation of Fingerprinting System for Preventing Internal Leakage of Sensitive Data

聴覚研究会資料 = Proceedings of the auditory research meeting   48 ( 7 )   661 - 666   2018.11

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Segment-Wise Watermarking Scheme for PDF Document File Considering The Applicability to Fingerprinting System

聴覚研究会資料 = Proceedings of the auditory research meeting   48 ( 7 )   655 - 660   2018.11

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Dynamic Estimation of Collusion Strategy for the Detection of Colluders in Fingerprinting Codes

安井 達哉, 栗林 稔, 舩曵 信生, 越前 功

映像情報メディア学会技術報告 = ITE technical report   42 ( 31 )   65 - 70   2018.9

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A Study on Synchronization and Error Correction for Cyclically Permutable Code

須磨尚大, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   118 ( 31(IT2018 1-11) )   13 - 18   2018.5

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A Study of Aesthetic QR Code Considering Local Characteristic of Image

栗林稔, 村上元貴, 舩曵信生

電子情報通信学会技術研究報告   118 ( 31(IT2018 1-11) )   19 - 24   2018.5

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Estimation of Collusion Strategy for Fingerprinting Codes

安井達哉, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   117 ( 476(EMM2017 77-93) )   17 - 22   2018.3

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Analysis on History of JPEG Compression Considering the Characteristic of Quantization Table

小浦啓太郎, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   117 ( 476(EMM2017 77-93) )   45 - 50   2018.3

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A Study of Tracing Algorithm for Fingerprinting Code Considering Erasure Symbols (マルチメディア情報ハイディング・エンリッチメント)

栗林 稔, 舩曵 信生

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 425 )   13 - 18   2018.1

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An Extension of Test Code Generation Support Tool Using Test Log to Java Method with Returning Value

日下 涼太, 舩曵 信生, 栗林 稔, 石原 信也

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 381 )   127 - 132   2018.1

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A Proposal of Code Correction Problem for Test Code Study in Java Programming Learning Assistant System

何 賽, 舩曵 信生, 栗林 稔, 石原 信也

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 381 )   161 - 166   2018.1

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An Introduction of Source Code Management System for Java Programming Learning Assistant System : JPLAS

松本 慎平, 舩曵 信生, 栗林 稔, 石原 信也

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 380 )   167 - 172   2018.1

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A test code generation method for coding standard input/output with exception handling in Java programming learning assistant system

Ei Ei Mon, Nobuo Funabiki, Ryota Kusaka, Khin Khin Zaw, Wen-Chung Kao

Advances in Science, Technology and Engineering Systems Journal   3 ( 1 )   30 - 37   2018

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A proposal of code completion problem for Java programming learning assistant system

Htoo Htoo, Sandi Kyaw, Shwe Thinzar Aung, Hnin Aye Thant, Nobuo Funabiki

Proceeding of The 10th International Workshop on Virtual Environment and Network-Oriented Applications (VENOA-2018)   855 - 864   2018

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A proposal of hardware channel bonding for IEEE802.11n wireless network using Raspberry Pi

Rahardhita Widyatra Sudibyo, Nobuo Funabiki, Wen-Chung Kao

Proceeding of 2018 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-TW 2018)   277 - 278   2018

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A study of MIMO host location optimization in active access-point configuration algorithm for elastic WLAN system

Mousumi Saha, Nobuo Funabiki, Sumon Kumar Debnath, Wen-Chung Kao

Proceeding of 2018 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-TW 2018)   275 - 276   2018

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A throughput estimation model for IEEE 802.11n MIMO link in wireless local-area networks

Sumon Kumar Debnath, Mousumi Saha, Nobuo Funabiki, Wen-Chung Kao

Proceedings of 3rd International Conference on Computer and Communication Systems (ICCCS-2018)   327 - 331   2018

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A holding access-point assignment algorithm for IEEE802.11 wireless local-area networks

Shigeto Tajima, Nobuo Funabiki, Teruo Higashino

International Journal of Space-Based and Situated Computing   8 ( 1 )   50 - 58   2018

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An improved informative test code approach for code writing problem in Java programming learning assistant system

Nobuo Funabiki, Khin Khin Zaw, Ei Ei Mon, Wen-Chung Kao

Proceeding of The 6th International Conference on Emerging Internet, Data and Web Technologies (EIDWT-2018)   687 - 698   2018

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Implementation and Evaluation of Fingerprinting System for Preventing Internal Leakage of Sensitive Data

上田貴大, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   118 ( 312(EA2018 63-80) )   2018

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Segment-Wise Watermarking Scheme for PDF Document File Considering The Applicability to Fingerprinting System

福島拓哉, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   118 ( 312(EA2018 63-80) )   2018

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Dynamic Estimation of Collusion Strategy for the Detection of Colluders in Fingerprinting Codes

安井達哉, 栗林稔, 舩曵信生, 越前功

電子情報通信学会技術研究報告   118 ( 223(IE2018 30-43)(Web) )   2018

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File access extension of test code generation tool for Java programming learning assistant system

Nobuo Funabiki, Ryota Kusaka, Nobuya Ishihara, Wen-Chung Kao

2017 IEEE 6th Global Conference on Consumer Electronics, GCCE 2017   2017-   1 - 2   2017.12

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To advance Java programming studies, we have developed the Java Programming Learning Assistant System (JPLAS). The test code plays a critical role in verifying the correctness of the source code from a student automatically at the server in the code writing problem in JPLAS. Previously, we proposed the test code generation tool that automatically generates the test code from the given source code containing standard inputs/outputs that novice students are expected to study in advance. In this paper, we extend this tool to handle the source code with file inputs/outputs. By applying the extended tool to three codes containing file inputs/outputs, the correctness of the generated test codes is confirmed.

DOI： 10.1109/GCCE.2017.8229400

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A holding access-point assignment algorithm for wireless local-area networks

Shigeto Tajima, Nobuo Funabiki, Sumon Kumar Debnath, Teruo Higashino

2017 9th IEEE International Conference on Communication Software and Networks, ICCSN 2017   2017-   367 - 371   2017.12

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Nowadays, various types of access-points (APs) and hosts such as dedicated APs, laptop personal computers, and mobile terminals have been used in IEEE802.11 wireless local-area networks (WLANs). As a result, the optimal assignment of holding APs into the network field depending on the host type distribution has become very important to improve the network performance. In this paper, we formulate this holding access-point assignment problem as a combinatorial optimization problem and propose its heuristic algorithm. Because plural non-overlapping channels are available in IEEE802.11 WLANs, we extend the algorithm to finding the channel assignment to the APs such that the total interference among them is minimized. The effectiveness of our proposal is verified through simulations in three instances.

DOI： 10.1109/ICCSN.2017.8230137

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Accumulator for monotone formulas and its application to anonymous credential system

Shahidatul Sadiah, Toru Nakanishi, Nasima Begum, Nobuo Funabiki

Journal of Information Processing   25   949 - 961   2017.12

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An anonymous credential system allows a user to convince a service provider anonymously that he/she owns certified attributes. Previously, a system to prove AND and OR relations simultaneously by CNF formulas was proposed. To achieve a constant-size proof of the formula, this system adopts an accumulator that compresses multiple attributes into a single value. However, this system has a problem: the proof generation requires a large amount of computational time in the case of lots of OR literals in the formula. Therefore, we convert the attribute relation from the CNF formula to a monotone formula to decrease the number of OR literals. The monotone formula is a logic formula that contains any combination of AND and OR relations. In this paper, we propose an extended accumulator to prove the monotone formula, and apply it to the anonymous credential system. Our approach to prove the monotone formula is that the tag assignment in the accumulator is extended to be adapted to the tree expressing the monotone formula. Using this type of formula, the number of public parameters multiplied in the accumulator is decreased, which greatly impacts the reduction of authentication time.

DOI： 10.2197/ipsjjip.25.949

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A Study of Throughput Estimation Model and Channel Assignment Algorithm for Partially Overlapping Channels in IEEE 802.11n Wireless Local-Area Networks (ネットワークシステム)

イスマエル・ムネネ クエンガ, 舩曵 信生, セリム・アル・マムン ムハマド, ソウ・ルイン キョウ, クマル・デブナ シュモン

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 303 )   23 - 28   2017.11

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A Study of Throughput Estimation Model for IEEE 802.11n MIMO Link in Wireless Local-Area Network (ネットワークシステム) Reviewed

クマル・デブナ シュモン, 舩曵 信生, ソウ・ルイン キョウ, セリム・アル・マムン ムハマド

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 303 )   17 - 22   2017.11

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A Study of DCT-OFDM-Based Watermarking Scheme Assisted by Error Correcting Code

重本章吾, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   117 ( 282(EMM2017 55-65) )   47 - 52   2017.11

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A study of obfuscation for the security enhancement of watermarking schemes

山下晃一郎, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   117 ( 282(EMM2017 55-65) )   53 - 58   2017.11

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Making of Code Clone Elimination Problem Function for Java Programming Learning Assistant System

石原 信也, 舩曵 信生, 栗林 稔

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 249 )   25 - 30   2017.10

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An Informative Test Code Approach for Code Writing Problem in Java Programming Learning Assistant System (ソフトウェアサイエンス)

キン ゾウ キン, 舩曵 信生

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 248 )   31 - 36   2017.10

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An Informative Test Code Approach for Code Writing Problem in Java Programming Learning Assistant System (ディペンダブルコンピューティング)

キン ゾウ キン, 舩曵 信生

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   117 ( 249 )   31 - 36   2017.10

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A software architecture for Java programming learning assistant system

Ishihara Nobuya, Funabiki Nobuo, Kuribayashi Minoru, Kao Wen-Chung

International Journal of Computer & Software Engineering   2 ( 1 )   116 - 116   2017.7

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For advancements of Java programming educations, we have developed a Web-based Java Programming Learning System (JPLAS). JPLAS provides four problems with different levels, namely, element fill-inblank problem, value trace problem, statement fill-in-blank problem, and code writing problem, to cover students at different learning stages. Unfortunately, since JPLAS has been implemented by a number of students who studied in our group at different years, the code has become complex and redundant, which makes further extensions of JPLAS extremely hard. In this paper, we propose a software architecture for JPLAS to avoid redundancy. Based on the MVC model, our proposal uses Java for the model (M), HTML/CSS/JavaScript for the view (V), and JSP for the controller (C). Besides, adopting a design pattern, the marking functions of the four problems are implemented uniformly. For evaluations, after JPLAS is implemented with this architecture, the number of code files is compared with that of the previous implementation, and the number of additional files is examined for two new functions.

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An offline answering function for code writing problem in Java Programming Learning Assistant System

Nobuo Funabiki, Yingxin Wang, Nobuya Ishihara, Wen-Chung Kao

2017 IEEE International Conference on Consumer Electronics - Taiwan, ICCE-TW 2017   241 - 242   2017.7

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In order to promote Java programming educations, the Web-based Java Programming Learning Assistant System (JPLAS) has been implemented. JPLAS provides the code writing problem, where students write Java codes that satisfy the given specifications and submit them to the JPLAS server to obtain the marks using test codes instantly. Unfortunately, JPLAS could be accessed simply when the Internet connections are available. In this study, we perform the offline answering function for the code writing problem for use of JPLAS even in places without the Internet connections. First, the teacher downloads the assignment files from the server and delivers them to the students using USB memories. Next, students solve the assignments on Eclipse including code writing and testing, then submit the results to the teacher. Finally, the teacher uploads the results to the server. To evaluate the proposed function, the questionnaire will be collected after giving five assignments to six students in our group.

DOI： 10.1109/ICCE-China.2017.7991085

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Watermarking Scheme with Large Capacity Considering the Internal Structure of PDF File

福島拓哉, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   117 ( 39(IT2017 1-15) )   13 - 18   2017.5

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A Proposal of Fingerprinting System for Protection of Sensitive Data from Internal Leakage

上田貴大, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   117 ( 39(IT2017 1-15) )   19 - 24   2017.5

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DCT-OFDM Watermarking Scheme Based on Communication System Model

Minoru Kuribayashi, Shogo Shigemoto, Nobuo Funabiki

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E100A ( 4 )   944 - 952   2017.4

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In conventional spread spectrum (SS) watermarking schemes, random sequences are used for the modulation of watermark information. However, because of the mutual interference among those sequences, it requires complicated removal operation to improve the performance. In this paper, we propose an efficient spread spectrum watermarking scheme by introducing the orthogonal frequency divisiion multiplexing (OFDM) technique at the modulation of watermark information. The SS sequences in the proposed method are the DCT basic vectors modulated by a pseudo-random number (PN) sequence. We investigate the SS-based method considering the host interference at the blind detection scenario and analyze the noise caused by attacks. Because every operation is invertible, the quantization index modulation (QIM)-based method is applicable for the OFDM modulated signals. We also consider the property of watermark extracting operation in SS-based and QIM-based method and formalize their models of noisy channel in order to employ an error correcting code. The performance of their methods with error correcting code is numerically evaluated under the constraints of same distortion level in watermarked content. The experimental results indicated a criteria for the selection of SS-based and QIM-based methods for given content, which is determined by the amount of host interference. In case that the host interference is 0.8 times smaller than a watermark signal, the SS-based method is suitable. When it is 1.0 times larger, the QIM-based method should be selected.

DOI： 10.1587/transfun.E100.A.944

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A Consideration of Partial Channel Interference in Channel Assignment for Holding Access-Point Assignment Problem in Wireless Local-Area Networks

116 ( 484 )   457 - 462   2017.3

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Cross-layer selective routing for cost and delay minimization in IEEE 802.11ac wireless mesh network

I. W. Lai, Nobuo Funabiki, Shigeto Tajima, Md. Selim Al Mamun, Sho Fujita

Wireless Networks   1 - 13   2017.2

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A Wireless Internet-access Mesh NETwork (WIMNET) provides scalable and reliable internet access through the deployment of multiple access points (APs) and gateways (GWs). In this work, we propose a selective routing algorithm aiming at a hierarchical minimization of the operational cost and the maximal end-to-end delay. In particular, by deploying redundant APs/GWs in the network field, the WIMNET becomes robust to the link or AP/GW failure. However, these redundant APs/GWs increase the operational cost like the power consumption. By using Dijkstra algorithm and 2-opt algorithm, the proposed algorithm iteratively deactivates the deployed APs/GWs and performs the routing that reduces the maximal end-to-end delay based on the APs/GWs remaining active. The generated route meets the real-world constraints like fairness criterion. We further propose a cross-layer design to enhance the routing performance by exploiting the MAC-layer frame aggregation technique. The selective routing algorithm is then implemented in the WIMNET simulator proposed by our group. The numerical experiments demonstrate that in both indoor and open space environments, the proposed selective routing greatly reduces the operational cost, i.e., up to (Formula presented.) APs/GWs can be deactivated.

DOI： 10.1007/s11276-017-1462-9

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Cross-layer selective routing for cost and delay minimization in IEEE 802.11ac wireless mesh network

I. W. Lai, Nobuo Funabiki, Shigeto Tajima, Md. Selim Al Mamun, Sho Fujita

Wireless Networks   1 - 13   2017.2

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A Wireless Internet-access Mesh NETwork (WIMNET) provides scalable and reliable internet access through the deployment of multiple access points (APs) and gateways (GWs). In this work, we propose a selective routing algorithm aiming at a hierarchical minimization of the operational cost and the maximal end-to-end delay. In particular, by deploying redundant APs/GWs in the network field, the WIMNET becomes robust to the link or AP/GW failure. However, these redundant APs/GWs increase the operational cost like the power consumption. By using Dijkstra algorithm and 2-opt algorithm, the proposed algorithm iteratively deactivates the deployed APs/GWs and performs the routing that reduces the maximal end-to-end delay based on the APs/GWs remaining active. The generated route meets the real-world constraints like fairness criterion. We further propose a cross-layer design to enhance the routing performance by exploiting the MAC-layer frame aggregation technique. The selective routing algorithm is then implemented in the WIMNET simulator proposed by our group. The numerical experiments demonstrate that in both indoor and open space environments, the proposed selective routing greatly reduces the operational cost, i.e., up to (Formula presented.) APs/GWs can be deactivated.

DOI： 10.1007/s11276-017-1462-9

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A Proposal of Code Clone Deletion Problem for Java Programming Learning Assistant System

石原 信也, 舩曵 信生, 栗林 稔

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 425 )   47 - 52   2017.1

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An Improvement of Naming Rule Testing Tool for Java Programming Learning

松本慎平, 舩曵信生, 栗林稔, 石原信也

電子情報通信学会技術研究報告   116 ( 426(SS2016 36-59) )   41‐46   2017.1

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Javaプログラミング学習のための命名規則検査ツールの改良—An Improvement of Naming Rule Testing Tool for Java Programming Learning—システム数理と応用

松本 慎平, 舩曵 信生, 栗林 稔, 石原 信也

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 425 )   41 - 46   2017.1

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Language：Japanese   Publisher：東京 : 電子情報通信学会  

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A parameter optimization tool and its application to throughput estimation model for wireless LAN

Nobuo Funabiki, Chihiro Taniguchi, Kyaw Soe Lwin, Khin Khin Zaw, Wen-Chung Kao

The 9th International Workshop on Virtual Environment and Network-Oriented Applications (VENOA-2017)   701 - 710   2017

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A graph-based blank element selection algorithm for fill-in-blank problems in Java programming learning assistant system

Nobuo Funabiki, Tana, Khin Khin Zaw, Nobuya Ishihara, Wen-Chung Kao

International Journal of Computer Science   44 ( 2 )   247 - 260   2017

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An element fill-in-blank problem application in UTYCC for Java programming learning assistant system

Htoo Htoo, Sandi Kyaw, Shwe Thinzar Aung, Hnin Aye Thant, Nobuo Funabiki

Proceedings of The 8th International Conference on Science and Engineering 2017 (ICSE 2017)   271 - 275   2017

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A proposal of informative test code approach for code writing problem in Java programming learning assistant system

Khin Khin Zaw, Nobuo Funabiki, Wen-Chung Kao

Proceedings of The 8th International Conference on Science and Engineering 2017 (ICSE 2017)   260 - 265   2017

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A design-aware test code approach for code writing problem in Java programming learning assistant system

Khin Khin Zaw, Nobuo Funabiki

International Journal of Space-Based and Situated Computing   7 ( 3 )   145 - 154   2017

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Dynamic access-point configuration approach for elastic wireless local-area network system

Md. Manowarul Islam, Md. Selim Al Mamun, Nobuo Funabiki, Minoru Kuribayashi

Proceedings of The Fifth International Symposium on Computing and Networking (CANDAR, ASON))   2017

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DOI： 10.1109/CANDAR.2017.20

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A Channel Assignment Extension of Active Access-Point Configuration Algorithm for Elastic WLAN System and Its Implementation Using Raspberry Pi

Mamun Md. Selim Al, Funabiki Nobuo, Lwin Kyaw Soe, Islam Md. Ezharul, Kao Wen-Chung

International Journal of Networking and Computing   7 ( 2 )   248 - 270   2017

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Recently, Wireless Local-Area Network (WLAN) has become prevailing as it provides flexible Internet access to users with low cost through installation of several types of access points (APs) in the network. Previously, we proposed the active AP configuration algorithm for the elastic WLAN system using heterogeneous APs, which dynamically optimizes the configuration by activating or deactivating APs based on traffic demands. However, this algorithm assumes that any active AP may use a different channel from the other ones to avoid interferences, although the number of non-interfered channels in IEEE 802.11 protocols is limited. In this paper, we propose the extension of the AP configuration algorithm to consider the channel assignment to the active APs under this limitation. Besides, AP associations of the hosts are modified to improve the network performance by averaging loads among channels. The effectiveness of our proposal is evaluated using the WIMNET simulator in two topologies. Finally, the elastic WLAN system including this proposal is implemented using Raspberry Pi for the AP. The feasibility and performance of the implementation are verified through experiments using the testbed.

DOI： 10.15803/ijnc.7.2_248

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A Minimax Approach for Access Point Setup Optimization in IEEE 802.11n Wireless Networks

Lwin Kyaw Soe, Funabiki Nobuo, Taniguchi Chihiro, Zaw Khin Khin, Mamun Md. Selim Al, Kuribayashi Minoru, Kao Wen-Chung

International Journal of Networking and Computing   7 ( 2 )   187 - 207   2017

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Recently, an IEEE 802.11n access point (AP) prevailed over the wireless local area network (WLAN) due to the high-speed data transmission using the multiple input multiple output (MIMO) technology. Unfortunately, the signal propagation from the 802.11n AP is not uniform in the circumferential and height directions because of the multiple antennas for MIMO. As a result, the data transmission speed between the AP and a host could be significantly affected by their relative setup conditions. In this paper, we propose a minimax approach for optimizing the 802.11n AP setup condition in terms of the angles and the height in an indoor environment using throughput measurements. First, we detect a bottleneck host that receives the weakest signal from the AP in the field using the throughput estimation model. To explore optimal values of parameters for this model, we adopt the versatile parameter optimization tool. Then, we optimize the AP setup by changing the angles and the height while measuring throughput. For evaluations, we verify the accuracy of the model using measurement results and confirm the throughput improvements for hosts in the field by our approach.

DOI： 10.15803/ijnc.7.2_187

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A fill-in-blank problem workbook for Java programming learning assistant system

Ta Na, Nobuo Funabiki, Khin Khin Zaw, Nobuya Ishihara, Shinpei Matsumoto, Wen-Chung Kao

International Journal of Web Information Systems   13 ( 2 )   140 - 154   2017

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Purpose-To advance Java programming educations, the authors have developed a Java Programming Learning Assistant System (JPLAS) as a web application system. JPLAS provides fill-in-blank problems for novices to study the grammar and basic programming skills through code reading. Design/methodology/approach-To select the blank elements with grammatically correct and unique answers from a given Java code, the authors have proposed the graph-based blank element selection algorithm. Then, the code for this problem should be highly readable to encourage novice students to study it. Because code readability can be improved by proper names for identifiers, the authors have also proposed the naming rule testing algorithm to identify codes with correct names. Findings-In this paper, the authors present a fill-in-blank problem workbook by collecting suitable Java codes from textbooks and Web sites and applying these algorithms with several extensions. The workbook consists of 16 categories with a considerable number of problems that follow the conventional learning order of Java programming. Originality/value-The proper set of ready-made fill-in-blank problems is effective in enhancing the usability of JPLAS both for teachers and students. For the preliminary evaluation, the authors assign a few problems to students. In coming semesters, the authors will use this workbook in the course to verify the adequacy of the proposal for novices.

DOI： 10.1108/IJWIS-12-2016-0076

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A Proposal of Software Architecture for Java Programming Learning Assistant System

Nobuya Ishihara, Nobuo Funabiki, Minoru Kuribayashi, Wen-Chung Kao

2017 IEEE 31ST INTERNATIONAL CONFERENCE ON ADVANCED INFORMATION NETWORKING AND APPLICATIONS (AINA)   2 ( 1 )   64 - 70   2017

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To improve Java programming educations, we have developed a Web-based Java Programming Learning System (JPLAS). To deal with students at different levels, JPLAS provides three levels of problems, namely, element fill-in-blank problems, statement fill-in-blank problems, and code writing problems. Unfortunately, since JPLAS has been implemented by various students who studied in our group at different years, the code has become complex and redundant, which makes further extensions of JPLAS extremely hard. In this paper, we propose the software architecture for JPLAS to avoid redundancy to the utmost at implementations of new functions that will be continued with this JPLAS project. Following the MVC model, our proposal basically uses Java for the model (M), JavaScript/CSS for the view (V), and JSP for the controller (C). For the evaluation, we implement JPLAS by this architecture and compare the number of code files with the previous implementation.

DOI： 10.1109/AINA.2017.56

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A Proposal of Test Code Generation Tool for Java Programming Learning Assistant System

Nobuo Funabiki, Ryota Kusaka, Nobuya Ishihara, Wen-Chung Kao

2017 IEEE 31ST INTERNATIONAL CONFERENCE ON ADVANCED INFORMATION NETWORKING AND APPLICATIONS (AINA)   51 - 56   2017

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To advance Java programming educations, we have developed the Java programming learning assistant system (JPLAS) that can verify the correctness of the code from a student automatically using the test-driven development (TDD) method. Then, to register a new assignment in JPLAS, teachers are required to write the test code in addition to the reference source code. Unfortunately, most teachers at schools are not accustomed to writing test codes. In this paper, we propose a test code generation tool that automatically generates the test cases from the reference source code by extracting the outputs for given inputs using functions in JUnit. As assignments for Java novice students, the code that contains standard inputs/outputs is emphasized. For evaluation, we collected 97 codes containing standard inputs/outputs from Java programming text books or Web sites. The experimental result has shown that the proposed tool correctly generated the test codes for them except for one code using a random generator.

DOI： 10.1109/AINA.2017.60

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A fill-in-blank problem workbook for Java programming learning assistant system

Ta Na, Nobuo Funabiki, Khin Khin Zaw, Nobuya Ishihara, Shinpei Matsumoto, Wen-Chung Kao

International Journal of Web Information Systems   13 ( 2 )   140 - 154   2017

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Purpose-To advance Java programming educations, the authors have developed a Java Programming Learning Assistant System (JPLAS) as a web application system. JPLAS provides fill-in-blank problems for novices to study the grammar and basic programming skills through code reading. Design/methodology/approach-To select the blank elements with grammatically correct and unique answers from a given Java code, the authors have proposed the graph-based blank element selection algorithm. Then, the code for this problem should be highly readable to encourage novice students to study it. Because code readability can be improved by proper names for identifiers, the authors have also proposed the naming rule testing algorithm to identify codes with correct names. Findings-In this paper, the authors present a fill-in-blank problem workbook by collecting suitable Java codes from textbooks and Web sites and applying these algorithms with several extensions. The workbook consists of 16 categories with a considerable number of problems that follow the conventional learning order of Java programming. Originality/value-The proper set of ready-made fill-in-blank problems is effective in enhancing the usability of JPLAS both for teachers and students. For the preliminary evaluation, the authors assign a few problems to students. In coming semesters, the authors will use this workbook in the course to verify the adequacy of the proposal for novices.

DOI： 10.1108/IJWIS-12-2016-0076

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A graph-based blank element selection algorithm for fill-in-blank problems in Java programming learning assistant system

Nobuo Funabiki, Tana, Khin Khin Zaw, Nobuya Ishihara, Wen Chung Kao

IAENG International Journal of Computer Science   44 ( 2 )   247 - 260   2017

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A User-PC computing system as ultralow-cost computation platform for small groups

Nobuo Funabiki, Kyaw Soe Lwin, Yuuki Aoyagi, Minoru Kuribayashi, Wen-Chung Kao

Application and Theory of Computer Technology   2 ( 3 )   10 - 24   2017

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A Proposal of Software Architecture for Java Programming Learning Assistant System

Nobuya Ishihara, Nobuo Funabiki, Minoru Kuribayashi, Wen-Chung Kao

2017 IEEE 31ST INTERNATIONAL CONFERENCE ON ADVANCED INFORMATION NETWORKING AND APPLICATIONS (AINA)   64 - 70   2017

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Language：English   Publisher：IEEE  

To improve Java programming educations, we have developed a Web-based Java Programming Learning System (JPLAS). To deal with students at different levels, JPLAS provides three levels of problems, namely, element fill-in-blank problems, statement fill-in-blank problems, and code writing problems. Unfortunately, since JPLAS has been implemented by various students who studied in our group at different years, the code has become complex and redundant, which makes further extensions of JPLAS extremely hard. In this paper, we propose the software architecture for JPLAS to avoid redundancy to the utmost at implementations of new functions that will be continued with this JPLAS project. Following the MVC model, our proposal basically uses Java for the model (M), JavaScript/CSS for the view (V), and JSP for the controller (C). For the evaluation, we implement JPLAS by this architecture and compare the number of code files with the previous implementation.

DOI： 10.1109/AINA.2017.56

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Javaプログラミング学習支援システムJPLASのステートメント補充問題のオフライン解答機能

TANG Lewei, 舩曵信生, 石原信也, 栗林稔

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM)   68th   2017

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A Channel Assignment Extension of Holding Access-Point Assignment Algorithm for Wireless Local-Area Networks

116 ( 382 )   95 - 100   2016.12

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Raspberry Pi Configuration for Access-Point and Its Throughput Measurements in IEEE802.11n Wireless Networks (ネットワークシステム)

KUMAR DEBNATH Sumon, 舩曵 信生, SOE LWIN Kyaw, SELIM AL MAMUN Md., WIDYATRA SUDIBYO Rahardhita, HUDA Samsul

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 382 )   101 - 106   2016.12

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A Development of Parameter Optimization Tool and Its Application to Throughput Estimation Model for Wireless LANs

谷口知弘, 舩曵信生, 栗林稔, SOE LWIN Kyaw, SUMON KUMAR Debnath, KHIN ZAW Khin

電子情報通信学会技術研究報告   116 ( 382(NS2016 118-140) )   89 - 94   2016.12

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Implementations of Problem Assignment and Offline Fill-in-blank Problem Learning Functions in Java Programming Learning Assistant System

佐々木伸, 舩曵信生, 栗林稔, 石原信也

電子情報通信学会技術研究報告   116 ( 351(ET2016 66-77) )   33 - 38   2016.12

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Offline Answering Function for Code Writing Problem in Java Programming Learning Assistant System

WANG Yingxin, 舩曵信生, 栗林稔, 石原信也

電子情報通信学会技術研究報告   116 ( 351(ET2016 66-77) )   39 - 44   2016.12

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Development of Aesthetic QR Code Encoder for Arbitrary Image

行地将智, 栗林稔, CHANG Ee-Chien, 舩曵信生, 石原信也

電子情報通信学会技術研究報告   116 ( 302(EA2016 48-67) )   49 - 54   2016.11

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Throughput Measurements for Access-Point Setup Optimization in IEEE802.11n Wireless Networks (ネットワークシステム) -- (WDN特集セッション)

ソウ ルウィン キョウ, 舩曵 信生, キン ゾウ キン, セリム アル マムン ムハマド, 栗林 稔

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 149 )   27 - 32   2016.7

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Throughput Measurements for Access-Point Setup Optimization in IEEE802.11n Wireless Networks (高信頼制御通信) -- (WDN特集セッション)

ソウ ルウィン キョウ, 舩曵 信生, キン ゾウ キン, セリム アル マムン ムハマド, 栗林 稔

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 145 )   45 - 50   2016.7

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Throughput Measurements for Access-Point Setup Optimization in IEEE802.11n Wireless Networks (無線通信システム) -- (WDN特集セッション)

ソウ ルウィン キョウ, 舩曵 信生, キン ゾウ キン, セリム アル マムン ムハマド, 栗林 稔

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 147 )   75 - 80   2016.7

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Considerations of Some Obfuscated Operations on the Security of Watermarking Schemes under the Kerckhoffs' Principle

山下 晃一郎, 栗林 稔, 舩曵 信生

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   116 ( 129 )   7 - 12   2016.7

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A Study of Employment of Error Correcting Codes for the Watermarking Scheme Considering the Characteristic of Noise

重本章吾, 栗林稔, 舩曵信生

電子情報通信学会技術研究報告   116 ( 130(SITE2016 7-31) )   1 - 6   2016.7

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A Proposal of Automatic Test Code Generation Tool for Java Programming Learning Assistant System

日下涼太, 舩曵信生, 栗林稔, 石原信也

電子情報通信学会技術研究報告   116 ( 85(ET2016 8-20) )   41 - 46   2016.6

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A Proposal of Coding Rule for Java Programming Learning Assistant System Using MVC Model and Its Implementation

石原信也, 舩曵信生, 栗林稔

電子情報通信学会技術研究報告   116 ( 85(ET2016 8-20) )   47 - 52   2016.6

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A Study of Holding Access-Point Assignment Algorithm for Wireless Local-Area Networks

116 ( 8 )   11 - 16   2016.4

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BS-3-31 EVALUATIONS OF ACTIVE ACCESS-POINT CONFIGURATION ALGORITHM UNDER LIMITED MOBILE ROUTER ALLOCATIONS(BS-3. Advanced Networking Technologies for Innovative Information Networks)

Mamun Md. Selim Al, Islam Md. Ezharul, Debnath Sumon Kumar, Funabiki Nobuo

Proceedings of the IEICE General Conference   2016 ( 2 )   "S - 72"-"S-73"   2016.3

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Previously, we proposed an active access point (AP) configuration algorithm with the dynamic mobile router placement using the K-means algorithm to realize the elastic Wireless Local-Area Network (WLAN) system. However, this algorithm assumed that mobile routers can be freely placed at any location in the network, although they should be managed personally by their owners and thus, it becomes unrealistic. In this paper, we consider the locations of hosts as the candidate locations for the mobile routers, because host owners may use mobile routers for the Internet access. We compare the throughput performance of the limited mobile router locations with the previous free locations using the WIMNET simulator.

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BS-3-33 PERFORMANCE EVALUATIONS OF ELASTIC WLAN SYSTEM TESTBED(BS-3. Advanced Networking Technologies for Innovative Information Networks)

Islam Ezharul, Funabiki Nobuo, Lwin Kyaw Soe, Mamun Md. Selim Al, Debnath Sumon Kumar, Kuribayashi Minoru

Proceedings of the IEICE General Conference   2016 ( 2 )   "S - 76"-"S-77"   2016.3

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The elastic wireless local-area network (WLAN) system has been proposed as an adaptive and elastic WLAN system to traffic load changes in the network. Using Linux PCs, we implemented a testbed for this system that collects necessary information for the Access-Point (AP) aggregation algorithm to determine the activation/deactivation of APs by using Linux commands. Then, it controls the active APs and the associations of hosts based on the algorithm output. In this paper, we present performance evaluations of this elastic WLAN system testbed in two network scenarios in our building.

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BS-3-35 THROUGHPUT MEASUREMENTS WITH VARIOUS INDOOR AP PLACEMENT CONDITIONS FOR IEEE802.11N WIRELESS NETWORKS(BS-3. Advanced Networking Technologies for Innovative Information Networks)

Lwin Kyaw Soe, Funabiki Nobuo, Islam Md. Ezharul

Proceedings of the IEICE General Conference   2016 ( 2 )   "S - 80"-"S-81"   2016.3

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Recently, the IEEE802.11n protocol has become popular for wireless local-area networks (WLANs). It adopts the MIMO (Multiple-Input-Multiple-Output) technology for high-speed data transmissions using multiple antennas. As a result, the device can be influenced by the installation environment in receiving/transmitting signals. This paper presents experimental performance evaluations of IEEE802.11n devices for WLAN by focusing on throughputs versus placement heights and orientations in indoor environments. Our results show that throughput performance is strongly affected by the placement heights and the orientations of access point (AP). These results should be considered in optimizing the placement of APs in the network field.

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A Proposal of Readable Code Learning Tool for Java Programming

小川卓也, 舩曵信生, 栗林稔, 石原信也, 天野憲樹

電子情報通信学会技術研究報告   115 ( 419(MSS2015 35-66) )   35 - 40   2016.1

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A Proposal of Job Scheduling with Performance Measurements by Benchmarks for User PC Computing System

青柳有輝, 舩曵信生, 栗林稔

電子情報通信学会技術研究報告   115 ( 419(MSS2015 35-66) )   153 - 158   2016.1

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Elastic WLAN System Model and Its Implementation on Linux-PC (ソフトウェアサイエンス)

ISLAM Md. EZHARUL, FUNABIKI Nobuo, KURIBAYASHI Minoru

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   115 ( 420 )   147 - 152   2016.1

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Elastic WLAN System Model and Its Implementation on Linux-PC (システム数理と応用)

ISLAM Md. EZHARUL, FUNABIKI Nobuo, KURIBAYASHI Minoru

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   115 ( 419 )   147 - 152   2016.1

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Value trace problems for graph theory algorithms in Java programming learning assistant system

Nobuo Funabiki, Khin Khin Zaw, Minoru Kuribayashi, Wen-Chung Kao

2016 5th International Conference on Educational and Information Technology (ICEIT 2016)   2016

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A Channel Assignment Extension of Active Access-Point Configuration Algorithm for Elastic WLAN System under Limited Channels

Md. Selim Al Mamun, Sumon Kumar Debnath, Kyaw Soe Lwin, Nobuo Funabiki

2016 FOURTH INTERNATIONAL SYMPOSIUM ON COMPUTING AND NETWORKING (CANDAR)   318 - 324   2016

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Previously, we proposed the active access-point (AP) configuration algorithm for elastic Wireless Local-Area Network (WLAN) systems using heterogeneous APs. This algorithm activates or deactivates APs depending on traffic demands, assuming that any active AP can use a different channel to avoid interferences among APs. However, the number of non-interfered channels in IEEE 802.11 protocols is limited. In this paper, we propose an extension of this algorithm to consider the channel assignment to the active APs under this limitation. After the channel assignment to the active APs, AP associations of hosts are improved to further minimize interferences by averaging loads among different channels. The effectiveness of our proposal is evaluated using the WIMNET simulator.

DOI： 10.1109/CANDAR.2016.32

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An active access-point configuration algorithm for elastic wireless local-area network system using heterogeneous devices

Khin Khin Zaw, Nobuo Funabiki, Wen-Chung Kao

International Journal of Networking and Computing   6 ( 2 )   395 - 419   2016

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Throughput measurements for access-point installation optimization in IEEE802.11n wireless networks

Nobuo Funabiki, Kyaw Soe Lwin, Minoru Kuribayashi, I-Wei Lai

2016 IEEE International Conference on Consumer Electronics - Taiwan (ICCE-TW 2016)   324 - 325   2016

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DOI： 10.1109/ICCE-TW.2016.7520994

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Worker PC Performance Measurements Using Benchmarks for User-PC Computing System

Nobuo Funabiki, Yuki Aoyagi, Minoru Kuribayashi, Wen-Chun Kao

2016 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS-TAIWAN (ICCE-TW)   277 - 278   2016

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The User-PC computing system (UPC) has been studied to provide a parallel computing platform for members in a group using idling computing resources in personal computers (PCs) of them. UPC adopts the master-worker model where we have implemented the programs for the master on Linux and for the worker on Linux and Windows. However, the current job scheduling method does not consider the real performance of a worker PC. In this paper, we implement a function to measure the performance of a worker PC using two benchmark programs. The experiment results for six PCs in our group show that there are three times difference in the CPU performance and eight times difference in the disk performance.

DOI： 10.1109/ICCE-TW.2016.7521026

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Offline Answering Function for Fill-in-blank Problems in Java Programming Learning Assistant System

Nobuo Funabiki, Hiroki Masaoka, Nobuya Ishihara, I-Wei Lai, Wen-Chung Kao

2016 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS-TAIWAN (ICCE-TW)   315 - 316   2016

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To assist Java programming educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS provides fill-in-blank problems to let students study the grammar and the code structure for Java by filling blank elements in a high-quality code that are composed of reserved words, identifiers, and control symbols. However, students can answer the problems only when connected with the Internet, which limits the time and place for them to use JPLAS. In this paper, we implement the offline answering function for fill-in-blank problems in JPLAS. To avoid cheating by students, we adopt the hash function and the message authentication technique. We confirm the effectiveness of our proposal through applications to the Java programming course in our department.

DOI： 10.1109/ICCE-TW.2016.7521045

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Toward Personalized Learning in JPLAS: Generating and Scoring Functions for Debugging Questions

Takato Mohri, Shingo Yamaguchi, Nobuo Funabiki

2016 IEEE 5TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS   216 - 219   2016

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Today, some Java program learning support systems have been proposed. Each student has his/her own learning level. It is important to give questions suitable for his/her learning level for each student. But it will cause an enormous burden to the teacher. In this paper, we implement the automatic generating function and the scoring function regarding debugging questions in Java programming learning assistant system called JPLAS. We proposed personalized learning with two functions such as automatic generating and scoring of debugging question used in JPLAS. We showed the effectiveness of proposed method with chi-squared test.

DOI： 10.1109/GCCE.2016.7800392

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A Proposal of Three Extensions in Blank Element Selection Algorithm for Java Programming Learning Assistant System

Khin Khin Zaw, Nobuo Funabiki, Minoru Kuribayashi

2016 IEEE 5TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS   3 - 5   2016

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To assist Java programming educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS provides fill-in-blank problems to let students study Java grammar and basic programming skills by filling the blanked elements in a given Java code. To generate the feasible problems, we have proposed a blank element selection algorithm using the constraint graph to select as many blanks as possible such that they have grammatically correct and unique answers. In this paper, to further increase the number of blanks and control the difficulty of the generated problem, we extend this algorithm by 1) adding operators in conditional expressions for blank candidates, 2) improving the edge generation method in the constraint graph to increase the number of blanks, and 3) introducing two parameters to change the frequency of selecting blanks. To verify the effectiveness, we apply the extended algorithm to 55 Java codes for fundamental data structure or algorithms, and confirm that these extensions can increase the number of blanks and change the problem difficulty.

DOI： 10.1109/GCCE.2016.7800312

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Analysis of Fill-in-blank Problem Solution Results in Java Programming Course

Nobuo Funabiki, Tana, Nobuya Ishihara, Wen-Chung Kao

2016 IEEE 5TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS   479 - 480   2016

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For advancing the educational quality of Java programming, we have proposed and implemented the Java Programming Learning Assistant System (JPLAS) as a Web application system. JPLAS offers fill-in-blank problems that request students to fill in the blank elements in a given Java code to study Java grammar and basic programming skills. In past years, we have utilized fill-in-blank problems at our Java programming courses. In this paper, we analyze solution results of students taking the course in 2015, and confirm the relatively high correlation between solution performances and course grades.

DOI： 10.1109/GCCE.2016.7800486

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A Proposal of Coding Rule Learning Function in Java Programming Learning Assistant System

Nobuo Funabiki, Takuya Ogawa, Nobuya Ishihara, Minoni Kuribayashi, Wen-Chung Kao

PROCEEDINGS OF 2016 10TH INTERNATIONAL CONFERENCE ON COMPLEX, INTELLIGENT, AND SOFTWARE INTENSIVE SYSTEMS (CISIS)   561 - 566   2016

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Recently, Java has been educated in many universities and professional schools due to reliability, portability, and scalability. However, because of its limited time in Java programming courses, coding rules arc rarely educated. As a result, codes made by students become far from readable codes. In this paper, we propose a coding rule learning function using static code analyzers in Java Programming Learning Assistant System (JPLAS), targeting students who have accomplished the grammar learning and are going to write practical codes for final projects. Coding rules for this function consist of naming rules, coding styles, and potential problems. We evaluate the improvement of readability in four codes refined by this function and the usability of this function through the questionnaires completed by five students. In future studies, we expect that this function will be employed in Java programming courses.

DOI： 10.1109/CISIS.2016.94

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A workbook design for fill-in-blank problems in Java programming learning assistant system

Nobuo Funabiki, Khin Khin Zaw, Wen-Chung Kao

The 11-th International Conference on Broadband and Wireless Computing, Communication and Applications (BWCCA2016)   331 - 342   2016

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Analysis of fill-in-blank problem solutions and extensions of blank element selection algorithm for Java programming learning assistant system

Nobuo Funabiki, Tana, Khin Khin Zaw, Nobuya Ishihara, Wen-Chung Kao

The World Congress on Engineering and Computer Science 2016 (WCECS 2016)   237 - 242   2016

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A minimax approach for access-point setup optimization using throughput measurements in IEEE802.11n wireless networks

Kyaw Soe Lwin, Nobuo Funabiki, Khin Khin Zaw, Md. Selim Al Mamun, Minoru Kuribayashi

The Fourth International Symposium on Computing and Networking (CANDAR, ASON)   311 - 317   2016

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DOI： 10.1109/CANDAR.2016.0062

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A core blank element selection algorithm for code reading studies by fill-in-blank problems in Java programming learning assistant system

Khin Khin Zaw, Nobuo Funabiki

The 7th International Conference on Science and Engineering 2016 (7th ICSE 2016)   204 - 208   2016

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Applications of coding rule learning function to workbook codes for Java programming learning assistant system

Nobuo Funabiki, Shinpei Matsumoto, Khin Khin Zaw, Wen-Chung Kao

The 7th International Conference on Science and Engineering 2016 (7th ICSE 2016)   1170 - 1175   2016

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A Proposal of Recipe Conversion Algorithm for Cooking-Step Schedule Optimization

115 ( 221 )   67 - 72   2015.9

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BS-6-2 A Blank Line Selection Algorithm for Value Trace Problem in Java Programming Learning Assistant System(BS-6.Network and service Design, Control and Management)

Zaw Khin Khin, Funabiki Nobuo

Proceedings of the Society Conference of IEICE   2015 ( 2 )   "S - 19"-"S-20"   2015.8

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To cultivate the code reading capability of Java novice students, we have studied the value trace problem for the Web-based Java Programming Learning Assistant System (JPLAS). This problem asks students to trace actual values of important variables in fundamental data structure or algorithms. To realize the automatic problem generation, the whole sequence of changing data of such variables are output in lines by executing the code for the data structure or algorithm. Then, output data lines that have difference from their previous lines are blanked to be filled. In this paper, we propose the blank line selection algorithm for the value trace problem, and show an example of the generated problem for the insertion sort algorithm.

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A Cooking-Step Scheduling Algorithm with Guidance System for Homemade Cooking

Yukiko Matsushima, Nobuo Funabiki

IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS   E98D ( 8 )   1439 - 1448   2015.8

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Homemade cooking plays a key role for a healthy and cost-efficient life. Unfortunately, preparing multiple dishes is generally time-consuming. In this paper, an algorithm is proposed to minimize the cooking time by scheduling the cooking-step of multiple dishes. The cooking procedure of a dish is divided into a sequence of six types of cooking-steps to consider the constraints in cooks and cooking utensils in a kitchen. A cooking model is presented to optimize the cooking-step schedule and estimate the cooking time for a given starting order of dishes under various constraints of cooks and utensils. Then, a high-quality schedule is sought by repeating the generation of a new order and the model application based on exhaustive search and simulated annealing. Our simulation results and cooking experiments confirm the effectiveness of our proposal.

DOI： 10.1587/transinf.2015EDP7048

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An Active Access-Point Configuration Algorithm for Wireless Local Area Networks with Heterogeneous Devices (ネットワークシステム)

セリム アル マムン ムハマド, エズハルル イスラム ムハマド, 舩曵 信生

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報   115 ( 159 )   147 - 152   2015.7

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Performance evaluations for multi-user MIMO using WIMNET simulator

115 ( 159 )   141 - 146   2015.7

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An Implementation and Evaluation of Job Scheduling Methods for User-PC Computing System

AOYAGI Yuki, FUNABIKI Nobuo, FUKUSHI Masaru

IEICE technical report   114 ( 477 )   553 - 558   2015.3

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We have proposed and implemented User-PC computing (UPC) system as a parallel computing platform using idling computing resources (CPU cycles) in personal computers (PCs) of members in the same organization such as a laboratory in a university. Because the original UPC system has adopted a sequential job scheduling method which assigns new jobs to workers in the descending order of their performance up to its permissible number, some workers may not be assigned any job. In this paper, we propose static and dynamic round-robin (RR)job scheduling methods of assigning a predefined number of new jobs to the workers in round-robin fashion. The dynamic RR method considers the change of the worker's performance by using the CPU time of recent jobs. Our experiment results show that when the performance difference among workers and the number of jobs are small, both RR methods performs well, and when both of them are large, the dynamic RR method shows better performance.

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Active Access Point Selection Algorithm for Scalable Wireless Mesh Networks

FUJITA Sho, FUNABIKI Nobuo

IEICE technical report   114 ( 477 )   427 - 432   2015.3

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The wireless Internet-access mesh network (WIMNET) can realize an inexpensive scalable Internet-access network by using multiple access points (APs) connected by wireless links. We have proposed the active AP selection algorithm of selecting active APs for high-speed and low-cost communications in large WIMNET. In this paper, we extend this algorithm to improve the performance of WIMNET by introducing mobile routers. Besides, we present the plural AP deactivation procedure using link speeds for better practicality. We show the effectiveness of the proposals through simulations in two instances.

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Javaプログラミング授業におけるエレメント空欄補充問題の実践

塔 娜, 舩曵 信生, 石原 信也

研究報告コンピュータと教育（CE）   2015 ( 11 )   1 - 8   2015.2

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本グループでは，プログラミング言語 Java の学習支援のために，Web を用いた Java プログラミング学習支援システム JPLAS(Java Programming Learning Assistant System) を開発している．JPLAS では，Java の初学者を対象としたエレメント空欄補充問題を提供しており，グラフ理論を用いた解の一意性を充たす問題生成のためのアルゴリズムを提案している．今回，本アルゴリズムを用いてエレメント空欄補充問題を生成し，本学科の Java プログラミング授業で実践活用した結果を報告する．

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学生用PCを用いたユーザPCコンピューティングシステムのWebインターフェース

金 奉洙, 舩曵 信生

研究報告コンピュータと教育（CE）   2015 ( 7 )   1 - 8   2015.2

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本グループでは，研究室内の学生が使用するパーソナルコンピュータ （PC） の空き資源を利用して，大規模シミュレーションなどの計算プロジェクトを実行する，ユーザ PC コンピューティングシステム UPC（User-PC Computing System） を開発している．UPC では，大規模コンピューティング環境の実現に関して，運営コストの低減と利便性の向上の実現を目指している．UPC では，計算プロジェクトの実行には，コマンド入力が必要となっており，その知識に乏しいユーザには UPC の使用が容易ではない．そこで本研究では，ブラウザで UPC の利用を可能とするために，Web 技術を用いた UPC ユーザインターフェース機能を開発する．UPC サーバ間とファイル共有ソフトを用いて連携することで，異なる複数の UPC へのインターフェース機能の提供を可能としている．本稿では，今回開発した UPC インターフェース機能の構成を示す．

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Javaコードのクラス間連携理解のためのコアステートメント抽出アルゴリズム

石原 信也, 舩曵 信生

研究報告コンピュータと教育（CE）   2015 ( 10 )   1 - 8   2015.2

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Java プログラミング学習では，既存のソースコードを読み，その処理や構造を理解することが有効である．このコードリーディングをプログラミング教育に取り入れるためには，学習者がソースコードを理解したか否かを確認する方法が必要となる．そのため本グループでは，ソースコード中の肝要なステートメント （コアステートメント） を空欄とし，その記述を要求する，ステートメント空欄補充問題の提案と授業適用を行っている．本研究では，ソースコード中の空欄化すべきコアステートメント抽出アルゴリズムを提案する．本アルゴリズムでは，コアステートメントとして，1） 要求仕様を充たすためのアルゴリズム要素，2） オブジェクト指向言語の特徴であるクラス間連携要素，3） データベースなど外部機能との連携要素，の 3 種類を想定し，それぞれの抽出法を定義している．提案アルゴリズムを実装し，5 つの Java ソースコードに適用して得られたコアステートメントを，Java 学習者による抽出結果と比較した．その結果，両者に高い一致がみられ，提案アルゴリズムの有効性が確認された．

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Revocable Group Signatures with Compact Revocation List Using Accumulators

Toru Nakanishi, Nobuo Funabiki

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E98A ( 1 )   117 - 131   2015.1

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A group signature scheme allows a group member to anonymously sign a message on behalf of the group. One of the important issues is the member revocation, and lots of revocable schemes have been proposed so far. A scheme recently proposed by Libert et al. achieves that O(1) or O(log N) efficiency of communication and computation except for the revocation list size (also the revocation cost), for the total number of members N and the number of revoked members R. However, since a signature is required for each subset separated from the set of non-revoked members, the size is about 900R Bytes in the 128-bit security. In the case of R = 100, 000, it amounts to about 80MB. In this paper, we extend the scheme to reduce the revocation list (also the revocation cost), by accumulating T subsets, which is signed for the revocation list. The revocation list size is reduced by 1/T. Unfortunately, the public key size, membership certificate size and the cost of a witness computation needed for signing increase related to T.

DOI： 10.1587/transfun.E98.A.117

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Cross-Layer Selective Routing for Active Access-Point Minimization in Wireless Mesh Network

I-Wei Lai, Wen-Chung Kao, Nobuo Funabiki

2015 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS - TAIWAN (ICCE-TW)   482 - 483   2015

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A Wireless Internet-access Mesh NETwork (WIMNET) provides the scalable and reliable internet access through the multiple access points (APs) and wireless relay communications. In particular, by redundantly deploying APs in the network field, the WIMNET becomes robust to the link or AP failure. However, these redundant APs increase the power consumption, and thus the number of active APs should be minimized by the selective routing without loss of the transmission performance. In this work, we propose to reinvent such selective routing algorithm by exploiting physical-layer technologies. An exemplar numerical simulation demonstrates that this cross-layer selective routing can further minimize the number of APs, leading to less operational costs in WIMNET.

DOI： 10.1109/ICCE-TW.2015.7217010

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An Operator Fill-in-blank Problem for Algorithm Understanding in Java Programming Learning Assistant System

Nobuo Funabiki, Shin Sasaki, Ta Na, Wen-Chung Kao

2015 IEEE 4TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE)   346 - 347   2015

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A Web-based Java Programming Learning Assistant System (JPLAS) has been developed to help novice students studying Java programming through self-learning. As one function, JPLAS provides the fill-in-blank problem that requests filling in the blank elements in a given code with several blanks. Currently, reserved words, identifiers, or control symbols can be blanked to have unique correct answers, which may be solved without reading the code carefully. In this paper, we propose to additionally blank operators in conditional expressions of core statements in the code so that students can understand the structure to realize the specification. For preliminary evaluations, we generated six operator fill-in-blank problems, and assigned them to students where the number of answer submissions per blank has increased from that of conventional problems.

DOI： 10.1109/GCCE.2015.7398539

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A proposal of statement fill-in-blank problem using program dependence graph in Java programming learning assistant system

Nobuya Ishihara, Nobuo Funabiki, Wen-Chung Kao

Information Engineering Express   1 ( 3 )   19 - 28   2015

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A proposal of value trace problem for algorithm code reading in Java programming learning assistant system

Khin Khin Zaw, Nobuo Funabiki, Wen-Chung Kao

Information Engineering Express   1 ( 3 )   9 - 18   2015

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A Worker Implementation on Windows OS for User-PC Computing System

Nobuo Funabiki, Yusuke Asai, Yuuki Aoyagi, Wen-Chung Kao

PROCEEDINGS OF 2015 THIRD INTERNATIONAL SYMPOSIUM ON COMPUTING AND NETWORKING (CANDAR)   279 - 282   2015

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Previously, we have proposed and implemented the User-PC computing (UPC) system as a highly parallel computing platform using idling CPU cycles in members' personal computers (PCs) of the same organization such as a laboratory in a university. This implementation for both the UPC master and the UPC worker covers only Linux OS. However, currently a lot of PCs adopt Windows OS. In this paper, we present an implementation of the UPC worker for Windows OS based on the implementation for Linux OS. During the implementation, we realize the CPU usage limitation and the automatic start-up of the worker program which can reduce loads for PC owner, aside from basic functions of master communications and job executions. Through evaluations, we conclude that the CPU usage rate does not exceed the given limitation except for starting time, and the job execution time on Windows is about twice the use of that on Linux.

DOI： 10.1109/CANDAR.2015.17

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A Function for Generating Debugging Questions in a Java Programming Learning Assistant System

Shingo Yamaguchi, Takato Mohri, Nobuo Funabiki

2015 IEEE 4TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE)   350 - 353   2015

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Today many universities offer courses for learning Java programming. Debugging cannot be avoided in programming. Nevertheless, there are not many chances for students to debugging programs, particularly written by another person. In this paper, for increasing that chance, we propose a function for generating a new kind of questions that are called debugging questions. A debugging question requires students to debug a program mixed with bugs. This function provides three ways of mixing bugs: deletion of reserved words, swapping of variables, and replacement by lists. We implemented this function into a Java programming learning assistant system, called JPLAS. We also discussed the usefulness by evaluating the function.

DOI： 10.1109/GCCE.2015.7398573

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An Extension of Statement Fill-in-blank Problem in Java Programming Learning Assistant System

Nobuya Ishihara, Nobuo Funabiki, Ta Na, Wen-Chung Kao

2015 IEEE 4TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE)   354 - 358   2015

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To assist Java programming studies, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). As one function in JPLAS, it provides a statement fill-in-blank problem that asks students to fill in proper statements to blanked ones in a Java code, so as to cultivate simultaneous code reading and writing abilities. Previously, we blanked only the core statement in a code with one class using the Program Dependence Graph (PDG), where we do not consider the features of object-oriented programming in Java that uses multiple classes and collaborations with other systems such as database. In this paper, we extend the statement fill-in-blank problem to deal with these features. We verify the effectiveness of our proposal through the Java programming course at our department.

DOI： 10.1109/GCCE.2015.7398543

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Correlation Analysis of Fill-in-blank Problem Solutions to Final Programming Results in Java Programming Course

Ta Na, Nobuo Funabiki, Nobuya Ishihara, Wen-Chung Kao

2015 IEEE 4TH GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE)   348 - 349   2015

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To assist Java programming educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS provides fill-in-blank problems to study the Java grammar and fundamental programming by filling blank elements that are composed of reserved words, identifiers, and control symbols in a high-quality code. During the last semester, we assigned 121 problems with 1,552 questions to 46 students taking our Java programming course. In this paper, we analyze correlations of problem solving results of students to their final programming results.

DOI： 10.1109/GCCE.2015.7398542

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Active Access-Point Configuration Algorithm with Dynamic Mobile Router Placement for Elastic WLAN System

Md. Selim Al Mamun, Md. Ezharul Islam, Nobuo Funabiki, I-Wei Lai

PROCEEDINGS OF 2015 THIRD INTERNATIONAL SYMPOSIUM ON COMPUTING AND NETWORKING (CANDAR)   246 - 252   2015

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Recently, a variety of wireless access points (APs) have been deployed by many organizations to meet different traffic demands. Previously, we proposed an active AP configuration algorithm that activates or deactivates heterogeneous AP devices depending on the traffic demand and network topology, in order to realize the elastic Wireless Local-Area Network (WLAN) system. Unfortunately, in this algorithm, the locations of the mobile routers have been fixed as the algorithm input, although they can be placed flexibly as portable APs using cellular networks. In this paper, we consider the elastic WLAN system with mobile routers which can be placed flexibly. The dynamic mobile router placement is proposed for the active AP configuration algorithm to meet stringent traffic requirements. Specifically, if some hosts fail to meet the throughput requirements, the locations of additional mobile routers are dynamically determined by applying the Kmeans algorithm to maximize the number of those failed hosts in its coverage. The effectiveness of this location determination is demonstrated by numerical examples with three network scenarios.

DOI： 10.1109/CANDAR.2015.55

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Extensions of Access-Point Aggregation Algorithm for Large-scale Wireless Local Area Networks

Islam Md. Ezharul, Funabiki Nobuo, Nakanishi Toru

IJNC   5 ( 1 )   200 - 222   2015

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Recently, many organizations such as universities and companies have deployed wireless local area networks (WLANs) to cover the whole site for ubiquitous network services. In these WLANs, wireless access-points (APs) are often managed independently by different groups such as laboratories or departments. Then, a host may detect signals from multiple APs, which can degrade the communication performance due to radio interferences among them and increase operational costs. Previously, we proposed the AP aggregation algorithm to solve this problem by minimizing the number of active APs through aggregating them using the virtual AP technology. However, our extensive simulations in various instances found that 1) the minimization of active APs sometimes excessively degrades the network performance, and 2) the sequential optimization of host associations does not always reach optimal where slow links are still used. In this paper, we propose two extensions of the AP aggregation algorithm to solve these problems by 1) ensuring the minimum average throughput for any host by adding active APs and 2) further optimizing host associations by changing multiple hosts simultaneously in the host association finalization phase. We verify the effectiveness through simulations in four network instances using the WIMNET simulator.

DOI： 10.15803/ijnc.5.1_200

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Practices of Fill-in-blank Problems in Java Programming Course

Nobuo Funabiki Tana, Nobuya Ishihara

2015 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS - TAIWAN (ICCE-TW)   120 - 121   2015

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To assist Java programming educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS provides fill-in-blank problems to study the Java grammar by filling blank elements in a high-quality code that are composed of reserved words, identifiers, and control symbols. A graph-based blank element selection algorithm has been proposed to automatically select as many blanks as possible that have grammatically correct unique answers. In this paper, we show and discuss their application results to a Java programming course in our department.

DOI： 10.1109/ICCE-TW.2015.7216810

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Concept of User-PC Computing System

Nobuo Funabiki, Bongsu Kim, Yuki Aoyagi

2015 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS - TAIWAN (ICCE-TW)   480 - 481   2015

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The User-PC computing system (UPC) is a technology of realizing a parallel computing environment using idling computing resources (CPU cycles) in Personal Computers (PCs) of members in the same organization or group such as a laboratory in a university and a section in a company. UPC can resolve drawbacks in the registration of computing projects, the reliability of computing results, and the continuity of computations that may often happen in Volunteer Computing (VC) systems using voluntary PCs in the Internet. Thus, UPC can be easily and comfortably used by computing users. In this paper, we show the concept of UPC and preliminary evaluations.

DOI： 10.1109/ICCE-TW.2015.7217009

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A proposal of graph-based blank element selection algorithm for Java programming learning with fill-in-blank problems

Tana, Nobuo Funabiki, Nobuya Ishihara

The International MultiConference of Engineers and Computer Scientists 2015 (IMECS 2015)   2015

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Practices of Cooking-Step Scheduling Algorithm for Homemade Cooking

Yukiko Matsushima, Nobuo Funabiki

2015 IIAI 4TH INTERNATIONAL CONGRESS ON ADVANCED APPLIED INFORMATICS (IIAI-AAI)   500 - 505   2015

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Homemade cooking is essential not only for keeping healthy and cost-efficient dietary lives but also for constructing good family relationships and identities. Previously, we proposed the cooking-step scheduling algorithm to help homemade cooking by finding a schedule of applying the cooking-steps for multiple dishes with minimal cooking time. In this algorithm, the cooking procedure for each dish is divided into a sequence of six types of cooking-steps to consider the constraints in cooks and cooking utensils in a kitchen. In this paper, we conduct practices of the algorithm in actually cooking dishes by following the generated schedules to show the effectiveness.

DOI： 10.1109/IIAI-AAI.2015.189

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A Concept of Value Trace Problem for Java Code Reading Education

Khin Khin Zaw, Nobuo Funabiki

2015 IIAI 4TH INTERNATIONAL CONGRESS ON ADVANCED APPLIED INFORMATICS (IIAI-AAI)   253 - 258   2015

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To assist Java programming educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS provides the fill-in-blank problem to help novice students studying Java programming at home, where some elements in a high-quality code including reserved words, identifiers, and control symbols are blanked to be filled by students. Unfortunately, this problem may be solved without reading out the algorithm in the code if students are familiar with Java grammar to some extent. In this paper, to further cultivate the code reading capability of students, we propose a concept of the value trace problem to ask the actual values of important variables in a code implementing some fundamental data structure or algorithm. A value trace problem can be generated by: 1) selecting a high-quality class code for the algorithm to be studied, 2) making the main class to instantiate the class in 1) if it does not contain the main method, 3) adding the functions to output variable values in questions into a text file, 4) preparing the input file to the code in 3) if necessary, 5) running this code to obtain the set of variable values in the text file, 6) blanking some values from the text file to be filled by students, and 7) uploading the final code, the blanked text file, and the correct answer file into the JPLAS server, and adding the brief description on the algorithm for a new assignment. To verify the feasibility of this concept, we manually generated five problems and asked four students with high Java programming skills in our group to solve them. Then, we analyzed the difficulty of the value trace problem for Quick Sort.

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A Proposal of Statement Fill-in-blank Problem in Java Programming Learning Assistant System

Nobuya Ishihara, Nobuo Funabiki

2015 IIAI 4TH INTERNATIONAL CONGRESS ON ADVANCED APPLIED INFORMATICS (IIAI-AAI)   247 - 252   2015

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As a reliable, portable, and practical programming language, Java has been educated in many universities and professional schools. To assist Java educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS provides the element fill-in-blank problem and the code writing problem. The former problem is designed for novice students to study the grammar and writing style of Java by filling correct words to the blanks in a given Java code that are automatically marked by checking coincidences with correct ones. The latter problem is for students to study writing Java codes for specifications described in natural language that are automatically verified using the test-driven development (TDD) method. Unfortunately, the transition between two problems is not smooth due to the difference in difficulties. In this paper, we propose the statement fill-in-blank problem in JPLAS to fill the gap by asking students to write one whole statement in a code where the correctness is verified by the TDD method. The blank statement is selected by generating the Program Dependence Graph (PDG) of the code and finding the statement that has the largest dependence with other ones. We verify the effectiveness of our proposal through applications to the Java programming course in our department.

DOI： 10.1109/IIAI-AAI.2015.192

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An Anonymous Reputation System with Reputation Secrecy for Manager

Toru Nakanishi, Nobuo Funabiki

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E97A ( 12 )   2325 - 2335   2014.12

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In anonymous reputation systems, where after an interaction between anonymous users, one of the users evaluates the peer by giving a rating. Ratings for a user are accumulated, which becomes the reputation of the user. By using the reputation, we can know the reliability of an anonymous user. Previously, anonymous reputation systems have been proposed, using an anonymous e-cash scheme. However, in the e-cash-based systems, the bank grasps the accumulated reputations for all users, and the fluctuation of reputations. These are private information for users. Furthermore, the timing attack using the deposit times is possible, which makes the anonymity weak. In this paper, we propose an anonymous reputation system, where the reputations of users are secret for even the reputation manager such as the bank. Our approach is to adopt an anonymous credential certifying the accumulated reputation of a user. Initially a user registers with the reputation manager, and is issued an initial certificate. After each interaction with a rater, the user as the ratee obtains an updated certificate certifying the previous reputation summed up by the current rating. The update protocol is based on the zero-knowledge proofs, and thus the reputations are secret for the reputation manager. On the other hand, due to the certificate, the user cannot maliciously alter his reputation.

DOI： 10.1587/transfun.E97.A.2325

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A Proposal of Blank Element Selection Algorithm for Java Programming Learning

Tana, FUNABIKI Nobuo, ISHIHARA Nobuya

Technical report of IEICE. SS   114 ( 271 )   1 - 6   2014.10

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

The programming language Java has been widely used in industries and educated in educational institutes due to its excellent developing environments, reliability, and portability. To assist Java educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS provides the fill-in-blank problem for Java novice students to learn it by filling proper elements into blanks in a Java code. In the paper, we propose a blank element selection algorithm to find a feasible problem that has the unique solution for any blank. This algorithm first generates a simple graph such that a vertex represents a candidate element in the code and an edge is made between two vertices that can be blanked simultaneously. Then, it extracts a clique of the graph to maximize the number of feasible blanks. We applied the algorithm to 100 Java codes and checked the uniqueness of the solutions manually. The results show that by showing the execution results of the three codes, we confirmed the uniqueness of the solutions.

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A Study of Access-Point Allocation Algorithm for Scalable Wireless Mesh Networks in Indoor Environments

FARAG Tamer, FUNABIKI Nobuo, HASSAN Walaa

IEICE technical report   114 ( 252 )   1 - 6   2014.10

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Previously, we proposed an access-point (AP) allocation algorithm for scalable Wireless Internet-access Mesh NETwork (WIMNET) with multiple gateways (GWs) and the hop count limitation. The algorithm for K GWs consists of 1) the partition of the network field into K clusters by the K-means algorithm, 2) the sequential AP allocation in each cluster by our AP allocation algorithm for one GW, and 3) the simultaneous routing in K clusters by our routing algorithm considering multiple GWs and the hop count limitation. In this paper, we study the AP allocation algorithm in indoor environments as common fields for WIMNET. We assume that one wall drops the transmission speed by 15%, which is equivalent to 10m increase of the distance in an open space. To handle situations unsuitable to the K-means algorithm where plural GWs are closely located in neighboring rooms, we regard these GWs as one virtual GW, and apply 1) and 2) in the algorithm. Then, we apply 3) to the individual real GWs. We verify the effectiveness of our proposal through simulations in an indoor field using the WIMNET simulator.

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A Consideration of Extended Wireless Internet-Access Mesh Network Simulator for MU-MIMO

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   114 ( 252 )   7 - 12   2014.10

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Recently, IEEE802.11ac has been focused as a new high-speed wireless communication protocol. IEEE802.11ac adopts the frame aggregation that can reduce communication overheads by aggregating multiple frames into one big frame and the MU-MIMO (Multi-User Multi-Input-Multi-Output) that can improve the channel efficiency by allowing simultaneous transmissions to multiple destinations using the same channel. We have studied the efficient use of this protocol in the Wireless Internet-access Mesh NETwork (WIMNET) that provides an expandable Internet-access network by connecting multiple access-points through wireless links. In this paper, we present an extension of the WIMNET simulator that has been developed by our group in considering frame aggregation and MU-MIMO in IEEE802.11ac to evaluate the performance of WIMNET using this protocol. We evaluate the effect of MU-MIMO in WIMNET through simulations using the extended WIMNET simulator.

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Robustness Evaluations of Cooking-Step Scheduling Algorithm under Operation Time Fluctuations

MATSUSHIMA Yukiko, FUNABIKI Nobuo

114 ( 222 )   5 - 10   2014.9

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To assist homemade cooking of busy people such as working people, child-growing families, and students, we have proposed a cooking-step scheduling algorithm for multiple dishes such that the total cooking time be minimized. For a given set of dishes where the cooking procedure for each dish is composed of a sequence of cooking-steps requiring certain time, this algorithm generates an optimal schedule for applying the cooking-steps of the dishes by considering the constraints of the cooks and the instruments. In this paper, we evaluate the robustness of this algorithm under time fluctuations in real cooking that can happen by variations of the proficiency of cooks and the cooking environment. First, we developed the evaluation cooking model to simulate the cooking process for a given schedule and time, and conducted simulations with randomly fluctuated time within 30% of the original one. Then, we actually cooked four dishes using the schedule found by the algorithm. In any result, the variation of the total cooking time is small compared to changes of cooking-step time. Thus, the robustness of the algorithm is confirmed.

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BS-6-2 Throughput Measurements in Big Room with Different Access Point Locations for IEEE 802.11ac Wireless Networks(BS-6.Network and service Design, Control and Management)

CHEW Chang Choon, FUNABIKI Nobuo

Proceedings of the Society Conference of IEICE   2014 ( 2 )   "S - 38"-"S-39"   2014.9

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The IEEE802.11ac wireless communication protocol has been introduced for high-speed wireless networks. In this paper, we provide throughput measurement results by Transmission Control Protocol (TCP) in a big room with various access point (AP) locations. Our measurement results show that TCP throughputs are greatly affected by AP locations for two-AP cases and are not affected for one-AP cases.

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BS-6-1 AN EXTENSION OF ACCESS-POINT AGGREGATION ALGORITHM FOR HOST MOBILITY(BS-6.Network and service Design, Control and Management)

Islam Md Ezharu, Funabiki Nobuo

Proceedings of the Society Conference of IEICE   2014 ( 2 )   "S - 36"-"S-37"   2014.9

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The AP aggregation algorithm has been proposed to reduce the number of active APs in overlapped WLANs by aggregating them to solve the problem of performance degradation due to interferences, and increased operational cost. However, this algorithm does not consider the mobility of hosts, although they usually join or leave the network randomly. In this paper, we propose an extension of the AP aggregation algorithm to deal with the mobility by considering the probability of each host to stay active. We verify the effectiveness of this extension through simulations using the WIM- NET simulator.

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Efficient Proofs for Monotone Formulas on Attributes Excluding Restriction in Anonymous Credential System

SADIAH Shahidatul, NAKANISHI Toru, FUNABIKI Nobuo

Technical report of IEICE. ISEC   114 ( 203 )   21 - 26   2014.9

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An anonymous credential system on attributes allows a user to convince a service provider anonymously that he/she owns the certified attributes. Previously, we proposed an anonymous credential scheme to prove the satisfaction of a monotone formula when only one attribute is true for any OR relation. A monotone formula represents any combination of AND relations and OR relations. However, this system has a drawback that it cannot verify a user's certificate such that two or more attributes for an OR relation are true. In this paper, we propose an extended scheme for proofs of arbitrary monotone formula by adopting Linear Homonorphic (LH) signature scheme to generate a certificate that contains the minimum attribute set as required in the verification.

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Robustness Evaluations of Cooking-Step Scheduling Algorithm under Operation Time Fluctuations

38 ( 36 )   5 - 10   2014.9

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Throughput Evaluations Using NS-2 for Access-Point Aggregation Algorithm in IEEE802.11n Wireless LANs

HASSAN Walaa, FUNABIKI Nobuo, ISLAM Md. EZHARUL, FARAG Tamer

IEICE technical report. Information networks   114 ( 110 )   25 - 30   2014.6

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The IEEE 802.11-based WiFi wireless technology has been commonly used in efficient wireless local area networks (WLANs). Recently, the IEEE 802.11n protocol among several ones has become popular as higher throughput operations with up to 600 Mbps. For a large-scale WLAN with multiple access-points (APs), we have proposed an access-point aggregation algorithm to minimize the operation cost while maximizing the performance. However, the effectiveness of this algorithm has been verified only through the WIMNET simulator that has been developed by our group as a simple network simulator. In this paper, we implement the modified 802.11n module that has been introduced by Wang and Wei on the NS-2 version 2.34, and evaluate the performance of this algorithm through simulations using it.

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An Extension of Access Point Allocation Algorithm for Wireless Mesh Networks with Multiple Gateways and Maximum Hop Limitation

FARAG Tamer, FUNABIKI Nobuo, HASSAN Walaa

IEICE technical report. Information networks   114 ( 110 )   31 - 36   2014.6

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As an inexpensive, scalable Internet-access wireless network, we have studied design optimizations of a Wireless Internet-access Mesh NETwork (WIMNET) that adopts multiple access-points (APs) connected by Wireless Distribution System (WDS). In WIMNET, the proper allocation of APs is essential in ensuring the communication quality while reducing the installation and management costs. Thus, previously we proposed an AP allocation algorithm for WIMNET where only one gateway (GW) to the Internet exists and no hop limitation is imposed. In this study, we extend this algorithm for multiple GWs and the maximum hop limitation, which is common for large-scale WIMNET using WDS. First, for given K GWs, we partition the whole network into K sub-networks using the k-means algorithm such that the hosts in each sub-network connects with one GW. Then, we apply the previous AP allocation algorithm to each sub-network sequentially to allocate the APs. Finally, we apply our existing routing algorithm to obtain the routing path satisfying the hop limitation. We verify the effectiveness of this extended algorithm through simulations in one instance using the WIMNET simulator.

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An Extension of Routing Algorithm for Wireless Mesh Networks Considering Frame Aggregation

TANI Yuma, FUNABIKI Nobuo, TAJIMA Shigeto

IEICE technical report. Information networks   114 ( 110 )   19 - 24   2014.6

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As a flexible inexpensive Internet-access network, we have studied the Wireless Internet-access Mesh NETwork (WIMNET) that is composed of wireless interconnected Access-Points (APs). We have proposed routing algorithm for WIMNET under realistic environments such as 1) multiple gateways, 2) communication speed changes, and 3) the limited number of hops. In this study, we extend the algorithm by considering the frame aggregation adopted in the IEEE802.11ac high-speed wireless communication protocol. We verify the effectiveness of our proposal through simulating three instances using the WIMNET simulator.

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A Draft Coding Rule for Codes in Java Programming Learning Assistant System

ISHIHARA Nobuya, FUNABUKI Nobuo

IEICE technical report. Education technology   114 ( 82 )   57 - 62   2014.6

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We have developed the Java programming learning support system JPLAS as a Web application using JSP, Servlet, and Java Beans, to support repetitive self-learning of Java programming through automatic verifications of answers from students to assignments. Because the codes in JPLAS have been implemented by students who have newly joined our group and taken over the codes from seniors, their managements and updates have become complicated. At the same time, they do not follow the Web standard including HTML5 and CSS3 that has become popular to realize rich Web clients. In this paper, we propose a draft coding rule to implement codes in JPLAS following the Web standard. By adopting HTML5 and Ajax, this rule makes it possible implementing codes that can be easily maintained by avoiding redundancy.

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An Extension of Fill-in-blank Problem Generation Algorithm for Java Programming Learning Assistant System

Tana, FUNABUKI Nobuo, ISHIHARA Nobuya, OGAWA Takuya

IEICE technical report. Education technology   114 ( 82 )   63 - 68   2014.6

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To help Java programming educations in universities and professional schools, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). Since JPLAS provides the fill-in-blank problem function for Java novice students, we have proposed a graph-based fill-in-blank problem generation algorithm for it. In this paper, we extend this algorithm for blanking grammatically related words so as to encourage students studying the Java grammar more deeply. Besides, we evaluate generated problems with up to 20 blanks in a Java code where we have limited maximally 10 blanks previously. We applied problems by the extended algorithm to middle level students and found that the length, numbers of classes and methods, the difficulty of the implemented algorithm, and the existence of comments in the Java code have large influences on the correct solution rate.

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An Implementation of Statement Fill-in-blank Problem Function for Java Programming Learning Assistant System

ISHIHARA Nobuya, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report. Education technology   113 ( 482 )   35 - 40   2014.3

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We have proposed a Web-based JPLAS (Java Programming Learning Assistant System) to help students studying Java programming by themselves at home. By adopting the Test-Driven Development (TDD) method to verify the codes from students, JPLAS aims to reduce loads of teachers in addition to enhancing learning activities of students. In this paper, we propose and implement the statement fill-in-blank problem function in JPLAS as a trial assistance for code reading that has not been underestimated, although it is very important in studies of programming. In the statement fill-in-blank problem, a student is requested to fill a statement to the blank in a given Java code. By using a Program Dependence Graph (PDG), this function blanks an essential statement in the code. To evaluate our proposal, we generated multiple statement fill-in-blank problems using codes with similar procedures and applied them to students in a Java programming course in our department. Then, we found that the solution time of students decreased as they solved more problems.

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A Difficulty Estimation Method of Fill-in-blank Problems for Java Programming Learning Assistant System

OGAWA Takuya, FUNABIKI Nobuo, NAKANISHI Toru, ISHIHARA Nobuya, NA Ta, AMANO Noriki

IEICE technical report. Education technology   113 ( 482 )   41 - 46   2014.3

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In our group, we have proposed a Web-based Java Programing Learning Assistant System (JPLAS) that helps students to study Java programing by themselves and the reduction of the burden on teacher. JPLAS has two kinds of blanks supplement (element fill-in-blank problem, statement fill-in-blank problem). These problems are applied to a student as a self-study problem in the classes of this school for Java programming abecedarians. In this thesis, after having enumerated indexes to estimate the difficulty of the problem that a teacher generated in JPLAS, we propose the index suitable for the difficulty estimate of each problem by performing the correlation analysis with the correct answer rate of each problem by the self-study result. We enable the presentation of the problem that a teacher accepted the level of the student by implementing difficulty estimation method of each fill-in-blank problem in JPLAS.

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An Extension of Active Access Point Selection Algorithm Considering Practical Conditions for Wireless Mesh Networks

FUJITA Sho, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report. Circuits and systems   113 ( 463 )   35 - 40   2014.3

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The wireless Internet-access mesh network (WIMNET) can realize an inexpensive flexible Internet-access network by using multiple access points (APs) connected by wireless links. For WIMNET with a single Internet Gateway (GW), we have proposed the active AP selection algorithm of selecting active APs from redundantly allocated APs for communications. However, in practical implementations of WIMNET, multiple GWs usually exist and the number of hops between a GW and a host is limited. Furthermore, the communication speed is dynamically changed by the link distance for the new high-speed communication protocol IEEE802.11ac. In this paper, we propose an extension of the active AP selection algorithm to consider these conditions. We verify the effectiveness of our proposal through simulations in four instances using the WIMNET simulator.

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File Synchronization Performance using Bittorrent Sync in IEEE802.11ac Wireless Networks

KIM Bongsu, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report. Circuits and systems   113 ( 463 )   29 - 34   2014.3

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Recently, Bittorrent Inc. has released a file synchronization software called Bittorrent Sync based on the peer-to-peer file sharing software Bittorrent. Using this software, users can synchronize the files on the designated folders across the multiple devices that are connected through the Internet without using a management server. These devices can be personal computers, smart phones, and tablets using different operating systems. To identify the folders to be synchronized, this software uses a 20-byte secret key that is randomly generated. We have considered the use of Bittorrent Sync to share files among nodes in a large wireless local area network (WLAN), where some nodes may be connected through mulithop wireless links. In this paper, we set up a simple WLAN test bed using the IEEE 802.1 lac protocol that has been recently introduced as a high-speed wireless communication protocol, and measure throughputs when various files with different sizes are synchronized among nodes using the software. Our results show that the throughput is quite high and stable, and a larger file can be transferred in a higher speed than a smaller file.

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An Extension of Wireless Internet-Access Mesh Network Simulator for Frame Aggregation

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report. Circuits and systems   113 ( 463 )   103 - 108   2014.3

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The Wireless Internet-access Mesh NETwork (WIMNET) can provide an inexpensive, flexible, and expandable Internet-access network by connecting multiple access-points (APs) through wireless links. To improve the performance of WIMNET, it is important to adopt high-speed wireless communication protocols IEEE 802.11n/ac that have recently become available, for heavily crowded links between APs. As one of the technologies to enhance the communication speed, the frame aggregation has been introduced so that multiple frames can be sent at the same time to reduce the communication overhead. Because each link between APs usually handles packets to/from multiple hosts in WIMNET, the effect of the frame aggregation can be further enhanced. In this paper, we present a model of the frame aggregation and an extension of the WIMNET simulator based on the model, which has been developed by our group to evaluate the performance of WIMNET. Through simulations in simple topologies, we show the effectiveness of the frame aggregation, and the necessity of the proper number of aggregated frames and the aggregated routing path.

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Throughput Measurements Using IEEE 802.11ac Devices for High-Speed Wireless Networks

CHEW Chang Choon, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report. Circuits and systems   113 ( 463 )   23 - 28   2014.3

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Recently, IEEE802.11ac communication protocols have been introduced for high-speed wireless networks. Then, commercial devices implementing this protocol have been available from several vendors. In this paper, we provide various TCP throughput measurement results using devices from three vendors implementing this protocol under a set of TCP parameters in various conditions including one or two-hop communications, wall obstacle existences, different link distances, and the use of a repeater. Our measurement results show that TCP throughputs are greatly affected by vendors and communication conditions.

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An Implementation of Moblie Anonymous Attribute Authentication System on Android Devices

IPSJ SIG Notes   2014 ( 45 )   1 - 6   2014.2

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In current ID-based authentication systems, service providers can collect user's history via user's ID. On the other hand, service providers often want to authenticate user's attributes. To solve this problem, an anonymous attribute authentication system was proposed, where the user's attribtes are autheticated without revealing any information that can speciy the user. In this paper, we implemented a mobile anonymous attribute system using NFC and Bluetooth, where, by bringing the device close to another one, we can perform a direct anonymous attribute authentication. From the experiments on real devices, the execution time of anonymous attribute authentication is 0.98 seconds, and the total processing time including the connection establishment is 1.85 seconds.

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A proposal of Web Browser-based Volunteer Computing Platform

Shogo Takaki, Kan Watanabe, Masaru Fukushi, Noriki Amano, Nobuo Funabiki, Toru Nakanishi

IPSJ SIG Notes   2014 ( 29 )   1 - 8   2014.2

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In Volunteer Computing (VC) systems, volunteer participants can contribute their idle computing resources by computing a piece of the computation (job) in their idle time. In existing VC systems, participants must put an extra effort, e.g. installing a dedicated software to their computers and register their personal E-mail addresses, which will be barriers to join as a participant. This paper proposes a web-based VC platform, in which participants can join to VC system by just accessing a specified URL with Web browsers. By using LLVM techniques such as PNaCL, VC jobs become convertible as fast-acting Web applications. As the results of our experiments based on Himeno Benchmark, we show that the performance of PNaCl codes on a web browser is equivalent of native one.

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A Web Recipe Conversion Algorithm for Cooking-Step Scheduling

ZHANG Yijia, FUNABIKI Nobuo, NAKANISHI Toru

Technical report of IEICE. SS   113 ( 422 )   11 - 16   2014.1

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Previously, we have proposed the cooking-step scheduling algorithm to assist home-made cooking by busy people such as working persons and students. When a cooking-step schedule of applying the cooking procedures in recipes in a Web site is generated by this algorithm, their conversion into the unique input form to the algorithm is required. In this paper, we propose a Web-recipe conversion algorithm that converts cooking procedures in a recipe into six types of cooking-steps and estimates the corresponding cooking time by extracting keywords in the recipe that correspond to the cooking-step types. We verified the effectiveness of the proposed algorithm through applying it to 100 recipes.

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A Clue Function Using Javadoc for Code Writing Problem in Java Programming Learning Assistant System

NAKAMURA Takuya, FUNABIKI Nobuo, NAKANISHI Toru, AMANO Noriki

IEICE technical report. Education technology   113 ( 377 )   115 - 120   2014.1

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Java has been educated in a lot of universities and professional schools due to the reliability, portability, and easy learning. To assist Java educations, our group has developed a Web-based Java Programming Learning Assistant System (JPLAS) that helps students to study Java programming by themselves through automatic testing of Java codes from students using the test-driven development method. Unfortunately, JPLAS is not suitable for less-experienced students in Java because they have to understand test codes that are necessary in automatic testing before writing source codes. In this paper, we propose a Javadoc-based hint function in the code design learning function of JPLAS to let such students learn how to collect the necessary information for a source code from a test code easily. It helps students to understand the whole structure of the source code and complete more accurate code design. We verify the effectiveness of our proposal through applications to 10 students in our laboratory.

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Implementation of Anonymous Credential System with Efficient Proofs for Monotone Formulas on Attributes Excluding Restriction

Shahidatul Sadiah, Toru Nakanishi, Nobuo Funabiki

2014 SECOND INTERNATIONAL SYMPOSIUM ON COMPUTING AND NETWORKING (CANDAR)   531 - 535   2014

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An anonymous credential system allows a user to convince a service provider anonymously that he/she owns certified attributes. Previously, we proposed an anonymous credential system to prove user's attributes to satisfy a monotone formula, i.e., a logic relation with any combination of AND/OR relations. However, this system has a restriction that the user can prove the monotone formula when only one attribute is true for any OR relation. Recently, we proposed the improved system to overcome the restriction, by adopting Linear Homonorphic (LH) signature scheme to generate a certificate that contains the minimum attribute set as required in the verification. However, the improved system has never been implemented, and thus the practicality is not evaluated. In this paper, we implement the system using a fast pairing library, and measure the processing times and data sizes, when changing the number of user's attributes and the size of the proved relation.

DOI： 10.1109/CANDAR.2014.35

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A Proposal of Routing Algorithm under Practical Conditions for Wireless Internet-Access Mesh Networks

Nobuo Funabiki, Toru Nakanishi, Wataru Maruyama

2014 IEEE INTERNATIONAL CONFERENCE ON CONSUMER ELECTRONICS - TAIWAN (ICCE-TW)   27 - 28   2014

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A Wireless Internet-access Mesh NETwork (WIMNET) can provide an expandable Internet-access network by flexibly adopting multiple Access-Points (APs) that have wireless connections in the field. Previously, we proposed a routing algorithm for generating an optimal routing path between the hosts and one Internet Gateway (GW). However, in practical situations, multiple GWs are usually necessary for scalability. Beside, in the high-speed IEEE802.11ac protocol, the link speed drastically decreases as the distance increases due to the lowered receiving signal quality. Furthermore, commercial APs implementing them have the limitation on the number of hops between a GW and a host. In this paper, we propose a routing algorithm to consider these practical conditions for large-scale WIMNET. We verify the effectiveness through simulating three topologies using the WIMNET simulator.

DOI： 10.1109/ICCE-TW.2014.6904085

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Extensions of Active Access-Point Selection Algorithm for Wireless Mesh Networks Using IEEE802.11ac Protocol

Chang Choon Chew, Nobuo Funabiki, Sho Fujita

2014 SECOND INTERNATIONAL SYMPOSIUM ON COMPUTING AND NETWORKING (CANDAR)   310 - 314   2014

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A wireless Internet-access mesh network (WIMNET) provides a scalable Internet-access network by flexibly allocating access points (APs) in the field that are connected by wireless links. Previously, we proposed an active AP selection algorithm to select the APs to be activated among the redundantly allocated APs for WIMNET that has a single Internet gateway (GW). However, in practical implementations of large-scale WIMNET, multiple GWs are usually necessary to increase the capacity of Internet connections. Besides, the number of hops between a GW and a host is limited for stable multihop communications, and the transmission speed of a wireless link is dynamically changed by the link condition such as the distance in the high-speed IEEE802.11ac protocol. Furthermore, the minimum throughput should be provided to a host as QoS (Quality of Service) when it is exclusively connected with the GW. In this paper, we propose extensions of the active AP selection algorithm to consider these conditions. We verify the effectiveness of our proposal through simulations in three topologies using the WIMNET simulator.

DOI： 10.1109/CANDAR.2014.29

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A Frame Aggregation Extension of Routing Algorithm for Wireless Mesh Networks

Nobuo Funabiki, Yuuma Tani, Shigeto Tajima

2014 SECOND INTERNATIONAL SYMPOSIUM ON COMPUTING AND NETWORKING (CANDAR)   238 - 242   2014

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As a scalable Internet-access network, an Wireless Internet-access Mesh NETwork (WIMNET) consists of multiple wireless access-points (APs) that are connected through wireless links. At least one AP acts as a gateway (GW) to the Internet where any host must reach there through multi-hop communications between APs. To handle large traffics, the latest highspeed IEEE 802.11ac protocol should be adopted for scalable WIMNET, where the routing path determines the performance under its practical implementations using commercial products. Therefore, we have proposed a routing algorithm considering 1) multiple GWs, 2) the link speed change, and 3) the limited number of hops. In this paper, to further improve the performance, we extend the routing algorithm to efficiently consider the frame aggregation in IEEE802.11ac. We verify the effectiveness of our proposal through simulating two topologies using the extended WIMNET simulator.

DOI： 10.1109/CANDAR.2014.28

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An extended active access-point selection algorithm for link speed changes in wireless mesh networks

International Journal Space-Based and Situated Computing   4 ( 3 )   184 - 193   2014

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A Proposal of Javadoc Hint Function for Java Programming Learning Assistant System

Nobuo Funabiki, Takuya Nakamura, Wen-Chung Kao

2014 IEEE 3RD GLOBAL CONFERENCE ON CONSUMER ELECTRONICS (GCCE)   304 - 308   2014

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As a reliable, portable, and practical programming language, Java has been educated in many universities and professional schools. To assist Java educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS) to help students studying Java programming by themselves through automatic testing of Java source codes using the test-driven development (TDD) method. Unfortunately, JPLAS is not suitable for novice students taking basic Java classes, because they need to extract necessary information such as the names of classes and methods from a test code for automatic testing before writing a source code. Previously, we implemented the code design learning function in JPLAS to assist such students. In this paper, we propose a Javadoc hint function in JPLAS to further assist students by showing the detailed information that is automatically generated from the reference code by a teacher for the assignment. We verify the effectiveness of our proposal through an experimental use by 41 students in our department.

DOI： 10.1109/GCCE.2014.7031127

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An Extension of Access-Point Allocation Algorithm for Adapting Link Speed Change in Wireless Mesh Network

FARAG Tamer, FUNABIKI Nobuo, HASSAN Walaa

IEICE technical report   113 ( 360 )   137 - 142   2013.12

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

As an inexpensive, scalable Internet-access wireless network, we have studied design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET uses multiple access-points (APs) that are connected by wireless links. In WIMNET, the proper allocation of APs is essential to ensure the communication quality of hosts and to minimize the installation and management cost. Previously, we have proposed an AP allocation algorithm for WIMNET assuming that every link has a constant speed regardless of the condition. However, our preliminary experiments found that the link speed is greatly affected by the distance and interferences in high-speed IEEE802.11n/ac protocols that have recently become popular. In this paper, we propose an extension of our AP allocation algorithm to adapt to this link speed change where the maximum link distance between two APs that has been fixed in the previous algorithm is optimized to provide the highest performance. We verify the effectiveness of our extended algorithm through simulations in simple topology instances using the WIMNET simulator.

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A Proposal of Routing Tree Algorithm for Scalable Wireless Mesh Networks Under Practical Conditions

MARUYAMA Wataru, FUNABIKI Nobuo, NAKANISHI Toru

Technical report of IEICE. RCS   113 ( 361 )   249 - 254   2013.12

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As a flexible cost-efficient Internet access network, we have studied the Wireless Internet-access Mesh NETwork (WIMNET) that is composed of multiple access points (APs) connected through wireless links. We have proposed a routing tree algorithm to find a routing path between one Internet gateway (GW) and the hosts. However, normally, several GWs exist in practical implementations of WIMNET. The number of hops between a GW and a host is limited for commercial APs. Furthermore, the communication speed is dynamically changed by the link distance for the new high-speed communication protocol IEEE802.11ac. In this study, we propose a new routing tree algorithm considering these conditions for WIMNET. We verify the effectiveness of our proposal through simulating two instances using the WIMNET simulator.

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An Extension of Access-Point Allocation Algorithm for Adapting Link Speed Change in Wireless Mesh Network

FARAG Tamer, FUNABIKI Nobuo, HASSAN Walaa

Technical report of IEICE. RCS   113 ( 361 )   255 - 260   2013.12

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

As an inexpensive, scalable Internet-access wireless network, we have studied design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET uses multiple access-points (APs) that are connected by wireless links. In WIMNET, the proper allocation of APs is essential to ensure the communication quality of hosts and to minimize the installation and management cost. Previously, we have proposed an AP allocation algorithm for WIMNET assuming that every link has a constant speed regardless of the condition. However, our preliminary experiments found that the link speed is greatly affected by the distance and interferences in high-speed IEEE802.11n/ac protocols that have recently become popular. In this paper, we propose an extension of our AP allocation algorithm to adapt to this link speed change where the maximum link distance between two APs that has been fixed in the previous algorithm is optimized to provide the highest performance. We verify the effectiveness of our extended algorithm through simulations in simple topology instances using the WIMNET simulator.

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Evaluation and Improvement of Credibility-based Voting for Volunteer Computing Systems with Dynamic Error Rate

2013 ( 26 )   1 - 8   2013.12

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An Implementation of Volunteer Computing System with Credibility-based voting

2013 ( 19 )   1 - 7   2013.12

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Efficient Proofs for CNF Formulas on Attributes in Pairing-Based Anonymous Credential System

Nasima Begum, Toru Nakanishi, Nobuo Funabiki

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E96A ( 12 )   2422 - 2433   2013.12

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To enhance user privacy, anonymous credential systems allow the user to convince a verifier of the possession of a certificate issued by the issuing authority anonymously. In the systems, the user can prove relations on his/her attributes embedded into the certificate. Previously, a pairing-based anonymous credential system with constant-size proofs in the number of attributes of the user was proposed. This system supports the proofs of the inner product relations on attributes, and thus can handle the complex logical relations on attributes as the CNF and DNF formulas. However this system suffers from the computational cost: The proof generation needs exponentiations depending on the number of the literals in OR relations. In this paper, we propose a pairing-based anonymous credential system with the constant-size proofs for CNF formulas and the more efficient proof generation. In the proposed system, the proof generation needs only multiplications depending on the number of literals, and thus it is more efficient than the previously proposed system. The key of our construction is to use an extended accumulator, by which we can verify that multiple attributes are included in multiple sets, all at once. This leads to the verification of CNF formulas on attributes. Since the accumulator is mainly calculated by multiplications, we achieve the better computational costs.

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A Proposal of Extended Anonymous Credential Scheme with Efficient Proof of Age Inequality (Information Security)

SADIAH Shahidatul, NAKANISHI Toru, WATANABE Kan, FUNABIKI Nobuo

Technical report of IEICE. ISEC   113 ( 217 )   21 - 28   2013.9

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An anonymous credential system on attributes allows a user to convince a service provider anonymously that he/she owns a certified attribute. Previously, an anonymous credential system to prove that user attributes satisfy a CNF formula on attributes was proposed. However, the system needs a large public key (PK) size and thus the large computation times, when proving the age in equation using the birthday attribute, because each birthday is assigned to one attribute and each attribute is mapped to one public parameter. In this paper, to reduce the PK size and computation times, we use the idea of dividing the birthday (year/month/day) attribute into the year, the month, and the day attributes. Consequently, the PK size is decreased, since the number of attributes is reduced to approximately 0.3%. In case of proving the age in equation, these attributes have to be expressed using monotone logic formulas. To adopt this idea on previous system, we extend the accumulator in the previous system and we propose an anonymous credential system to prove monotonic formulas. Also, we show the effectiveness of proposed system by measuring the process times for the implementation.

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A Clustering Algorithm Considering Link Speed for Wireless Mesh Networks

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   113 ( 129 )   155 - 160   2013.7

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A Wireless Internet-access Mesh Network (WIMNET) can provide a scalable Internet-access network by using multiple access point (APs) connected through wireless communications. In previous studies, we proposed a clustering algorithm for efficiently composing large scale WIMNET by partitioning the APs into a set of clusters. For this algorithm, we assume that any link has a constant speed, although our preliminary experiments found that the link speed is greatly changed by the link distance and interferences for the new high-speed IEEE802.11n protocol that has recently become popular. In this paper, we extend the clustering algorithm in considering the link speed change for effectively introducing IEEE802.11n to WIMNET. We verify the effectiveness of our proposal through simulations in grid topology instances using the WIMNET simulator.

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A Fixed Backoff-Time Switching Method for CSMA/CA Protocol in Wireless Mesh Networks

Sritrusta Sukaridhoto, Nobuo Funabiki, Toru Nakanishi, Kan Watanabe, Shigeto Tajima

IEICE TRANSACTIONS ON COMMUNICATIONS   E96B ( 4 )   1019 - 1029   2013.4

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As a flexible and cost-efficient scalable Internet access network, we studied architectures, protocols, and design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET is composed of multiple access points (APs) connected through multihop wireless communications on IEEE 802.11 standards. The increasing popularity of real-time applications such as IF-phones and IP-TV means that they should be supported in WIMNET. However, the contention resolution mechanism using a random backoff-time in the CSMA/CA protocol of 802.11 standards is not sufficient for handling real-time traffic in multihop wireless communications. In this paper, we propose a Fixed Backoff-time Switching (FBS) method for the CSMA/CA protocol to improve the real-time traffic performance in WIMNET by giving the necessary activation chances to each link. We implement our proposal on the QualNet simulator, and verify its effectiveness through simulations on three network topologies with four scenarios.

DOI： 10.1587/transcom.E96.B.1019

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BS-1-26 A Design for OpenFlow lmplementation of Fixed Backoff-time Switching Method in Wireless Mesh Networks

Sukaridhoto Sritrusta, Funabiki Nobuo, Nakanishi Toru, Watanabe Kan

Proceedings of the IEICE General Conference   2013 ( 2 )   "S - 50"-"S-51"   2013.3

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D-9-27 AN EXPERIMENTAL EVALUATION OF COOKING-STEP SCHEDULING ALGORITHM IN COOKING FOUR DISHES

Matsushima Yukiko, Okada Tomoya, Funabiki Nobuo, Nakanishi Toru, Watanabe Kan

Proceedings of the IEICE General Conference   2013 ( 1 )   125 - 125   2013.3

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BS-1-2 AN IMPROVED HOST ASSOCIATION OPTIMIZATION STAGE IN ACCESS-POINT AGGREGATION ALGORITHM FOR WIRELESS LOCAL AREA NETWORKS

Islam Ezharul, Funabiki Nobuo, Nakanishi Toru, Watanabe Kan

Proceedings of the IEICE General Conference   2013 ( 2 )   "S - 3"-"S-4"   2013.3

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D-9-7 A Proposal of Web-based Receipt Information Management System

na Ta, Funabiki Nobuo, Nakanishi Toru, Watanabe Kan

Proceedings of the IEICE General Conference   2013 ( 1 )   105 - 105   2013.3

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An Extension of Routing Tree Algorithm Considering Link Speed Change for Wireless Mesh Networks

MARUYAMA Wataru, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report   112 ( 392 )   1 - 6   2013.1

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As a flexible inexpensive Internet-access network, we have studied the Wireless Internet-access Mesh NETwork (WIMNET) that is composed of wirelessly interconnected Access-Points (APs). Previously, we proposed the routing tree algorithm to generate a routing path connecting the APs in WIMNET such that the performance can improved by reducing congestions at links around the Internet Gate Way (GW). For this algorithm, we assume that every link has the same constant speed to transmit data packets regardless of its distance However, when we adopt the new high-speed IEEE802. 11n protocol for wireless communications, our preliminary experiments found that the speed decreases drastically as the distance increases. In this paper, we extend the routing tree algorithm in order to consider the link speed change and generate the routing path to the hosts. We show the effectiveness of this extension through simulations in three instances.

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An Extension of Active Access Point Selection Algorithm for Wireless Mesh Networks

FUJITA Sho, FUNABIKI Nobuo, NAKANISHI Tom, WATANABE Kan

IEICE technical report   112 ( 392 )   19 - 24   2013.1

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The wireless Internet-access mesh network (WIMNET) has been studied to realize an inexpensive, scalable Inter-net-access network by using multiple access points (APs) connected by wireless links. WIMNET can improve the dependability to failures of links and APs by allocating APs redundantly. Since redundant APs may cause the increase of the operational cost and the degradation of the throughput due to increasing radio interferences, we have proposed the active AP selection algorithm for selecting functioning APs for communications. In this algorithm, we assume that every link speed is constant for simplicity, although our preliminary expenments found that the link speed greatly is affected by the distance in the new high-speed IEEE802.11 n protocol that has recently become popular. In this paper, we extend the active AP selection algonthm in considering this link speed change. We verify the effectiveness of our proposal through simulations in four instances using the WIMNET simulator.

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An Extension of Access-Point Aggregation Algorithm Considering Link Speed Change for Wireless Local Area Networks

ISLAM Md. EZHARUL, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report   112 ( 392 )   7 - 12   2013.1

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These days, multiple wireless local area networks (WLANs) have been often deployed in the same building of a university or a company. In those WLANs, access points (APs) are usually managed independently by different groups such as laboratories or departments. Then, a host can detect signals from multiple APs, which may degrade the communication performance due to their interferences and increase the operational cost Previously, we have proposed an AP aggregation algorithm to minimize the number of active APs in the field by aggregating them using the virtual AP technology. Recently, the IEEE802. 11n protocol has become popular as a high-speed communication protocol for WLANs However, our preliminary experiments using this protocol found that the link speed drastically decreases as its distance increases. In this paper, we extend our AP aggregation algorithm to considering this speed change so that any host can ensure the minimum speed with an AP while maximizing the overall throughput of the network. We verify the effectiveness of our extension through simulations in a network scenario using the WIMNET simulator.

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Database Design and Input Data Processing Algorithm for Receipt Information System

Tana, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report. Life intelligence and office information systems   112 ( 379 )   85 - 90   2013.1

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Recently, due to the lasting economic depression, an economical life has been desired for many people. For their assistance, our group is developing a Web-based receipt information system to help keeping household accounts to grasp daily expenses, and sharing latest information of selling products at nearby shops to buy products as inexpensively as possible. In this paper, we present the database design for this system, and propose the input data processing algorithm composed of the functions for 1) product name corrections, 2) discount price corrections, and 3) category classifications, to solve problems in the character recognition software on receipts adopted in this system. Our preliminary experiments found that this software often falsely recognizes product names, cannot correct discount prices, and cannot automatically classify categories of products. We implemented the proposed algorithm as a Java application, and applied it to 113 products from 12 receipts where every product was correctly processed.

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An Android Application of Cooking Guidance Function in Homemade Cooking Assistance System

OKADA Tomoya, MATSUSHIMA Yukiko, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report. Information and communication management   112 ( 378 )   91 - 96   2013.1

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In order to assist economical and healthy lives with homemade cooking, our group has developed a Web-based HOmemade Cooking Assistance System (HOCAS) Previously, we have implemented the menu planning function and the cooking-step scheduling function at the server, so that busy persons such as working people, students, and nurturing families can make menus and cooking-step schedules for one week including bulk cooking in weekends. In this paper, we implement the cooking guidance function as an Android application of cooking guidance. Using outputs of the existing functions, it provides the three functions for the menu indication, the cooking guidance, and the cooking time measurement. For experimental evaluations, we cooked four dishes by following the guidance from the system, and confirmed its effectiveness. Through comparing cooking times between expected and measured ones, we analyzed its problems and discussed future works.

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An Android Application of Cooking Guidance Function in Homemade Cooking Assistance System

OKADA Tomoya, MATSUSHIMA Yukiko, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report. Life intelligence and office information systems   112 ( 379 )   91 - 96   2013.1

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In order to assist economical and healthy lives with homemade cooking, our group has developed a Web-based HOmemade Cooking Assistance System (HOCAS) Previously, we have implemented the menu planning function and the cooking-step scheduling function at the server, so that busy persons such as working people, students, and nurturing families can make menus and cooking-step schedules for one week including bulk cooking in weekends. In this paper, we implement the cooking guidance function as an Android application of cooking guidance. Using outputs of the existing functions, it provides the three functions for the menu indication, the cooking guidance, and the cooking time measurement. For experimental evaluations, we cooked four dishes by following the guidance from the system, and confirmed its effectiveness. Through comparing cooking times between expected and measured ones, we analyzed its problems and discussed future works.

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An Extension of Fill-in-the-blank Problem Function in Java Programming Learning Assistant System and Its Application to Classes

KORENAGA Yousuke, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan, AMANO Noriki

IEICE technical report. Education technology   112 ( 374 )   63 - 68   2013.1

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Nowadays, a programming language Java has been educated in many universities and professional schools To assist its self-studies by students, we have developed a Web-based Java Programming Learning Assis-tant System (JPLAS) In this work, we extend the fill-in-the-blank problem functcon in JPLAS, so that this function can select variables and grammar symbols into problems in addition to conventional reserved words This function can automatically generate fill-in-the-blank problems by randomly blanking symbols in a sample Java code that correspond to the words specified by a teacher, where the constraints for unique answers are observed For evalu-ations of this function, we applied it to students in a Java programming course in our department after preparing 100 problems with various levels using JPLAS Then, we assigned them a quiz of the related problems to verify the learning effect The result shows that those who solved more problems in JPLAS could obtain better scores in the quiz

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A Java programming learning assistant system using test-driven development method

Nobuo Funabiki, Yukiko Matsushima, Toru Nakanishi, Kan Watanabe, Noriki Amano

IAENG International Journal of Computer Science   40 ( 1 )   38 - 46   2013

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An Extension of Access-Point Aggregation Algorithm to Ensure Minimum Host Throughput for Wireless Local Area Networks

Md. Ezharul Islam, Nobuo Funabiki, Toru Nakanishi, Kan Watanabe

2013 FIRST INTERNATIONAL SYMPOSIUM ON COMPUTING AND NETWORKING (CANDAR)   141 - 147   2013

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Recently, many organizations such as universities and companies are deploying multiple wireless local area networks (WLANs) even in the same building. In these WLANs, wireless access-points (APs) are usually managed independently by different groups such as laboratories or departments. In this overlapped WLAN environment, a host can detect signals from multiple APs, which may degrade the communication performance due to their interferences and increase the operational cost. To solve this problem, previously, we have proposed the AP aggregation algorithm to minimize the number of active APs in the field by aggregating them using the virtual AP technology. However, the minimization of active APs may excessively degrade the performance of WLANs, where more active APs can usually increase it. In this paper, we propose an extension of the AP aggregation algorithm to ensure the minimum average throughput for each host in the field. This average throughput is estimated using the cost function defined in the algorithm, and the number of active APs is increased when it does not reach the given threshold. We verify the effectiveness of this extension through extensive simulations in two network instances using the WIMNET simulator.

DOI： 10.1109/CANDAR.2013.27

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An improvement of graph-based fill-in-blank problem generation algorithm in Java programming learning assistant system

Tana, Nobuo Funabiki, Toru Nakanishi, Noriki Amano

International Workshop on ICT   1 - 4   2013

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A cooking guidance function on Android tablet for Homemade Cooking Assistance System

Yukiko Matsushima, Nobuo Funabiki, Tomoya Okada, Toru Nakanishi, Kan Watanabe

2013 IEEE Region 10 Humanitarian Technology Conference, R10-HTC 2013   249 - 254   2013

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To assist busy people such as working persons, students, and nurturing families to have economical and healthy lives with homemade cooking, we have proposed a Web-based HOmemade Cooking Assistance System (HOCAS). Previously, we implemented the menu planning function and the cooking-step scheduling function at the server using JSP/Servlet, so that a user can plan a menu for the whole week and make a cooking-step schedule to efficiently cook multiple dishes at the same time. Unfortunately, a user needs to refer the next cooking-step on a paper during cooking process, which is actually not easy at critical timing in a kitchen, because the schedule is output as a PDF file. In this paper, we propose a cooking guidance function on an Android tablet as a Java application to navigate cooking-steps through touch panel operations. We confirmed the effectiveness by experimentally cooking four dishes using this function. © 2013 IEEE.

DOI： 10.1109/R10-HTC.2013.6669050

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An extension of fill-in-the-blank problem function in Java programming learning assistant system

Nobuo Funabiki, Yousuke Korenaga, Toru Nakanishi, Kan Watanabe

2013 IEEE Region 10 Humanitarian Technology Conference, R10-HTC 2013   85 - 90   2013

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Nowadays Java has been educated in many universities and professional schools as a reliable, portable, and practical programming language. To assist self-studies by students, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS has the two main functions of code writing problem and fill-in-the-blank problem to support studies at different levels. The former function intends that a student can write a whole code from scratch, where the submitted code is automatically tested on the server using the test-driven development (TDD) method. The latter function intends that a novice student can study Java reserved words, where a problem is generated by randomly removing the specified ones from a selected sample code and the removed one becomes the correct answer to each blank. In this paper, we extend this latter function for removing more general elements including variables and control symbols in problems. We analyze the conditions for selecting blanked elements with unique correct answers. For evaluations, we generated 100 problems with various levels using the extended function, and assigned them to students in the Java programming course in our department. Then, we gave a short test and a questionnaire with nine questions, where we found that students solving more problems achieved better scores in general, and their opinions support the effectiveness of our proposal. © 2013 IEEE.

DOI： 10.1109/R10-HTC.2013.6669019

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A Modified Active Access-Point Selection Algorithm Considering Link Speed Change in IEEE 802.11n for Wireless Mesh Networks

Nobuo Funabiki, Sho Fujita, Toru Nakanishi, Kan Watanabe

2013 SEVENTH INTERNATIONAL CONFERENCE ON COMPLEX, INTELLIGENT, AND SOFTWARE INTENSIVE SYSTEMS (CISIS)   714 - 719   2013

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As an inexpensive, scalable Internet-access wireless network, we have studied the architecture, protocols, and design optimizations of the wireless Internet-access mesh network (WIMNET) that uses multiple access-points (APs) connected by wireless links. WIMNET can improve the dependability to failures of links and/or APs by allocating APs redundantly in the network field. Because redundant APs can increase the operational cost and degrade the performance due to increasing radio interferences, only the necessary APs for connections between the hosts and the Internet gateway should be activated at communications. Previously, we have defined the active AP selection problem of selecting the minimum number of active APs, and proposed its heuristic algorithm, assuming that every link has the same constant speed for simplicity. However, our preliminary experiments found that the link speed is greatly affected by the distance in the high-speed IEEE802.11n protocol that has recently become popular. In this paper, we propose a modification of the active AP selection algorithm to consider the link speed change, where we introduce a new design parameter for WIMNET to select links that have sufficient throughputs. We verify the effectiveness of our modified algorithm through simulations in four instances using the WIMNET simulator.

DOI： 10.1109/CISIS.2013.128

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A Modified Routing Tree Algorithm Considering Link Speed Change in IEEE 802.11n for Wireless Mesh Network

Nobuo Funabiki, Toru Nakanishi, Kan Watanabe, Wataru Maruyama

2013 IEEE 17TH INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS (ISCE)   29 - 30   2013

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A Wireless Internet-access Mesh NETwork (WIMNET) can provide an expandable Internet-access network by adopting multiple Access-Points (APs) that have wireless connections with each other. Previously, we proposed a routing tree algorithm for generating an optimal routing path between the APs and the Internet Gate Way (GW) with a minimal transmission delay, assuming that every link has the same data transmission speed. However, our preliminary experiments found that the link speed using the IEEE802.11n as a new high-speed protocol for wireless communications, decreases drastically as the distance increases due to the lowered receiving signal quality. In this paper, we propose a modified routing tree algorithm to consider the large speed change in order to adopt the IEEE 802.11n in WIMNET effectively. In addition to links between APs, our modified algorithm selects the links between hosts and their associated APs. We verify the effectiveness of the modified algorithm through simulations in three topologies.

DOI： 10.1109/ISCE.2013.6570233

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Reducing public-key size in an anonymous credential system for CNF formulas with constant-size proofs

Nasima Begum, Toru Nakanishi, Nobuo Funabiki

2013 IEEE 2nd Global Conference on Consumer Electronics, GCCE 2013   530 - 533   2013

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To enhance the user privacy at authentications, an anonymous credential system has been designed to allow a user to anonymously convince a verifier of the possession of a certificate issued by the issuing authority. In this system, a user can prove relations on his/her attributes embedded into the certificate. Previously, we have proposed an anonymous credential system with constant-size proofs and faster proof generations for CNF formulas than the existing system. In the system, in the verification, some value should be included in some set Φ. Unfortunately, this system has a problem of requiring long public parameters that is proportional to the size of the set Φ. In this paper, we propose an extension to reduce the public key by separating this set Φ into two sets Φ1 and Φ2 with logarithmic sizes such that u1 Φ1 and u2 Φ2 if and only if u1 +u2 Φ. Furthermore, we evaluate the efficiency based on the implementation. © 2013 IEEE.

DOI： 10.1109/GCCE.2013.6664912

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An extension of clustering algorithm for considering link speed in wireless mesh networks

Shigeto Tajima, Nobuo Funabiki, Teruo Higashino

2013 IEEE 2nd Global Conference on Consumer Electronics, GCCE 2013   500 - 504   2013

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As a scalable Internet-access network, we have studied Wireless Internet-access Mesh Network (WIMNET) using multiple access point (APs) that are connected through wireless communications. In previous studies, we proposed a clustering algorithm for efficiently composing a large scale WIMNET by partitioning the APs into a set of clusters. This algorithm assumes that any link speed is constant for simplicity, whereas our preliminary experiments found that it is greatly changed as the link distance increases due to interferences when adopting the new high-speed IEEE802.11n protocol. In this paper, we extend our clustering algorithm to consider this link speed change to introduce IEEE802.11n into WIMNET. We verify the effectiveness of the extended algorithm through simulations in a grid topology instance using the WIMNET simulator. © 2013 IEEE.

DOI： 10.1109/GCCE.2013.6664902

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Extensions of cooking guidance function on Android tablet for homemade cooking assistance system

Yukiko Matsushima, Nobuo Funabiki, Yijia Zhang, Toru Nakanishi, Kan Watanabe

2013 IEEE 2nd Global Conference on Consumer Electronics, GCCE 2013   397 - 401   2013

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Previously, we proposed a cooking-step scheduling algorithm to find a schedule of applying the cooking steps in the recipes for efficiently cooking multiple dishes simultaneously, to help healthy and cost-efficient lives for busy person. Then, we implemented a cooking guidance function on an Android tablet to navigate the cooking schedule in a kitchen. Although we confirmed the effectiveness through cooking experiments, we found three problems: 1) a user may click a starting button even if the previous required steps are not completed, 2) a user may miss the proper timing to stop a cooking-step, and 3) the duration time for a cooking-step may be varied by a user skill or a dish nature. In this paper, we extend the cooking guidance function by adding three features of starting condition checking, time-up alarming, and cooking rescheduling to solve these problems. We verify the effectiveness of the extended guidance function through experimentally cooking four dishes. © 2013 IEEE.

DOI： 10.1109/GCCE.2013.6664869

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An extension of menu planning algorithm for two-phase homemade cooking

Nobuo Funabiki, Yukiko Matsushima, Toru Nakanishi, Kan Watanabe

2013 IEEE 2nd Global Conference on Consumer Electronics, GCCE 2013   352 - 356   2013

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Nowadays, many people keep busy lives due to working in companies, studying in schools, or taking care of children or senior parents. As a result, it has become very hard for them to cook foods for suppers by themselves at home after long-hour duties at daytime in weekdays. Previously, to assist homemade cooking of such busy people, we proposed a two-phase cooking such that the preparation phase of cooking foods that they will eat on the following weekdays is performed on a weekend, and the finishing phase for the foods for a supper is completed on the day in short time. Then, we presented a menu planning algorithm to assist generating one-week menus for this two-phase cooking. Unfortunately, we found that this algorithm has the following drawbacks in practical use: 1) the selection of food preference is not easy, 2) the use of preferred ingredients for cooking cannot be directly specified, and 3) the nutrition balance of foods in a menu is not considered. In this paper, we extend this algorithm to solve them by newly defining a preference index and the food balance guide by Japanese government. We verify the effectiveness of the extended algorithm through generating five-day menus from 241 food candidates. © 2013 IEEE.

DOI： 10.1109/GCCE.2013.6664853

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A graph-based algorithm for fill-in-blank problem generation in Java programming learning assistant system

Nobuo Funabiki, Tana, Toru Nakanishi, Kan Watanabe

The 3rd International Conference on Applied and Theoretical Information Systems Research (ATISR2013)   2013

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A fixed backoff-time switching method for wireless mesh networks: Design and Linux implementation

Sritrusta Sukaridhoto, Nobuo Funabiki, Dadet Pramudihanto, Zainal Arief

Proceedings - 2013 International Conference on Information Technology and Electrical Engineering: "Intelligent and Green Technologies for Sustainable Development", ICITEE 2013   248 - 253   2013

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As a flexible and cost-efficient scalable Internet access network, we have studied architectures, protocols, and design optimizations of the Wireless Internet-Access Mesh NETwork (WIMNET). WIMNET is composed of wirelessly connected access points (APs), where any host can basically access to the Internet through multihop communications between APs with IEEE 802.11 standard. In WIMNET, undesirable situations can often happen such that some links dominate the bandwidth while others become insufficient due to the limited shared bandwidth. However, the contention resolution mechanism using a random backoff-time in the CSMA/CA protocol of 802.11 standards is not sufficient for handling real-time traffic in multihop wireless communications. Previously, we have proposed the concept of the CSMA-based Fixed Backoff time Switching (CSMA-FBS) method for WIMNET to improve the performance by giving necessary link activation chances for multi-hop communications. We implemented our proposal on the QualNet simulator, and verify its effectiveness through simulations. In this paper, we present an implementation of the FBS method in Linux kernel to show its practicality and investigate the performance in a real network. Our design consists of implementations or modifications of the five programs: Kernel configuration, Debugfs, Minstrel, iw, and FBSdaemon. © 2013 IEEE.

DOI： 10.1109/ICITEED.2013.6676247

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An access-point aggregation approach for energy-saving wireless local area networks

Md. Ezharul Islam, Nobuo Funabiki, Toru Nakanishi, Kan Watanabe

IEICE Transactions on Communications   E96-B ( 12 )   2986 - 2997   2013

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Nowadays, with spreads of inexpensive small communication devices, a number of wireless local area networks (WLANs) have been deployed even in the same building for the Internet access services. Their wireless access-points (APs) are often independently installed and managed by different groups such as departments or laboratories in a university or a company. Then, a user host can access to multiple WLANs by detecting signals from their APs, which increases the energy consumption and the operational cost. It may also degrade the communication performance by increasing interferences. In this paper, we present an AP aggregation approach to solve these problems in multiple WLAN environments by aggregating deployed APs of different groups into limited ones using virtual APs. First, we formulate the AP aggregation problem as a combinatorial optimization problem and prove the NP-completeness of its decision problem. Then, we propose its heuristic algorithm composed of five phases. We verify the effectiveness through extensive simulations using the WIMNET simulator. Copyright © 2013 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1587/transcom.E96.B.2986

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An Extension of Credibility Formula in Desktop Grid to Different Workers' Performance

2012 ( 16 )   1 - 8   2012.12

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A Web Service Implementation of ◆ Attribute Authentication

HAMADA Yuji, NAKANISHI Toru, WATANABE Kan, FUNABIKI Nobuo

IEICE technical report. Life intelligence and office information systems   112 ( 306 )   41 - 46   2012.11

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Our research group has proposed the anonymous authentication scheme using user's attributes. In this scheme, the user can anonymously convince a verifier of the possession of attributes specified by the service provider with the complexity independent of the number of attributes. Previously, we have implemented Web system where the user proves the AND relations to a verifier. However, we cannot prove CNF fomulas that is the conbination of AND and OR relations at our Web system. In this study, we implemented the anonymous attributes authentication system for CNF fomulas using proxies and a questionnaire service as a Web service. We measured the communication times including the authentication times. The results show that our system is sufficiently practical.

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An Implementation of Anonymous Attributes Authentication System on Android Smart Phone

2012 ( 3 )   146 - 152   2012.10

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An Implementation of Reputation System with Secrecy Even for Administrators

2012 ( 3 )   828 - 834   2012.10

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An Extension of Wireless Internet-Access Mesh Network Simulator for Smart Antenna Use and Evaluations Using Simple Topologies

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   112 ( 231 )   125 - 130   2012.10

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As an inexpensive, flexible, and scalable Internet-access network, we have studied architecture, protocols, and design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET consists of multiple access-points (APs) as wireless routers that are connected through wireless links. To improve the performance by realizing high-speed and simultaneous plural link communications, we have considered use of the smart antenna as a generalized technology of the Multiple-Input-Multiple-Output (MIMO) channel and the Adaptive Array Antenna (AAA). In this paper, we present an extension of the WIMNET simulator for the smart antenna use, which has been developed by our group to estimate the throughput in WIMNET. Through simulations in simple topologies, we investigate impacts of two smart antenna use methods and of interval changes between adjacent nodes including APs and hosts, into the performance of WIMNET.

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An Implementation of Code Design Learning Function in Java Programming Learning Assistant System

NAKAMURA Takuya, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan, AMANO Noriki

IEICE technical report. Education technology   112 ( 224 )   17 - 22   2012.9

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Java has been educated in a lot of universities and professional schools due to the reliability, portability, and easy learning. To assist Java educations, our group has developed a Web-based Java Programming Learning Assistant System (JPLAS) that helps students to study Java programming by themselves through automatic testing of Java codes from students using the test-driven development method. Unfortunately, JPLAS is not suitable for less-experienced students in Java because they have to understand test codes that are necessary in automatic testing before writing source codes. In this paper, we propose a code design learning function in JPLAS to let such students learn how to collect the necessary information for a source code from a test code. A code design result from a student is automatically verified through comparisons with the corresponding model answer from a teacher. We verify the effectiveness of our proposal through applications to 24 students in our department.

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A Linux Implementation Design of Fixed Backoff-time Switching Method for Wireless Mesh Networks

SUKARIDHOTO Sritrusta, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan, Shigeto TAJIMA

IEICE technical report   112 ( 208 )   83 - 88   2012.9

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As a flexible and cost-efficient scalable Intenet access network, we have studied architectures, protocols, and design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET is composed of wirelessly connected access points(APs), where any host can basically access to the Internet through multihop communications between APs.In WIMNET, undesirable situations can often happen such that some links dominate the bandwidth while others become insufficient due to the limited shared bandwidth. To improve the performance by avoiding them, controls of activation chances for wireless links depending on their traffics are effective. Thus, previously, we have proposed the Fixed Backoff-time Switching (FBS) method for the CSMA/CA protocol, and verified the effectiveness using the QualNet simulator. In this paper, we present an implementation design of the FBS method in Linux kemel to show its practicality and investigate the performance in a real network. Our design consists of implementations or modifications of the five programs:Kernel configuration, Debugfs,Minstrel,iw, and FBSdaemon.

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BS-5-29 An Idea of Linux Implementation of Fixed Backoff-time Switching Method for Wireless Mesh Networks(BS-5. Network and Service Design, Control and Management)

Sukaridhoto Sritrusta, Funabiki Nobuo, Nakanishi Toru, Watanabe Kan, Tajima Shigeto

Proceedings of the Society Conference of IEICE   2012 ( 2 )   "S - 82"-"S-83"   2012.8

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As a flexible and cost-efficient scalable Internet access network, we have studied architectures,protocols, and design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET is composed of wireless connected access points. Previously, we proposed the Fixed Backoff-time Switching (FBS) method for the CSMA/CA protocol to improve the real-time traffic performance in WIMNET by giving the necessary activation chances to each link, and verified the effectiveness using the QualNet simulator. In this paper, we present an idea of the FBS method implementation at Linux kernel after quickly reviewing it.

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An Extension of Cooking-Step Scheduling Algorithm for Simultaneous Cooking of Multiple Dishes

MATSUSHIMA Yukiko, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report. Life intelligence and office information systems   112 ( 188 )   1 - 6   2012.8

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To assist homemade cooking of busy persons such as working people and child-growing families, we have proposed a cooking-step scheduling algorithm for multiple dishes. By composing the cooking procedure for each dish as a sequence of cooking-steps, this algorithm generates an optimal schedule of the cooking-steps for multiple dishes to minimize the cooking time while considering the constraints of cooks and instruments as a cooking model. In this paper, to enhance the practicality, we extend the algorithm in 1) accommodating the continuous cooking-steps such as boiling ingredients soon after stirring for a dish cooked by boiling or stewing, 2) suggesting the clearance chance of used instruments at a long waiting time, 3) preferentially assigning any possible cooking-step of the preferred dish to the sub-cook, and 4) considering the skill level of a cook in the operating time of a cooking-step. Through simulations and cooking experiments using five dishes, we verify the effectiveness of our algorithm extensions.

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An Extension of Cooking-Step Scheduling Algorithm for Simultaneous Cooking of Multiple Dishes

MATSUSHIMA Yukiko, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report. Image engineering   112 ( 189 )   1 - 6   2012.8

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To assist homemade cooking of busy persons such as working people and child-growing families, we have proposed a cooking-step scheduling algorithm for multiple dishes. By composing the cooking procedure for each dish as a sequence of cooking-steps, this algorithm generates an optimal schedule of the cooking-steps for multiple dishes to minimize the cooking time while considering the constraints of cooks and instruments as a cooking model. In this paper, to enhance the practicality, we extend the algorithm in 1) accommodating the continuous cooking-steps such as boiling ingredients soon after stirring for a dish cooked by boiling or stewing, 2) suggesting the clearance chance of used instruments at a long waiting time, 3) preferentially assigning any possible cooking-step of the preferred dish to the sub-cook, and 4) considering the skill level of a cook in the operating time of a cooking-step. Through simulations and cooking experiments using five dishes, we verify the effectiveness of our algorithm extensions.

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A Pairing-Based Anonymous Credential System with Efficient Attribute Proofs

Amang Sudarsono, Toru Nakanishi, Nobuo Funabiki

53 ( 6 )   11p   2012.6

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Other Link： http://id.nii.ac.jp/1001/00082615/

A Generalization of WDS Clustering Algorithm Extension to Smart-Antenna in Wireless Mesh Networks

TAJIMA Shigeto, FUNABIKI Nobuo, TOMISATO Shigeru, HATA Masaharu, HIGASHINO Teruo

IEICE technical report   112 ( 8 )   37 - 42   2012.4

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As a scalable inexpensive Internet-access network, we have studied the Wireless Internet-access Mesh Network (WIMNET) that is composed of multiple access point (APs) connected through the Wireless Distribution System (WDS). Because all the traffics pass through an Internet gateway (GW) in WIMNET, the resolution of link congestions around the GW is very important. For this problem, we have proposed a WDS clustering algorithm to partition the APs into a set of WDS clusters where the APs in each cluster shares an GW, and have considered the adoption of a smart antenna for a Smart AP (SAP). Since the smart antenna is usually expensive, we have extended the WDS clustering algorithm to a cluster where only one or two SAPs are used. In this paper, we generalize this extension to a cluster with an arbitrary number of SAPs. Besides, we investigate the priority action of the smart antenna for multiple SAPs in one cluster. We evaluate the effectiveness through simulations using grid topology instances.

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BS-3-17 LOAD BALANCING STAGE FOR AN ACCESS-POINT AGGREGATION ALGORITHM IN WIRELESS LOCAL AREA NETWORKS(BS-3. Management and Control Technologies for Innovative Networks)

Islam Md. Ezharul, Funabiki Nobuo, Nakanishi Toru, Watanabe Kan

Proceedings of the IEICE General Conference   2012 ( 2 )   "S - 33"-"S-34"   2012.3

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Currently, many organizations such as universities and companies are using multiple wireless local area networks (WLANs) even in the same building, where wireless access-points (APs) are independently managed by different groups such as departments or laboratories. As a result, a WLAN user host can detect signals from multiple APs, which may increase the interference and degrade the communication performance. Therefore, we have proposed an AP aggregation algorithm to minimize the number of active physical APs by aggregating the APs in the field by introducing virtual APs. In this paper, we introduce a load balancing stage to this algorithm to maximize the throughput by balancing loads among APs. The effectiveness has been verified through simulations in two instances.

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An Extension of Web-based Assistance System for Computer-Scored Paper Tests

TAKAKI Shogo, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan, AMANO Noriki

IEICE technical report. Education technology   111 ( 473 )   243 - 248   2012.3

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A frequent application of mini-exams and quizzes during classes can be effective to enhance the educational effects to students in universities. However, teachers may have to spend much time to prepare the test papers before classes, and grade the test papers from students after them. In order to ease such burdens of teachers, we have proposed a Web-based assistance system for computer-scored paper tests in conventional lecture rooms without computers for students. This system supports the test paper generation, the test paper grading, and the score management. In this paper, we extend the system by adding two new question types, implementing the test paper preview function, and providing the data export function to the Web quiz function in an existing learning assistant system. We evaluate the effectiveness of our proposal through an experiment in one class in our department.

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An Extension of Fill-in-the-blank Problem Function in Java Programming Learning Assistant System and Its Application to Class

KORENAGA Yousuke, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan, AMANO Noriki

IEICE technical report. Education technology   111 ( 473 )   7 - 12   2012.3

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The programming language Java has been educated in a lot of universities and professional schools due to the reliability, portability, and easy learning. To assist this Java education, our group has developed a Web-based Java Programming Learning Assistant System (JPLAS) by supporting self-studies of students. JPLAS has the fill-in-the-blank problem function for Java novice students to study Java reserved words. In this function, a teacher first generates fill-in-the-blank problems automatically by removing the specified reserved words randomly from a sample Java code in the database. Then, a student can repeatedly submit answers to the problems until all the answers are correct as self-studies. In this paper, we implement the score graph function so that the students can complete with each other in solving fill-in-the-blank problems by referring the current scores of other students. We apply the function to students in a Java programming class in our department to evaluate the effectiveness of our proposal.

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An Implementation of Erroneous Code Indication Function in Java Programming Learning Assistant System Using Test-Driven Development Method

FUKUYAMA Yuki, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan, AMANO Noriki

IEICE technical report. Education technology   111 ( 473 )   1 - 6   2012.3

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To enhance the effect of the Java programming education by assisting self-studies of students, we have proposed a Web-based Java Programming Learning Assistant System (JPLAS) using the test-driven development (TDD) method. In this system, a teacher first registers an exercise subject, a model source code, and a test code. Then, a student submits the answer code on the subject. The answer code is automatically verified by the verification tool at the server, and the verification result log is returned to the student. However, in the current system, even reading the log to find the errors is actually difficult for a student who is a Java programming beginner. In this paper, we implement an erroneous code indication function in JPLAS of graphically showing the error parts on the code. We evaluate the effectiveness of this function through an experiment to 42 students who are learning Java.

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An Internship Instance of Developing an Assistance System for Promoting Group Events Using Ruby

OKADA Tomoya, KORENAGA Yousuke, HAMADA Yuji, IKEDA Daiki, SHIMIZU Junki, TAKEBAYASHI Tatuya, FUNABIKI Nobuo, NAKANISHI Toru, Ishihara HIROYUKI, SATOU Junyuki, OTORI Yoshinori, KOHMOTO Takayuki, OHTA Mayumi

IEICE technical report. Education technology   111 ( 394 )   35 - 40   2012.1

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The Graduate School of Natural Science and Technology in Okayama University has offered a special exercise class named "Internship in Engineering and Science" so that the students can experience practical works in companies through long term internships there. In the past two years, we have had the exercise at Systems Nakashima Co., Ltd. in developing a Web application system using Ruby for promoting events such as travels and parties in groups by helping the event planning, the attendance confirmation, and the schedule management. In this paper, we introduce the content of this exercise and the outline of the developed system. Besides, we describe the feedbacks of the students on this exercise.

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Training Program for Practical Engineering Design through the Collaboration with Regional Companies

GOFUKU Akio, TABATA Nobuhisa, TOMITA Eiji, FUNABIKI Nobuo

Journal of Jsee   60 ( 1 )   52 - 57   2012.1

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An education program to bring up engineering design capabilities through long-term internship by the collaboration with regional companies has been put in practice for five years. The program is composed of two types of long-term internships and several lectures for patent systems and engineering ethics. This paper describes the outline of the program, educational effects, and our experiences. The program was improved into two educational programs in 2011. The one is a special course to educate engineers and scientists who can lead the technologies of their domains. The other is a long-term internship program for master students in engineering divisions of graduate school. This paper also describes the current activities of the latter program.

DOI： 10.4307/jsee.60.1_52

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Combinational Effect of Spot-checking in Sabotage-tolerance for Volunteer Computing

WATANABE Kan, FUNABIKI Nobuo, NAKANISHI Toru, FUKUSHI Masaru

111 ( 408 )   103 - 108   2012.1

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An Improved Java Programming Learning System Using Test-Driven Development Method

Nobuo Funabiki, Yuuki Pukuyama, Yukiko Matsushima, Toru Nakanishi, Kan Watanabe

INTERNATIONAL MULTICONFERENCE OF ENGINEERS AND COMPUTER SCIENTISTS, IMECS 2012, VOL I   597 - 602   2012

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To enhance educational effects of Java programming by assisting self-studies of students and reducing teaching loads of teachers, we have proposed a Web-based Java programming learning system using the test-driven development method. In this system, a teacher should register Java programming assignments with statements, model source codes, and test codes using a Web browser. Then, a student can submit a test code and an answer source code for each assignment, where both codes are tested automatically by a testing tool called Junit at the server. Unfortunately, the current system cannot identify an incomplete test code that does not contain the complete test procedures if it has no grammatical error. In this paper, we introduce a code coverage measurement tool called Cobertura to detect such a test code by measuring the coverage rate when the submitted test code tests the model source code. We evaluate the effectiveness of our improved system through experiments with two simple assignments to 11 students who have studied Java.

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A dynamic rescheduling extension of cooking-step scheduling algorithm for multiple dish cooking

Yukiko Matsushima, Nobuo Funabiki, Toru Nakanishi, Kan Watanabe

The 2nd International Conference on Applied and Theoretical Information Systems Research (2nd ATISR2012)   2012

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A code design learning function in Java programming learning assistant system using test-driven development method

Nobuo Funabiki, Takuya Nakamura, Yukiko Matsushima, Toru Nakanishi, Kan Watanabe

The 2nd International Conference on Applied and Theoretical Information Systems Research (2nd ATISR2012)   2012

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An application of cooking-step scheduling algorithm for homemade cooking and its extensions

Yukiko Matsushima, Nobuo Funabiki, Toru Nakanishi, Kan Watanabe

1st IEEE Global Conference on Consumer Electronics 2012, GCCE 2012   94 - 98   2012

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Homemade cooking can have a key role for a healthy and cost-efficient life. To help this activity for busy people such as workers, students, and child-rearing families, we have proposed a cooking-step scheduling algorithm to suggest an optimal sequence of the cooking-steps when multiple dishes are cooked within a limited time. In this algorithm, the cooking procedure for each dish is divided into a set of cooking-steps, and the execution sequence of all the cooking-steps for the dishes is optimized such that the total cooking time is minimized. In this paper, we first show our application result of this algorithm in cooking five dishes and the arisen problems through this experiment. Then, we present four extensions of this algorithm to solve them. Through simulations and cooking experiments, we verify the effectiveness of the algorithm extensions. © 2012 IEEE.

DOI： 10.1109/GCCE.2012.6379977

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An extension of routing tree algorithm for smart antenna use in wireless Internet-access mesh network

Nobuo Funabiki, Toru Nakanishi, Kan Watanabe

1st IEEE Global Conference on Consumer Electronics 2012, GCCE 2012   633 - 637   2012

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As a cost-efficient scalable Internet-access network, we have studied the architecture, protocols, and design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET is composed of wirelessly connected multiple access-points (APs), where at least one AP acts as a Gateway (GW) to the Internet. Two types of APs are used for the hierarchical configuration to achieve scalability with sufficient bandwidth and low costs, namely, a programmable Smart AP (SAP) equipped with multiple antennas, and a non-programmable Conventional AP (CAP) with a single antenna. For a SAP, a smart antenna using an array antenna should be adopted to enhance the performance by allowing simultaneous activations of multiple links. Because the transmission capacity of a SAP with m antennas can be ideally m times of that of a CAP, the routing path should consider this difference so that the average delay between the GW and any AP be minimized to avoid bottlenecks. In this paper, we present an extension of our previous routing tree algorithm for this smart antenna use in WIMNET to improve the throughput by considering the feature. We evaluate the throughput improvement through simulations using the WIMNET simulator. © 2012 IEEE.

DOI： 10.1109/GCCE.2012.6379938

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Implementation and Evaluation of an Pairing-Based Anonymous Credential System with Constant-Size Proofs and Efficient Proof Generations

Nasima Begum, Toru Nakanishi, Nobuo Funabiki

2012 THIRD INTERNATIONAL CONFERENCE ON NETWORKING AND COMPUTING (ICNC 2012)   264 - 268   2012

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To enhance user privacy, anonymous credential systems allow the user to convince a verifier of the possession of a certificate issued by the issuing authority anonymously. In the systems, the user can prove logical relations on his/her attributes embedded into the certificate. Previously, we proposed a pairing-based system with constant-size proofs. In the system, the proof generation needs only multiplications depending on the size of the proved relations, and it is more efficient than other existing system that needs the exponentiations whose costs are much larger than multiplications. However, our efficient system has never been implemented, and thus the practicality is not evaluated. In this study, we implemented the system, and measured the processing times and data size, when changing the parameters describing the size of the proved relation. The verification time is very fast and constant, and the proof size is also constant, from which we can confirm the practicality. However, the proof generation time increases, when the parameters increase. Although we confirm the practicality in case of small relations, we clarify the problems in case of larger relations, which should be solved in our future works.

DOI： 10.1109/ICNC.2012.48

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Efficient proofs for CNF formulas on attributes in pairing-based anonymous credential system

Nasima Begum, Toru Nakanishi, Nobuo Funabiki

15th Annual International Conference on Information Security and Cryptology (ICISC 2012)   2012

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An Error Code Highlighting Function in Java Programming Learning Assistant System Using Test-Driven Development Method

Nobuo Funabiki, Yuuki Fukuyama, Yukiko Matsushima, Toru Nakanishi, Kan Watanabe

WORLD CONGRESS ON ENGINEERING AND COMPUTER SCIENCE, WCECS 2012, VOL I   230 - 235   2012

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Recently, the objected-oriented programming language Java has been used in many practical systems including enterprise servers, smart phones, and embedded systems due to its high reliability and portability. To enhance effects of Java programming educations, we have developed a Web-based Java Programming Learning Assistant System (JPLAS). JPLAS adopts the Test-Driven Development (TDD) method for automatic testing of source codes written by students on the server to assist their self-learning. In JPLAS, a teacher needs to register each Java programming assignment with a statement, a reference source code, and a test code. Then, students should write source codes by referring this statement and the test code so that their source codes can be tested automatically at the server by a testing software tool called JUnit with the test code. Unfortunately, the current JPLAS is not friendly to students who have difficulty in reading the log message from JUnit that contains the information on the errors in the source code. In this paper, we implement the error code highlighting function to help such students to find erroneous lines in the code by highlighting them graphically. We evaluate the effectiveness of this function through an experiment for 42 students who are currently taking the Java programming class.

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An extension of clustering algorithm for smart-antenna use in wireless mesh networks

Shigeto Tajima, Nobuo Funabiki, Shigeru Tomisato, Masaharu Hata, Teruo Higashino

1st IEEE Global Conference on Consumer Electronics 2012, GCCE 2012   638 - 642   2012

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As a scalable cost-efficient Internet-access network, we have studied the Wireless Internet-access Mesh Network (WIMNET) that is composed of multiple access point (APs) connected through the Wireless Distribution System (WDS). Because all the traffics pass through an Internet Gateway (GW), the resolution of link congestions around the GW is very important. To solve this problem, we have proposed a clustering algorithm to partition the APs into a set of clusters where each cluster consists of the APs sharing the same GW. In addition, we have considered the use of a smart antenna at a special AP called a Smart AP (SAP). In this paper, we extend this clustering algorithm for smart antenna use at SAPs. Besides, we investigate the link activation strategy for the smart antenna, because it allows a variety of link activations for packet transmissions. We evaluate the effectiveness through simulations using the WIMNET simulator. © 2012 IEEE.

DOI： 10.1109/GCCE.2012.6379939

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A proposal of access-point aggregation approach for multiple wireless local area networks

Nobuo Funabiki, Md. Ezharul Islam, Toru Nakanishi, Kan Watanabe

4th International Workshop on Virtual Environment and Network-Oriented Applications (VENOA 2012)   668 - 673   2012

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A pairing-based anonymous credential system with efficient attribute proofs

Amang Sudarsono, Toru Nakanishi, Nobuo Funabiki

Journal of Information Processing   20 ( 3 )   774 - 784   2012

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To enhance user privacy, anonymous credential systems allow the user to convince a verifier of the possession of a certificate issued by the issuing authority anonymously. The typical application is the privacy-enhancing electronic ID (eID). Although a previously proposed system achieves the constant complexity in the number of finiteset attributes of the user, it requires the use of RSA. In this paper, we propose a pairing-based anonymous credential system excluding RSA that achieves the constant complexity. The key idea of our proposal is the adoption of a pairing-based accumulator that outputs a constant-size value from a large set of input values. Using zero-knowledge proofs of pairing-based certificates and accumulators, any AND and OR relation can be proved with the constant complexity in the number of finite-set attributes. We implement the proposed system using the fast pairing library, compare the efficiency with the conventional systems, and show the practicality in a mobile eID application. © 2012 Information Processing Society of Japan.

DOI： 10.2197/ipsjjip.20.774

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A proposal of CSMA fixed backoff-time switching protocol and its implementation on QualNet simulator for wireless mesh networks

Sritrusta Sukaridhoto, Nobuo Funabiki, Toru Nakanishi, Kan Watanabe

Proceedings - 26th IEEE International Conference on Advanced Information Networking and Applications Workshops, WAINA 2012   520 - 525   2012

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As an inexpensive and scalable Internet access network, we have studied the architecture, protocols, and design optimizations of the Wireless Internet access Mesh Network (WIMNET). WIMNET is composed of multiple access points (APs) that are connected through wireless links. Previously, we have proposed the concept of the CSMA-based Fixed Back off-time Switching (CSMA-FBS) method for WIMNET to improve the performance by giving necessary link activation chances for multi-hop communications. In this paper, we propose a protocol for this CSMA-FBS method implement able on APs, and its actual implementation on the QualNet simulator for evaluations in realistic network environments. The simulation results in two network topologies confirm the effectiveness of our proposal. © 2012 IEEE.

DOI： 10.1109/WAINA.2012.69

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An online fill-in-the-blank problem function for learning reserved words in Java programming education

Nobuo Funabiki, Yousuke Korenaga, Yukiko Matsushima, Toru Nakanishi, Kan Watanabe

Proceedings - 26th IEEE International Conference on Advanced Information Networking and Applications Workshops, WAINA 2012   375 - 380   2012

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The Java programming education to students has been held in a lot of universities and professional schools due to the reliability, portability, and easy learning. To assist this education, our group has developed a Java programming learning system based on the test-driven development method. However, this Web system targets students who have studied Java to some extent. In this paper, we propose a fill-in-the-blank problem function for this system to assist the learning of the Java reserved words by novice Java learners. Our function consists of a teacher service process and a student service process. By the former one, a teacher can generate a fill-in-the-blank problem easily by blanking the specified reserved words randomly from a sample Java code in the database. By the latter one, a student can repeatedly submit answers of a problem until all the questions are correctly solved for self-study. The function is implemented on an existing Web system and is applied to students who are currently learning Java. The questionnaire result confirms the effectiveness of our proposal. © 2012 IEEE.

DOI： 10.1109/WAINA.2012.64

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An Extension of Routing Tree Algorithm Considering Link Speed Change in IEEE 802.11n Protocol for Wireless Mesh Network

Nobuo Funabiki, Wataru Maruyama, Toru Nakanishi, Kan Watanabe

2012 9TH INTERNATIONAL CONFERENCE ON UBIQUITOUS INTELLIGENCE & COMPUTING AND 9TH INTERNATIONAL CONFERENCE ON AUTONOMIC & TRUSTED COMPUTING (UIC/ATC)   600 - 605   2012

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As an inexpensive, flexible, and scalable Internet-access network, we have studied architecture, protocols, and design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET consists of multiple access-points (APs) as wireless routers that are connected through wireless links. One AP acts as a gateway (GW) to the Internet, where any host must reach there for the Internet access through multi-hop communications between APs. Because a lot of traffic must be handled by these links, the latest IEEE 802.11n protocol should be adopted to provide high-speed communications. In this paper, we first show that our throughput measurement results using commercial products implementing this protocol, reveal the quick drop of the throughput as the increase of the link distance. Then, we present extensions of our previously proposed routing tree algorithm for WIMNET and the WIMNET simulator in considering this link speed change by the distance. We verify the effectiveness of our proposals through simulations in four cases with different topologies.

DOI： 10.1109/UIC-ATC.2012.162

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A Lattice Implementation of High-precision IIR Filter for X-ray CT Reconstruction

Kazuhisa Hayashi, Hiroshi Tsutsu, Yoshitaka Morikawa, Nobuo Funabiki

INTERNATIONAL MULTICONFERENCE OF ENGINEERS AND COMPUTER SCIENTISTS, IMECS 2012, VOL I   751 - 756   2012

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The authors previously proposed forward and backward one round (FBOR) method to accelerate the filtering process by realizing the discrete Hilbert transform (DHT) function using an IIR filter in the convolution backprojection (CB) method that is a typical reconstruction algorithm for the X-ray CT. The FBOR method cascades causal and anticausal allpass filters to realize the linear phase DHT, and implements them by parallel ladders of allpass filters. Unfortunately, this method has to adopt the DHT that has the brickwall transition at the zero frequency and thus, requires high sensitivity coefficients in order to reduce distortions of a reconstructed image. As a result, it needs to rely on double precision floating points to avoid cancellations of significant digits. In this paper, we propose a successive-scan one-round (SSOR) method of implementing the DHT by cascading primary lattice allpass filters that allows the use of single precision floating points. We confirm the effec-tiveness of our proposal through simulations.

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Modeling and Performance Evaluation of Colluding Attack in Volunteer Computing Systems

Kan Watanabe, Nobuo Funabiki, Tom Nakanishi, Masaru Fukushi

INTERNATIONAL MULTICONFERENCE OF ENGINEERS AND COMPUTER SCIENTIST, IMECS 2012, VOL II   1658 - 1663   2012

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This paper proposes a model of a colluding attack in Volunteer Computing (VC), where some of participants are unreliable and may return incorrect results. The colluding attack is one of the most important issues to realize reliable VC because it may ruin the most basic assumption, i.e. "the majority in voting is correct". Especially, check-by-voting archives the largest efficiency by sorting reliable participants based on whether their results are the majority or not. Thus, if some incorrect results become the majority by colluding attack, it may have significant impacts on check-by-voting. In this paper, we perform a Monte Carlo simulation of VC using the proposed colluding model and evaluate the sabotage-tolerance performance of voting methods. Simulation results show that check-by-voting works well if colluding attack happens.

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A Proposal of an Access-Point Aggregation Algorithm for Wireless Local Area Networks

ISLAM Md. EZHARUL, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report   111 ( 344 )   1 - 6   2011.12

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Nowadays, multiple wireless local area networks (WLANs) have been deployed in the same building of an institute including a company and a university. Usually, their wireless acess-points (APs) have been independently managed and operated by different groups in the building such as departments or laboratories. As a result, a WLAN user host can detect signals from multiple APs, which may increase the interference and degrade the communication performance. Thus, the minimization of the number of active physical APs by aggregating the allocated APs in the field by introducing virtual APs becomes one of the major challenges in WLANs. In this paper, we formulate this AP aggregation problem for WLANs of aggregating the APs into the minimum number of active APs, and propose its heuristic algorithm that is composed of four phases. The effectiveness of our proposal has been verified through simulations in two instances.

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A Clustering Algorithm for WDS Clusters with Two Access-Points Using Smart Antenna in Wireless Mesh Networks

TAJIMA Shigeto, FUNABIKI Nobuo, TOMISATO Shigeru, HATA Masaharu, HIGASHINO Teruo

Technical report of IEICE. RCS   111 ( 345 )   81 - 86   2011.12

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As a scalable Internet access network, we have studied the Wireless Internet-access Mesh Network (WIMNET) that is composed of multiple access point (APs) connected through the Wireless Distribution System (WDS). For large scale WIMNET, because the traffic through the Internet gateway (GW) becomes very high, it is composed of multiple WDS clusters where one cluster consists of APs sharing the same GW. Even in this hierarchial WIMNET, links around the GW are still crowded in each WDS cluster and may become bottlenecks of whole communications. Hence, we have proposed the adoption of a Smart AP (SAP) using the smart antenna technology for bandwidth enhancements. In this paper, we propose an extension of our WDS clustering algorithm for WIMNET such that the GW and one adjacent AP are selected as SAPs in each WDS cluster. Through simulations using grid topology instances, we verify the effectiveness of our algorithm extension.

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A Proposal of Efficient Range Proof Protocol for Anonymous Credential System

IKEDA Daiki, NAKANISHI Toru, FUNABIKI Nobuo

Technical report of IEICE. ISEC   111 ( 337 )   7 - 14   2011.12

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An anonymous credential system allows a user to convince a verifier of the possession of user's attributes anonymously. A range proof protocol in an anonymous credential system is the protocol where the user can show that user's attribute belongs to a certain integer range without revealing the attribute. In the previous scheme, while the constant computational complexity is achieved, the size of the public parameters depends on the number of the attributes N. This paper proposes a range proof protocol with O (logTV) public parameter size. We also implement and evaluate it.

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Proposal of Reputation System with Strong Secrecy for Managers

NOMURA Tomoya, NAKANISHIV Toru, FUNABIKI Nobuo

Technical report of IEICE. ISEC   111 ( 337 )   15 - 20   2011.12

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In a P2P service such as Internet auctions, there is need for keeping users anonymous, but, in this case, misbehaving user becomes a problem. So, the anonymous users use a reputation system to evaluate each other, where the user can decide whether the other user is misbehaving user or not. However, in the system, the administrator can grasp the change of user's reputation point, it becomes a problem of privacy. In this study, we propose a reputation system with the anonimity even for the administrator by user's managing reputation points in the anonymous certificate. We evaluate the proposed system by processing time of the implementation.

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Modeling and Performance Evaluation of Colluding Attack in Volunteer Computing

WATANABE Kan, FUNABIKI Nobuo, NAKANISHI Toru, FUKUSHI Masaru

IEICE technical report. Dependable computing   111 ( 252 )   25 - 30   2011.10

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This paper proposes a model of a colluding attack in Volunteer Computing (VC), where some of participants are unreliable and may return incorrect results. The colluding attack is one of the most important issues to realize reliable VC because it may ruin the most basic requirement, i.e. "the majority in voting is correct". It is used in most current sabotage-tolerance techniques such as M-first voting. Especially, checkbyvoting archives the largest efficiency in current sabotage-tolerance techniques by using the technique called "check by voting" (using the result of a voting as a check). Thus, if some results of votings have been incorrect by colluding attack, it may have significant impacts on checkbyvoting. In this paper, we perform a Monte Carlo simulation of VC using the proposed model and evaluate the sabotage-tolerance performance for both checkbyvoting and M-first voting.

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An Implementation of an Anonymous Authentication System with Exclusion of Illegal Users in the Web Services

2011 ( 3 )   66 - 71   2011.10

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An Implementation of Anonymous Attributes Authentication System for Web Services

2011 ( 3 )   60 - 65   2011.10

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An Improvement of Active Access-Point Selection Algorithm for Throughput Maximization in Wireless Mesh Networks

SHIMIZU Junki, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan

IEICE technical report   111 ( 232 )   25 - 30   2011.10

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The wireless Internet-access mesh network (WIMNET) has been studied to realize the inexpensive, scalable Internet-access network by adopting multiple access points (APs) connected by wireless links. WIMNET can improve the dependability to failures of APs and/or links by allocating APs redundantly, whereas redundant APs may cause the increase of the operational cost and the degradation of the throughput due to increasing radio interferences. Therefore, we have formulated the active AP selection problem of selecting the minimum number of active APs among redundant APs in WIMNET and proposed its heuristic algorithm. The simulation results indicated the existence of an active AP selection maximizing the throughput whose number of active APs is larger than the minimum. In this paper, we improve this algorithm for the throughput maximization. We verify the effectiveness of our algorithm improvement through simulations in three instances.

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An Improvement of Code Verifications in Java Programming Learning System Using Test-Driven Development Method

FUKUYAMA Yuki, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan, AMANO Noriki

IEICE technical report   111 ( 213 )   13 - 18   2011.9

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For the enhancement of the Java programming education by assisting self-studies of students and reducing loads of teachers, we have proposed and developed a Web-based Java programming learning system using the test-driven development method. In this system, the teacher first registers an exercise subject, a model source code, and a test code. Then, the student submits the test code and the answer code, which are verified by the verification tool at the server. Unfortunately, the current system cannot detect an incomplete test code from a student that does not contain necessary test procedures if it has no grammatical error. In this paper, we introduce a code coverage verification tool into the system in order to find an incomplete test code. After implementing this proposal, we evaluate the effectiveness of the improved system through experiments to 11 students who have studied Java.

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An Implementation and Evaluation of Fixed Backoff-time Switching Method on QualNet for Wireless Mesh Network

SUKARIDHOTO Sritrusta, FUNABIKI Nobuo, NAKANISHI Toru, WATANABE Kan, TAJIMA Shigeto

IEICE technical report   111 ( 91 )   33 - 38   2011.6

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As an inexpensive and scalable access network to the Internet, we have studied the architecture, protocols, and design optimizations of Wireless Internet access Mesh Network (WIMNET). WIMNET is composed of multiple access points (APs) connected through wireless links. Previously, we have proposed the CSMA -based Fixed Backoff-time Switching (CSMA-FBS) method for WIMNET to improve the performance by giving necessary link activation chances for multi-hop communications. In this study, we implement the CSMA-FBS method on the QualNet simulator for evaluations in more realistic network environments. The simulation results in three network topologies confirm the effectiveness of our proposal.

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A WDS Clustering Algorithm for Wireless Mesh Network with Gateway using MIMO Channel

TAJIMA Shigeto, FUNABIKI Nobuo, TOMISATO Shigeru, HATA Masaharu, HIGASHINO Teruo

IEICE technical report   111 ( 8 )   55 - 60   2011.4

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We have studied the Wireless Internet-access Mesh NETwork (WIMNET) as a scalable wireless local area network that is composed of multiple access points (APs) connected through the Wireless Distribution System (WDS). To avoid the performance degradation due to traffic overloads, the number of APs in a single WDS is limited. Hence, we have proposed a WDS clustering algorithm to partition a given set of APs into a disjoint set of WDS clusters where the APs in one WDS cluster shares a single gateway (GW) to the Internet and are connected by a single WDS. As all the traffics from/to the Internet pass through the GW in a WDS cluster, links incident to the GW can be bottlenecks of whole communications. In this paper, in order to increase the throughput there by adopting the MIMO channel at the GW, we propose an extension of the WDS clustering algorithm to the WIMNET with the MIMO channel GW. Through simulations using several instances, we verify the effectiveness of our algorithm extension.

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An Implementation of an Online Fill-in-the-blank Problem Function for Learning Reserved Words in Java Programming

KORENAGA Yousuke, MATSUSHIMA Yukiko, FUNABIKI Nobuo, NAKANISHI Toru, AMANO Noriki

IEICE technical report   110 ( 453 )   125 - 130   2011.2

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The Java programming has been educated to students in a lot of universities and professional schools due to its reliability, portability, and easy learning. To assist the education, our group has developed a Java programming education assistant system based on the test-driven development method. However, this system targets students who have studied Java to some extent. In this paper, we propose the online fill-in-the-blank problem function for this Web system to assist the learning of the reserved words of Java for Java beginners. This function consists of the teacher service function and the student service function. By the former function, a teacher can generate a fill-in-the-blank problem automatically by removing the specified reserved words randomly from a sample Java code in the database. By the latter function, a student can repeatedly submit answers of a problem until all the answers are correct for self-study. The function is implemented at the existing system and is applied to students who are Java beginners, where the questionnaire result confirms the effectiveness of our proposal.

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An Implementation of a Web-based Assistance System for Computer-Scored Tests

KAWANO Hiroki, FUNABIKI Nobuo, NAKANISHI Toru, AMANO Noriki

IEICE technical report   110 ( 453 )   193 - 198   2011.2

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Mini-exams and quizzes during classes can be effective to enhance their educational effects to students in universities. However, teachers may have to spend much time to prepare test materials before classes, and grade the test papers from students after them. In this paper, we propose a Web-based assistance system for computer-scored tests in order to reduce these loads by teachers. Our system consists of the question generation & management function, the test generation & management function, the subject generation & management function, the test grading function, and the learning history management function. By treating questions and tests separately such that one test is composed of individual questions, this system makes it possible to reuse existing questions and tests in various subjects by sharing them among teachers. Besides, by automatically generating test papers containing randomly shuffled options, it can prevent students from cheating by peeking at papers of other students at neighbor seats. To evaluate the efficiency, we implemented the system by extending the existing learning management system NOBASU, and applied it to one class in our department.

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An Implementation of Menu Planning and Cooking Step Optimization Functions in a Web-based Homemade Cooking Assistance System for Busy Persons

OKADA Tomoya, MATUSHIMA Yukiko, TANIGUCHI Shiho, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   110 ( 453 )   205 - 210   2011.2

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For busy persons such as workers, students, and child-growing families, preparations of dishes by homemade cooking may become heavy burdens on weekdays. To solve this problem, our group has developed a Web-based homemade cooking assistance system composed of four main functions. In this paper, we implement the two functions of the menu planning and the cooking step optimization for this system. The first function helps a user to generate a menu manually, or automatically by using the menu selection algorithm. Besides, it allows the user to register the menu information into Google calendar so that the information can be accessed even from a mobile terminal. The second function optimizes the schedule of the cooking steps by using the cooking step optimization algorithm. By outputting the result into a PDF file, the user can use it at cooking. The effectiveness of these functions is confirmed through questionnaire results by 16 students in our department.

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A Proposal of a Management System for Open Source Software Usage Manuals Using Content Management System

RI Denzai, MURAKAMI Yukikazu, FUNABIKI Nobuo

IEICE technical report   110 ( 453 )   187 - 192   2011.2

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Recently, the Open Source Software (OSS) has become used at many places. Even the installation and initial configuration of an OSS can be difficult for novice users, because there are few documents and manuals. To address this problem, we have proposed an automatic generation method of installation/configuration manuals for OSS However, this method has another problem of requiring different manuals even for the same OSS, because installation commands or configuration parameters can be different depending on OS distributions and OS/OSS versions. In this paper, we propose an OSS manual management system using a content management system "Joomla!" so that the manuals can be consolidated in a community. We implement the system composed of the four functions for general users, manual creators, community managers, and system managers, and show the effectiveness through usability evaluations using a questionnaire.

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Development of an Automatic Generation System of Configuration Manuals for Open Source Software

KAGAWA Erina, MURAKAMI Yukikazu, FUNABIKI Nobuo

IEICE technical report   110 ( 448 )   247 - 252   2011.2

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Recently, Open Source Software (OSS) has become used at many places. However, the use of an OSS is hard for its novice users, because many OSSes have few good manuals. To solve this problem, we have proposed a method of automatically generating a web manual for installing an OSS by editing the log information recorded during the installation process by a skilled user. However, many OSS require to make changes the configuration file. In addition to that more systems are adopting OSS as middlewares such as application servers and DBMSs (Database Management Systems). For these OSS middlewares, it is known that even the processing performance is low under their default settings a great improvement is seen by optimizing their system setting. Therefore, in this research, aiming at accumulation of system optimizing technology, an automatic generation of web-based configuration manual is proposed.

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An Application of the WEB Page Layout Optimization Method for Integration of Open Source Software Heterogeneous Manuals

HORI Yuki, MURAKAMI Yukikazu, FUNABIKI Nobuo

IEICE technical report   110 ( 448 )   241 - 246   2011.2

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Recently, the Open Source Software (OSS) has become used at many places. Even the installation and initial configuration of an OSS can be difficult for novice users, because there are few documents and manuals. To address this problem, we have proposed an automatic generation method of installation/configuration manuals for OSS. However, in the conventional system, an installation manual and a configuration manual are managed as an individual file. Therefore, the conventional system had bad convenience. We integrate an installation manual and a configuration manual and define this as an OSS usage manual. When integrate manuals, it is necessary to give a priority and to show information. When the size of a Web manual is changed by the user, a layout changes and visibility falls. In order to solve this problem, we applied to the web-page layout optimization method to proposed manuals.

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A Proposal of Cooking Model and Cooking Step Scheduling Algorithm for Multiple Dishes

MATSUSHIMA Yukiko

IMECS 2011   127 - 131   2011

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An active access-point selection approach for dependable wireless mesh networks

Nobuo Funabiki, Junki Shimizu, Masaharu Hata, Shigeru Tomisato, Toru Nakanishi, Kan Watanabe

Journal of Interconnection Networks   12 ( 3 )   137 - 154   2011

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Authorship：Lead author   Language：English   Publisher：World Scientific Publishing Co. Pte Ltd  

As an inexpensive, flexible, and scalable Internet-access wireless network, we have studied the architecture, protocols, and design optimizations of the Wireless Internet-access Mesh NETwork (WIMNET) that adopts multiple access-points (APs) connected through wireless links. WIMNET can improve the dependability to failures of APs and/or their links by allocating APs redundantly in the network field. Because redundant APs may increase the operational cost and degrade the throughput due to increasing radio interferences, only the necessary APs for connectivity between the hosts and the Internet gateway should be activated in communications. In this paper, we first define the active AP selection problem of selecting the minimum number of active APs, and prove the NP-completeness of its decision version through reduction from the known minimum set cover problem. Then, we propose an active AP selection algorithm of deactivating APs one by one until no more AP can be deactivated. Due to the limited transmission capacity in WIMNET, we further present an algorithm extension for throughput maximization. We verify the effectiveness of our proposal through simulations in three instances, where the number of active APs is reduced by more than 40% and the throughput is improved by more than 10% from the original in any instance. © 2011 World Scientific Publishing Company.

DOI： 10.1142/S0219265911002915

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An implementation of fixed backoff-time switching method on IEEE 802.11 MAC protocol for wireless Internet-access mesh network

Nobuo Funabiki, Sritrusta Sukaridhoto, Zhe Wang, Toru Nakanishi, Kan Watanabe, Shigeto Tajima

The 2011 International Workshop on Smart Info-Media System in Asia (SISA 2011)   67 - 72   2011

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A proposal of an active access-point selection algorithm in wireless mesh networks

Nobuo Funabiki, Junki Shimizu, Toru Nakanishi, Kan Watanabe

Proceedings - 2011 International Conference on Network-Based Information Systems, NBiS 2011   112 - 117   2011

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The wireless Internet-access mesh network (WIMNET) has been studied to offer an inexpensive, scalable Internetaccess wireless network by adopting multiple access points (APs) connected by wireless links. WIMNET can improve the dependability to failures of links and/or APs by allocating APs redundantly in the network field. However, redundant APs may increase the operational cost and degrade the throughput due to increasing radio interferences. One solution to this problem is to activate only the necessary APs to provide the connectivity to the hosts while maximizing the throughput. In this paper, we first define this active AP selection problem of selecting the activated APs for communications, and propose its heuristic algorithm. The simulation results in three instances confirm the effectiveness of the proposed algorithm, and indicate the existence of an active AP selection that maximizes the throughput. Then, we present the average hop count and the traffic bias as the indices to seek the active AP selection with the maximal throughput, and the extension of our active AP selection algorithm using them. © 2011 IEEE.

DOI： 10.1109/NBiS.2011.26

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A smart access-point selection algorithm for scalable wireless mesh networks

Nobuo Funabiki, Sritrusta Sukaridhoto, Masaharu Hata, Shigeru Tomisato, Toru Nakanishi, Kan Watanabe, Shigeto Tajima

IAENG International Journal of Computer Science   38 ( 3 )   260 - 267   2011

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Efficient Proofs of Attributes in Pairing-Based Anonymous Credential System

Amang Sudarsono, Toru Nakanishi, Nobuo Funabiki

PRIVACY ENHANCING TECHNOLOGIES   6794   246 - 263   2011

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Language：English   Publisher：SPRINGER-VERLAG BERLIN  

An anonymous credential system allows the user to convince a verifier of the possession of a certificate issued by the issuing authority anonymously. One of the applications is the privacy-enhancing electronic ID (eID). A previously proposed anonymous credential system achieves constant complexity in the number of finite-set attributes of the user. However, the system is based on the RSA. In this paper, we show how to achieve the constant complexity in a pairing-based anonymous credential system excluding the RSA. The key idea of the construction is the use of a pairing-based accumulator. The accumulator outputs a constant-size value from a large set of input values. Using zero-knowledge proofs of pairing-based certificates and accumulators, we can prove AND and OR relations with constant complexity in the number of finite-set attributes.

DOI： 10.1007/978-3-642-22263-4_14

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An extension of active access-point selection algorithm for throughput maximization in wireless mesh networks

Nobuo Funabiki, Junki Shimizu, Toru Nakanishi, Kan Watanabe, Shigeru Tomisato

Proceedings - 3rd IEEE International Conference on Intelligent Networking and Collaborative Systems, INCoS 2011   367 - 372   2011

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In order to offer an inexpensive, scalable Internetaccess wireless network, we have studied the architecture, protocols, and design optimizations of the wireless Internet-access mesh network (WIMNET) that adopts multiple access-points (APs) connected by wireless links. WIMNET can improve the dependability to failures of links and/or APs by allocating APs redundantly in the network field. Because redundant APs may increase the operational cost and degrade the throughput due to increasing radio interferences, only the necessary APs for the connectivity between the hosts and the Internet gateway should be activated in communications. Previously, we have defined the active AP selection problem of selecting the minimum number of active APs, and proposed its heuristic algorithm. However, the throughput should be maximized in WIMNET as a bandlimited wireless network, even if the number of active APs is slightly increased. In this paper, we propose the extension of the active AP selection algorithm for the throughput maximization using the average hop count. We confirm the effectiveness of our algorithm extension through simulations in three instances, where the throughput is improved by about 10% with 7-14 additional active APs on average. © 2011 IEEE.

DOI： 10.1109/INCoS.2011.50

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A throughput evaluation of wireless Internet-access mesh network using MIMO and adaptive array antenna

Shigeto Tajima, Nobuo Funabiki, Shigeru Tomisato, Masaharu Hata, Teruo Higashino

The 2011 International Workshop on Smart Info-Media System in Asia (SISA 2011)   79 - 84   2011

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Automatic generation of configuration manuals for open-source software

Yukikazu Murakami, Erina Kagawa, Nobuo Funabiki

Proceedings of the International Conference on Complex, Intelligent and Software Intensive Systems, CISIS 2011   653 - 658   2011

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The installation and initial configuration of an open-source software can be difficult for novice users because of a common lack of adequate manuals. To address this problem, we have proposed a method of automatically generating Web based installation manuals for open-source software by editing the log information recorded during the installation process by a skilled user. A lot of systems using open-source software require changes of configuration files. Actually, middleware systems such as application servers and database management systems, often exhibit the low performance under their default configuration files. Thus, the optimization of such systems by setting the optimal confirmation is essential for significant performance improvements. In this paper, we propose the extension of our previous method to the automatic generation of Web-based configuration manuals. We verify the effectiveness of our proposal through experiments. © 2011 IEEE.

DOI： 10.1109/CISIS.2011.109

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A proposal of fixed backoff-time switching method by link activation rate for wireless mesh networks

Shigeto Tajima, Nobuo Funabiki, Teruo Higashino

Proceedings of the International Conference on Complex, Intelligent and Software Intensive Systems, CISIS 2011   647 - 652   2011

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As an inexpensive and scalable access network to the Internet, we have extensively studied the Wireless Internet-access Mesh Network (WIMNET) that is composed of multiple access points (APs) connected through wireless links. Because most traffic in WIMNET passes through the gateway (GW) to the Internet, the links around the GW are much crowded so that they should be activated with higher priorities than others. In this paper, we propose the Fixed Back off-time Switching (CSMA-FBS) method for WIMNET using the CSMA/CA protocol to improve the performance by giving necessary activation chances to such links. Before starting communications, the target link activation rate and the active/passive back off-times for collision avoidance are calculated from the expected traffic load for each link. During communications, these back off-times are switched by comparing the actual link activation rate with the target one. By assigning different fixed values to these back off-times, the conflicts among the interfered links can be avoided. Through extensive simulations using two types of network topologies, we verify the effectiveness of our proposal. © 2011 IEEE.

DOI： 10.1109/CISIS.2011.108

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A proposal of a menu planning algorithm for two-phase cooking by busy persons

Nobuo Funabiki, Shiho Taniguchi, Yukiko Matsushima, Toru Nakanishi

Proceedings of the International Conference on Complex, Intelligent and Software Intensive Systems, CISIS 2011   668 - 673   2011

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For busy persons such as working people, students, and nurturing parents, it is very hard to spend a long time in cooking foods by themselves at home after working for long hours on weekdays. As one solution, the cooking process can be divided into two phases, where the preparation steps for foods that they will eat on the following weekdays are performed on a weekend, and the final steps for some foods are finished on the eating day in a short time. Then, the task of generating a menu planning with this two-phase cooking becomes a complex problem to satisfy the limited cooking time. In this paper, we formulate this time-constrained menu planning problem with the two-phase cooking, and prove the NP-completeness of its decision problem through the reduction from the NP-complete knapsack problem. Then, we present its heuristic algorithm based on a simple greedy method for the knapsack problem, where foods are sequentially selected into the menu in descending order of food priorities. We apply the algorithm to the generation of one week menu plan from 53 food candidates, where the result verifies the effectiveness of our approach. © 2011 IEEE.

DOI： 10.1109/CISIS.2011.112

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A proposal of a traffic control method with consumed bandwidth estimation for real-time applications in wireless mesh networks

Sritrusta Sukaridhoto, Nobuo Funabiki, Toru Nakanishi

Proceedings of the International Symposium on Consumer Electronics, ISCE   143 - 148   2011

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As a flexible and cost effective solution for a scalable Internet-access network, we have studied the Wireless Internet-access Mesh NETwork (WIMNET) that is composed of multiple access points (APs). WIMNET utilizes multi-hop communications between APs to provide access to the Internet through a gateway (GW) from associated hosts, which becomes increasingly vulnerable to problems of the available bandwidth degradation and the network latency. As a result, real-time applications such as Voice-over-IP (VoIP) and video conferences are hard in WIMNET. In this paper, we propose a traffic control method with consumed bandwidth estimation to afford real-time applications in WIMNET. After the consumed bandwidth by the requesting applications is estimated, the least priority application is repeatedly dropped at GW using the leaky bucket traffic shaping, until it does not exceed the available bandwidth in WIMNET. The effectiveness of our proposal is verified through simulations using the QualNet simulator. © 2011 IEEE.

DOI： 10.1109/ISCE.2011.5973801

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Minimal smart access-point selection for maximal throughput in wireless mesh networks

Nobuo Funabiki, Tatsuya Takebayashi, Toru Nakanishi

The International MultiConference of Engineers and Computer Scientists 2011 (IMECS 2011)   594 - 599   2011

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無線メッシュネットワークでの動作アクセスポイント選択アルゴリズムの提案

清水淳基, 舩曵信生, 中西透

電子情報通信学会論文誌(B)   J94-B ( 2 )   264 - 273   2011

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A proposal of a web-based computer-scored test assistance system for university education

Nobuo Funabiki, Hiroki Kawano, Toru Nakanishi, Kan Watanabe

Proceedings of the International Symposium on Consumer Electronics, ISCE   580 - 585   2011

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Frequent applications of short tests or quizzes during classes can be effective to enhance educational effects to students in universities. However, teachers may have to spend much time to prepare test materials before classes, and mark the test papers from students after them. In this paper, in order to reduce these loads of teachers, we propose a Web-based computer-scored test assistance system that consists of the five functions for problem generation &amp
management, test generation &amp
management, grading, subject generation &amp
management, and learning profile management. By handling problems and tests separately where one test is composed of several problems, this system allows users to reuse existing problems and tests in various subjects by sharing them among teachers. Besides, by automatically generating test papers containing the randomly shuffled choices for each problem, it can prevent students from cheating by peeking at test papers of other students at neighbor seats. We implemented the system by extending our learning management system called NOBASU, and applied it to one class in our department, where the questionnaire result confirms the effectiveness of the system. © 2011 IEEE.

DOI： 10.1109/ISCE.2011.5973897

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An implementation of a pairing-based anonymous credential system with constant complexity

Amang Sudarsono, Toru Nakanishi, Nobuo Funabiki

The International MultiConference of Engineers and Computer Scientists 2011 (IMECS 2011)   630 - 635   2011

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A Proposal of Traffic Control Method with Bandwidth Usage Estimation for Real-Time Applications in Wireless Mesh Networks

SUKARIDHOTO Sritrusta, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   110 ( 339 )   25 - 30   2010.12

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As a flexible and cost effective solution for a large-scale Internet access network, we have studied the Wireless Internet-access Mesh NETwork (WIMNET) that is composed of multiple access points (APs). WIMNET utilizes multi-hop communications between APs to access to the Internet through a gateway (GW), which becomes increasingly vulnerable to the problems of the available bandwidth degradation and the network latency. As a result, real-time applications such as Voice-over-IP and Video conferences become hard to work in WIMNET. In this paper, we propose a traffic control method with a bandwidth usage estimation to afford real-time applications in WIMNET. After the consumed traffic is estimated, the least priority traffic is repeatedly dropped at GW using the leaky bucket traffic shaping, until it does not exceed the available bandwidth in WIMNET. The effectiveness of our proposal is verified through simulations using the QualNet simulator.

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A Study of an Active Access-Point Selection Index for Throughput Maximization in Wireless Mesh Networks

SHIMIZU Junki, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   110 ( 339 )   13 - 18   2010.12

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The wireless Internet-access mesh network (WIMNET) has been studied to realize the inexpensive, scalable Internet-access network by composed of multiple access points (APs) connected by wireless links. WIMNET can improve the dependability to failures of links and APs by allocating APs redundantly, whereas redundant APs may cause the increase of the operational cost and the degradation of the throughput due to increasing radio interferences. Hence, we have formulated the active AP selection problem for selecting functioning APs for communications and proposed its heuristic algorithm. The simulation results indicate the existence of an active AP selection maximizing the throughput. In this paper, we present the average hop count and the traffic bias as the indices for this active AP selection with the maximum throughput. We verify their effectiveness through simulations in three instances.

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An Application of the Web-Page Layout Optimization Method to Installation Manuals for Open Source Software

HORI Yuki, MURAKAMI Yukikazu, FUNABIKI Nobuo

IEICE technical report   110 ( 339 )   215 - 218   2010.12

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Recently, the Open Source Software (OSS) has become used at many places. However, the use of an OSS is hard for its novice users, because many OSSes have few good manuals. To solve this problem, we have proposed a method of automatically generating a web manual for installing an OSS by editing the log information recorded during the installation process by a skilled user. However, generated manuals have been designed to fit to the standard size. Many users often change a manual size to watch a manual and a terminal window together. When a manual size is small, the screen scroll operation is needed to look at the main content of the page. When the size is big, the blank space may also be large. In order to solve this problem, we applied to the web-page layout optimization method to proposed manuals.

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A Proposal of Fixed Waiting Time Switching Method by Link Activation Rate in Wireless Mesh Networks

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   110 ( 339 )   137 - 142   2010.12

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As an access network to the Internet, we have studied the Wireless Internet-access Mesh NETwork (WIMNET) that is composed of multiple access points (APs) connected with wireless links. Because most traffics pass through the gateway (GW) to the Internet, the links around the GW are crowded which should be activated with higher priorities in WIMNET. In this paper, we propose the fixed waiting time switching method based on the CSMA/CA protocol (CSMA-FWS) to improve the performance of WIMNET. Before communications, the target link activation rate and the fixed waiting times for link activation/waiting are calculated from expected traffics of each link. During communications, these waiting times are switched by evaluating the link activation rate. Besides, by assigning different values to these waiting times among the links, the conflicts among interfered links are avoided. Through simulations using two types of network topologies, we verify the effectiveness of our proposal.

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Ant Colony Optimization for the Node Placement Problem

OHKURA Keiichi, KATAYAMA Kengo, FUNABIKI Nobuo, MINAMIHARA Hideo, NISHIHARA Noritaka

IEICE technical report   110 ( 339 )   173 - 178   2010.12

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We address a problem of finding an optimal node placement that minimizes the amount of traffics reducing the weighted hop distances in multihop lightwave networks. The problem is called Node Placement Problem (NPP). For the NPP, several metaheuristic algorithms have been proposed so far such as genetic algorithm, tabu search, simulated annealing, iterated local search, and memetic algorithm. However, ant colony optimization (ACO) approach, one of the most representative metaheuristics, has not been presented for the NPP yet. In this paper we present an ACO algorithm incorporating k-swap local search (KLS) based on variable depth search for the NPP. To evaluate the performance of the ACO, we tested it on the benchmark problem instance of the NPP. We showed the performance of the ACO with KLS through comparisons with those of the iterated local search and the memetic algorithm that are known to be the highly effective metaheuristics for the NPP.

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A Proposal of an Automatic Generation Method of Web-based Configuration Manuals for Open Source Software

KAGAWA Erina, MURAKAMI Yukikazu, FUNABIKI Nobuo

IEICE technical report   110 ( 339 )   209 - 214   2010.12

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Recently, Open Source Software (OSS) has become used at many places. However, the use of an OSS is hard for its novice users, because many OSSes have few good manuals. To solve this problem, we have proposed a method of automatically generating a web manual for installing an OSS by editing the log information recorded during the installation process by a skilled user. However, many OSS require to make changes the configuration file. In addition to that more systems are adopting OSS as middlewares such as application servers and DBMSs (Database Management Systems). For these OSS middlewares, it is known that even the processing performance is low under their default settings a great improvement is seen by optimizing their system setting. Therefore, in this research, aming at accumulation of system optimizing technology, an automatic generation of web-based configuration manual is proposed.

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Extensions of Cooking Model for Cooking Step Optimization and Effects of Role Changes of Sub-Cook

MATSUSHIMA Yukiko, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   110 ( 301 )   19 - 24   2010.11

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In order to support homemade cooking of busy persons including working people, students, and child-growing families, we have proposed a cooking model to estimate the cooking time by simulating cooking steps by a main cook and a sub-cook who helps the main cook, and a cooking step scheduling algorithm using this model. In this paper, we propose extensions of the model by including additional two cooking steps, namely the nuke step and the mix step, so as to improve the accuracy of the estimated cooking time and the efficiency of the model. At the same time, we investigate effects in cooking time reductions by the increase of possible cooking steps to the sub-cook. The cooking experiment with six foods shows the improvement of the estimation accuracy, where the cooking time difference between the model and the actual cooking was about two minutes. The model calculations with various numbers of foods show that the cooking time can be reduced by the increase of possible cooking steps to the sub-cook.

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Menu Selection and Bulk-Buying Ingredient Selection Algorithms for Home Cooking Support by Busy Persons

TANIGUCHI Shiho, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   110 ( 301 )   25 - 30   2010.11

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For busy persons such as working people and students, it is very important to reduce the time for buying ingredients and cooking foods after working for long hours on a weekday. As one solution to achieve it, they buy ingredients in bulk and finish the preparation steps of foods as the preparation phase on a weekend after planning the menus of the following weekdays. On a weekday, they only need to buy remaining ingredients and cook the finishing steps of the foods as the finishing phase that they will eat on the day, which can reduce the necessary time for home cooking. In this paper, we propose the menu planning algorithm and bulk-buying ingredient selection algorithm for this two-phase cooking. Because these problems can be reduced from the NP-complete knapsack problem, these algorithms are based on greedy methods for the knapsack problem. Through solving instances for these problems, we verify the effectiveness of the proposed algorithms.

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Forward-Secure Group Signatures from Pairings

Toru Nakanishi, Yuta Hira, Nobuo Funabiki

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E93A ( 11 )   2007 - 2016   2010.11

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To reduce the damage of key exposures forward secure group signature schemes have been first proposed by Song In the forward secure schemes a secret key of a group member is updated by a one way function every interval and the previous secret key is erased Thus even if a secret key is exposed the signatures produced by the secret keys of previous Intervals remain secure Since the previous forward secure group signature schemes are based on the strong RSA assumption the signatures are longer than pairing based group signatures In addition the complexity of the key update or signing/verification is O(T) where T is the total number of Intervals In this paper a forward secure group signature scheme from pairings is proposed The complexity of our key update and signing/verification is O(log T)

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A Minimum Smart Access-Point Allocation for Maximal Throughput in Scalable Wireless Mesh Networks

TAKEBAYASHI Tatsuya, FYNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   110 ( 240 )   69 - 74   2010.10

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As a flexible and low-cost access network to the Internet, we have studied WIMNET (Wireless Internet-access Mesh NETwork) that is composed of multiple access-points (APs) as wireless routers. WIMNET utilizes two types of APs to achieve the scalability and the communication bandwidth while reducing the cost. One type is an expensive, PC-based smart AP (SAP) that can use multiple channels for wireless communications and has various functions for the Internet access. The other type is an inexpensive, commercial-based conventional AP (CAP) that can use only one channel. By adopting a small number of SAPs and a large number of CAPs, the large-scale WIMNET can achieve the bandwidth expansion and the cost reduction. In this paper, we propose a minimal SAP allocation algorithm for maximal throughput in WIMNET using our conventional SAP allocation algorithm. Our algorithm finds a solution that minimizes the reduction of the cost function when the number of SAPs increases. Through simulations in four instances, we show the effectiveness of our proposal.

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Developments of the Node Configuration Problem for WDM Ring Networks

ISOGAI MEGUMI, FUNABIKI NOBUO, NAKANISHI TORU

2010 ( 3 )   1 - 8   2010.9

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An Extension of the Cooking Step Scheduling Algorithm for Various Dishes to Two Cooks

MATSUSHIMA Yukiko, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   110 ( 172 )   19 - 24   2010.8

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The reduction of the cooking time with helps of partners, friends, and children is very important for busy persons. In this paper, we present the extension of the cooking step scheduling algorithm for various dishes to the case of two cooks, and the generalization of the cooking model for this extension by defining the state transition diagrams of dishes, pans and pots, a sink, stoves, and cooks, which have been proposed by our group. We implemented the algorithm as the Java application, and applied it to an instance of six dishes. The result confirmed the effectiveness of our proposal, where the case with two cooks reduced the cooking time by 16 minutes from the case with one cook.

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Extensions of the Access Point Allocation Algorithm for Wireless Mesh Networks

Walaa Hassan, Nobuo Funabiki, Toru Nakanishi

IEICE TRANSACTIONS ON COMMUNICATIONS   E93B ( 6 )   1555 - 1565   2010.6

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Previously, we have proposed an access point (AP) allocation algorithm in indoor environments for the Wireless Internet-access Mesh NETWork (WIMNET) using one gateway (GW) to the Internet. WIMNET consists of multiple APs that are connected wirelessly mainly by the Wireless Distribution System (WDS), to expand the coverage area inexpensively and flexibly In this paper, we present two extensions of this algorithm to enhance the applicability to the large-scale WIMNET. One is the multiple GW extension of the algorithm to increase the communication bandwidth with multiple GWs, where all the rooms in the network field are first partitioned into a set of disjoint GW clusters and then, our previous allocation algorithm is applied to each GW cluster sequentially. The APs in a GW cluster share the same GW. The other is the dependability extension to assure the network function by maintaining the connectivity and the host coverage, even if one link/AP fault occurs, where redundant APs are added to the AP allocation by our previous algorithm. The effectiveness of our proposal in terms of the number of APs and the throughput is verified through simulations using the WIMNET simulator.

DOI： 10.1587/transcom.E93.B.1555

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A prioritized link activation method for access-point communications in wireless mesh networks

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   110 ( 4 )   47 - 52   2010.4

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

As a flexible, inexpensive access network to the Internet, we have studied the Wireless Internet-access Mesh NETwork (WIMNET) that is composed of multiple access points (APs) connected with wireless links. Because most traffics pass through the gateway (GW) to the Internet, the links around the GW are crowded and can become bottlenecks in WIMNET. In this paper, we propose the prioritized link activation method based on the TDMA protocol to improve the performance of WIMNET. At each time slot, the links scheduled there are activated if they have packets. Then, other links are sequentially activated in descending order of priorities given by the traffics, if they have packets and do not cause interferences. Through simulations using two types of network topologies, we verify the effectiveness of our proposal.

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A WDS Clustering Algorithm for Wireless Mesh Networks

Shigeto Tajima, Nobuo Funabiki, Teruo Higashino

IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS   E93D ( 4 )   800 - 810   2010.4

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Wireless mesh networks have been extensively studied as expandable. flexible. and inexpensive access networks to the Internet This paper focuses on one composed of multiple access points (APs) connected through multihop wireless communications mainly by the wireless distribution system (WDS) For scalability, the proper partition of APs into multiple WDS clusters is essential, because the number of APs in one cluster is hinted due to the increasing radio interference and control packets In this paper, we formulate this WDS clustering problem and prove the NP-completeness of its decision version through reduction from a known NP-complete problem Then we propose its heuristic algorithm. using a greedy method and a variable depth search method. to satisfy the complex constraints while optimizing the cost function We verify the effectiveness of our algorithm through extensive simulations. where the results confirm as superiority to the existing algorithm in terms of throughput.

DOI： 10.1587/transinf.E93.D.800

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Test Code Assignment Function in Java Programming Education Support System Using Test-Driven Development Method

FUKUYAMA YUKI, FUNABIKI NOBUO, NAKANISHI TORU, AMANO NORIKI

2010 ( 21 )   1 - 8   2010.2

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A Proposal of the Active Access Point Selection Algorithm for Wireless Internet-access Mesh Networks

SHIMIZU Junki, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   109 ( 421 )   7 - 12   2010.2

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

As a scalable, inexpensive Internet-access network, we have studied the wireless Internet-access mesh network (WIMNET) that is composed of multiple access points (APs) connected by wireless links. WIMNET can improve the dependability to failures of links and APs by allocating APs redundantly. However, redundant APs may cause the increase of the operational cost and the degradation of the communication performance due to increasing radio wave interferences. In this paper, we formulate the active AP selection problem for selecting functioning APs for communications, and propose its algorithm. After finding the communication path using all the APs, our algorithm seeks the minimization of active APs by repeating the removal of one active AP and the check of the path existence. Through simulations using the WIMNET simulator, we show that our algorithm can reduce the number of active APs and there exists the best number of active APs in terms of the throughput.

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Revocable Group Signature Schemes with Constant Costs for Signing and Verifying

Toru Nakanishi, Hiroki Fujii, Yuta Hira, Nobuo Funabiki

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E93A ( 1 )   50 - 62   2010.1

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Lots of revocable group signature schemes have been proposed so far. In one type of revocable schemes, signing and/or verifying algorithms have O(N) or O(R) complexity, where N is the group size and R is the number of revoked members. On the other hand, in Camenisch-Lysyanskaya scheme and the followers, signing and verifying algorithms have O(1) complexity. However, before signing, the updates of the secret key are required. The complexity is O(R) in the worst case. In this paper, we propose a revocable scheme with signing and verifying of O(1) complexity, where any update of secret key is not required. The compensation is the long public key of O(N). In addition, we extend it to the scheme with O( root N)-size public key, where signing and verifying have constant extra costs.

DOI： 10.1587/transfun.E93.A.50

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Anonymous IEEE802.1X authentication system using group signatures

Amang Sudarsono, Toru Nakanishi, Yasuyuki Nogami, Nobuo Funabiki

Journal of Information Processing Society Japan   51 ( 3 )   691 - 702   2010

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A Node Aggregation Approach for WDM Ring Networks

Nobuo Funabiki, Toru Nakanishi, Megumi Isogai

TENCON 2010: 2010 IEEE REGION 10 CONFERENCE   829 - 834   2010

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For a high-speed metropolitan area network (MAN), a ring network based on the wavelength-division multiplexing (WDM) technology has been deployed to solve global information explosions in the Internet. To enhance the network performance, we have studied the node configuration problem, particularly for the one with the double-ring architecture where each node is equipped with fast-tunable transmitters and wavelength-fixed receivers (TT-FR) as fiber interfaces. In our studies, by adopting additional transmitters/receivers, nodes can afford far larger traffics than conventional ones. This fact indicates that plural nodes should be aggregated into one so that the transmitters/receivers can be utilized more efficiently. This paper presents a definition of the node aggregation problem for the WDM ring network and its simple greedy heuristic algorithm. The simulation results using the network simulator show the effectiveness of our approach.

DOI： 10.1109/TENCON.2010.5686576

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An extension of the web-page layout optimization method for multimodal browsing sizes

Nobuo Funabiki, Junki Shimizu, Megumi Isogai, Toru Nakanishi

Proceedings - 13th International Conference on Network-Based Information Systems, NBiS 2010   139 - 146   2010

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Recently, Web-page browsings at various terminals have become popular due to deployments of small mobile devices and large flat displays. To deal with this recent trend, we have proposed a Web-page layout optimization method for multimodal browsing sizes. It dynamically changes box locations and font sizes by switching CSS files for different browsing sizes, so that the main content can be accessed without the screen scroll operation even at a small size whereas the blank space is avoided at a large size. However, in this method, any box location must be specified by the absolute value in HTML/CSS files, which is not easy under a variety of browsing sizes. In this paper, we propose the extension of this method for flexible Web-page designs using the normal flow, the liquid layout, and the float property, where the browser automatically arranges the boxes. Using Ajax, the box location and the font size is switched to fit to the current browsing size by our method. The effectiveness of our proposal is verified through a usability test using sample Web-pages at small sizes. © 2010 IEEE.

DOI： 10.1109/NBiS.2010.18

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Software architecture and characteristic functions in learning management system "NOBASU"

Nobuo Funabiki, Toru Nakanishi, Noriki Amano, Hiroki Kawano, Yuuki Fukuyama, Megumi Isogai

Proceedings - 2010 10th Annual International Symposium on Applications and the Internet, SAINT 2010   109 - 112   2010

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Recently, a learning management system (LMS) using the Web technology has been used at many educational institutions. To support educational activities in our department, we have independently developed an LMS called NOBASU (NetwOrk-Based Assistant System for University education) to improve the quality while reducing costs. Besides conventional functions in LMS, NOBASU has incorporated several original ones such as the keyword submission function for preparing and reviewing class contents. In this paper, we present two new characteristic functions for the Java programming education in NOBASU. The Java code test function verifies the specifications in source codes from students using the test-driven development (TDD) method. The Java test code submission function requests students to submit test codes so that they can generate detailed program specifications by themselves. © 2010 IEEE.

DOI： 10.1109/SAINT.2010.24

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A Proposal of a Smart Access Point Allocation Algorithm for Scalable Wireless Mesh Networks

Kanako Uemura, Nobuo Funabiki, Toru Nakanishi

INTERNATIONAL MULTICONFERENCE OF ENGINEERS AND COMPUTER SCIENTISTS (IMECS 2010), VOLS I-III   848 - 853   2010

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Authorship：Lead author   Language：English   Publisher：INT ASSOC ENGINEERS-IAENG  

As a flexible, inexpensive, and extensive Internet access network, we have studied WIMNET (Wireless Internet-access Mesh NETwork) composed of multiple access points (APs) as wireless mesh routers. WIMNET utilizes two types of APs to achieve the scalability with sufficient bandwidth while reducing costs. One is the expensive, programmable smart AP (SAP) that can use plural channels for wireless communications and has various functions for the Internet access. Another is the inexpensive, non-rogrammable conventional AP (CAP) that can use only one channel. To enhance the performance, the proper SAP allocation is critical, because the number of SAPs is much smaller than that of CAPs. In this paper, we present the definition of the SAP allocation problem, and its algorithm of extracting the optimum solution in terms of the newly defined cost function after finding the communication route configuration by applying our previous algorithms. We verify the effectiveness through simulations in three network topologies using the WIMNET simulator.

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Software Architecture and New Functions in Learning Management System "NOBASU"

Nobuo Funabiki, Toru Nakanishi, Noriki Amano, Hiroki Kawano, Kanako Uemura

INTERNATIONAL MULTICONFERENCE OF ENGINEERS AND COMPUTER SCIENTISTS (IMECS 2010), VOLS I-III   665 - 670   2010

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Authorship：Lead author   Language：English   Publisher：INT ASSOC ENGINEERS-IAENG  

Recently, the learning management systems (LMS) using the Web technology has been developed and used at a lot of educational institutions. We have continuously developed an original LMS called NOBASU (NetwOrk-Based Assistant System for University education) to support various educational activities in our department to improve the quality while reducing costs. In this paper, we describe the software architecture and the outline of distinguishing functions in NOBASU. In addition to conventional functions in LMS, NOBASU has incorporated several original ones such as the keyword submission function for preparing and reviewing classes, the lecture-scene playback function using the digital picture-card show, and the writing style check function for report submissions. We have implemented them in NOBASU and evaluated the effectiveness through applications to real classes in our department.

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A Proposal of a Cooking Order Optimization Algorithm of Various Menus

MATSUSHIM YUKIKO, FUNABIKI NOBUO, NAKANISHI TORU

2009 ( 13 )   1 - 6   2009.12

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Improvement of Dependable Access Point Allocation Algorithm and Introduction of Route Availability for Wireless Mesh Networks

HASSAN Walaa, FARAG Tamer, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   109 ( 326 )   11 - 16   2009.12

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

As a scalable, flexible, and inexpensive network, we have studied the wireless Internet-access mesh network (WIMNET) that is composed of multiple access points (APs) connected by the wireless distribution system (WDS). Previously, we have proposed the AP allocation algorithm, and its dependability extensions such that one link fault or one AP fault does not impair the connectivity of the network. In this paper, we improve this heuristic algorithm by adding the improvement stage using the local search method. Besides, we introduce the route availability (RA) index to estimate the certainty of connections between hosts and the Internet gateway. We verify the effectiveness of our proposal through simulations in two instances.

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A Proposal of Efficient Attribute-Based Group Signature Schemes Using Pairings

FUJII Hiroki, NAKANISHI Toru, FUNABIKI Nobuo

IEICE technical report   109 ( 271 )   15 - 22   2009.11

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Group signature scheme is the digital signature scheme enhancing the privacy of the user, and efficient pairing-based schemes have been proposed. Recently, some attribute-based group signature schemes are proposed, where the signer's attributes can be verified. The attribute-group signature allows us to construct more complex groups, because it can prove the logical relation of attributes such as 'AND' and 'OR'. However, the previouse schemes, the number of pairings and exponentiations in signing and verification depends on the number of attributes. In this paper, we propose an efficient attribute-base group signature scheme, where the computational complexity doesn't depend on the number of attributes.

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A Proposal of a Smart Access Point Allocation Algorithm for Scalable Wireless Mesh Networks

UEMURA Kanako, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   109 ( 228 )   13 - 18   2009.10

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

For a flexible and low-cost access network to the Internet, we have studied WIMNET (Wireless Internet-access Mesh NETwork) that is composed of multiple access points (APs) as wireless routers. WIMNET utilizes two types of APs to achieve the scalability and the communication bandwidth while reducing the cost. One type is the expensive, note-PC based smart AP (SAP) that can use multiple channels for wireless communications and has various functions for the Internet access. Another type is the inexpensive, commercial-based conventional AP (CAP) that can use only one channel. For the performance enhancement, the proper allocation of SAPs among APs is critical in WIMNET, because the number of SAPs is usually much smaller than that of CAPs. In this paper, we present the formulation of the SAP allocation problem for WIMNET and its heuristic algorithm. Our algorithm seeks the best SAP allocation in terms of the newly defined cost function, after finding the communication route by applying our previous algorithms. We verify the effectiveness of our proposal through simulations in three instances using the WIMNET simulator.

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A node configuration algorithm with bandwidth bottleneck resolution for WDM ring networks

Megumi Isogai, Nobuo Funabiki, Toru Nakanishi, Yosuke Isshiki

PHOTONIC NETWORK COMMUNICATIONS   18 ( 2 )   218 - 226   2009.10

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Language：English   Publisher：SPRINGER  

The wavelength-division multiplexing (WDM) technology has been extensively studied and actually deployed as a key technology to solve global information explosions by multiplexing plural signal paths using different wavelengths into one optical fiber. Among WDM-based network architectures, this article focuses on a double-ring one for a next-generation metropolitan area network (MAN), where each node is normally equipped with two pairs of fast-tunable transmitters and wavelength-fixed receivers (TT-FR) as interface to two fibers. To enhance the network performance, additional transmitters/receivers at nodes and receiver wavelengths should be assigned optimally, so that the bandwidth bottleneck can be resolved both on nodes and fiber links. This article formulates this node configuration problem with bandwidth bottleneck resolution as a combinatorial optimization problem, and proves the NP-completeness of its decision version. Then, it presents the two-phase heuristic algorithm composed of a greedy method and a variable depth search (VDS) method. Our algorithm is evaluated through extensive network simulations, where the results support the effectiveness of this joint assignment approach.

DOI： 10.1007/s11107-009-0185-y

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Improvement of Anonymous Authentication System Using Proxies and Its Application to an Anonymous Bulletin Board

YANO Masaya, NAKANISHI Toru, FUNABIKI Nobuo

IEICE technical report   109 ( 207 )   45 - 50   2009.9

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Our research group has implemented the anonymous authentication system based on a group signature scheme for Web services. To avoid modifications of Web servers and browsers, this system uses proxies. However, the system has problems that the lack of the session management causes the communication delay, and that any application of the system has not been implemented, yet. In this study, we implemented the session management function and applied it to an anonymous bulletin board. The experimental results show that the communication time is reduced in a session due to the session management and that the anoymous bulletin board is available in practical time.

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An accessibility improvement in the Web-page layout optimization method for adapting to browsing size

ISOGAI Megumi, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   109 ( 160 )   81 - 86   2009.7

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A Proposal of an Educational-support System for Java Programming Using the Test-driven Development Method

MATSUSHIMA Yukiko, KASAI Yasuhiro, FUNABIKI Nobuo, NAKANISHI Toru, AMANO Noriki

IEICE technical report   109 ( 82 )   7 - 12   2009.6

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This paper presents an educational-support system for Java programming using the test-driven development method, with the goals of reducing the teacher load in evaluating program codes submitted from students and giving corrections and comments to them, and improving the student learning environments. To achieve our goals, this system adopts a Java program verification tool called JUnit, and can generate the test code to verify the student codes from the model code to the assignment made by the teacher in a semi-automatic way. By providing the test code to students as the code specification in the assignment, the verification accuracy is enhanced with reduction of the ambiguity in code implementations. The questionnaire results from both teachers and students confirm the effectiveness of the proposed system in the Java programming education.

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An Implementation of a Group Signature Scheme with Efficient Verifier-Local Revocation Check

SUDARSONO Amang, NAKANISHI Toru, SAKEMI Yumi, NOGAMI Yasuyuki, FUNABIKI Nobuo

IEICE technical report   109 ( 42 )   37 - 42   2009.5

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A group signature scheme with efficient verifier-local revocation check has been proposed. This scheme provides a more efficient revocation check, using the multi-pairing technique for a product of pairings. However, this scheme has not been implemented and evaluated. This paper presents an implementation of the group signature scheme and the experimental results.

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A Generalized Access Point Allocation Algorithm for Wireless Mesh Networks in Indoor Environments

FARAG Tamer, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   109 ( 36 )   31 - 36   2009.5

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Previously, we have proposed an access point (AP) allocation algorithm in indoor environments for the Wireless Internet-access Mesh NETwork (WIMNET) with one gateway (GW) to the Internet. WIMNET is composed of multiple APs that are connected with wireless links, mainly using the wireless distribution system (WDS). In this paper, we generalize this algorithm to handle multiple GWs in the field that are essential for the large scale WIMNET. The generalized algorithm first divides the rooms in the network field into a set of GW clusters by two steps, initial greedy clustering and clustering search improvement. Where the APs allocated in the rooms of the same cluster are connected to the same GW. Then, the previous AP allocation algorithm is applied to the rooms in each cluster sequentially. The effectiveness of our proposal is verified through extensive simulations using the WIMNET simulator.

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Dependability Extensions of the Access Point Allocation Algorithm for Wireless Mesh Networks

HASSAN Walaa, FARAG Tamer, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   109 ( 36 )   37 - 42   2009.5

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As a scalable, flexible, and inexpensive network, we have studied the wireless Internet-access mesh network (WIMNET) that is composed of multiple access points (APs) connected by the wireless distribution system (WDS). WIMNET may suffer from failures of links or APs due to hardware faults or network environmental changes. In this paper, we propose dependability extensions to link/AP faults of the AP allocation algorithm for WIMNET in indoor environments that has been proposed by our group. The extended algorithm finds AP allocations where even if one link/AP is failed, the connectivity of the APs is maintained, while seeking the minimization of the number of additional APs and the maximization of the performance. The effectiveness of our proposal is verified through simulations using the WIMNET simulator.

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An Access Point Allocation Algorithm for Indoor Environments in Wireless Mesh Networks

Tamer Farag, Nobuo Funabiki, Toru Nakanishi

IEICE TRANSACTIONS ON COMMUNICATIONS   E92B ( 3 )   784 - 793   2009.3

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As a flexible, cost effective solution for a large-scale access network to the Internet, we have studied the design optimization of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET consists of multiple access points (APs) that have wireless links between them mainly on the wireless distribution system (WDS). In WIMNET, the links around the Internet gateway can be bottlenecks because every packet passes through it after multihop link activations. Besides, the link quality may be degraded by obstacles in indoor environments. Thus, the proper allocation of APs is essential in WIMNET, so that the communication quality should be ensured while the installation and management cost be minimized. In this paper, we formulate this AP allocation problem for indoor environments in WIMNET with the proof of the NP-completeness of its decision version. Then, we present its two-stage heuristic algorithm composed of the initial greedy allocation and the iterative improvement. The effectiveness of our proposal is verified through extensive simulations in three indoor environments.

DOI： 10.1587/transcom.E92.B.784

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An Online Check Function of Writing Style in the Learning Management System "NOBASU"

KAWANO Hiroki, FUNABIKI Nobuo, NAKANISHI Toru, AMANO Noriki

IEICE technical report   108 ( 470 )   169 - 174   2009.2

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Our research group has developed an original Learning Management System (LMS) named NOBASU to improve educational services to students in our department. This paper presents an online check function of writing style on NOBASU. This function checks the writing styles of "Rhetoric", "Report Length" and "Keywords" in students' reports, and quickly provides results to them. The latest list of frequently used words selected from all submitted reports are also shown. To evaluate efficiency of this function, we implemented and applied it to a lecture in our department. According to the questionnaire survey, we found the effectiveness for students in learning writing styles.

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A WEB Database System for Managing Open Source Software Installation Manuals

MURAKAMI Yukikazu, KAN Etsu, FUNABIKI Nobuo, NAKANISHI Toru, TOKUNAGA Hidekazu, SHIGETA Kazuhiro

IEICE technical report   108 ( 470 )   163 - 168   2009.2

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Recently, the Open Source Software (OSS) has become used at many places. However, the use of an OSS is hard for its novice users, because many OSSes have few good manuals, and the installation of an OSS package sometimes requires installations of multiple OSS packages to be integrated together. To solve this problem, we have proposed a method of automatically generating a WEB manual for installing an OSS by editing the log information recorded during the installation process by a skilled user. This method has a problem of requiring different manuals even for the same OSS, because installation commands may be different depending on the OS distribution for the PC and the OS/OSS versions. It is impossible to create all the manuals to cover any difference. In this paper, we propose a WEB database system for managing installation manuals so that skilled OSS users can easily upload new manuals for OSSes with new versions, and the similar manual display function after investigating differences of installation commands under different OS/OSS versions and OS distributions.

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Improvements in the WDS Clustering Algorithm for Wireless Internet-access Mesh Networks

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   108 ( 457 )   343 - 348   2009.2

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We have studied the Wireless Internet-access Mesh NETwork (WIMNET) as a large-scale multihop wireless network using Wireless Distribution System (WDS) for Internet access network. We have proposed the heuristic algorithm for the WDS clustering problem to achieve the scalable WIMNET. In this paper, we propose the four improvements of our algorithm; 1) consideration of total hop counts and total interferences in the cost function, 2) random selection of starting APs, 3) modification of the cost function for the gateway AP selection, and 4) consideration of interferences for the route selection. Through simulations using two types of network topologies, we verify the effectiveness of these improvements.

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A Multi-Server Video Encoding System Using Divided Video Files at Scene Changes

OKADA Genya, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   108 ( 392 )   79 - 82   2009.1

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Recently, with spread of high-performance personal computers and broadband networks, the use of video contents has become popular. As a result, the fast encoding process of video files is very important to improve the convenience of video contents. In this paper, we present a multi-server video encoding system to speed up the encoding process by dividing one video file into multiple fragments and encoding them in parallel using multiple servers. To improve the quality of the reunited video file, we divide the source video file at scene changes of the content. We have implemented the proposed system, and confirmed that our system using three servers can reduce the encoding process time into the half of the single server case.

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A Proposal of an Web Page Layout Optimization Method for Various Browser Sizes

ISSHIKI Yosuke, FUNABIKI Nobuo, NAKANISHI Toru, ISOGAI Megumi

IEICE technical report   108 ( 392 )   83 - 88   2009.1

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Recently, the opportunity of Web browsing using terminals with various sizes has increased due to the development of a variety of terminals. Unfortunately, most Web pages have been designed to be fit to terminals with the standard size. As a result, the screen scroll operation is necessary to access the main content at a small-size terminal, whereas the blank space becomes large at a large-size terminal. In this paper, we focus on the separation of the document structure description by an XHTML file and the appearance description by a CSS file. Then, we propose a method of delivering the Web page layout fit to the browsing size. This method first generates the CSS file fit to each size automatically from the Web page files that have been produced by a user for the standard size. Then, it dynamically changes the CSS file using JavaScript. We confirm the effectiveness of our proposal at various sizes by generating an Web page using this method.

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スケーラブル無線メッシュネットワークのための通信路構成最適化アルゴリズム

上村香菜子, 舩曵信生, 中西透

スケーラブル無線メッシュネットワークのための通信路構成最適化アルゴリズム   J92-B ( 9 )   1526 - 1537   2009

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A web-based lecture scene playback system using digital picture-card show with structured learning assistance function

Aki Mouri, Nobuo Funabiki, Toru Nakanishi

INTERNATIONAL JOURNAL OF WEB AND GRID SERVICES   5 ( 4 )   372 - 389   2009

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Computer-aided slide presentations have become common at lectures in universities. To improve the educational quality, this paper presents it Web-based lecture scene playback system using the digital picture-card show with the structured learning, assistance function. Fine still images of lecture scenes are periodically taken by a digital camera, and the lecturer voice is recorded by a personal computer, which are edited to produce the digital picture-card show. The structured learning assistance function classifies the picture cards representing the slides containing each important concept into five structures, and generates their links. The system was applied to freshman courses in our department where questionnaire results confirmed the effectiveness.

DOI： 10.1504/IJWGS.2009.030265

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An implementation of writing style check function in learning management system “NOBASU”

Hiroki Kawano, Nobuo Funabiki, Toru Nakanishi, Noriki Amano

An implementation of writing style check function in learning management system “NOBASU”   227 - 228   2009

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A Heuristic Optimization Algorithm for Panoramic Image Generation Problem from Multiple Cameras

Megumi Isogai, Nobuo Funabiki, Toru Nakanishi

EMERGING INTELLIGENT COMPUTING TECHNOLOGY AND APPLICATIONS, PROCEEDINGS   5754   297 - 306   2009

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Recently, a panoramic image has been expected in various applications due to the advantage of expressing a wide range of scenes by one image. In this paper, we propose a heuristic optimization algorithm for the panoramic image generation problem from multiple cameras. Our-three-stage algorithm composed of the approximate calibration, the detailed calibration, and the image synthesis, transforms the images of the side cameras to be fit to the image of the central camera as best as possible. The image parameters are optimized by a local search method with a. Tabu period as a typical heuristic optimization method. Through experiments, we show the effectiveness of our proposal.

DOI： 10.1007/978-3-642-04070-2_34

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An Implementation of Anonymous Authentication System for Web Services Using Proxies

Toru Nakanishi, Hiroki Obayashi, Nobuo Funabiki

ISCE: 2009 IEEE 13TH INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2   121 - 123   2009

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This paper shows an implementation of the anonymous authentication system for Web services. This system uses privacy-enhancing digital signatures, called group signatures, which allow the user to be anonymously authenticated. Since the adopted group signature scheme utilizes novel cryptographic algorithms, the simple introduction or the authentication to the Web browsers and servers needs modifications of them. Thus, we use proxies in our implementation to avoid the modifications. We show that the authentication time is practical by the experiments.

DOI： 10.1109/ISCE.2009.5156831

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Revocable Group Signature Schemes with Constant Costs for Signing and Verifying

Toru Nakanishi, Hiroki Fujii, Yuta Hira, Nobuo Funabiki

PUBLIC KEY CRYPTOGRAPHY-PKC 2009, PROCEEDINGS   5443   463 - 480   2009

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Lots of revocable group signature schemes have been proposed so far. In one type of revocable schemes, signing and/or verifying algorithms have O(N) or O(R) complexity, where N is the group size and It is the number of revoked members. On the other hand, in Camenisch-Lysyanskaya scheme and the followers, signing and verifying algorithms have O(1) complexity. However, before signing, updates of the secret key are required. The complexity is O(R) in the worst case. In this paper, we propose a revocable scheme with signing and verifying of O(1) complexity, where no updates of secret key are required. The compensation is the long public key of O(N). In addition, we extend it to the scheme with O(root N)-size public key, where signing and verifying have constant extra costs.

DOI： 10.1007/978-3-642-00468-1_26

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A Proposal of Structured Learning Assistance Function in Lecture-Scene Playback System Using Digital Picture-Card Show

Nobuo Funabiki, Aki Mouri, Kanako Uemura, Toru Nakanishi

CISIS: 2009 INTERNATIONAL CONFERENCE ON COMPLEX, INTELLIGENT AND SOFTWARE INTENSIVE SYSTEMS, VOLS 1 AND 2   983 - 988   2009

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Authorship：Lead author   Language：English   Publisher：IEEE  

The Web-based lecture-scene playback system using the digital picture-card show has been studied to improve the educational quality of lectures with computer-aided slide presentations in universities. In this system, fine still images of lecture scenes, containing the lecturer the blackboard, and the presentation screen, are periodically taken by a commercial digital photo camera, and the lecturer voice is recorded into a digital file by a personal computer during a class. Then, the digital picture-card show to play back the lecture scenes is edited by selecting one image and the voice file section corresponding to one lecture scene that is defined as the time span of teaching one slide page by the lecturer The picture-card show is delivered to students through the World-Wide Web system on demand. In this paper we propose the structured learning assistance function for this lecture-scene playback system, so that students can study important technical concepts in the lecture structurally This function classifies the lecture scenes corresponding to one concept into five structures, and generates the links between them automatically. Through applications to one course for freshmen in our department, we show the effectiveness of our proposal.

DOI： 10.1109/CISIS.2009.103

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操作ログを用いたオープンソースソフトウエアのインストールマニュアル自動生成法の提案

村上幸一, 舩曵信生, 徳永秀和, 重田和弘, 中西透

情報処理学会論文誌   50 ( 3 )   926 - 939   2009

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A web-based installation manual management system for open source software

Yukikazu Murakami, Nobuo Funabiki, Hidekazu Tokunaga, Kazuhiro Shigeta, Toru Nakanishi

NCM 2009 - 5th International Joint Conference on INC, IMS, and IDC   1261 - 1266   2009

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Recently, Open Source Software (OSS) has become commonly used at many places. Unfortunately, although the use of OSS is often hard for novice users, many OSSes have few good manuals. To solve this problem, we have proposed a method of automatically generating a Web-based installation manual for an OSS by editing the log information recorded during the installation process by a skilled user. However, this method has another problem of requiring several manuals even for the same OSS, because installation commands may be different depending on the installation environment such as Linux distributions and versions. In addition, novice users sometimes make input mistakes during installation process that cannot be detected by themselves. In this paper, we propose a Web-based system to manage the created manuals so that users can easily use them. By incorporating the analogous manual search algorithm after investigating command changes under different environments, our system is able to show similar manuals if no existing manual matches to the search condition. Besides, we propose the installation guidance function to avoid mistakes by users. It monitors the input commands by a user, and displays the correct commands with the error message if a mistake is found. The experimental results in installing OSS packages by novice users confirm the effectiveness our proposal. © 2009 IEEE.

DOI： 10.1109/NCM.2009.183

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Forward-Secure Group Signatures from Pairings

Toru Nakanishi, Yuta Hira, Nobuo Funabiki

PAIRING-BASED CRYPTOGRAPHY - PAIRING 2009   5671   171 - 186   2009

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To reduce the damage of key exposures, forward-secure group signature schemes have been first proposed by Song. In the forward-secure schemes, a secret key of a, group member is updated by a one-way function every interval and the previous secret key is erased. Thus, even if a secret key is exposed, the signatures produced by the secret keys of previous intervals remain secure. Since the previous forward-secure group signature schemes are based on the strong RSA assumption, the signatures are longer than pairing-based group signatures. In addition, the complexity of the key update or signing/verification is O(T), where T is the total number of intervals. In this paper, a forward-secure group signature scheme from pairings is proposed. The complexity of our key update and signing/verification is O(log T).

DOI： 10.1007/978-3-642-03298-1_12

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A Proposal of a Web-page Layout Optimization Method for Multimodal Browsing Sizes

Nobuo Funabiki, Yosuke Isshiki, Megumi Isogai, Toru Nakanishi

ISCE: 2009 IEEE 13TH INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2   449 - 453   2009

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Recently, Web-page browsing opportunities at multimodal browsing sizes have increased due to developments of various terminals. Meanwhile, most Web pages have been designed to fit to the standard size. As a result, the screen scroll operation is necessary to access the main content at a small size, whereas the blank space becomes large at a large size. In this paper, we propose a Web-page layout optimization method for multimodal browsing sizes by focusing on the standard Web design style with the separation of the document structure description by an XHTML file and the appearance description by a CSS file. Our method automatically generates a set of CSS files fit to different sizes from the files designed for the standard size by a user. Then, it dynamically switches to the CSS file fit to the current browsing size using JavaScript. We confirm the practicality of our proposal through experiments of the Web page generation and access at various sizes.

DOI： 10.1109/ISCE.2009.5156917

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A Comparative Study of Open Source Softwares for Virtualization with Streaming Server Applications

Sritrusta Sukaridhoto, Nobuo Funabiki, Toru Nakanishi, Dadet Pramadihanto

ISCE: 2009 IEEE 13TH INTERNATIONAL SYMPOSIUM ON CONSUMER ELECTRONICS, VOLS 1 AND 2   333 - +   2009

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Currently, several streaming servers are available to provide a variety of multimedia applications such as VoD (Video-on-Demand), IP-phone, and IP-TV. As a result, the provision of multiple streaming servers on a single machine using the virtualization technology has become important in order to save the operational/management costs while enhancing the performance and the reliability of the system. In this paper, we show the performance evaluation of two :representative open source softwares for the virtualization technology, Xen and OpenVZ, in various configurations of applications on three open source streaming servers, Red5, Darwin, and VLC. Our experimental results indicate that OpenVZ provides the better performance for streaming applications with Darwin and VLC whereas Red5 can run only on Xen.

DOI： 10.1109/ISCE.2009.5156885

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A Proposal of a Scalable Web Server System Using Virtual Machine Monitor "Xen"

SHOJI Tomoya, INOUE Yuuki, FUNABIKI Nobuo, NAKANISHI Toru, KAGOTANI Hiroto

IEICE technical report   108 ( 286 )   105 - 108   2008.11

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Recently, the virtualization technology has been often used to construct servers due to the efficiency of the computer resource utilization and the easiness of the system extension. The method of composing cluster systems using the virtualized servers has also been proposed. In this paper, we propose a safe and scalable Web server system using the virtualization technology. In this system, the SSL authentication protocol is adopted to authenticate the server hosts and the encrypted data communications. Besides, the system management tool is incorporated for the simple system management by realizing the automatic update functions of the system softwares such as the operating system and the Web server. We implemented the proposed system using Puppet as the system management tool, Ruby SNMP as the system management library, and Xen as the virtualization machine monitor. The experimental result using our implementation confirms the short time for the Web server extension.

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A Construction of the Smart Access Point for Practical Wireless Mesh Networks

HIRAKATA Kengo, HORIUCHI Satoshi, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   108 ( 286 )   63 - 68   2008.11

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Recently, the demand for the expansion of the service area by the wireless local area network (WLAN) has become strong due to rapid deployments of WLANs. We have studied WIMNET (wireless Internet-access mesh network) as the WLAN technology of constructing the Internet access network to the large area with the low cost and the short preparation time. In WIMNET, the service area can be flexibly expanded by adding new access points (APs) that are wirelessly connected using WDS (Wireless Distribution System). In this paper, we present the smart access paint (SAP) equipped with the Web cache function, and the multiple network interfaces, in order to solve the throughput shortage problem when the size of WIMNET increases to afford a number of hosts. We construct a simple WIMNET using multiple SAPs that were implemented on mobile personal computers, and evaluate the functions in SAP through communication experiments.

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A Proposal of an Efficient Forward-Secure Group Signature Scheme Using Pairing

HIRA Yuta, NAKANISHI Toru, FUNABIKI Nobuo

IEICE technical report   108 ( 284 )   47 - 54   2008.11

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Group signature scheme is one of signature schemes which keep signer's identity information secret. To prevent a problem that an adversary who obtains valid user's secret key can forge the signature easily in conventional group signature schemes, an RSA-based group signature scheme with forward-security that means unforgeability for signatures signed before a key exposure was proposed. However, this scheme requires O(T) complexity for key up-dating or signing/verifying. Then, in this paper, we propose a pairing-based forward-secure group signature scheme with a key update of O(1) complexity and signing/verifying of O(log T) complexity, by adding a key updating based on a tree structure. We also show that the proposed scheme satisfies the forward-security.

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A Proposal of an Optimal Assignment Algorithm for General Academic Subject Registrations

SHOJI Tomoya, FUJII Hiroki, UEMURA Kanako, KAWANO Hiroki, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   108 ( 247 )   51 - 56   2008.10

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Currently, general academic subjects in Okayama University consist of four categories, namely, "main subjects", "individual subjects", "guidance subjects", and "foreign language subjects". Among them, for "main subjects" and "foreign language subjects" that have much freedom in choice, students are requested to submit the ranks of the subjects that they want to take in the next semester beforehand. Then, the assignment of subjects to students is processed manually using the submitted ranks. However, this assignment task is very hard because it is necessary to assign fairly several thousand students at the same time while considering the capacity of each classroom, the bias in popularity among subjects, and movements of students between two distant campuses. In this paper, we define the assignment problem of general academic subjects to students as a combinational optimization problem, and propose its heuristic algorithm composed of two stages. We implement the algorithm as a Ruby application, and verify the effectiveness using real data in our university.

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Reduction of Public-Key Size in a Revocable Group Signature Scheme with Constant Costs for Signing and Verifying

FUJII Hiroki, HIRA Yuta, NAKANISHI Toru, FUNABIKI Nobuo

IEICE technical report   108 ( 207 )   33 - 38   2008.9

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Group signature scheme is the digital signature scheme enhancing the privacy of the user. We proposed a revocable scheme where signing and verifying require only O(1) costs, while various schemes were previously proposed. However, the scheme has a problem that the public key size is O(N). In this paper, we extend the scheme to reduce the public key size into O(√N). In addition, we implement it to confirm the reduction of the size and show that the scheme works at practical execution times.

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Extensions of Supporting Functions in the Learning Management System "NOBASU"

KASAI Yasuhiro, FUNABIKI Nobuo, AMANO Noriki, NAKANISHI Toru

108 ( 88 )   45 - 50   2008.6

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A Proposal of a 4-layered Software Architecture for Learning Management Systems and Its Implementation for "NOBASU"

BABA SHOTA, FUNABIKI NOBUO, AMANO NORIKI, NAKANISHI TORU

IPSJ SIG Notes   2008 ( 31 )   55 - 60   2008.3

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

The Learning Management System (LMS), as a platform using the World Wide Web, has been introduced for educational activities in recent years. Our research group has actually developed an original LMS named NOBASU for educational services in our department. LMS usually needs to be extended and modified to meet the changing demands in educations. In this research, we propose a 4-layered software architecture to construct LMS with the simple structure for easy developments. Through the implementation of our proposed architecture to NOBASU, we verified the effectiveness of our approach.

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Other Link： http://id.nii.ac.jp/1001/00041803/

A Proposal of An Automatic Manual Generation Method for Installing Several Open Source Soft Wares Cooperation

MURAKAMI Yukikazu, FUNABIKI Nobuo, TOKUNAGA Hidekazu, SHIGETA Kazuhiro

IPSJ SIG Notes   2008 ( 31 )   79 - 84   2008.3

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An open source software (OSS) is a software whose source code has been public through the Internet, so that everybody can use and modify it freely. As a result, a lot of companies, governments, and universities have now become using OSSs. However, the use of an OSS is actually hard for its beginners, because many OSSs have few good manuals, where an OSS has usually been developed by volunteers, and the installation of an OSS sometimes requires installations of several OSS packages before it. To solve this problem, we have proposed a method of automatically generating an installation manual of an OSS. In this paper, we implement the system for this method. Then, we extend our proposed method to generating the installation manual of an OSS that requires installations of other OSS packages at the same time. We conduct experiments using an OSS example requiring installations of four OSS packages to verify the usefulness of our method.

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Other Link： http://id.nii.ac.jp/1001/00041807/

An Extension of the Routing Tree Algorithm for Two-Layer Wireless Mesh Networks

UEMURA Kanako, FUNABIKI Nobuo, NAKANISHI Toru, FARAG Tamer

IEICE technical report   107 ( 524 )   329 - 334   2008.3

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Currently, we have studied the Wireless Internet-access Mesh NETwork (WIMNET) as a scalable, flexible, and low-cost access network to the Internet, using multiple access points (APs) that are connected with each other through wireless links. In WIMNET, two types of APs are actually adopted to realize the scalability and the communication bandwidth while reducing the cost. One is the expensive, note-PC based smart AP (SAP) that can use multiple channels for wireless communications and has various functions for the Internet access. Another is the inexpensive, commercial-based conventional AP (CAP) that can use only one channel. In this paper, we propose the extension to this two-layer WIMNET of our routing tree algorithm that have been proposed for the single-layer WIMNET using only SAPs. The simulation results in two instances by the WIMNET simulator show that using our extended routing tree algorithm, the throughput of the two-layer WIMNET with a small number of SAPs does not become worse than that of the single-layer one.

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A Proposal of a Classification and Link Method of Lecture Scenes for Structured Learning

MOURI AKI, FUNABIKI NOBUO, NAKANISHI TORU

IPSJ SIG Notes   2008 ( 13 )   87 - 92   2008.2

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We have studied the Web-based assistance system for the structured learning using five categories of keywords in university lectures. In this paper, we propose the method for classifying into five categories the lecture scenes that are generated in our Digital picture-card based LECTure scene playback system (DILBCT), and for linking these scenes related to the same keyword on the Web system. The proposed method first generates the list of the keywords for the structured learning from the keywords that have been submitted to NOBASU, our Web-based learning management system, from students for the preparation and the review of each class. Then, it extracts the keywords and their locations in the presentation slides for the lecture. Finally, for each keyword, it classifies the slides containing the same keyword into five categories, and generates the links between the corresponding lecture scenes. For evaluations, we implemented the experimental system for the proposed method by modifying DILECT, and applied it to one class for freshmen in Department of Communication Network Engineering at Okayama University. The questionnaire results from students show that our method effectively improves their understanding of this class.

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A Two-Stage Algorithm for Access Point Allocation in Indoor Environments for Wireless Mesh Networks

Tamer Farag, Nobuo Funabiki, Toru Nakanishi, Kanako Uemura

2008 14TH ASIA-PACIFIC CONFERENCE ON COMMUNICATIONS, (APCC), VOLS 1 AND 2   261 - 265   2008

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As a flexible, inexpensive large-scale access network to the Internet, we have studied WIMNET (Wireless Internet-access Mesh NETwork). WIMNET is composed of multiple access points (APs) as wireless routers, where each AP has multihop wireless connections with others by the wireless distribution system (WDS). In WIMNET, communications between APs and the Internet gateway can become the bottleneck due to multihop link activations. Besides, the link quality in indoor environments may be degraded by obstacles such as walls. Thus, the proper allocation of APs is essential, such that the installation cost and the maximum hop count between APs should be minimized while any host in the service area must be covered by at least one AP In this paper, we formulate this AP allocation problem in indoor environments for WIMNET, and present its two-stage heuristic algorithm composed of the initial AP allocation and the AP allocation optimization with the association host optimization. The effectiveness of our approach is verified through extensive simulations using our WIMNET simulator.(1)

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A bandwidth bottleneck resolution approach to node configuration optimization in WDM ring networks

Megurni Isogai, Nobuo Funabiki, Yosuke Isshiki, Toru Nakanishi

2008 IEEE SARNOFF SYMPOSIUM   2008 ( S13.4 )   340 - 344   2008

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The wavelength-division multiplexing (WDM) technology has been extensively studied as a key technology to solve global information explosions. WDM multiplexes plural signal paths using different wavelengths into one optical fiber. Among WDM-based network architectures, this paper focuses on a double-ring network for a next-generation metropolitan area network (MAN). Each node is normally. equipped with two pairs of fast-tunable transmitters and wavelength-fixed receivers (TT-FR) as interface to two fibers. To enhance the network performance, additional transmitters/receivers at nodes and receiver wavelengths should be assigned optimally depending on its design requirement, so that the bandwidth bottleneck can be resolved both on nodes and fibers. This paper formulates this node configuration problem as a combinatorial optimization problem and presents its two-phase heuristic algorithm using the greedy and variable depth search (VDS) methods. Our approach is evaluated through network simulations, where the results verify the effectiveness of this joint assignment approach.

DOI： 10.1109/SARNOF.2008.4520106

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A Dynamic Channel Assignment Technique for Wireless Internet-access Mesh Networks

Walaa Hassan, Nobuo Funabiki, Toru Nakanishi

2008 14TH ASIA-PACIFIC CONFERENCE ON COMMUNICATIONS, (APCC), VOLS 1 AND 2   271 - 275   2008

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The wireless Internet-access mesh network (WIMNET) has been studied to provide a flexible, inexpensive large-scale access network to the Internet. WIMNET is composed of multiple access points (APs) as wireless routers that are communicated with each others through multihop wireless links mainly by the wireless distribution system (WDS). In WIMNET, hosts may move in the field, which can raise issues such as the quality of service, the channel interference, and the network load management. As a result, the adaptive channel assignment to the wireless links between APs to host distributions, becomes essential to improve the performance of WIMNET. In this paper, we formulate this dynamic channel assignment (DCA) problem for WIMNET, and present a DCA technique through modifications of our existing study with the newly defined decision function for the channel reassignment. The effectiveness of our approach is verified through extensive simulations using the WIMNET simulator.

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A minimum-delay routing tree algorithm for access-point communications in wireless mesh networks

Nobuo Funabiki, Kanako Uemura, Toru Nakanishi, Walaa Hassan

RIVF 2008 - 2008 IEEE International Conference on Research, Innovation and Vision for the Future in Computing and Communication Technologies   2008   161 - 166   2008

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As a scalable, flexible access network to the Internet, we have studied the design optimization and the implementation of the Wireless Internet-access Mesh NETwork (WIMNET). WIMNET is composed of multiple access points (APs) that are connected with each other by wireless communications. At least one AP performs as the gateway (GW) to the Internet. Any host in the network can access to the Internet through this GW, after associating its neighbor AP and communicating with multihop wireless links between APs. The delay along the routing path degrades the performance of WIMNET. To avoid the bottleneck of communications by minimizing the maximum delay, we formulate the routing tree problem for AP communications, and prove the NP-completeness of its decision version. Then, we propose the greedy heuristic algorithm of sequentially selecting one link that minimizes the delay of the predicted tree containing the link. The effectiveness of our algorithm is verified through extensive simulations in instances with 25 APs using the WIMNET simulator. ©2008 IEEE.

DOI： 10.1109/RIVF.2008.4586349

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A Proposal of an Installation Manual Generation Method for Open Source Software Using Operation Logs

Yukikazu Murakami, Nobuo Funabiki, Hidekazu Tokunaga, Kazuhiro Shigeta, Toru Nakanishi

SITIS 2008: 4TH INTERNATIONAL CONFERENCE ON SIGNAL IMAGE TECHNOLOGY AND INTERNET BASED SYSTEMS, PROCEEDINGS   547 - 554   2008

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Language：English   Publisher：IEEE COMPUTER SOC  

An Open Source Software (OSS) is the software whose source code has been public, usually through the Internet, so that everybody can use and modify it freely. A lot of companies, governments, and universities are now using OSS technologies because of the advantages they bring. However the use of an OSS is actually hard for its beginners, because many OSSes have few good manuals, where they have usually been developed by volunteers. Besides, the installation of an OSS package sometimes requires installations of multiple OSS packages to be integrated together In this paper we propose a method of automatically generating an installation manual of an OSS package, including the one requiring the integration of multiple OSS packages. Then, we implement the proposed method for evaluations. Our experimental results in installations of OSS packages including the one requiring the integration of four packages by generated manuals verify the effectiveness of our method.

DOI： 10.1109/SITIS.2008.62

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A Lecture Scene Playback System using Digital Picture-Card Show for Distance Learning

Nobuo Funabiki, Aki Mouri, Walaa Hassan, Toru Nakanishi

2008 22ND INTERNATIONAL WORKSHOPS ON ADVANCED INFORMATION NETWORKING AND APPLICATIONS, VOLS 1-3   2008   1071 - 1076   2008

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Recently, computer-aided slide presentations have been commonly used at lectures in universities. To improve their educational quality, this paper presents an Web-based lecture scene playback system using the digital picture-card show for distance teaming. In this system, fine still images of lecture scenes containing the lecturer, the blackboard, and the screen, are periodically taken by an off-the-shell digital photo camera, and the lecturer voice is recorded into a digital file by a personal computer during a class. Then, the digital picture-card show to play back the lecture scenes is edited by selecting one image and the voice file interval corresponding to one lecture scene defined as the time span of teaching one slide page by the lecturer The picture-card show is delivered to students through the World-Wide Web system on demand. We have implemented and applied our System to one course for freshmen in our department. The system performance and the questionnaire results from students show that our system is very efficient and practical to improve understandings and motivations of students for study of this course.

DOI： 10.1109/WAINA.2008.73

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Efficient revocable group signature schemes using primes

Toru Nakanishi, Nobuo Funabiki

IPSJ Journal   49 ( 9 )   2951 - 2962   2008

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An implementation of anonymous IEEE802.1X authentication with user revocation

Amang Sudarsono, Toru Nakanishi, Kouhei Miki, Nobuo Funabiki

3rd Joint Workshop on Information Security (JWIS 2008)   240 - 245   2008

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An Implementation of an Anonymous IEEE802.1X Authentication with User Revocation Reducing Mobile Host's Load

MIKI KOUHEI, NAKANISHI TORU, KAWASHIMA JUN, FUNABIKI NOBUO

IPSJ SIG Notes   2007 ( 126 )   43 - 48   2007.12

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The IEEE802.1X authentication has been used well as an authentication protocol in the Access Point for the Internet connection. There is a problem that mobile host's privacy information can be leaked to the Internet service provider in this protocol. To solve this problem, we have proposed and implemented an anonymous authentication with user revocation using the group signature. However, there is a problem of this method that mobile host's load increases in proportion to the number of moblie hosts in the system. In this paper, an anonymous IEEEd02.1X authentication with a user revocation reducing mobile host's load is implemented by using a pairing-based group signature with verifier-local revocation, and the authentication time is evaluated.

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Throughput Measurements under Various Contention Window Sizes in Wireless Mesh Networks

KATO Hideaki, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   107 ( 403 )   55 - 60   2007.12

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As a scalable access netwok to the Internet, we have studied the Wireless Internet-access Mesh NET-work (WIMNET) that is composed of multiple access points (APs) with multihop communications. In WIMNET, the throughput shortage can be caused by interferences among communication links between APs, and the thoughput unfairness between APs can be caused by the difference on numbers of hops from APs to the gateway. As a solution to these problems, we have proposed the contention window (CW) size control method in CSMA/CA protocol, and have evaluated it through simulations. In this paper, we evaluate the effect of our proposal through throughput measurements in real environments after implementing it on a Linux-PC. Our results show that the optimal CW size is actually different depending on the number of APs in WIMNET, and there is a trade-off between the increase of the average throughput and the fairness of the throughput between APs.

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An Implementation of a Privacy Enhancing SSL/TLS Protocol Based on Group Signatures

OBAYASHI Hiroki, NAKANISHI Toru, KAWASHIMA Jun, FUNABIKI Nobuo

IEICE technical report   107 ( 397 )   79 - 84   2007.12

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While various Web services have spread, a lot of private information leaks have been often caused by the service vendors. One method to solve this problems is the use of the anonymous authentication based on group signatures. Group signatures allow the service vendors to verify that a signature is signed by a valid user, but they cannot know who is the signer. Therefore, the anonymous authentication based on group signatures can protect user's privacy while preventing illigal access. In this paper, we implement a privacy enhancing SSL/TLS protocol based on group signatures with membership revocation that does not need the change of user's certificate, and evaluate the authentication time. In a group with 5000 members where 10% of its members are revoked, the authentication needs about 3 seconds. This result shows the practicality of this anonymous authentication protocol for a medium scale group.

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A Heuristic Algorithm for Access Point Allocation in Indoor Environments for Wireless Mesh Networks

FARAG Tamer, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   107 ( 378 )   55 - 60   2007.12

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

We have studied WIMNET (Wireless Internet-access Mesh NETwork) as a flexible and inexpensive large-scale access network to the Internet. WIMNET is composed of multiple access points (APs) as wireless routers, where each AP has multihop wireless connections with others by the wireless distribution system (WDS). In WIMNET, communications between APs can become the bottleneck due to their multihop link activations. Besides, the link quality may be degraded by obstacles such as walls in indoor environments. Thus, the proper allocation of APs is essential, such that the maximum hop count between APs should be minimized while any host in the field must be covered by at least one AP. In this paper, we formulate this AP allocation problem in indoor environments for WIMNET. Then, we present its three-stage heuristic algorithm composed of the initial AP allocation, the AP allocation optimization, and the association host optimization. The effectiveness of our approach is verified through extensive simulations using our WIMNET simulator.

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An Implementation of uClinux-VServer for Embedded Systems

KAWASHIMA JUN, NAKANISHI TORU, FUNABIKI NOBUO

2007 ( 121 )   7 - 12   2007.12

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In this paper, we report an implementation of uClinux-VServer and its evaluations. This uClinux-VServer is actually implemented by porting Linux-VServer, an OS-level virtualization system, to uClinux. uClinux can run on a CPU with no MMU (Memory Management Unit), and thus it is suitable for embedded systems. VServer offers a virtual operating platform to a machine so that application programs can be tested there while restricting the interference to the host system on the machine. The evaluation results of the implemented uClinux-VServer show the porting overhead is very small, and the performance of applications on it has no difference from the performance on the conventional uClinux.

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A Proposal of a Routing Tree Generation Algorithm for Minimizing the Maximum Delay in Wireless Mesh Networks

UEMURA Kanako, FUNABIKI Nobuo, NAKANISHI Toru, FARAG Tamer

IEICE technical report   107 ( 261 )   57 - 62   2007.10

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

We have studied the Wireless Internet-access Mesh NETwork (WIMET) as a scalable wireless network to access the Internet. WIMNET is composed of multiple access points (APs) that have wireless connections with each other where at least one AP performs as the gateway AP (GW-AP) to the Internet. Each host can access to the Internet through a GW-AP after multihop wireless communications between APs from its associated AP. Thus, the increases of the transmission delay at communication links around the GW-AP and the propagation delay through the routing path between an AP and a GW-AP can degrade the performance of WIMNET. In this paper, we formulate the routing tree generation problem for AP communications to minimize the maximum delay for the bottleneck solution, and propose its heuristic algorithm. We show the effectiveness of our algorithm through simulations in two instances by using the WIMNET simulator.

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An Improved Node Configuration Algorithm for WDM Ring Networks

ISSHIKI Yosuke, ISOGAI Megumi, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   107 ( 250 )   27 - 32   2007.10

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Recently, the Wavelength-Division Multiplexing (WDM) technology has attracted great interests as a key technology of realizing high-speed communications by multiplexing multiple optical signals using different wavelengths into a single optical fiber. As a WDM-based ring network for the next generation platform of metropolitan area networks, we have studied the optimal design of HORNET (Hybrid Optoelectronic Ring NETwork) for the performance improvement. In fact, we have defined the node configuration problem of assigning additional transmitters and receivers to each node under their total limits and of assigning a wavelength to each receiver, such that the communication collision rate is minimized, and presented its heuristic algorithm. In this paper, we propose the improved objective function of minimizing bottleneck bandwidth and wavelength assignment algorithm based on the variable depth search. The effectiveness of our proposal is verified through simulations, where the performance is compared with the conventional method.

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A short verifier-local revocation group signature scheme with backward unlinkability

Toru Nakanishi, Nobuo Funabiki

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E90A ( 9 )   1793 - 1802   2007.9

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Previously Verifier-Local Revocation (VLR) group signature schemes from bilinear maps were proposed. In VLR schemes, only verifiers are involved in the revocation of a member, while signers are not. Thus, the VLR schemes are suitable for mobile environments. Furthermore, the previously proposed schemes satisfy the important backward unlinkability. This means that even after a member is revoked, signatures produced by the member before the revocation remain anonymous. This property is needed in case of a voluntary leave of a member or in case of a key loss. However, in the previous schemes, signatures become long, due to the adopted assumption, which should be improved in order to apply the schemes to the mobile environments. In this paper an improved VLR scheme is proposed with the shorter group signatures. This is achieved by using a different assumption, DLDH assumption, and improving zero-knowledge proofs in the group signatures. The length of the proposed group signatures is reduced to about 53% of that of the previous ones.

DOI： 10.1093/ietfec/e90-a.9.1793

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An Implementation of a Pairing-Based Group Signature Scheme with Verifier-Local Revocation

HIRA Yuta, KATO Hidehiro, NAKANISHI Toru, NOGAMI Yasuyuki, FUNABIKI Nobuo, MORIKAWA Yoshitaka

IEICE technical report   107 ( 209 )   69 - 76   2007.8

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Group signature scheme is one of signature schemes which keep signer's identity information secret. A pairing-based group signature scheme which can make a signer sign without any revocation information and has the short length of the signature was proposed. However this scheme has a problem that the anonymity cannot be proved in case of using the twisted pairing which is known for an efficient implementation of pairing. Then, in this paper, we extend the previous scheme to have the provable anonymity in case of using twisted pairing. In addition, we efficiently implemented the extended scheme by transforming some equations and introducing parallel processing, and then we show that the extended scheme can be executed for a practical time on a server with multi-core CPU even if about 500 members are revoked.

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A Proposal of An Automatic Manual Generation Method for Installing Open Source Soft Wares using Log Files

MURAKAMI Yukikazu, FUNABIKI Nobuo, TOKUNAGA Hidekazu, SHIGETA Kazuhiro

IEICE technical report   107 ( 205 )   51 - 56   2007.8

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An open source software (OSS) is a software whose source code is public through the Internet, so that everybody can use and modify it freely. As a result, a lot of companies, governments, and universities are now using OSS. However, the use of OSS is actually hard for beginners because OSS has few good manuals, where OSS has been developed by volunteers. In this paper, we propose a method of automatically generating a manual for installing OSS using log files at the installation process by a trained user. Our experimental results for its evaluations using the installation of Tomcat, an Web OSS, show that more people could complete the installation of this OSS by using the manual generated by the proposed method than by using the existing manual on an Web site.

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Extensions of an Web-based Learning Management System "NOBASU"

OKADA Genya, FUNABIKI Nobuo, NAKANISHI Toru, AMANO Noriki

IEICE technical report   107 ( 205 )   75 - 80   2007.8

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In this paper, we present the two new functions, the keyword submission function and the Web quiz function, for NOBASU. NOBASU is the Web-based learning management system (LMS) that has been developed by our research group to improve educational services in our department. The keyword submission function requests students to submit three keywords in each class before and after the class from the course materials so as to encourage them to prepare and review it. These keywords are disclosed to all the students after the submission deadline so that they can refer them for self-study. The Web quiz function enables students to take short tests about contents in classes on NOBASU. The test results are automatically graded after the student submits them. The teacher can easily register a new Web quiz by uploading a CSV file that describes the questions and the answers following the newly defined format. This CSV file can be completed at any place without Internet connections. We have implemented the two functions and have applied them to one class for freshmen at Department of Communication Network Engineering in Okayama University. From the results of the questionnaire from students about their usability, we confirm that they are very effective to improve motivations and understanding of students for this class.

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A Proposal of a Lecture Scene Playback System using Digital Picture-Card Show

MOURI Aki, ISSHIKI Yosuke, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   107 ( 155 )   1 - 6   2007.7

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In this paper, we propose a lecture scene playback system using the "digital picture-card show" to support the reviewing process of lectures by students. Our proposed system produces digital picture-cards by combining digital still fine images with their corresponding voices of the lecturer, and delivers them through the World-Wide Web system. We have implemented the system, and have applied it to one class for freshmen at Communication Network Department in Okayama University. From results of the questionnaire from students after using our system, we show that our system is effective to improve motivations and understanding of students for this class.

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An Implementation of Embedded Linux for Remote I/O System

SHOJI Tomoya, KAWASHIMA Jun, FUNABIKI Nobuo, NAKANISHI Toru, IIJIMA Hideki, MAEDA Yasuyuki

IEICE technical report   107 ( 36 )   73 - 76   2007.5

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In recent years, Lin has been getting popularity as the operating system for embedded systems, due to its various software assets and robustness. Thus, we have studied the use of Linux in remote I/O systems for industries. In this paper, we present how to adopt Linux into a remote I/O system produced from M-system Ltd. and to implement device drivers so that Linux can control I/O boxes in a fixed cycle. The evaluation using our implementation shows the practicality of the remote I/O system with Linux.

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A Discussion of a Design Method of Hierarchical Chordal Ring Network for Multihop WDM Networks with Mesh Topology

KITANI Tomoya, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   107 ( 36 )   7 - 12   2007.5

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We have proposed a hierarchical logical topology called Hierarchical Chordal Ring Network (HCRN) on WDM multi-hop ring networks. HCRN achieves a smaller network diameter with a less number of wavelengths. In this paper, we propose a design method to configure HCRN on mesh networks. The problem of constructing a optical logical topology on WDM networks is an NP-hard combinatorial problem. Thus, we propose a heuristic algorithm to construct HCRN topology on mesh networks. We evaluate our algorithm by comparing the network performance indices with existing algorithms.

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An Implementation of an Anonymous IEEE802.1X Authentication with User Revocation

MIKI KOUHEI, NAKANISHI TORU, KAWASHIMA JUN, FUNABIKI NOBUO

IPSJ SIG Notes   2007 ( 16 )   129 - 134   2007.3

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

The IEEE802.1X authentication is used well as an authentication protocol in the Access Point for the Internet connection. There is a problem that mobile host's privacy information is leaked to the Internet service provider in this protocol. To solve this problem, we have proposed and implemented an anonymous authentication using the group signature. However, there is a problem that the user revocation is not considered. In this paper, an anonymous IEEE802.1X authentication with a user revocation is implemented by using a group signature with a user revocation function, and the authentication time is evaluated.

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A WDS Clustering Problem for Wireless Infrastructure Mesh Networks

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   106 ( 577 )   323 - 328   2007.3

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

We have studied the Wireless Infrastructure Mesh NETwork(WIMNET) as a large-scale multihop wireless network. WIMNET is composed of multiple access points (APs) that have wireless connections with each other through Wireless Distribution System (WDS). Because the number of APs in a single WDS is limited due to the broadcast packet problem, the AP clustering for multiple WDS connections is necessary to construct a large-scale WIMNET. In this paper, we formulate this WDS clustering problem of APs for WIMNET and prove the NP-completeness of its decision version. Then, we present its heuristic algorithm where we evaluate our approach through simulations.

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Verifier-local revocation group signature schemes with backward unlinkability from bilinear maps

Torn Nakanishi, Nobuo Funabiki

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E90A ( 1 )   65 - 74   2007.1

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Language：English   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

An approach of membership revocation in group signatures is verifier-local revocation (VLR for short). In this approach, only verifiers are involved in the revocation mechanism, while signers have no involvement. Thus, since signers have no load, this approach is suitable for mobile environments. Although Boneh and Shacham recently proposed a VLR group signature scheme from bilinear maps, this scheme does not satisfy the backward unlikability. The backward unlinkability means that even after a member is revoked, signatures produced by the member before the revocation remain anonymous. In this paper, we propose VLR group signature schemes with the backward unlinkability from bilinear maps.

DOI： 10.1093/ietfec/e90-a.1.65

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A WDS clustering algorithm for wireless mesh networks

Shigeto Tajima, Teruo Higashino, Nobuo Funabiki, Toru Nakanishi

2007 IFIP INTERNATIONAL CONFERENCE ON WIRELESS AND OPTICAL COMMUNICATIONS NETWORKS   323 - +   2007

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Language：English   Publisher：IEEE  

The wireless mesh network has been studied as an expandable wireless access network to the Internet. This paper focuses on the network composed of only access points (APs) that has multihop wireless connections with each other through Wireless Distribution System (WDS). Because the number of APs in a single WDS cluster is limited due to transmission loads of broadcasting control packets, the proper partition of APs for multiple WDS clusters is essential for its scale-up. In this paper, we formulate this WDS clustering problem, and prove the NP-completeness of its decision version through reduction from the bin packing problem. Then, we present its two-stage heuristic algorithm where we verify the effectiveness of our approach through extensive simulations.

DOI： 10.1109/WOCN.2007.4284191

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A Proposal of a Group Siganture Scheme with Membership Revocation Using Prime Numbers and Its Implementation

HAMADA Naoto, NAKAYAMA Takuya, NAKANISHI Toru, FUNABIKI Nobuo

IEICE technical report   106 ( 411 )   47 - 54   2006.12

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

Group signature schemes with membership revocation have been intensively researched. In this paper, we propose a new group signature scheme where the computational cost for signing/verification is lower than an existing scheme without the update of signers' private keys. In the proposed scheme, a group manager issues the membership certificate with a unique prime number to every member of the group. A revocation of a membership certificate is performed by using this prime number. To show the practicality of the proposed scheme, we implemented the scheme on a PC, and measured the execution time. In a group with 1000 members, the signature signing/verification needs about 1.3 seconds. Since this time is less than half of the time that needed in the existing scheme, the practicality of the proposed scheme is sufficiently shown.

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Research on Making of Electronic Whiteboard Secure

YASUKAWA Yukihiro, KOUMOTO Takuya, FUNABIKI Nobuo, SUGIYAMA Yuji

IEICE technical report   106 ( 263 )   7 - 12   2006.9

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

It is not easy to see the screen from the back seat at conference with commodious room. To solve this problem, an electronic whiteboard system using the IP multicast communication can be used, but an existing system has the problem concerning security. In this research, an existing whiteboard system is made secure and extended to a practicable whiteboard. The whiteboard system is introduced into an actual conference, and effectiveness is shown by the questionnaire from users.

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8-107 Development and Management of an WEB-based Educational Activity Support System "NOBASU" : For unification of education and research activities in university

FUNABIKI Nobuo, NAGAO Noriaki, NAGATA Yoshinori, BABA Shota

18   152 - 153   2006.7

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Language：Japanese   Publisher：Japanese Society for Engineering Education  

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A design method for a multiplexed hierarchical logical topology to balance communication loads for multi-hop WDM networks and its routing algorithm

KITANI Tomoya, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   106 ( 117 )   13 - 16   2006.6

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In this paper, we propose a hierarchical topology and its routing algorithm to achieve traffic balancing. In a hierarchical topology, traffic concentrates on the link of high-level layers. Thus, we make the node group in the lowest level layer as a cluster, and set the links hierarchically between nodes as well as a high-level layer. By using these links, traffic is relaid to a far away node via the nodes in the low-level layer. We also propose the routing algorithm of this topology.

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An Improvement of License Plate Recognition Algorithm Considering Image Brightness and Character Arrangements

SHINOHARA Yosuke, KAWASHIMA Jun, FUNABIKI Nobuo

IEICE technical report   105 ( 534 )   7 - 12   2006.1

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The automatic recognition of characters and numbers on license plates for vehicles is very important for various applications such as vehicle managements in parking lots, automatic fare collections in toll roads, traffic flow measurements and congestion surveillance on roads, and identifications of illegal parking vehicles on streets. In this paper, we propose an improvement of the license number plate recognition algorithm by improving the binarization process and the character recognition area process that are the keys determining the recognition accuracy. In the former process, the histogram of pixel brightness obtained from the input image is classified into three patterns according to the shape, and the different thresholds are used in each pattern. In the latter process, extractions of noisy character regions are enabled by extrapolating them from successfully extracted regions using their relative positions. The effectiveness of our proposal is verified by applications to sample license images.

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無線メッシュネットワークにおけるゲートウェイ用アクセスポイント選択問題

田島

第3回アドホックネットワーク ワークショップ, Jan. 2006   2006

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最大重みクリーク問題に対する局所探索法

片山謙吾, 濱本明宏, 貞松政史, 成久洋之, 南原英生, 舩曵信生

電子情報通信学会論文誌A   2006

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メモリカードのためのセキュアファイルシステムSASの提案と実装

川島潤, 舩曵信生, 中西透, 竹内 順一, 石崎 雅幸, Andre Caldas de Souza

情報処理学会論文誌   2006

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プライバシを保護した授業評価アンケートの実装

谷川浩司, 中西透, 舩曵信生

電子情報通信学会技術研究報告   2006

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VNCプロクシのネットワーク負荷分散性能の評価

松本康平, 籠谷裕人, 甲本卓也, 舩曵信生

電子情報通信学会技術研究報告   2006

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A proposal of anonymous IEEE802.IX authentication protocol for wireless networks

Nobuo Funabiki, Toru Nakanishi, Hideo Takahashi, Kouhei Miki, Jun Kawashima

2006 SECOND WORKSHOP ON SECURE NETWORK PROTOCOLS (NPSEC)   26 - +   2006

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Language：English   Publisher：IEEE  

Recently, wireless network services are available at a variety of public spaces such as stations, airports, and hotels. In such services, the IEEE802.1X-based authentication protocol has been often used to permit only registered users in network connections. However, this protocol allows Internet service providers (ISPs) to collect the privacy information of users such as their access locations and network service use records. Besides, ISPs have to keep in secret the personal information of their users for authentication, although they only need the legitimacy of them. To solve these problems. this paper presents an anonymous authentication protocol based on IEEE802.1X. The group signature scheme is adopted to anonymously verify the legitimacy of users, whereas misbehaving users can be traced in case. We implement the proposed protocol by modifying open source soft-wares for IEEE802.1X and verify the effectiveness in terms of the processing time and the packet size.

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デジタル紙芝居システムのための配信経路生成アルゴリズムの提案

毛利亜紀, 篠原陽介, 舩曵信生, 中西透

電子情報通信学会技術研究報告   2006

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An optimal access-point allocation for wireless infrastrcuture mesh netwroks

Nobuo Funabiki, Toru Nakanishi, Yohei Nomura, Tamer Farag, Shigeto Tajima, Teruo Higashino

Proc. of 16th International Conference on Computer Theory and Applications   2006

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無線メッシュネットワークのアクセスポイント間通信での優先度制御に関する一検討

野村洋平, 新田友里子, 田島滋人, 舩曵信生, 中西透

電子情報通信学会技術研究報告   2006

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無線メッシュネットワークでの帯域測定実験とその考察

加藤秀明, 野村洋平, 舩曵信生, 中西透

電子情報通信学会技術研究報告   2006

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無線メッシュネットワークにおけるアクセスポイントのチャネル割当アルゴリズムの提案と配置アルゴリズムの評価

野村洋平, 舩曵信生, 中西透

第3回アドホックネットワークワークショップ   2006

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An internet gateway access-point selection problem for wireless infrastructure mesh networks

Shigeto Tajima, Teruo Higashino, Nobuo Funabiki, Shoji Yoshida

Proceedings - IEEE International Conference on Mobile Data Management   2006   2006

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This paper presents a study of the gateway access-point selection problem for the wireless infrastructure mesh network (WIMNET). WIMNET is a wireless mesh network composed of multiple access-points (APs) that communicate mutually using radio transmissions, and all the traffics to/from the Internet go through the limited number of gateway APs. Thus, the selection of these gateway APs often determines the whole performance of WIMNET, because heavy congestions at gateway APs and their peripheries can drastically increase the delay and the link failure due to radio interferences. In this paper, we define a cost function to minimize the total traffic in WIMNET in order to reduce congestions and present a simple algorithm. Through simulations using the newly developed WIMNET simulator, we show the effectiveness of our approach. © 2006 IEEE.

DOI： 10.1109/MDM.2006.36

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WDMリングネットワークのノード構成問題の一般化

磯貝愛, 舩曵信生, 中西透

電子情報通信学会技術研究報告   2006

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A LECCS model parameter optimization algorithm for EMC designs of IC/LSI systems

Nobuo Funabiki, Yohei Nomura, Jun Kawashima, Yuichiro Minamisawa, Osami Wada

2006 17TH INTERNATIONAL ZURICH SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, VOLS 1 AND 2   304 - +   2006

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In this paper, we propose a parameter optimization algorithm for EMC macro-modeling of IC/LSI power currents called the LECCS (Linear Equivalent Circuit and Current Source) model. The unnecessary electro-magnetic wave from a digital electronics device may cause the electromagnetic interference (EMI) to other apparatus. Thus, its reduction has been regarded as one of the highest priority issues in digital electronics device designs. In order to accurately simulate high-frequency currents from power-supply sources that are the primary sources of EMI, the LECCS model has been proposed as a linear macro-model of a power-supply circuit. A LECCS model consists of multiple RLC-series circuits in parallel to represent the equivalent circuit between the voltage source and the ground. Given a set of measured impedances at various frequencies, our proposed algorithm first finds the number of RLC-series circuits corresponding to the number of valleys. Then, it searches optimal values of RLC parameters by a local search method. The effectiveness of our algorithm is verified through applications to a real system, where the accuracy and the required processing time by our algorithm are compared with the conventional method.

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WEBによる教育支援システム"NOBASU"での課題プログラム評価

馬場章太, 長尾憲暁, 中西透, 舩曵信生

情報処理学会研究報告   2006

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VNCにおける負荷分散と操作権限制御を目的としたプロクシの提案

松本康平, 籠谷裕人, 甲本卓也, 舩曵信生

電子情報通信学会技術研究報告   2006

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複数ネットワークインターフェースを有するエンドホストでのサービス指向型ルーティングの実装

東根俊, 川島潤, 舩曵信生, 中西透

電子情報通信学会技術研究報告   2006

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無線メッシュネットワークのためのWIMENTシミュレータの開発

吉田翔志, 舩曵信生, 中西透

第3回アドホックネットワークワークショップ   2006

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PeerCastをベースとしたマルチメディア配信システムPeerStreamの構築とその評価

斎藤正隆, 磯貝愛, 甲本卓也, 舩曵信生

電子情報通信学会技術研究報告   2006

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アプリケーションレベルマルチキャスト通信におけるマルチホーム化ホスト選択アルゴリズムの改良

加藤秀明, 川島潤, 舩曵信生, 中西透

電子情報通信学会技術研究報告   2006

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An optical-drop wavelength assignment algorithm for efficient wavelength reuse under heterogeneous traffic in WDM ring networks

N Funabiki, J Kawashima, T Nakanishi, K Okayama, T Higashino

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E88A ( 5 )   1234 - 1240   2005.5

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Language：English   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

The wavelength-division multiplexing (WDM) technology has been popular in communication societies for providing very large communication bands by multiple lightpaths with different wavelengths on a single optical fiber. Particularly, a double-ring optical network architecture based on the packet-over-WDM technology such as the HORNET architecture, has been extensively studied as a next generation platform for metropolitan area networks (MANs). Each node in this architecture is equipped with a wavelength-fixed optical-drop and a fast tunable transmitter so that a lightpath can be established between any pair of nodes without wavelength conversions. In this paper, we formulate the optical-drop wavelength assignment problem (ODWAP) for efficient wavelength reuse under heterogeneous traffic in this network, and prove the NP-completeness of its decision problem. Then, we propose a simple heuristic algorithm for the basic case of ODWAP. Through extensive simulations, we demonstrate the effectiveness of our approach in reducing waiting times for packet transmissions when a small number of wavelengths are available to retain the network cost for MANs.

DOI： 10.1093/ietfec/e88-a.5.1234

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A Link Activation Scheduling Algorithm Considering Transmission Success Rates in Packet Radio Networks

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

2005 ( 2 )   81 - 86   2005.1

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

In packet radio networks such as wireless local areas networks and ad-hoc mobile networks, periodic activations of the communication links between adjacent hosts by following the conflict-free link activation schedule is effective to realize the multi media streaming of motion pictures and voices. For better schedules, success rates of link activations should be considered, because packets may be lost before reaching receiving hosts when transmission path conditions are not good, even though these communication hosts are located within the range of radio transmissions. In this paper, we present a link scheduling algorithm for periodic link activations in packet radio networks when the transmission success rate is given for every link. In this algorithm, the number of activation times in one cycle is calculated for each link beforehand that satisfies the minimum success rate, and the schedule of activating the link by this number without conflict is found. Through simulations in randomly generated instances, we show that the schedule by our algorithm can reduce the total transmission time required to complete packet transmissions.

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Other Link： http://id.nii.ac.jp/1001/00047069/

A proposal of an access-point allocation algorithm for WDS in wireless LAN

KUMANO Eiji, MITANI Chie, FUNABIKI Nobuo, NAKANISHI Toru

2005 ( 2 )   45 - 50   2005.1

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Language：Japanese   Publisher：Information Processing Society of Japan (IPSJ)  

The wireless distribution system (WDS) provides wireless connections between multiple access points (APs) to compose a large-scale wireless local area network (WLAN). In this paper, we formulate the AP allocation problem for WDS, and present its two-stage heuristic algorithm. In this problem, a feasible allocation of APs is requested, such that the total number of APs is not only minimized, but also the load of each AP is equalized. The proposed algorithm consists of the first stage of allocating APs in a regular interval and the second stage of improving their allocations by random perturbations. The effectiveness of our algorithm is confirmed through simulations in two host movement models, namely random waypoint model (RWM) and seating space model (SSM). This newly presented SSM assumes a seating space of shops, restaurants, and event fields, so that it can simulate more realistic situations.

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Other Link： http://id.nii.ac.jp/1001/00047063/

A License Plate Recognition Algorithm Using Cross Count and Template Matching Methods

SHINOHARA Yosuke, FUNABIKI Nobuo, KAWASHIMA Jun, TAKEUCHI Junichi, ISHIZAKI Masayuki

Technical report of IEICE. PRMU   104 ( 573 )   39 - 44   2005.1

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The automatic recognition of characters and numbers on license plates for vehicles is very important for various applications such as vehicle managements in parking lots, automatic fare collections in toll roads, traffic flow measurements and congestion surveillance on roads, and identifications of illegal parking vehicles on streets. In this paper, we propose a license number plate recognition algorithm from digital color images, using the cross count method for character recognitions and the template matching method for number recognitions. Since input images for this algorithm are usually taken in fields manually, and have deformations and effects by shadows, we adopt an adaptive threshold adjustment mechanism for binarization of images in order to deal with undesirable situations. Besides, we introduce an automatic generation method of representative vectors for the cross count method, so that it can handle the increase of complex Chinese characters on license plates. We show that the proposed algorithm provides the 100% success rate for noiseless images taken from an WEB site and the 80% success rate for noisy images taken by a PDA camera.

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An Improvement of a Tooth Contour Extraction Method and a Tooth Contour Database Design Based on WEB Applications

SU Tie, FUNABIKI Nobuo, KISHIMOTO Etuo

Technical report of IEICE. PRMU   104 ( 573 )   31 - 36   2005.1

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In recent years, various image-processing technologies have been applied in the field of dentistry, in which, a tooth contour extraction method is strongly expected for the dental treatment and tooth shape classification. At the same time, designing a database based on the extraction result is helpful for the tooth statistical analysis aimed at the clinical treatment. In this paper, a tooth contour extraction method based on deformable template matching is introduced, and its improvement in the automatic threshold adjusting algorithm for cutting gum region around the tooth is proposed. The simulation results using sample images show that the tooth region is separated from the input image by the detected threshold automatically. Then, a tooth contour database design based on WEB applications is proposed to support dental diagnoses. Using the definitions of tooth shape features, the database will be useful in analyzing the difference of tooth shapes according to age, sex, and regions.

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A proposal of an access-point allocation algorithm for WDS in wireless LAN

KUMANO Eiji, MITANI Chie, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report   104 ( 553 )   45 - 50   2005.1

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

The wireless distribution system (WDS) provides wireless connections between multiple access points (APs) to compose a large-scale wireless local area network (WLAN). In this paper, we formulate the AP allocation problem for WDS, and present its two-stage heuristic algorithm. In this problem, a feasible allocation of APs is requested, such that the total number of APs is not only minimized, but also the load of each AP is equalized. The proposed algorithm consists of the first stage of allocating APs in a regular interval and the second stage of improving their allocations by random perturbations. The effectiveness of our algorithm is confirmed through simulations in two host movement models, namely random waypoint model (RWM) and seating space model (SSM). This newly presented SSM assumes a seating space of shops, restaurants, and event fields, so that it can simulate more realistic situations.

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A Link Activation Scheduling Algorithm Considering Transmission Success Rates in Packet Radio Networks

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report   104 ( 553 )   81 - 86   2005.1

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In packet radio networks such as wireless local areas networks and ad-hoc mobile networks, periodic activations of the communication links between adjacent hosts by following the conflict-free link activation schedule is effective to realize the multi media streaming of motion pictures and voices. For better schedules, success rates of link activations should be considered, because packets may be lost before reaching receiving hosts when transmission path conditions are not good, even though these communication hosts are located within the range of radio transmissions. In this paper, we present a link scheduling algorithm for periodic link activations in packet radio networks when the transmission success rate is given for every link. In this algorithm, the number of activation times in one cycle is calculated for each link beforehand that satisfies the minimum success rate, and the schedule of activating the link by this number without conflict is found. Through simulations in randomly generated instances, we show that the schedule by our algorithm can reduce the total transmission time required to complete packet transmissions.

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A Proposal of a WWW-Based Support System for Class Arrangements to English Teachers (ECASOU)

TAKAHASHI Noriyuki, FUNABIKI Nobuo, YANO Masaaki

The IEICE transactions on information systems Pt. 1   88 ( 1 )   89 - 98   2005.1

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マルチホップ WDM ネットワークにおけるトラヒック分散のための静的トポロジ構成法の改善

木谷友哉, 舩曵信生, 東野輝夫

電子情報通信学会技術研究報告, NS2005-76   2005

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Group signature schemes with membership revocation for large groups

T Nakanishi, F Kubooka, N Hamada, N Funabiki

INFORMATION SECURITY AND PRIVACY, PROCEEDINGS   3574   443 - 454   2005

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Language：English   Publisher：SPRINGER-VERLAG BERLIN  

Group signature schemes with membership revocation have been intensively researched. However, signing and/or verification of some existing schemes have computational costs of O(R), where R is the number of revoked members. Existing schemes using a dynamic accumulator or a similar technique have efficient signing and verifications with 0(l) complexity. However, before signing, the signer has to modify his secret key with O(N) or O(R) complexity, where N is the group size. Therefore, for larger groups, signers suffer from enormous costs. On the other hand, an efficient scheme for middle-scale groups with about 1,000 members is previously proposed, where the signer need not modify his secret key. However this scheme also suffers from heavy signing/verification costs for larger groups. In this paper, we adapt the middle-scale scheme to the larger groups. At the sacrifice of the group manager's cost, our signing/verification has only O(1) complexity.

DOI： 10.1093/ietfec/e89-a.5.1275

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仮想OSを用いたセキュアなプログラミング課題検証支援システム

長尾憲暁, 舩曵信生, 中西透

電子情報通信学会技術研究報告, ET2005-45   2005

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階層型コーダルリングネットワークにおけるコンパクトルーティングアルゴリズム

木谷友哉, 舩曵信生, 東野輝夫

電子情報通信学会技術研究報告, NS2005-145   2005

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A proposal of a node configuration algorithm for WDM ring networks

Megumi Isogai, Nobuo Funabiki, Toru Nakanishi, Teruo Higashino

Proc. of International Conference on Optical Communications and Networks (ICOCN-2005)   2005

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Compact tree plus algorithms for application-level multicast communications in multihome networks

N Funabiki, M Isogai, T Nakanishi, T Higashino

2005 13TH IEEE INTERNATIONAL CONFERENCE ON NETWORKS JOINTLY HELD WITH THE 2005 7TH IEEE MALAYSIA INTERNATIONAL CONFERENCE ON COMMUNICATIONS, PROCEEDINGS 1 AND 2   139 - 144   2005

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Language：English   Publisher：IEEE COMPUTER SOC  

Application-level multicast (ALM) communications replicate packets on host level to deliver them from a single source to multiple clients, so that it can efficiently realize a variety or network applications using moving pictures such as video conferences, distance learning, and video-on-demands. In this paper, we propose the CT+ (Compact Tree Plus) algorithm for finding a better ALM routing tree in terms of delay minimization between hosts. CT+ consists of a tree construction stage from the existing CT algorithm, and a newly added iterative tree improvement stage. Then, we define the extended ALM routing problem and its heuristic algorithm ExCT+, to optimize the effectiveness of the multihome network in ALM communications by selecting multihomed hosts and connections in the ALM routing tree simultaneously. For their evaluations, we construct a network simulation model named MINET (Multiple-ISP NETwork simulator), where the topology is composed of multiple ISP backbone networks with IX connections, and the network traffic is generated by following the M/M/1 queuing process. The simulation results using MINET verify the effectiveness of our algorithms.

DOI： 10.1109/ICON.2005.1635456

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アプリケーションレベルマルチキャスト経路木アルゴリズムCT+法の提案とマルチホーム環境の効果

磯貝愛, 舩曵信生, 中西透

電子情報通信学会論文誌D-Ⅰ   2005

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Optical-drop wavelength assignment problem for wavelength reuse in WDM ring metropolitan area networks

N Funabiki, M Isogai, T Nakanishi, T Higashino

19TH INTERNATIONAL CONFERENCE ON ADVANCED INFORMATION NETWORKING AND APPLICATIONS, VOL 1, PROCEEDINGS   999 - 1004   2005

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Language：English   Publisher：IEEE COMPUTER SOC  

This paper presents a formulation of the optical-drop wavelength assignment problem (ODWAP) and its heuristic algorithm for WDM ring networks. The wavelength-division multiplexing (WDM) technology has been popular in communication societies for providing very large communication bands by multiple lightpaths with difterent wavelengths on a single optical fiber Particularly, a double-ring optical network architecture based on the packet-over-WDM technology such as the HORNET architecture, has been studied as a next generation platform for metropolitan area networks (MANs). Each node in this architecture is equipped with a wavelength-fixed optical-drop and a tunable transmitter so that a lightpath can be established between any pair, of nodes without wavelength conversions. In this paper we formulate ODWAP for efficient wavelength reuse under heterogeneous traffic in this network. Then, we propose a simple heuristic algorithm for ODWAP. Through extensive simulations, we demonstrate the effectiveness of our approach in reducing waiting times for packet transmissions when a small number of wavelengths are available to retain the network cost for MANs.

DOI： 10.1109/AINA.2005.267

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モバイルホストのユーザ情報を秘匿するアドレス配信プロトコルの提案

高橋秀郎, 川島潤, 中西透, 舩曵信生

情報処理学会研究報告, 2005-CSEC-28   2005

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メモリカードのためのセキュアファイルシステムSASの提案

川島潤, 舩曵信生, 中西透, 竹内順一, 石崎雅幸, Andre Caldasde Souza

電子情報通信学会技術研究報告, OIS2005-05   2005

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アプリケーションレベルマルチキャスト通信における伝送遅延モデルの一考察

永田佳範, 川島潤, 舩曵信生, 中西透

電子情報通信学会技術研究報告, NS2005-61   2005

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アプリケーションレベルマルチキャストにおけるマルチホーム化ホスト選択アルゴリズムの提案

加藤秀明, 川島潤, 舩曵信生, 中西透

電子情報通信学会技術研究報告, NS2005-62   2005

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WDMネットワークにおける階層型コーダルリングトポロジ構成法

木谷友哉, 舩曵信生, 東野輝夫

情報処理学会論文誌   2005

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WDMリングネットワークのノード構成問題

磯貝愛, 舩曵信生, 中西透

電子情報通信学会技術研究報告, NS2005-91   2005

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アプリケーションレベルマルチキャストにおける遠隔講義のための複数経路木生成法の提案

東根俊, 川島潤, 舩曵信生, 中西透

電子情報通信学会技術研究報告, NS2005-63   2005

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無線LANのアクセスポイント配置アルゴリズムの改良

野村洋平, 舩曵信生, 中西透

電子情報通信学会技術研究報告, NS2005-73   2005

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無線LANのWDSにおけるAP間通信へのリンクスケジューリングアルゴリズムの適用

田島滋人, 舩曵信生, 東野輝夫

電子情報通信学会技術研究報告, NS2005-74   2005

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A proposal of a panoramic image synthesizing algorithm using an optimization method

ISOGAI Megumi, FUNABIKI Nobuo, KOUMOTO Takuya, SUGIYAMA Yuji, OZAKI Ryo, OKAMOTO Takuji

104 ( 512 )   17 - 24   2004.12

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Recently, a panoramic image has been expected in applications to various monitoring systems and virtual space presentation systems due to the advantage of expressing a wide range of scenes by one image. In this paper, we propose a panoramic image synthesizing algorithm for a panoramic image generating system to monitor indoor scenes, which is composed of,one personal computer and three inexpensive cameras set in row. This system has been studied in our group with the view of applications to home/store monitoring and safety confirmation of seniors living alone. The proposed algorithm consists of the approximate calibration stage and the detailed calibration stage, to fit images from side cameras to the image of the central camera as best as possible. The first stage transforms the coordinates of the side image to resolve the difference caused by view directions and locations of cameras, where the parameters are calculated using the limited number of feature points in overlapped regions of two images. The second stage applies both the coordinate transformation and the color correction with the parameters calculated using every pixel in overlapped regions. In both stages, parameters are searched by a local search method that is a typical optimization method. Through experiments with a variety of still images taken in our office, we show the effectiveness of our proposed algorithm.

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A proposal of a parameter optimization algorithm for LECCS : EMC macro-modeling of IC/LSI power current

NOMURA Yohei, KAWASHIMA Jun, FUNABIKI Nobuo, TOYOTA Tomohiro, MINAMISAWA Yuichirou, WADA Osami

IEICE technical report. Electromagnetic compatibility   104 ( 499 )   71 - 76   2004.12

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In this paper, we propose a parameter optimization algorithm for the EMC macro-modeling of IC/LSI power currents called the LECCS (Linear Equivalent Circuit and Current Source) model. The unnecessary electro-magnetic wave from a digital electric device causes an electromagnetic interference to other apparatus, and thus, its reduction has been emphasized as one of the highest priority issues in digital electric device design societies. In order to simulate accurately high frequency current from the power-supply system in IC/LSIs that is its primary resource, the LECCS model has been proposed as a linear macro-model of a device power-supply circuit. In the LECCS model, the circuit between the power supply and the ground in a circuit is described as a combination of RLC-series circuits in parallel. Given a set of measured impedances at various frequencies, our algorithm first finds the number of .RLC-series circuits from the number of valleys, and then, it searches optimal values of RLC parameters by the local search method. The validity of our algorithm is verified through applications to the results of a real device where the accuracy and the required processing time in our result are compared with those by the manual model tuning.

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A Group Signature Scheme with Membership Revocation for Large Groups

KUBOOKA Fumiaki, NAKANISHI Toru, FUNABIKI Nobuo

IEICE technical report. Office Information Systems   104 ( 423 )   27 - 34   2004.11

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Some group signature schemes with membership revocation were proposed. In a scheme using an accumulator, the computation cost is O (1) but the communication cost is O (Kln), where K is the group size, and in is the size of the RSA modulus. On the other hand, a scheme is more efficient for only groups with the size ln and the communication cost is only O (K) though the computation cost is O (K/ln). Thus, these schemes are not efficient for large groups. In this paper, by combining these schemes, we propose an efficient group signature scheme with membership revocation for large groups. In the proposed scheme, the computation cost is O (1) and the communication cost is O (K).

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A study of a WEB-based educational service support system for lectures and exercises in universities

TAKAHASHI Noriyuki, FUNABIKI Nobuo, NAKANISHI Toru

IEICE technical report. Education technology   104 ( 342 )   45 - 50   2004.10

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This paper presents a Web-based education supporting system for lectures and exercises in universities, named NOBASU (NetwOrk-Based Assistant System for University education). The use of WWW (World-Wide Web) technology has been effective in improving the quality of educational services in universities while alleviating the increase of burdens by teachers. Actually, several education supporting systems using WWW technology have been developed recently, which have been introduced by more and more universities. We have developed an original education supporting system that is suitable for lectures and exercises in our department. We are now implementing this NOBASU system using JSP/Servlet mainly, and soon we will apply it to lectures in our department.

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A minimum dead space algorithm for generalized isochronous channel reuse problems in DQDB networks

N Funabiki, J Kawashima, K Okayama, T Nakanishi, T Higashino

IEICE TRANSACTIONS ON COMMUNICATIONS   E87B ( 9 )   2692 - 2698   2004.9

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With the explosive growth of the Internet system, demands for broadband communication networks have rapidly increased to provide high quality network services. For this purpose, the IEEE 802.6 MAC standard protocol defines the distributed-queue dual bus (DQDB) for metropolitan area networks (MANs). The isochronous channel reuse problem (ICRP) has been studied for efficient use of DQDB by finding proper channel assignments to incoming connection requests. In this paper, we first define the generalized isochronous channel reuse problem (GICRP) as a generalization of ICRP, to afford demands of simultaneously satisfying plural connection requests such as for multicast applications, where certain sets of connection requests must be assigned channels simultaneously. We prove the NP-completeness of its decision problem. Then, we propose a minimum dead space (MDS) algorithm as a heuristic approach to GICRP. The extensive simulation results show that with shorter computation time, our MDS algorithm can always find better channel assignments reducing the waiting time for packet transmissions than the best existing algorithm for conventional ICRP.

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An Electronic Weighted Voting Protocol with Tallying Cost Reduced

NAKATAKE Shinji, NAKANISHI Toru, FUNABIKI Nobuo, SUGIYAMA Yuji

IPSJ SIG Notes   2004 ( 75 )   329 - 334   2004.7

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A weighted voting is a system such that a voter submits a vote with a weight, e.g・, voting in stockholders' meetings. A weighted voting protocol that can keep weights secret has been proposed. However, this protocol has a problem that a tallying cost is large when there are many voters, since a management server must re-encrypt and permute all votes. In this paper, we propose a weighted voting protocol with tallying cost reduced.

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Other Link： http://id.nii.ac.jp/1001/00044919/

An Electronic Weighted Voting Protocol with Tallying Cost Reduced

NAKATAKE Shinji, NAKANISHI Toru, FUNABIKI Nobuo, SUGIYAMA Yuji

Technical report of IEICE. ISEC   104 ( 200 )   135 - 140   2004.7

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A weighted voting is a system such that a voter submits a vote with a weight, e.g., voting in stockholders' meetings. A weighted voting protocol that can keep weights secret has been proposed. However, this protocol has a problem that a tallying cost is large when there are many voters, since a management server must re-encrypt and permute all votes. In this paper, we propose a weighted voting protocol with tallying cost reduced.

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Route securement by introduction of relay antennas for adhoc networks

MITANI Chie, KUMANO Eiji, FUNABIKI Nobuo, NAKANISHI Toru

Technical report of IEICE. RCS   104 ( 185 )   59 - 62   2004.7

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An adhoc network is a network composed of mobile hosts, where hosts communicate with each other by the capability of wireless connections without using base stations or wireless hubs. When hosts are located in the neighborhod, they communicate with each other directly. When they are located distantly, their intermediate hosts relay the packets. The adhoc network, however, does not function as a network when such intermediate hosts do not exist to relay packets. In this paper, we propose the introduction of relay antennas to secure a route between any pair of hosts located at any place. Besides, we proposed a routing algorithm of selecting a commuication route that consists of desirable hosts with less future movility and smaller transmission loads. We evelaute the effect of these proposals through simulations using the random waypoint model.

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P2PMM router: A two-stage heuristic algorithm to peer-to-peer multicast routing problems in multihome networks

N Funabiki, J Kawashima, S Yoshida, K Okayama, T Nakanishi, T Higashino

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E87A ( 5 )   1070 - 1076   2004.5

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A variety of real-time multicast applications such as video conferences. remote lectures, and video-on-demand have become in commonplace with the expansion of broadband Internet services. Due to nontrivial problems in the IP multicast technology, the peer-to-peer multicast technology (P2P-multicast) has emerged as a practical implementation, although its network resource utilization is less efficient. A multihome network has the potential of alleviating this inefficiency by providing flexibility in communication path selections for each host with multiple gateways to the Internet. This paper has first formulated the P2P-multicast routing problem in the multihome network, and has proved the NP-completeness of its decision problem. Then, a two-stage heuristic algorithm called P2PMM_router has been presented for this P2P Multicast Multihome-network routing problem. The first stage constructs an initial multicast routing tree from an optimum spanning tree by Prim algorithm. through satisfying the constraints. The second stage improves the tree by repeating partial modifications and constraint satisfactions. The extensive simulation results using random network instances support the effectiveness of our P2PMM_router.

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A WEB-based supporting system for class assignments to English teachers

TAKAHASHI Noriyuki, FUNABIKI Nobuo, YANO Masaaki

IEICE technical report. Education technology   103 ( 697 )   23 - 27   2004.2

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This paper presents a WEB-based supporting system for class assignments to English teachers in Okayama University. Currently, this assignment of class times and subjects to English teachers has been handled manually, after the preference data for them are provided on paper from teachers, which takes costs and long time. In our proposed system, the requests can be input by English teachers through their browsers, and the assignment is automatically computed on a server computer. For this purpose, we develop a heuristic algorithm for this class assignment problem after defining the formulation as a combinatorial optimization problem. By using real preference data by teachers, we compare assignment results between our method and the conventional one. The result shows the superiority of our method in terms of the assignment quality and the required process time.

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A perfect k-ary peer-to-peer multicast routing tree search algorithm for multihome networks

KAWASHIMA Jun, FUNABIKI Nobuo, OKAYAMA Kiyohiko

Technical report of IEICE. OCS   103 ( 627 )   5 - 8   2004.1

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In this paper, we present a two-stage heuristic algorithm for the peer-to-peer multicast routing problem in a multihome network. This problem requires finding a multicast routing tree satisfying the delay constraint between any two hosts and the degree constraint of any host while minimizing the total cost of the tree. In our algorithm, the routing tree topology is fixed to the perfect k-ary tree so as to always satisfy the degree constraint while minimizing the maximum hop count between hosts. The first stage of the algorithm greedily constructs an initial tree of minimizing the cost, and the second stage iteratively searches a feasible tree based on the annealing method. Through simulations using random network instances, we compare the performance of our algorithm to that of a similar existing algorithm.

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A Proposal of a Tooth Contour Extraction Method Using Deformable Template Matching

NYUNOYA Yoshinori, FUNABIKI Nobuo, KISIMOTO Etuo

Technical report of IEICE. PRMU   103 ( 585 )   43 - 48   2004.1

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Our group has studied contour extraction methods for various face components such as lips and eyes from digital face images using the deformable template matching method. In our method, each template expressing a contour is composed of fixed number of simple mathematical functions including quadratic functions. This simple template enables us to compare component contours of various persons and to analyze statistical features of them through processing the limited number of parameters. In this paper, we propose a tooth contour extraction method using the deformable template matching, where the template is composed of four elliptic curves. Our method optimizes the parameters of the template by a local search method so that it is best fit to the edge image of a tooth, after automatically identifying the tooth region from a given teeth image. We describe the details of the proposed algorithm and show simulation results for several sample images.

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A proposal of hierarchical chordal ring network topology for WDM networks

T Kitani, N Funabiki, T Higashino

2004 12TH IEEE INTERNATIONAL CONFERENCE ON NETWORKS, VOLS 1 AND 2 , PROCEEDINGS   605 - 609   2004

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This paper presents a hierarchical chordal ring network topology (HCRN) as a regular logical topology for multihop WDM networks. In order to minimize the traffic increase and the transmission delay through the network due to packet relays or hops on intermediate nodes in the multihop network, the network topology is hierarchically constructed in HCRN, so that more lightpaths are assigned to connections between nearby nodes than those for distant nodes, while the maximum hop between any pair of nodes is restrained. This hierarchical topology is also beneficial to reduce the number of required wavelengths through increasing their reuses by multiple lightpaths, which is important for cost-conscious metropolitan area networks. Through comparisons on the network diameter and the number of required wavelengths with the original chordal ring network topology, we show the effectiveness of our proposed HCRN.

DOI： 10.1109/ICON.2004.1409241

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A minimum dead space algorithm for wavelength reuse problems in WDM ring networks

Nobuo Funabiki, Toru Nakanishi, Yoshitaka Toyota, Jun Kawashima, Teruo Higashino

Proc. of International Conference on Optical Communications and Networks (ICOCN-2004)   2004

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無線ネットワークのリンクスケジューリング問題に対するヒューリスティック解法の提案

田島滋人, 舩曵信生, 東野輝夫

情報処理学会論文誌, vol. 45, no. 2   2004

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A Proposal of Improved Lip Contour Extraction Method Using Deformable Template Matching and Its Application to Dental Treatment

YOKOGAWA Yujin, FUNABIKI Nobuo, HIGASHINO Teruo, ODA Masashi, MORI Yoshihide

IEICE transactions on information and systems   86 ( 8 )   1474 - 1474   2003.8

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Deformable Templateマッチング法による唇輪郭抽出法の改良と歯科医療応用を目的とした評価

横川勇仁, 小田政志, 舩曵信生, 東野輝夫, 森悦秀

電子情報通信学会論文誌D-Ⅱ，vol. J86-D-Ⅱ, no.8   2003

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A proposal of a two-stage heuristic algorithm for peer-to-peer multicast routing problems in multihome networks

Nobuo Funabiki, Jun Kawashima, Akihito Kubo, Kiyohiko Okayama, Teruo Higashino

Proc. of The Fifth Metaheuristics International Conference (MIC-2003)   2003

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A two-stage hierarchical algorithm for wavelength assignment in WDM-based bidirectional Manhattan Street Networks

T Kitani, M Yonedu, N Funabiki, T Nakanishi, K Okayama, T Higashino

ICON 2003: 11TH IEEE INTERNATIONAL CONFERENCE ON NETWORKS   419 - 424   2003

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Wavelength Division Multiplexing (WDM) technology provides a wideband communication networks by realizing multiple communication channels with different wavelengths on a single optical fiber. In this technology, each node (wavelength router) has a finite number of transmitters/receivers dealing with different wavelengths, where each wavelength is exclusively used for the communication channel between a specific pair of nodes. Thus, some transmission request may require multiple wavelengths going through several nodes before reaching its destination. As a result, the wavelength assignment to nodes is very important for efficient transmission in WDM-based networks. Among regular wavelength assignment topologies, Bidirectional Manhattan Street Network (BMSN) gives high performance to WDM-based networks. In this paper, we present a two-stage heuristic algorithm for the wavelength assignment in BMSN, called a HIWAS (HIerarchical Wavelength ASsignment algorithm for BMSN). The first stage of HIWAS finds an initial wavelength assignment hierarchically, not only to avoid a local minimum as best as possible but also to reduce the time complexity. The second stage improves the wavelength assignment by adopting the simulated annealing. The performance of HIWAS is verified through solving two types of random instances, where HIWAS provides a better solution with a shorter time than the best-known existing algorithm.

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Deformable-Templateマッチング法による眼の輪郭線抽出に関する研究

小田政志, 舩曵信生, 東野輝夫

電子情報通信学会技術研究報告, PRMU2003-140   2003

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A proposal of a minimal-state processing search algorithm for link scheduling problems in packet radio networks

S Tajima, N Funabiki, A Sugano, T Higashino

2003 SYMPOSIUM ON APPLICATIONS AND THE INTERNET, PROCEEDINGS   128 - 135   2003

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In a large scale communication network, packets are transmitted from source nodes to destinations by going through several nodes on routes connecting them, because each node usually does not have a direct link to every node in the network. To maximize the usability in the network, the problems of selecting a transmission route for each connection request and of scheduling the link activations such that the total transmission time is minimized. This paper presents a four-stage approximation algorithm for the link scheduling problem (LSP) in a packet radio network, called MIPS-LSP, a MInimal-state Processing Search algorithm for LSR It is assumed that every link activation in the network is synchronously controlled by a single clock with a fixed time interval called a time slot. The first stage of MIPS-LSP computes the lower bound on the number of time slots for a given LSP instance. The second stage generates a link compatibility graph to represent the conflicts between links to be activated simultaneously. The third stage gives the initial state for search by a greedy method. The last stage iteratively searches a solution by a minimal-state evolution method. The performance of the algorithm is verified through extensive simulations using benchmarks in literature.

DOI： 10.1109/SAINT.2003.1183041

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双方向マンハッタンストリートネットワークのノード配置問題に対する階層型近似アルゴリズムの提案

米津正隆, 舩曵信生, 木谷友哉, 横平徳美, 中西透, 東野輝夫

電子情報通信学会論文誌D-I   2003

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A proposal of a minimal-state processing search algorithm for isochronous channel reuse problems in DQDB networks

N Funabiki, A Sugano, T Higashino

AINA 2003: 17TH INTERNATIONAL CONFERENCE ON ADVANCED INFORMATION NETWORKING AND APPLICATIONS   229 - 232   2003

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The IEEE 802.6 MAC standard protocol defines the distributed-queue dual bus (DQDB) for metropolitan area networks (MANs). The isochronous channel reuse problem (ICRP) has been studied for the efficient use of DQDB. Given a set of established connections and a set of connection requests, the goal of ICRP is to maximize the number of satisfied requests by finding a proper channel assignment, such that no established connection is not only reassigned a channel, but also any pair of active connections does not interfere each other. In this paper, we propose a minimal-state processing search algorithm for ICRP (MIPS-ICRP). The simulation results show that MIPS-ICRP always provides near-optimum solutions.

DOI： 10.1109/AINA.2003.1192877

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A Proposal of Test Sequence Generation Method for Communication Protocols Using SAT Algorithm

MORI Takanori, OTSUKA Hirotaka, FUNABIKI Nobuo, NAKATA Akio, HIGASHINO Teruo

IEICE transactions on information and systems   85 ( 11 )   1886 - 1887   2002.11

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A Method to Generate Test Sequences for FSM Protocols using SAT Algorithm

2002 ( 15 )   75 - 80   2002.10

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A quasi-solution state evolution algorithm for channel assignment problems in cellular networks

N Funabiki, T Nakanishi, T Yokohira, S Tajima, T Higashino

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E85A ( 5 )   977 - 987   2002.5

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For efficient use of limited electromagnetic wave resource, the assignment of communication channels to call requests is very important in a cellular network. This task has been formulated as an NP-hard combinatorial optimization problem named the channel assignment problem (CAP). Given a cellular network and a set of call requests, CAP requires to find a channel assignment to the call requests such that three types of interference constraints between channels are not only satisfied, but also the number of channels (channel span) is minimized. This paper presents an iterative search approximation algorithm for CAP, called the Quasi-solution state evolution algorithm for CAP (QCAP). To solve hard CAP instances in reasonable time, QCAP evolutes quasi-solution states where a subset of call requests are assigned channels and no more request can be satisfied without violating the constraint QCAP is composed of three stages. The first stage computes the lower bound on the channel span for a given instance. After the second stage greedily generates an initial quasi-solution state, the third stage evolutes them for a feasible channel assignment by iteratively generating best neighborhoods, with help of the dynamic state jump and the gradual span expansion for global convergence. The performance of QCAP is evaluated through solving benchmark instances in literature, where QCAP always finds the optimum or near-optimum solution in very short time. Our simulation results confirm the extensive search capability and the efficiency of QCAP.

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A minimal-state processing search algorithm for satisfiability problems

N Funabiki, T Yokohira, T Nakanishi, S Tajima, T Higashino

2001 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS, VOLS 1-5   2769 - 2774   2002

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The satisfiability problem (SAT) is a typical NP-complete problem where a wide range of applications has been studied. Given a set of variables U and a set of clauses C, the goal of SAT is to find a truth assignment to variables in U such that every clause in C is satisfied if it exits, or to derive the infeasibility otherwise. This paper presents an approximation algorithm called a minimal,state processing search algorithm for SAT (MIPS_SAT). MIPS_SAT repeatedly transits minimal states in terms of the cost function for searching a solution through a construction stage and a refinement stage. The first stage greedily generates an initial state composed of as many satisfied clauses as possible. The second stage iteratively seeks a solution while keeping state minimality. The performance of MIPS_SAT is verified through solving DIMACS benchmark instances.

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Binary neural networks for N-queens problems and their VLSI implementations

N Funabiki, T Kurokawa, M Ohta

CONTROL AND CYBERNETICS   31 ( 2 )   271 - 296   2002

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Combinatorial optimization problems compose an important class of mathematical problems that include a variety of practical applications, such as VLSI design automation, communication network design and control, job scheduling, games, and genome informatics. These problems usually have a large number of variables to be solved. For example, problems for VLSI design automation require several million variables. Besides, their computational complexity is often intractable due to NP-hardness. Neural networks have provided elegant solutions as approximation algorithms to these hard problems due to their natural parallelism and their affinity to hardware realization. Particularly, binary neural networks have great potential to conform to current digital VLSI design technology, because any state and parameter in binary neural networks are expressed in a discrete fashion. This paper presents our studies on binary neural networks to the N-queens problem, and the three different approaches to VLSI implementations focusing on the efficient realization of the synaptic connection networks. Reconfigurable devices such as CPLDs and FPGAs contribute the realization of a scalable architecture with the ultra highs speed of computation. Based on the proposed architecture, more than several thousands of binary neurons can be realized on one FPGA chip.

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ネットワークのリンクスケジューリングにおけるタイムスロット数下限値算出法の改善

田島滋人, 舩曵信生, 東野輝夫

マルチメディア，分散，協調とモバイルシンポジウム(DICOMO 2002)講演集   2002

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ユーザの移動情報を利用したモバイル・マルチキャストルーティング問題の一解法

常村和史, 田島滋人, 中田明夫, 舩曵信生, 東野輝夫

マルチメディア，分散，協調とモバイルシンポジウム(DICOMO 2002)講演集   2002

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Webバグに基づくファイルの不正開封検知システムの提案

小林正憲, 舩曵信生, 中西透

コンピュータセキュリティシンポジウム2002講演集   2002

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通信プロトコルの試験系列生成問題に対するSATアルゴリズム適用法の提案

森 亮憲, 大塚裕孝, 舩曵信生, 中田明夫, 東野輝夫

電子情報通信学会論文誌D-I   2002

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静的およびモバイル・マルチキャストルーティング問題に対する最適パス選択解法の提案

藤井雅和, 舩曵信生, 横平徳美, 田島滋人, 常村和史, 東野輝夫

電子情報通信学会論文誌A   2002

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A proposal of a quasi-solution state evolution algorithm for channel assignment problems

Nobuo Funabiki, Tokumi Yokohira, Toru Nakanishi, Shigeto Tajima, Teruo Higashino

Proc. of 16th international conference on information networking (ICOIN-16)   2002

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A Proposal of an Optimal Path Selection Algorithm for Static and Mobile Multicast Routing Problems

FUJII M., FUNABIKI Nobuo, YOKOHIRA Tokumi, TAJIMA Shigeto, TSUNEMURA Kazufumi, HIGASHINO Teruo

IEICE Journal   85 ( 3 )   730 - 730   2002

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In this paper, we present an approximation algorithm called OPSAM (Optimal Path Selection Algorithm for Multicast) for the static multicast routing problem and the newly defined mobile multicast routing problem. Given a graph with the cost and the delay associated to each edge, a data source, a destination set, and the delay time limit, the first problem requires finding a multicast tree such that the total edge cost is not only minimized, but also the delay of any path from source to a destination does not surpass its limit. OPSAM first extracts plural path candidates for each destination to satisfy the delay constraint. Then, it repeatedly selects better paths among candidates so as to find a lowcost tree within a short computation time. The performance of OPSAM is verified through simulations in the random graph model and the Tiers model, where OPSAM is better than the best existing algorithm BSMA, especially for Tiers model instances. The second problem requires finding a sequence of multicast trees which should be modified to follow changes of mobile user locations, such that the sum of the total edge costs and the difference between two consecutive trees is minimized. The simulation results show the performance of OPSAM is better than BSMA.

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通信プロトコルの試験系列生成問題へのSATアルゴリズム適用法の提案

大塚裕孝, 中田明夫, 舩曵信生, 東野輝夫

電子情報通信学会技術研究報告, COMP2001-75   2002

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双方向マンハッタンストリートネットワークのノード配置問題に対する階層型近似アルゴリズムの提案

米津正隆, 舩曵信生, 横平徳美, 中西透, 田島滋人, 中田明夫, 東野輝夫

電子情報通信学会技術研究報告, COMP2001-77   2002

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An improved lip contour extraction method using deformable template and its automatic threshold adjusting method

YOKOGAWA Yujin, FUNABIKI Nobuo, HIGASHINO Teruo, MORI Yoshihide

IEICE technical report.   101 ( 434 )   37 - 44   2001.11

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The precise extraction of the lip contour has been strongly demanded to plan the surgery and evaluate the recovery for patients with harelips and cleft palates. In this paper, we explain a non-symmetrical deformable template for the lip contour extraction using the template matching method to improve the existing symmetrical deformable template, and the transformation method of the lip contour model into the coordinate system based on the medial canthus point. Then, we propose an algorithm for adjusting the thresholds to extract the hue and value images. Through evaluations using face image samples including patients, we show the accuracy of our proposed method.

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Relaxation of coefficient sensitiveness to performance for neural networks using neuron filter through total coloring problems

Y Takenaka, N Funabiki, T Higashino

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E84A ( 9 )   2367 - 2370   2001.9

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Language：English   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

In this paper we show that the neuron filter is effective for relaxing the coefficient sensitiveness of the Hopfield neural network for combinatorial optimization problems. Since the parameters in motion equation have a significant influence on the performance of the neural network, many studies have been carried out to support determining the value of the parameters. However, not a few researchers have determined the value of the parameters experimentally yet. We show that the use of the neuron filter is effective for the parameter tuning, particularly for determining their values experimentally through simulations.

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A Proposal of a Lip Contour Approximation Method Using the Function Synthesis

SEKIOKA Tetsuya, YOKOGAWA Yuzin, FUNABIKI Nobuo, HIGASHINO Teruo, YAMADA Tomohiro, MORI Yoshihide

The Transactions of the Institute of Electronics,Information and Communication Engineers.   84 ( 3 )   459 - 470   2001.3

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唇の輪郭線は, 口腔外科における口唇裂症などの術式検討や術後トレースに重要であり, シンプルかつ高精度のモデルでの自動抽出が望まれている.そこで本論文では, 顔画像を入力とし, 前処理, 1次検出, 2次検出の3段階の処理を経て, 唇の輪郭線を関数で合成する手法を提案する.まず前処理では, 顔画像から唇の位置を検出し, おおよその大きさを決定する.次に1次検出ではDeformable templateマッチング法により唇のおおよその輪郭線を探索する.そして2次検出では, 遺伝的プログラミングを用いて置換と分割によって詳細な唇の輪郭線を探索する.本提案手法が従来の動的輪郭モデル(SNAKES)よりも精度, パラメータ数, 探索時間の点で優れていることを一般人の唇, 口唇裂症患者の唇のサンプルに対するシミュレーションにより示す.

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An Optimal Path Selection Algorithm for Static Multicast Routing Problems

FUJII MASAKAZU, FUNABIKI NOBUO, NAKATA AKIO, KITAMICHI JUNJI, HIGASHINO TERUO

IEICE technical report. Theoretical foundations of Computing   100 ( 568 )   39 - 46   2001.1

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In this paper, we present a heuristic algorithm called OPSAM(Optimal Path Selection Algorithm for Multicast)for the static multicast routing problem. Given a directed connected graph with two weights associated to each edge, representing the cost and the delay, a source sending out data, and a set of destinations receiving data, this problem requires to provide a multicast tree such that the total cost of edges in the tree is not only minimized, but also every path delay from the source to a destination is less than its upper limit. OPSAM first extracts plural candidates to each destination that satisfy the delay constraint. Then, it iteratively selects better paths among them so that it can find a low-cost tree within short time. The performance of OPSAM is verified through simulations in two types of network models, where especially, OPSAM shows the high performance for Tiers model instances, which are close to real networks.

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A proposal of a lip contour extraction method using deformable template and a transformation method into coordinate system based the medial canthus point

YOKOGAWA Yuzin, FUNABIKI Nobuo, HIGASHINO Teruo, YAMADA Tomohiro, MORI Yoshihide

Technical report of IEICE. PRMU   100 ( 566 )   31 - 38   2001.1

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Recently, shapes and relative positions of face components such as the lip contour have been intensively studied in areas including medicine and psychology. Actually, the precise extraction of the lip contour and its position has been strongly demanded to plan the surgery and evaluate the recovery for patients with harelips and cleft palates. In this paper, we propose a non-symmetrical deformable template for the lip contour extraction using the template matching method to improve the existing symmetrical deformable template. Besides, we propose the transformation method of the lip contour model into the coorinate system based on the medial canthus point. Through evaluations using face image samples including patients, we show the accuracy of our proposed method.

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Relaxation of coefficient sensitiveness to performance for neural networks using neuron filter through total coloring

Yoichi Takenaka, Nobuo Funabiki, Teruo Higashino

IEICE Transactions on Fundamentals   2001

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A global routing technique for wave-steered design methodology

N. Funabiki, A. Singh, A. Mukherjee, M. Marek-Sadowska

Proceedings - Euromicro Symposium on Digital Systems Design: Architectures, Methods and Tools, DSD 2001   430 - 436   2001

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Wave-Steering is a new circuit design methodology to realize high throughput circuits by embedding layout friendly structures in silicon. Latches guarantee correct signal arrival times at the input of synthesized modules and maintain the high throughput of operation. This paper presents a global routing technique for networks of wave-steered blocks. Latches can be distributed along interconnects. Their number depends on net topologies and signal ordering at the inputs of wave steered blocks. here, we route nets using Steiner tree heuristics and determine signal ordering and latch positions on interconnect. The problem of total latch number minimization is solved using SAT formulation. Experimental results on benchmark circuits show the efficiency of our technique. We achieve on average a 40% latch reduction at minimum latency over un-optimized circuits operating at 250 MHz in 0.25 μm CMOS technology.

DOI： 10.1109/DSD.2001.952358

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モバイル・マルチキャストルーティング問題に対する最適パス選択解法の提案

常村和史, 田島滋人, 藤井雅和, 中田明夫, 横平徳美, 舩曵信生, 東野輝夫

マルチメディア通信と分散処理ワークショップ講演集   2001

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ネットワークのリンクスケジューリングへのグラフ彩色アプローチ

田島滋人, 舩曵信生, 東野輝夫, 横平徳美, 中西透

電子情報通信学会技術研究報告, COMP2001-71   2001

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A proposal of neuron filter: A constraint resolution scheme of neural networks for combinatorial optimization problems

Y Takenaka, N Funabiki, T Higashino

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E83A ( 9 )   1815 - 1823   2000.9

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A constraint resolution scheme in the Hopfield-type neural network named "Neuron Filter" is presented for efficiently solving combinatorial optimization problems. The neuron filter produces an output that satisfies the constraints of the problem as best as possible according to both neuron inputs and outputs. This paper defines the neuron filter and shows its introduction into existing neural networks for N-queens problems and FPGA board-level routing problems. The performance is evaluated through simulations wharf the results show that our neuron filter improves the searching: capability of the neural network with the shorter computation time.

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A proposal of neuron filter a constraint resolution scheme of neural networks for combinatorial optimization problems

Yoichi Takenaka, *Nobuo Funabiki, Teruo Higashino

IEICE Transactions on Fundamentals   E83-A ( 9 )   1815 - 1823   2000.9

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A Formulation of an FPGA Logic-Block Pin Assignment Problem and Its Two-Stage Discrete Optimization Method

FUNABIKI Nobuo, IKENAGA Katsuyoshi, EGAWA Shinji, HIGASHINO Teruo

The Transactions of the Institute of Electronics,Information and Communication Engineers. A   83 ( 8 )   976 - 988   2000.8

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A minimal-state procssing search algorithm for graph coloring problems

FUNABIKI Nobuo, HIGASHINO Teruo

IEICE Transactions on Fundamentals   E83-A ( 7 )   1420 - 1430   2000.7

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This paper presents a heuristic graph coloring algorithm named MIPS_CLR, a MInimal-state Processing Search algorithm for the graph CoLoRing problem. Given a graph G(V, E), the goal of this NP-complete problem is to find a color assignment to every vertex in V such that any pair of adjacent vertices must not receive the same color but also the total number of colors should be minimized. The graph coloring problem has been widely studied due to its large number of practical applications in various fields. In MIPS_CLR, a construction stage first generates an intial minimal state composed of as many as colored vertices by a simple greedy algorithm, after a miximal clique of G is found by a maximum clique algorithm. Then, a refinement stage iteratively seeks a solution state while keeping minimality in terms of a cost function by a minimal-state transition method. In this method, the schemes of a best color selection, a random color selection, a color assignment shuffle, and a gradual color expansion are used together to realize the discrete descent search with hill-climbing capabilities. The performance of MIPS_CLR is evaluated through solving DIMACS benchmark graph instances, where the solution quality is generally better than existing algorithms while the computation time is comparable with the best existing one. In particular, MIPS_CLR provides new lower bound solutions for several instances. The simulation results confirm the extensive search capability of our MIPS_CLR approach for the graph coloring problem.

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A minimal-state processing search algorithm for graph coloring problems

N Funabiki, T Higashino

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E83A ( 7 )   1420 - 1430   2000.7

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This paper presents a heuristic graph coloring algorithm named MIPS_CLR, a MInimal-state Processing Search algorithm for the graph CoLoRing problem. Given a graph G(V, E), the goal of this NP-complete problem is to find a color assignment to every vertex in II such that arty pair of adjacent vertices must not receive the same color but also the total number of colors should be minimized. The graph coloring problem has been widely studied due to its large number of practical applications in various fields. In MIPS-CLR, a construction stage first generates an initial minimal state composed of as many as: colored vertices by a simple greedy algorithm, after a maximal clique of G is found by a maximum clique algorithm. Then, a refinement stage iteratively seeks a solution state while keeping minimality in terms of a cost function by a minimal-state transition method. In this method, the schemes of a best color selection, a random color selection, a color assignment shuffle, and a gradual color expansion are used together to realize the discrete descent starch with hill-climbing capabilities. The performance of MIPS_CLR is evaluated through solving DIMACS benchmark graph instances, where the solution quality is generally better than existing algorithms while the computation time is comparable with the Lest existing one. In particular, MIPS-CLR provides new lower bound solutions for several instances. The simulation results, confirm the extensive search capability of our MIPS_CLR approach For the graph coloring problem.

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A Proposal of a Two-Stage Approximation Algorithm for Link Scheduling Problems in Radio Networks

TAJIMA Shigeto, FUNABIKI Nobuo, HIGASHINO Teruo

IEICE technical report. Theoretical foundations of Computing   99 ( 724 )   65 - 72   2000.3

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

In a multihop radio network, packets are transmitted from source nodes to destination nodes by activating connected links between them. Each node can either send a packet to or receive a packet from at most one of its adjacent nodes simultaneously. In order to minimize the transmission time for given requests, the problems must be solved of selecting a transmission route for each request (the routing problem) and of finding a link schedule (the link scheduling problem). In this paper, we propose a two-stage approximation algorithm for the link scheduling problem. The link scheduling problem is composed of SAS to satisfy the sequence of link activations and NAS not to satisfy it. We verify the performance through simulations for NAS and SAS, where our algorithm finds better solutions in shorter time than the existing algorithms.

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A three-stage heuristic combined neural-network algorithm for channel assignment in cellular mobile systems

N Funabiki, N Okutani, S Nishikawa

IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY   49 ( 2 )   397 - 403   2000.3

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A three-stage algorithm of combining sequential heuristic methods into a parallel neural network is presented for the channel assignment problem in cellular mobile communication systems in this paper. The goal of this NP-complete problem is to find a channel assignment to requested calls with the minimum number of channels subject to interference constraints between channels. The three-stage algorithm consists of: 1) the regular interval assignment stage; 2) the greedy assignment stage; and 3) the neural-network assignment stage. In the first stage, the calls in a cell determining the lower bound on the total number of channels are assigned channels at regular intervals. In the second stage, the calls in a cell with the largest degree and its adjacent cells are assigned channels by a greedy heuristic method. In the third stage, the calls in the remaining cells are assigned channels by a binary neural network, The performance is verified through solving well-known benchmark problems, Especially for Sivarajan's benchmark problems, our three-stage algorithm first achieves the lower bound solutions in all of the 13 instances, while the computation time is comparable with existing algorithms.

DOI： 10.1109/25.832970

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無線通信網における信頼度制約通信経路割当問題に対するニューラルネットワーク併用二段階解法の提案

馬場孝之, 船曵信生, 田島滋人

電子情報通信学会論文誌A   2000

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A three-stage heuristic combined neural-network algorithm for channel assignment in cellular mobile systems

Nobuo Funabiki, Noriko Okutani, Seishi Nishikawa

IEEE Transactions on Vehicular Technology   49 ( 2 )   397 - 403   2000

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A three-stage algorithm of combining sequential heuristic methods into a parallel neural network is presented for the channel assignment problem in cellular mobile communication systems in this paper. The goal of this NP-complete problem is to find a channel assignment to requested calls with the minimum number of channels subject to interference constraints between channels. The three-stage algorithm consists of: 1) the regular interval assignment stage
2) the greedy assignment stage
and 3) the neural-network assignment stage. In the first stage the calls in a cell determining the lower bound on the total number of channels are assigned channels at regular intervals. In the second stage the calls in a cell with the largest degree and its adjacent cells are assigned channels by a greedy heuristic method. In the third stage the calls in the remaining cells are assigned channels by a binary neural network. The performance is verified through solving well-known benchmark problems. Especially for Sivarajan's benchmark problems our three-stage algorithm first achieves the lower bound solutions in all of the 13 instances while the computation time is comparable with existing algorithms. © 2000 IEEE.

DOI： 10.1109/25.832970

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A three-stage heuristic combined neural-network algorithm for channel assignment in cellular mobile systems

Nobuo Funabiki, Noriko Okutani, Seishi Nishikawa

IEEE Transactions on Vehicular Technology   49 ( 2 )   397 - 403   2000

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A three-stage algorithm of combining sequential heuristic methods into a parallel neural network is presented for the channel assignment problem in cellular mobile communication systems in this paper. The goal of this NP-complete problem is to find a channel assignment to requested calls with the minimum number of channels subject to interference constraints between channels. The three-stage algorithm consists of: 1) the regular interval assignment stage
2) the greedy assignment stage
and 3) the neural-network assignment stage. In the first stage the calls in a cell determining the lower bound on the total number of channels are assigned channels at regular intervals. In the second stage the calls in a cell with the largest degree and its adjacent cells are assigned channels by a greedy heuristic method. In the third stage the calls in the remaining cells are assigned channels by a binary neural network. The performance is verified through solving well-known benchmark problems. Especially for Sivarajan's benchmark problems our three-stage algorithm first achieves the lower bound solutions in all of the 13 instances while the computation time is comparable with existing algorithms. © 2000 IEEE.

DOI： 10.1109/25.832970

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A greedy digital neural-network algorithm for subgraph isomorphism problems

Nobuo Funabiki, Teruo Higashino

Proc. of World Multiconference on Systemics, Cybernetics, and Informatics   2000

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A greedyneural combined discrete optimization algorithm for triangle and Kn-subgraph partition problem

OHTSUKA H.

Proc. World Multiconference on Systemics, Cybernetics and Informatics (SCI2000)   12   557 - 562   2000

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A proposal of a neuron filter algorithm with a thinning-out method for total coloring problems

Yoichi Takenaka, Nobuo Funabiki

Proc. of World Multiconference on Systemics, Cybernetics, and Informatics   2000

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遺伝的プログラミングを用いた関数合成アルゴリズムの改良法の提案

関岡哲也, 船曵信生, 東野輝夫

電子情報通信学会論文誌D1   2000

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静的マルチキャストルーティング問題に対する２段階解法の提案

藤井雅和, 船曵信生, 東野輝夫

第13回回路とシステム(軽井沢)ワークショップ講演集   2000

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A two-stage discrete optimization method for largest common subgraph problems

N Funabiki, J Kitamichi

IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS   E82D ( 8 )   1145 - 1153   1999.8

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A novel combinatorial optimization algorithm called 2-stage discrete optimization method (2DOM) is proposed for the largest common subgraph problem (LCSP) in this paper. Given two graphs G = (V-1, E-1) and H = (V-2, E-2), the goal of LCSP is to find a subgraph G' = (V-1', E-1') of G and a subgraph H' = (V-2', E-2') of H such that G' and H' are not only isomorphic to each other but also their number of edges is maximized. The two graphs G' and H' are isomorphic when \V-1'\ = \V-2'\ and \E-1'\ = \E-2'\, and there exists one-to-one vertex correspondence f : V-1' --> V-2' such that {u, v} is an element of E-1' if and only if {f(u), f(v)} is an element of E-2'. LCSP is known to be NP-complete in general. The 2DOM consists of a construction stage and a refinement stage to achieve the high solution quality and the short computation time for large size difficult combinatorial optimization problems. The construction stage creates a feasible initial solution with considerable quality, based on a greedy heuristic method. The refinement stage improves it keeping the feasibility, based on a random discrete descent method. The performance is evaluated by solving two types of randomly generated 1200 LCSP instances with a maximum of 500 vertices for G and 1000 vertices for H. The simulation result shows the superiority of 2DOM to the simulated annealing in terms of the solution quality and the computation time.

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A gradual neural network approach for FPGA segmented channel routing problems

N Funabiki, M Yoda, J Kitamichi, S Nishikawa

IEEE TRANSACTIONS ON SYSTEMS MAN AND CYBERNETICS PART B-CYBERNETICS   29 ( 4 )   481 - 489   1999.8

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A novel neural network approach called gradual neural network (GNN) is presented for segmented channel routing in field programmable gate arrays (FPGA's). FPGA's contain predefined segmented channels for net routing, where adjacent segments in a track can be interconnected through programmable switches for longer segments. The goal of the FPGA segmented channel routing problem, known to be NP-complete, is to find a conflict-free net routing with the minimum routing cost. The GNN for the N-net-M-track problem consists of a neural network of N x M binary neurons and a gradual expansion scheme. The neural network satisfies the constraints of the problem, while the gradual expansion scheme seeks the cost minimization by gradually increasing activated neurons. The energy function and the motion equation are newly defined with heuristic methods, The performance is verified through solving 30 instances, where GNN finds better solutions than existing algorithms within a constant number of iteration steps.

DOI： 10.1109/3477.775264

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A gradual neural network approach for FPGA segmented channel routing problems

Nobuo Funabiki, Makiko Yoda, Junji Kitamichi, Seishi Nishikawa

IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics   29 ( 4 )   481 - 489   1999.8

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A novel neural network approach called gradual neural network (GNN) is presented for segmented channel routing in field programmable gate arrays (FPGA's). FPGA's contain predefined segmented channels for net routing, where adjacent segments in a track can be interconnected through programmable switches for longer segments. The goal of the FPGA segmented channel routing problem, known to be NP-complete, is to find a conflict-free net routing with the minimum routing cost. The GNN for the N-net-M-track problem consists of a neural network of N x M binary neurons and a gradual expansion scheme. The neural network satisfies the constraints of the problem, while the gradual expansion scheme seeks the cost minimization by gradually increasing activated neurons. The energy function and the motion equation are newly defined with heuristic methods. The performance is verified through solving 30 instances, where GNN finds better solutions than existing algorithms within a constant number of iteration steps. © 1999 IEEE.

DOI： 10.1109/3477.775264

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A gradual neural network approach for FPGA segmented channel routing problems

Nobuo Funabiki, Makiko Yoda, Junji Kitamichi, Seishi Nishikawa

IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics   29 ( 4 )   481 - 489   1999.8

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A novel neural network approach called gradual neural network (GNN) is presented for segmented channel routing in field programmable gate arrays (FPGA's). FPGA's contain predefined segmented channels for net routing, where adjacent segments in a track can be interconnected through programmable switches for longer segments. The goal of the FPGA segmented channel routing problem, known to be NP-complete, is to find a conflict-free net routing with the minimum routing cost. The GNN for the N-net-M-track problem consists of a neural network of N x M binary neurons and a gradual expansion scheme. The neural network satisfies the constraints of the problem, while the gradual expansion scheme seeks the cost minimization by gradually increasing activated neurons. The energy function and the motion equation are newly defined with heuristic methods. The performance is verified through solving 30 instances, where GNN finds better solutions than existing algorithms within a constant number of iteration steps. © 1999 IEEE.

DOI： 10.1109/3477.775264

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A gradual neural network algorithm for broadcast scheduling problems in packet radio networks

N Funaibiki, J Kitamichi

IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES   E82A ( 5 )   815 - 824   1999.5

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A novel combinatorial optimization algorithm called "Gradual neural network (GNN)" is presented for NP-complete broadcast scheduling problems in packet radio (PR) networks. A PR network provides data communications services to a set of geographically distributed nodes through a common radio channel. A time division multiple access (TDMA) protocol is adopted for conflict-free communications, where packets are transmitted in repetition of fixed-length time-slots called a TDMA cycle. Given a PR network, the goal of GNN is to find a TDMA cycle with the minimum delay time for each node to broadcast packets. GNN for the N-node-M-slot TDMA cycle problem consists of a neural network with N x M binary neurons and a gradual expansion scheme. The neural network not only satisfies the constraints but also maximizes transmissions by two energy functions, whereas the gradual expansion scheme minimizes the cycle length by gradually expanding the size of the neural network. The performance is evaluated through extensive simulations in benchmark instances and in geometric graph instances with up to 1000 vertices, where GNN always finds better TDMA cycles than existing algorithms. The result in this paper supports the credibility of our GNN algorithm for a class of combinatorial optimization problems.

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"A gradual neural network approach for broadcast scheduling in packet radio networks"

*Nobuo Funabiki, Junji Kitamichi

IEICE Transactions on Fundamentals   E-82-A ( 5 )   815 - 824   1999.5

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A Proposal of an Improved Function Synthesis Algorithm with Genetic Programming

SEKIOKA TETSUYA, FUNABIKI NOBUO

IEICE technical report. Nonlinear problems   98 ( 663 )   9 - 16   1999.3

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

The function synthesis problem for an unknown system requires to produce an approximate function which satisfies the relationships of given input and output data sets of the system. This problem is essential for the proper control of the system. When the system has the non-linearity characteristics, this problem becomes very difficult where the number of combinations of variables, constants, and operators quickly increases the computational complexity. This paper presents three improved methods for the genetic programming algorithm which is one of the function synthesis methods. They are the gradual expansion of function trees, the constant optimization by a local search, and the partial structure fixation of function trees based on the characteristics of the target system. The performance evaluation through the two-spirals problem and the sunspot prediction problem shows the effectiveness of the proposed three methods.

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A proposal of a neural network algorithm for route assignment problems with reliability in multihop radio networks

BABA Takayuki, FUNABIKI Nobuo

IEICE technical report. Nonlinear problems   98 ( 583 )   17 - 24   1999.2

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A multihop radio network is a large communication network between many nodes distributed around wide areas. Through a radio channel, each node can either send a packet to, or receive a packet from, at most one of its adjacent nodes simultaneously. Packets are transmitted from source nodes to destination nodes by activating several links between these nodes. In order to maximize the throughput or minimize the transmission time for given transmission requests, it is required to assign a transmission route and a link activation schedule for each request. In this network, each node has is different reliability to perform its function properly depending on the difference of running period, design specification, and environment. In this paper, we propose a two-stage algorithm to assign routes whose reliabilities are more than the specified threshold. This algorithm is composed of the iterated candidate extraction method with reliability satisfaction to extract route candidates and the greedy neural network algorithm to select a route to minimize a cost among plural candidates. Through simulations up to-500-node networks, we verify that our algorithm finds good solutions effectively.

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Formal verification method for combinatorial circuits at high level design

J Kitamichi, H Kageyama, N Funabiki

PROCEEDINGS OF ASP-DAC '99   319 - 322   1999

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In this paper, we propose a formal verification method for combinatorial circuits at high level design. The specification is described by both integer and Boolean variables for input and output variables, and the implementation is described by only Boolean variables. Our verification method judges the equivalence between the specification and the implementation by deciding the truth of Presburger sentence. We show experimental results on some benchmarks, such as 4bit ALU, multiplier, by our method.

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プレスブルガー文真偽判定アルゴリズムのためのBDDの応用とそれを用いた回路検証

景山洋行, 北道淳司, 船曵信生

情報処理学会論文誌   1999

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A proposal of a two-stage discrete optimization method for the maximum clique problem

Nobuo Funabiki, Teruo Higashino

Proc. of International Symposium on Nonlinear Theory and Its Applications   1999

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チャネル割当問題を対象とした拡張マキシマムニューラルネットワーク解法の提案

池永勝芳, 船曵信生, 竹中要一

電子情報通信学会論文誌A   1999

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貪欲法とGAを併用したデータ転送路資源最適化問題解法の提案

四方康人, 船曵信生, 北道淳司

電子情報通信学会論文誌A   1999

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A non-feedback neuron filter algorithm for separated board-level routing problems in FPGA-based logic emulation systems

Yoichi Takenaka, Nobuo Funabiki

Proc. of IEEE International Joint Conference on Neural Networks   1999

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A gradual neural network approach for broadcast scheduling in packet radio networks

Nobuo Funabiki, Yoichi Takenaka, Teruo Higashino

Proc. of IEEE International Joint Conference on Neural Networks   1999

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A Neuron Filter Algorithm for Board-Level Routing Problems in FPGA-Based Logic Emulation Systems

TAKENAKA Yoichi, FUNABIKI Nobuo

IEICE technical report. Nonlinear problems   98 ( 443 )   23 - 29   1998.12

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

In this paper, we propose a non-feedback neuron filter algorithm in the neural network. for the board-level routing problem (BLRP) in an FPGA-based logic emulation system. For a rapid prototyping of large scale digital systems, multiple FPGA's provide an efficient logic emulation system, where signals or nets between design partitions embedded on different FPGA's are connected through crossbars. We propose a new neuron filter algorithm to satisfy the two constraints of the problem simultaneously. The simulation results in randomly generated benchmark size instances show that our neuron filter algorithm with the thinning out application provides the better routing capability with the shorter computation time.

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A proposal of a three-stage greedy neural-network algorithm for FPGA routing problems

EGAWA Shinji, KURODA Eiji, KITAMICHI Junji, FUNABIKI Nobuo

IEICE technical report. Computer systems   98 ( 291 )   69 - 75   1998.9

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In this paper, we propose a three-stage routing algorithm for two-dimensional Field-Programmable Gate Arrays (FPGAs) by combining the greedy algorithm and the neural network algorithm. The three-stage algorithm consists of the route-candidate extraction stage, the greedy routing stage, and the neural network routing stage to achieve the high routability. The first stage extracts necessary route-candidates composed of a sequence of routing segments for every net. The second stage selects one of the candidates and assigns one track for each net so as to avoid short circuits. The final stage rearranges locations of shorter nets by the second stage to reduce the necessary tracks. We evaluate the performance of our algorithm by solving nine randomly generated instances, where the simulation results show that our three-stage algorithm achieves the high performance by used together.

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A proposal of a three - stage greedy neural - network algorithm for FPGA routing problems

EGAWA SHINJI, KURODA EIJI, KITAMICHI JUNJI, FUNABIKI NOBUO

IPSJ SIG Notes   1998 ( 87 )   121 - 127   1998.9

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In this paper, we propose a three-stage routing algorithm for two-dimensional Field-Programmable Gate Arrays (FPGAs)by combining the greedy algorithm and the neural network algorithm. The three-stage algorithm consists of the route-candidate extraction stage, the greedy routing stage, and the neural network routing stage to achieve the high routability. The first stage extracts necessary route-candidates composed of a sequence of routing segments for every net. The second stage selects one of the candidates and assigns one track for each net so as to avoid short circuits. The final stage rearranges locations of shorter nets by the second stage to reduce the necessary tracks. We evaluate the performance of our algorithm by solving nine randomly generated instances, where the simulation results show that our three-stage algorithm achieves the high performance by used together.

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A Maxumum Neural Network Algorithm for a Channel Assignment Problem in Cellular Radio Networks

IKENAGA Katsuyoshi, FUNABIKI Nobuo, TAKENAKA Yoichi, KITAMICHI Junji

IEICE technical report. Nonlinear problems   97 ( 592 )   85 - 92   1998.3

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In this paper, we propose a neural network algorithm using the maximum neuron model for the static channel assignment problem in cellular radio networks under the minimization of mutual interferences. The goal of this problem is to minimize the total interferences between calls subject to the constraint that all requested calls must be accepted. Our algorithm uses the expanded maximum neuron model to satisfy the constraint. In order to improve the solution quality, the regular interval assignment is adopted into a cell with the largest demands. In addition, the shaking term, the hill-climbing term, and the omega function are used together in the motion equation. We verify the performance through simulations using benchmark problems, where our algorithm finds better solutions than the existing algorithms.

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A Performance Evaluation of Digital Neural Network Algorithms for Stable Marriage Problems

TAJIMA Shigeto, FUNABIKI Nobuo, KITAMITI Junji

IEICE technical report. Nonlinear problems   97 ( 592 )   77 - 84   1998.3

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In this paper, we evalute the performance of digital neural network algorithms using three neuron models (binary neuron model, hysteresis binary neuron model, and maximum neuron model) and three computation methods (synchronous parallel computation method, N-parallel computation method, and sequential computation method) for the stable marriage problem. The goal of the problem is to find N stable pairs of N men and N women under given preference lists. A pair becomes unstable when there is an unpaired couple of a man and a woman who prefers each other to their actual partners. The simulation results through randomly generated instances show that the performance of the maximum neuron model on the sequential computation method surpasses the other methods in terms of the convergence properly and the solution quality.

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An Application of Convex Hull to Genetic Algorithm for Traveling Salesman Problem

TAKENAKA Yoichi, FUNABIKI Nobuo

Technical report of IEICE. SS   97 ( 521 )   17 - 24   1998.1

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In this paper, we propose an application of the "visiting order restriction theorem" to Pal's algorithm, a genetic algorithm for the traveling salesman problem (TSP). The visiting order restriction theorem gives a necessary condition for the shortest tour of TSP on the Euclidean plane by using the convex hull. The convex hull of a set of points S on a plane is defined as the smallest convex polygon that encloses S. The O (|S|log|S|)-time algorithm has been known to find the convex hull of a set of points S. The genetic algorithm, which simulates the process of the natural selection, is known as one of best approximate algorithms for TSP. In our method, the initial tours are produced to satisfy the necessary condeition for the shortest path in order to improve the solution quality. The simulation results using benchmark problems show our genetic algorithm finds shorter tours than P'al's algorithm at the large size benchmark problems.

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A gradual neural-network algorithm for jointly time-slot/code assignment problems in packet radio networks

Nobuo Funabiki, Junji Kitamichi

IEEE Transactions on Neural Networks   9 ( 6 )   1523 - 1528   1998

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A gradual neural network (GNN) algorithm is presented for the jointly time-slot/code assignment problem (JTCAP) in a packet radio network in this paper. The goal of this newly defined problem is to find a simultaneous assignment of a time-slot and a code to each communication link, whereas time-slots and codes have been independently assigned in existing algorithms. A time/code division multiple access protocol is adopted for conflict-free communications, where packets are transmitted in repetition of fixed-length time-slots with specific codes. GNN seeks the time-slot/code assignment with the minimum number of time-slots subject to two constraints: 1) the number of codes must not exceed its upper limit and 2) any couple of links within conflict distance must not be assigned to the same time-slot/code pair. The restricted problem for only one code is known to be NP-complete. The performance of GNN is verified through solving 3000 instances with 100-500 nodes and 100-1000 links. The comparison with the lower bound and a greedy algorithm shows the superiority of GNN in terms of the solution quality with the comparable computation time. © 1998 IEEE.

DOI： 10.1109/72.728402

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An evolutionary neural network approach for module orientation problems

Nobuo Funabiki, Junji Kitamichi, Seishi Nishikawa

IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics   28 ( 6 )   849 - 855   1998

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A novel neural network approach called "Evolutionary Neural Network (ENN)" is presented for the module orientation problem. The goal of this NP-complete problem is to minimize the total wire length by flipping circuit modules with respect to their vertical and/or horizontal axes of symmetry. In order to achieve high quality VLSI systems, it is strongly desired to solve the problem as quickly as possible in the design cycle. Based on the concept of the genetic algorithm, the evolutionary initialization scheme on neuron states is introduced so as to provide a high quality solution within a very short time. The performance of ENN is compared with three heuristic algorithms through simulations on 20 examples with up to 500 modules. The results show that ENN can find the best solutions in the shortest time. © 1998 IEEE.

DOI： 10.1109/3477.735394

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A Formal Method of Proving Invariants for Synchronous Sequential Circuits with Plural Controllers

SAITOH YOSHIKATSU, TAKENAKA TAKASHI, KITAMICHI JUNJI, FUNABIKI NOBUO

IPSJ SIG Notes   97 ( 119 )   41 - 48   1997.12

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In this paper, we propose a formal method of proving invariants for synchronous sequential circuits with plural controllers in high level design. The invariant is the relationship among registers and signals that the user asserts. The circuit design consists of several finite state machines (controllers) and datapath. The invariants can be set at arbitrary finite states by user. The execution conditions, operations in datapath, and invariants are described with variables and functions over Boolean, integer, and abstract data type defined by user. The invariants are proved on the assumption that several invariants, datapath, execution conditions, and lemmas for user-defined functions are correct. This proof uses the structural induction on finite states. On proving invariants, the system a product controller which is equivalent to each controllers and proves by structural induction with the product controller. We eliminate unreachable states on generating the product controller. The sufficient conditions of expressions to prove are proved with a decision algorithm for the truth of Presburger sentence. We evaluate the proposed method for verifying the correctness of the PCI bus interface circuit design.

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A Neural Network for One-Shot Scheduling Problems in Multicast Packet Switching Systems

BABA Takayuki, FUNABIKI Nobuo, NISHIKAWA Seishi

The Transactions of the Institute of Electronics,Information and Communication Engineers. A   80 ( 11 )   1973 - 1981   1997.11

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A Proposal of a Neuro-GA Hybrid Algorithm for Data Transfer Binding Problems

SHIKATA Yasuhito, FUNABIKI Nobuo, KITAMICHI Junji, NISHIKAWA Seishi

Technical report of IEICE. SS   97 ( 261 )   23 - 30   1997.9

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High-level synthesis from behavioral descriptions for VLSI systems is devided into three sub-problems. In this paper, we propose an approximation algorithm using a neural network and a genetic algorithm for the data transfer binding problem which is one of the sub-problems. Our algorithm adopts the bus-oriented interconnection style. The simulation results through benchmark instances show that the proposed algorithm is superior to existing algorithms in terms of the solution quality, although it is inferior in computational time.

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A neural network approach for multilayer over-the-cell channel routing problems

Nobuo Funabiki, Seishi Nishikawa

Neurocomputing   16 ( 4 )   319 - 332   1997.9

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A new algorithm for multilayer over-the-cell channel routing problems using two neural networks is presented in this paper. In the multilayer over- the-cell channel routing problem, signal nets may be placed not only in the multilayer channel between two cells, but also on the multilayer routing area over the cells. The goal of our algorithm is to route all the given nets in both routing areas with the minimum number of tracks in the channel. Our algorithm consists of four steps: (1) extracting nets for the over-the-cell routing, (2) routing nets in the multilayer over-the-cell muting area by the neural network, (3) transforming nets for the channel routing and (4) routing nets in the multilayer channel by the neural network. The performance of our algorithm was verified through seven benchmark problems with 1-4 layers for the over-the-cell and 2-8 layers for the channel. The simulation results support the flexibility of our algorithm in the multilayer over-the-cell channel routing problem.

DOI： 10.1016/S0925-2312(97)00039-8

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The Stability of Discrete Neural Network for Combinational Optimization

UMETANI Shunji, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   97 ( 201 )   1 - 8   1997.7

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In this paper, we study the convergence property of the Hopfield neural network using the binary neuron model named Discrete Neural Network (DNN). First, we present that DNN converges to a local minimum when the following two conditions are satisfied; (1)DNN has no self-interaction, and (2)the state of each neuron is updated asynchronously. Then, we discuss the behaviour of DNN if either condition is not satisfied so that we explain the cause of oscillatory behaviour.

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A proposal of a greedy neural network algorithm for route assignment problems in multihop radio networks

BABA Takayuki, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Theoretical foundations of Computing   97 ( 157 )   41 - 48   1997.7

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In a multihop radio network, packets are transmitted from source nodes to destination nodes by activating several links between nodes. Each node can either send a packet to, or receive a packet from, at most one of its adjacent nodes simultaneously. In order to minimize the transmission time for given requests, the route assignment problem must be solved to assign a transmission route for each request, and the link activation problem must be solved to find a link activation schedule. The route assignment problem is decomposed into two sub-problems: the candidate extraction problem and the route selection problem. In this paper, we introduce a new cost function for the route assignment problem, propose the plural candidates extraction method for the candidate extraction problem, and propose the greedy neural network algorithm for the route selection problem. Through simulations up to 500-node networks, we verify that our algorithm finds better solutions in shorter time and with smaller space than the existing algorithms.

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A proposal of "Neuron Filter" for Hopfield-type Neural Networks through Traveling Salesman Problems

TAKENAKA Yoichi, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   96 ( 583 )   287 - 294   1997.3

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In this paper, we propose "Neuron Filter" as restricting the neural region to satify some constraints in order to improve the performance of Hopfield-type neural networks. Neuron Filter processes neuron states to satisfy constraints of combinatorial optimization problems. Neuron Filter is classified into "Maximum Neuron" and "Neuron Mask". Maximum Neuron feedbacks the outputs for the state update computations of neural networks, while Neuron Mask does not feedback them. This paper presents the definition of Neuron Filter and the introduction into the neural network through the travelling salesman problem. We verify the performance by solving benchmark problems, where the simulation results show Neuron Filter improves the performance of the neural network.

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A Maximum Neural Network Algorithm for Stable Marriage Problems

TAJIMA Shigeto, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   96 ( 583 )   295 - 302   1997.3

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In this paper, we propose a maximum neural network algorithm for the stable marriage problem using the maximum neuron model. The goal of the stable marriage problem is to find N stable pairs of N men and N women under given preference lists. A pair becomes unstable when there is an unpaired couple of a man and a woman who prefer each other to their actual partners. The simulation results through randomly generated instances show that the performance of our maximum neural network surpasses the existing neural network using the binary neuron model in terms of the convergence properly and the solution quality.

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A Proposal of the N-Parallel Computation Method of the Neural Network for N-Queens Problems

YOSHIO Hiroaki, BABA Takayuki, FUNABIKI Nobuo, NISHIKAWA Seishi

The Transactions of the Institute of Electronics,Information and Communication Engineers. A   80 ( 1 )   205 - 212   1997.1

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A study on a two-phase neural network algorithm for channel assignment in cellular radio networks

OKUTANI Noriko, FUNABIKI Nobuo, NISHIKAWA Seishi

Technical report of IEICE. SS   96 ( 490 )   33 - 40   1997.1

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This paper presents a two-phase neural network algorithm for the channel assignment problem in a cellular radio network. For a set of call requests, the goal of this NP-complete problem is to find a channel assignment, which does not only satisfy interference constraints between channels, but also minimizes the total number of frequency bands or channels. The proposed algorithm consists of two phases: 1) calls in most crowded cells are assigned channels by a heuristic method, and 2) calls in the other cells are assigned channels by a neural network. The performance is verified through eight benchmark problems, where our algorithm always finds the optimum or near-optimum solutions. The comparison of simulation results shows that the solution quality is better than the existing algorithms.

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A gradual neural-network approach for frequency assignment in satellite communication systems

Nobuo Funabiki, Seishi Nishikawa

IEEE Transactions on Neural Networks   8 ( 6 )   1359 - 1370   1997

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A novel neural-network approach called gradual neural network (GNN) is presented for a class of combinatorial optimization problems of requiring the constraint satisfaction and the goal function optimization simultaneously. The frequency assignment problem in the satellite communication system is efficiently solved by GNN as the typical problem of this class in this paper. The goal of this NP-complete problem is to minimize the cochannel interference between satellite communication systems by rearranging the frequency assignment so that they can accommodate the increasing demands. The GNN consists of N × M binary neurons for the N-carrier-M-segment system with the gradual expansion scheme of activated neurons. The binary neural network achieves the constrain satisfaction with the help of heuristic methods, whereas the gradual expansion scheme seeks the cost optimization. The capability of GNN is demonstrated through solving 15 instances in practical size systems, where GNN can find far better solutions than the existing algorithm. © 1997 IEEE.

DOI： 10.1109/72.641459

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A Binary Neural Network Algorithm for the Graph Partitioning Problem

TAMAKI Yasuhiro, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   96 ( 430 )   49 - 56   1996.12

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In this paper, we present a neural network algorithm using binary neurons for a graph two-partitioning problem. For a given graph G(V, E), the goal of this NP-hard problem is to find a partition of vertices in V into two groups such that not only the sum of vertex-weights in each group is within the upper bound, but also the sum of edge-weights between groups is minimized. We formulate a new energy function and introduce a shaking term in the motion equation in order to improve the solution quality. We compare the performance of the neural network with two existing typical algorithms through simulations in unweighted and weighted random graphs. The results show that the neural network is comparable with existing algorithms for vertex-unweighted graphs in terms of the solution quality, and that it is much better for vertex-weighted graphs.

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An Evaluation of Four Existing Algorithms and a New Neural Network Algorithm for Traveling Salesman Problems

SHIKATA Yasuhito, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   96 ( 430 )   33 - 40   1996.12

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The traveling salesman problem is a well-known NP-hard combinatorial optimization problem. To solve the problem many researchers have developed algorithms. In this paper, first, we compare the features of 4 main algorithms. Second, we propose a new neural network algorithm whose energy function takes 0 when the neuron outputs represent a tour. At last, we compare their performance with 5 bench mark problems .The results show that It is found that a proposal algorithm is superior to trivial neural network but inferior to these algorisms.

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A Neural Network Algorithm for the Minimum Maximal Matching Problem

UMETANI Shunji, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   96 ( 393 )   17 - 24   1996.11

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For a given graph G(V,E), a subset M of E is called a matching of G if no pair of edges in M is adjacent to each other. In this paper, we present a neural network parallel algorithm for the minimum maximal matching problem. This NP-complete problem requires to find a maximal matching composed of the least number of edges in G. The neural network consists of N × N binary neurons for the N-vertex graph problem. In order to improve the solution quality, we present a heuristic term into the motion equation for diagonal neurons which represent the exclusion of vertices from the matching. We verify the performance through simulations using random graph, where our neural network finds better solutions than the greedy algorithm and the simulated annealing.

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"Winner-take-all" methods of Maximum neuron model

TAKENAKA Yoichi, FUNABIKI Nobuo, NISHIKAWA Seishi

Technical report of IEICE. SS   96 ( 347 )   25 - 32   1996.11

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The maximum neuron model provides efficient neural network solutions for combinatorial optimization problems. In this "winner-take-all" model, one and only one neuron with the maximum input value is always fired in each group of neurons to satisfy the selection constrain. The maximum neuron model can not only reduce the searching space, but also save the computation load. In this paper, we propose two methods of selecting one neuron from two or more neurons which have same maximum input value, named "Least index method" and "Previous selection method". The simulation results show that the performance of the previous selection method performs better than the least index method generally.

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A maximum neural network algorithm for route selection problems in multihop radio networks

BABA Takayuki, HIROAKI Yoshio, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   96 ( 331 )   9 - 16   1996.10

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In a multihop radio network, packets are transmitted from source nodes to destination nodes by activating several links between nodes. Each node can either send a packet to or receive a packet from at most one of its adjacent nodes simultaneously. In order to minimize the transmission time for given requests, the problems must be solved of selecting a transmission route for each request (the routing problem) and of finding a link activation schedule (the link activation problem). The routing problem is decomposed into two sub-problems; the candidate extraction problem and the route selection problem. In this paper, we propose a neural network algorithm using the maximum neuron model for the route selection problem. We verify the performance through simulations, where our algorithm finds better solutions in shorter time than the existing algorithms. We also prove the NP-hardness of this problem.

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A Neural Network Algorithm for the Graph Partitioning Problem

TAMAKI Yasuhiro, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   96 ( 178 )   99 - 106   1996.7

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The graph partitioning problem requires to partition the vertices of a given graph into several groups within the specified size so as to minimize the sum of the edge weights between groups. In this paper, we propose a neural network algorithm for the graph two-partitioning problem using the binary neuron model. We introduce the shaking term inthe motion equation in order to improve the solution quality. For the performance evaluation, we applied the proposed algorithm for random graphs to compare the running time and the solution quality with existing algorithms. As for solution quality, our algorithm is nearly equal to the KL algorithm, whereas as for the running time, our algorithm is much faster than the KL algorithm.

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Maximum Neural Network Algorithms for N-Queen Problems

TAKENAKA Yoichi, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Theoretical foundations of Computing   95 ( 498 )   77 - 84   1996.1

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This paper presents maximum neural network algorithms for N-queen problems using the maximum neuron model. The maximum neuron model is proposed by Takefuji et al. in order to provide efficient neural network solutions for combinatorial optimization problems. In this model, one and only one neuron is always fired in each group of neurons, which can not only reduce the searching space drastically but also save the computation load. The simulation results show that the performance of our maximum neural network surpasses the existing neural network for the same problem. Particularly, the maximum neural network is shown to be much suitable for the semi-synchronous computation.

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A Neural Network Parallel Algorithm for One-shot Scheduling Problems in Multicast Packet Switching Systems with the Windowed Service

BABA Takayuki, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Theoretical foundations of Computing   95 ( 498 )   93 - 102   1996.1

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The multicast packet switching system with the windowed service can replicate a packet in each window and sent out the copies from different output ports simultaneously. In order to maximize the throughput, the problem must be solved in real time to find a switching configuration not only satisfying the constraints on the system, but also maximizing the number of copied packets under transmission demands. In this paper, we focus on the one-shot scheduling problem in the system where all copies of each packet must be sent simultaneously. First, we prove the NP-hardness of the problem. Then, we propose the neural network composed of W x N binary neurons for the N-input-port-W-window system. We verify the performance through simulations in up to 100-ports-3-window systems, where our neural network always finds near-optimum solutions within the constant number of iteration steps.

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A Proposal of a Neural Network Parallel Algorithm for Stable Marriage Problems

TAJIMA Shigeto, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Theoretical foundations of Computing   95 ( 498 )   85 - 92   1996.1

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The stable marriage problem requires to find N stable pairs of N men and N women under given preference lists. A pair is unstable when a man and a woman who are not partners prefer each other to their actual partners. In this paper, we propose a neural network parallel algorithm for the stable marriage problem. We verify the performance through simulations on the synchronous parallel computation.

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A neural network model for multilayer topological via minimization in a switchbox

Nobuo Funabiki, Seishi Nishikawa

IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems   15 ( 8 )   1012 - 1020   1996

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This paper presents a new approach using a neural network model for the multilayer topological via minimization problem in a switchbox. Our algorithm consists of three steps: 1) dividing multiterminal nets into two-terminal nets, 2) finding a layer-assignment of the twoterminal nets by a neural network model so as to minimize the number of unassigned nets, and 3) embedding one via for each imassigned net by Marek-Sadowska's algorithm. The neural network model is composed of N x M processing elements to assign N two-terminal nets in an M -layer switchbox. The performante of our algorithm is verified by 15 benchmark problems where it can find optimum or near-optimum solutions. In the two-layer Burstein's switchbox, our algorithm finds a 15-via solution while the best known solution requires 20 vias. © 1996 IEEE.

DOI： 10.1109/43.511580

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Comparisons of energy-descent optimization algorithms for maximum clique problems

FUNABIKI N.

IEICE Trans. Fundamentals   79 ( 4 )   452 - 460   1996

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A clique of a graph G (V,E) is a subset of V such that every pair of vertices is connected by an edge in E. Finding a maximum clique of an arbitrary graph is a well-known NP-complete problem. Recently, several polynomial time "energy-descent optimization" algorithms have been proposed for approximating the maximum clique problem, where they seek a solution by minimizing the energy function representing the constraints and the goal function. In this paper, we propose the binary neural network as an efficient synchronous energy-descent optimization algorithm. Through two types of random graphs, we compare the performance of four promising energy-descent optimization algorithms. The simulation results show that "RaCLIQUE," the modified Boltzmann machine algorithm, is the best asynchronous algorithm for random graphs, while the binary neural network is the best one for k random cliques graphs.

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Neural networks for the unicast problem and the multicast problem in the multicast packet switching system

BABA Takayuki, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   95 ( 405 )   83 - 89   1995.12

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With the packet replication, the multicast packet switching system with N input ports and N output ports can send n(≦N) copies of each packet to different output ports simultaneously. In order to maximize the throughput, the problem must be solved in real time to find a switching configuration not only satisfying the constraints on the system but also sending the maximum number of copied packets under transmission demands. In this paper, first, we focus on the unicast problem (n=1) in the multicast packet switching system and we solve by using the improved neural network. Then, we extend this idea to the multicast problem (n≧2) and we newly propose a neural network. We verified the performance through simulations, where our neural network can always find optimum solutions within constant number of iteration steps.

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A study on the parallel computation of the neural network for N-Queen problems

YOSHIO Hiroaki, FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE technical report. Neurocomputing   95 ( 405 )   75 - 82   1995.12

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The N-Queen problem has been studied by many researchers as the typical combinatorial optimization problem. In this paper, we first compared the performance of two existing neural networks both on the sequential computation and on the synchronous parallel computation. Then, we improved the parallel computation so as to avoid the degradation of the convergence rate. Finally, we proposed the asynchronous parallel computation which is suitable for a parallel machine with a maximum of N processors. We verified through simulations that the proposed method provides 100% convergence rate in up to 500-Queen problems.

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"An improved neural network for channel assignment problems in cellular mobile communication systems,"

FUNABIKI Nobuo, NISHIKAWA Seishi

IEICE Transactions on Communications   E78-B ( 8 )   1187 - 1196   1995.8

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This paper presents an improved neural network for channel assignment problems in cellular mobile communication systems in the new co-channel interference model. Sengoku et al. first proposed the neural network for the same problem, which can find solutions only in small size cellular systems with up to 40 cells in our simulations. For the practical use in the next generation's cellular systems, the performance of our improved neural network is verified by large size cellular systems with up to 500 cells. The newly defined energy function and the motion equation with two heuristics in our neural network achieve the goal of finding optimum or near-optimum solutions in a nearly constant time.

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Neural Networks for Access Control in Multicast Packet Switching System

BABA Takayuki, FUNABIKI Nobuo, NISHIKAWA Seishi

Proceedings of the IEICE General Conference   75 - 75   1995

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Neural Networks for The N-Queen problems

YOSHIO Hiroaki, FUNABIKI Nobuo, NISHIKAWA Seishi

Proceedings of the IEICE General Conference   17   17 - 17   1995

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

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A parallel algorithm for traffic control problems in three-stage connecting networks

Nobuo Funabiki, Yoshiyasu Takefuji

Journal of Parallel and Distributed Computing   20 ( 2 )   236 - 240   1994

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A parallel heuristic algorithm for traffic control problems in three-stage connecting networks is presented in this paper. A three-stage connecting network consists of an input crossbar switching stage, an intermediate crossbar switching stage, and an output crossbar switching stage. The goal of our algorithm is to quickly and efficiently find a conflict-free switching assignment for communication demands through the network. The algorithm requires n2 × m processing elements for the network composed of n input/output switches and m intermediate switches, where it runs not only on a sequential machine, but also on a parallel machine with maximally n2 × m processors. The algorithm was verified by 1100 simulation runs with the network size from 102 × 7 to 502 × 27. The simulation results show that the algorithm can find a solution in nearly constant time with n2 × m processors. © 1994 Academic Press, Inc.

DOI： 10.1006/jpdc.1994.1022

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A Parallel Algorithm for Time-Slot Assignment Problems in TDM Hierarchical Switching Systems

Nobuo Funabiki, Yoshiyasu Takefuji

IEEE Transactions on Communications   42 ( 10 )   2890 - 2898   1994

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This paper presents a parallel algorithm for timeslot assignment problems in TDM hierarchical switching systems, based on the neural network model. The TDM systems are operated. in repetitive frames composed of several Time-Slots. A Time-Slot represents a switching configuration where one packet is transmitted through an I/O line. The goal of our algorithm is to find conflict-free Time-Slot assignments for given switching demands. The algorithm runs on a maximum of n2×m processors for m-Time-Slot problems in n×n TDM systems. In small problems up to a 24×24 TDM system, the algorithm can find the optimum solution in a nearly constant time, when it is performed on n2×m processors. © 1994 IEEE

DOI： 10.1109/26.328959

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A parallel multi-layer channel router on the HVH model

Nobuo Funabaki, Yoshiyasu Takefuji

Parallel Computing   19 ( 1 )   63 - 77   1993

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With the advancement of the silicon technology multi-layered VLSI circuits and PCBs (printed circuit boards) have been widely used. Based on the neural network model this paper presents the first parallel algorithm for multi-layer channel routing problems on the HVH model which minimize wiring areas in VLSI circuits and PCBs. The algorithm requires n × m × 2s processing elements for the n-net-m-track-3s-layer problem. The algorithm not only runs on a sequential machine but also on a parallel machine with maximally n × m × 2s processors. The algorithm is verified by solving seven benchmark problems where it finds better solutions than the existing algorithms for 6-12-layer problems in nearly constant time on a parallel machine. © 1993.

DOI： 10.1016/0167-8191(93)90105-T

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Comparisons of Seven Neural Network Models on Traffic Control Problems in Multistage Interconnection Networks

Nobuo Funabiki, Yoshiyasu Takefuji, Kuo Chun Lee

IEEE Transactions on Computers   42 ( 4 )   497 - 501   1993

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This paper presents performance comparisons of seven neural network models on traffic control problems in multistage interconnection networks. The decay term, three neuron models, and two heuristics were evaluated. The goal of the traffic control problems is to find conflict-free switching configurations with the maximum throughput. Our simulation results show that the hysteresis McCulloch-Pitts neuron model without the decay term and with two heuristics has the best performance. © 1993 IEEE

DOI： 10.1109/12.214695

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A Neural Network Approach to Topological Via-Minimization Problems

Nobuo Funabiki, Yoshiyasu Takefuji

IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems   12 ( 6 )   770 - 779   1993

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Toooloeical via-minimization (TVM) algorithms in two-layer channels based on the artificial neural network model are presented in this paper. TVM problems require not only assigning wires or nets between terminals without an intersection to one of two layers, but also a minimization of the number of vias, which are the single contacts of nets between two layers. The goal of our algorithms is to embed the maximum number of nets without an intersection. Two types of TVM problems are examined: split rectangular TVM (RTVM) problems and split circular TVM (CTVM) problems. Our algorithms require 3n processing elements for the n-net split RTVM problems, and 5n processing elements for the n-net split CTVM problems. The algorithms were verified by solving seven problems with 20 to 80 nets. The algorithms can be easily extended for more-than-two-layer problems. © 1993 IEEE

DOI： 10.1109/43.229751

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A Parallel Algorithm for Broadcast Scheduling Problems in Packet Radio Networks

Nobuo Funabiki, Yoshiyasu Takefuji

IEEE Transactions on Communications   41 ( 6 )   828 - 831   1993

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A parallel algorithm based on an artificial neural network model for broadcast scheduling problems in packet radio networks is presented. The algorithm requires n x m processing elements for an n-node-MSlot radio network problem. The algorithm is verified by simulating 13 different networks. © 1993 IEEE.

DOI： 10.1109/26.231903

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A neural network model for finding a near-maximum clique

Nubuo Funabiki, Yoshiyasu Takefuji, Kuo Chun Lee

Journal of Parallel and Distributed Computing   14 ( 3 )   340 - 344   1992.3

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A parallel algorithm based on the neural network model for finding a near-maximum clique is presented in this paper. A maximum clique of a graph G is a maximum complete subgraph of G where any two vertices are adjacent. The problem of finding a maximum clique is NP-complete. The parallel algorithm requires n processing elements for an n-vertex graph problem. The algorithm is verified by solving 230 different graph problems. The simulation results show that our computation time on a Macintosh IIfx is shorter than that of two better known algorithms on a Cray 2 and an IBM 3090 while the solution quality is similar. The algorithm solves a near-maximum clique problem in nearly constant time on a parallel machine with n processors. © 1992.

DOI： 10.1016/0743-7315(92)90072-U

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A Parallel Improvement Algorithm for the Bipartite Subgraph Problem

Kuo Chun Lee, Nobuo Funabiki, Yoshiyasu Takefuji

IEEE Transactions on Neural Networks   3 ( 1 )   139 - 145   1992

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Since McCulloch and Pitts proposed an artificial neuron model in 1943, several neuron models have been investigated. This paper proposes the first parallel improvement algorithm using the maximum neural network model for the bipartite subgraph problem. The goal of this NP-complete problem is to remove the minimum number of edges in a given graph such that the remaining graph is a bipartite graph. A large number of instances have been simulated to verify the proposed algorithm, with the simulation result showing that our algorithm finds a solution within 200 iteration steps and the solution quality is superior to that of the best existing algorithm. The algorithm is extended for the k-partite subgraph problem, where no algorithm has been proposed. © 1992 IEEE

DOI： 10.1109/72.105427

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A neural network parallel algorithm for clique vertex-partition problems

Nobuo Funabiki, Yoshiyasu Takefuji, Kuo Chun Lee, Yong Beom Cho

International Journal of Electronics   72 ( 3 )   357 - 372   1992

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A parallel algorithm based on a neural network model for solving clique vertex-partition problems in arbitrary non-directed graphs is presented in this paper. A clique of a graph G = (V, E) with a set of vertices V and a set of edges E is a complete subgraph of G where any pair of vertices is connected with an edge. A clique vertex-partition problem of a graph G is to partition every vertex in V into a set of disjointed cliques of G. The clique vertex-partition problem with the minimum number of cliques in an arbitrary graph is known to be NP-complete. The algorithm requires nm processing elements for the n vertex m partition problem. A total of 10 different problems with 8 vertex to 300 vertex graphs were examined where the algorithm found a solution in nearly constant time. The circuit diagram of the neural network model is also proposed in this paper. © 1992 Taylor &amp
Francis Ltd.

DOI： 10.1080/00207219208925578

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A Neural Network Parallel Algorithm for Channel Assignment Problems in Cellular Radio Networks

Nobuo Funabiki

IEEE Transactions on Vehicular Technology   41 ( 4 )   430 - 437   1992

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A parallel algorithm for channel assignment problems in cellular radio networks is presented in this paper. The channel assignment problem involves not only assigning channels or frequencies to each radio cell, but also satisfying frequency constraints given by a compatibility matrix. The proposed parallel algorithm is based on an artificial neural network composed of nm processing elements for an n-cell-m-frequency problem. The algorithm runs not only on a sequential machine but also on a parallel machine with up to a maximum of nm processors. The algorithm was tested by solving eight benchmark problems where the total number of frequencies varied from 100 to 533. The algorithm found the solutions in nearly constant time with nm processors. The simulation results showed that the algorithm found better solutions than the existing algorithm in one out of eight problems. © 1992 IEEE

DOI： 10.1109/25.182594

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A Parallel Algorithm for Channel Routing Problems

Nobuo Funabiki, Nobuo Funabiki, Yoshiyasu Takefuji

IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems   11 ( 4 )   464 - 474   1992

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A parallel algorithm for channel routing problems is presented in this paper. The channel routing problem is very important in the automatic layout design of VLSI circuits and printed circuit boards. The problem is to route the given interconnections between two rows of terminals on a multilayer channel where the channel area must be minimized. Although several algorithms have been proposed for two-layer problems, two-Iayer-and-over-the-cell problems, and three-layer problems, the current advancement of VLSI chip technology allows us to use four layers composed of two metal layers and two polysilicon layers for routing in a chip. The goal of the proposed parallel algorithm is to find the near-optimum routing solution for the given interconnections in a short time. The algorithm is applied for the four-layer channel routing problems where it requires n × m × 2 processing elements for the n-netm-track problem. The algorithm has three advantages over the conventional algorithms: 1) it can be easily modified for accommodating more than four-layer problems, 2) it runs not only on a sequential machine but also on a parallel machine with maximally n ×m × 2 processors, and 3) the program size is very small. The algorithm is verified by solving seven benchmark problems where the algorithm finds routing solutions in a nearly constant time with n × m × 2 processors. © 1992 IEEE

DOI： 10.1109/43.125094

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A Parallel Algorithm for Allocation of Spare Cells on Memory Chips

Nobuo Funabiki, Yoshiyasu Takefuji

IEEE Transactions on Reliability   40 ( 3 )   338 - 346   1991.8

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In manufacturing memory chips, Redundant Random Access Memory (RRAM) technology has been widely used because it not only provides repair of faulty cells but also enhances the production yield. RRAM has several rows and columns of spare memory cells which are used to replace the faulty cells. The goal of our algorithm is to find a spare allocation which repairs all the faulty cells in the given faulty-cell map. The parallel algorithm requires In processing elements for the n x n faulty-cell map problem. The algorithm is verified by many simulation runs. Under the simulation the algorithm finds one of the near-optimum solutions in a nearly constant time with 0(n) processors. The simulation results show the consistency of our algorithm. The algorithm can be easily extended for solving rectangular or other shapes of fault map problems. Reader Aids - Purpose: Present a new algorithm Special math needed for explanations: Probability Special math needed to use results: None Results useful to: Reliability theoreticians and analysts. © 1991 IEEE

DOI： 10.1109/24.85454

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A NEURAL NETWORK APPROACH TO BROADCASTING IN MULTIHOP PACKET RADIO NETWORKS

N FUNABIKI, Y TAKEFUJI, KC LEE, YB CHO, T KUROKAWA, H AISO

1991 IEEE INTERNATIONAL JOINT CONFERENCE ON NEURAL NETWORKS, VOLS 1-3   2540 - 2545   1991

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