Faculty Profiles - FUNABIKI Nobuo

MISC - FUNABIKI Nobuo

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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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Language：English Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

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

Language：Japanese Publisher：Information Processing Society of Japan (IPSJ)

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

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

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

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

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

Language：English Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

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

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

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

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

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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