2021/07/12 更新

写真a

ヨコヒラ トクミ
横平 徳美
YOKOHIRA Tokumi
所属
ヘルスシステム統合科学学域 教授
職名
教授
外部リンク

学位

  • 工学博士 ( 大阪大学 )

研究キーワード

  • 計算機・通信システムの性能評価

  • 通信プロトコル

  • コンピュータネットワーク

  • Performance Evaluation of Computer and Communication Systems

  • Communication Protocol

  • Computer Networks

研究分野

  • 情報通信 / 情報学基礎論

  • ものづくり技術(機械・電気電子・化学工学) / 通信工学

学歴

  • 大阪大学   Graduate School, Division of Engineering Science  

    - 1989年

      詳細を見る

  • 大阪大学    

    - 1989年

      詳細を見る

    国名: 日本国

    researchmap

  • 大阪大学   Faculty of Engineering Science  

    - 1984年

      詳細を見る

  • 大阪大学   基礎工学部   情報工学科

    - 1984年

      詳細を見る

    国名: 日本国

    researchmap

経歴

  • - Professor,Industrial Innovation Sciences,Graduate School of Natural Science and Technology,Okayama University

    2005年

      詳細を見る

  • - 岡山大学自然科学研究科産業創成工学専攻 教授

    2005年

      詳細を見る

  • Professor,Faculty of Engineering,Okayama University

    2003年 - 2005年

      詳細を見る

  • 岡山大学工学部通信ネットワーク工学科 教授   Faculty of Engineering, Department of Communication Network Engineering

    2003年 - 2005年

      詳細を見る

  • Associate Professor,Faculty of Engineering,Okayama University

    2000年 - 2003年

      詳細を見る

  • 岡山大学工学部通信ネットワーク工学科 助教授   Faculty of Engineering, Department of Communication Network Engineering

    2000年 - 2003年

      詳細を見る

  • 岡山大学工学部情報工学科 助教授   Faculty of Engineering

    1994年 - 2000年

      詳細を見る

  • Associate Professor,Faculty of Engineering,Okayama University

    1994年 - 2000年

      詳細を見る

  • Senior Assistant Professor,Faculty of Engineering,Okayama University

    1990年 - 1994年

      詳細を見る

  • 岡山大学工学部情報工学科 講師   Faculty of Engineering

    1990年 - 1994年

      詳細を見る

  • 岡山大学工学部情報工学科 助手   Faculty of Engineering

    1989年 - 1990年

      詳細を見る

  • Research Associate,Faculty of Engineering,Okayama University

    1989年 - 1990年

      詳細を見る

▼全件表示

所属学協会

 

MISC

  • Link Capacity Provisioning and Server Location Decision in Server Migration Service

    Yukinobu Fukushima, Tutomu Murase, Tokumi Yokohira

    IEEE International Conference on Cloud Networking (CloudNet 2018)   ???-???   2018年

     詳細を見る

  • The Effect of Using Attribute Information in Network Traffic Prefdiction with Deep Learning

    Yusuke Tokuyama, Yukinobu Fukushima, Tokumi Yokohira

    International Conference on ICT Convergence 2018 (ICTC 2018)   ???-???   2018年

     詳細を見る

  • Backoff Algorithms to Avoid TCP Incast in Data Center Networks

    Shigeyuki Osada, Daichi Izumi, Shiden Kishimoto, Yukinobu Fukushima, Tokumi Yokohira

    International Conference on ICT Convergence 2018 (ICTC 2018)   ???-???   2018年

     詳細を見る

  • Determining Server Locations in Server Migration Service to Minimize Monetary Penalty of Dynamic Server Migration

    Yukinobu Fukushima, Tutomu Murase, Gen Motoyoshi, Tokumi Yokohira, Tatsuya Suda

    Journal of Network and Systems Management   26 ( 4 )   993 - 1033   2018年

     詳細を見る

  • Workplace Capacity Design Using the Minimum Dominating Set in Server Migration Services

    Yukinobu Fukushima, Itsuho Goda, Tutomu Murase, Tokumi Yokohira

    The 9th IFIP International Conference on New Technologies, Mobility and Security (NTMS 2018)   ???-???   2018年

  • Improvement of a TCP incast avoidance method using a fine-grained kernel timer

    Shigeyuki Osada, Shogo Wakai, Yukinobu Fukushima, Tokumi Yokohira

    International Conference on Information and Communication Technology Convergence: ICT Convergence Technologies Leading the Fourth Industrial Revolution, ICTC 2017   2017-   147 - 152   2017年12月

     詳細を見る

    記述言語:英語   出版者・発行元:Institute of Electrical and Electronics Engineers Inc.  

    When a standard TCP implementation using the minimum retransmission timeout (RTOmin) of 200 ms is used in distributed file systems in data centers, a well-known throughput degradation called TCP Incast occurs, because 200 ms is too large as an RTOmin in data centers. In order to avoid TCP Incast, a TCP implementation using a much smaller RTOmin attained by a fine-grained kernel timer is proposed. However, throughput still decreases in the implementation when the number of servers in distributed file systems is large. In this paper, we propose an improvement method introducing a new TCP option which enables a client to request servers to retransmit packets in a better timing. Numerical examples obtained by extensive simulation runs show the effectiveness of the improved method.

    DOI: 10.1109/ICTC.2017.8190962

    Scopus

    researchmap

  • A Prototype Virtual Network Embedding System Using OpenStack,

    Yukinobu Fukushima, Kohei Sato, Itsuo Goda, Heung-Gyoon Ryu, Tokumi Yokohira

    IEIE Transactions on Smart Processing & Computing   6 ( 1 )   60 - 65   2017年

     詳細を見る

  • Power-Aware server location decision in server migration service

    Yukinobu Fukushima, Tokumi Yokohira, Tutomu Murase, Tatsuya Suda

    2016 International Conference on Information and Communication Technology Convergence, ICTC 2016   150 - 155   2016年11月

     詳細を見る

    記述言語:英語   出版者・発行元:Institute of Electrical and Electronics Engineers Inc.  

    The server migration service (SMS) is an optional service that improves communication QoS of the IaaS cloud service. In the SMS, small-scale data centers (micro data centers) called work places (WPs) are deployed at various locations in the network. In the SMS, a network application (a NW-App) consists of one or more server-side processes of the application (servers) and one or more client-side processes of the application (clients). In the SMS, servers migrate among WPs in order to improve communication QoS between the servers and their clients, unlike in the IaaS cloud service where locations of the servers are always fixed at a data center in the network. In our previous study, we developed an integer programming model and solved it to determine when and to which WPs servers should migrate in the SMS in order to minimize the financial penalty, i.e., SMS provider's financial loss due to degradation of the communication QoS. In this paper, we consider the electricity power cost, an important component of the operational cost of the SMS, in addition to the financial penalty considered in our previous study, in determining when and to which WPs servers should migrate in the SMS. In this paper, we define the operational cost of the SMS as the sum of the financial penalty and electricity power cost and consider a power-Aware server location decision problem in order to minimize the operational cost of the SMS. We formulate the problem as a mixed-integer programming model and solve the model numerically. Numerical examples show that our mixed-integer programming model optimally determines the locations of the servers and decreases the operational cost by up to 15.5% compared to our previous integer programming model, where the power cost was not considered.

    DOI: 10.1109/ICTC.2016.7763457

    Scopus

    researchmap

  • TCP Incast avoidance based on connection serialization in data center networks

    Shigeyuki Osada, Ryo Miyayama, Yukinobu Fukushima, Tokumi Yokohira

    International Journal of Computer Networks and Communications   8 ( 4 )   83 - 102   2016年

     詳細を見る

    記述言語:英語   出版者・発行元:Academy and Industry Research Collaboration Center (AIRCC)  

    In distributed file systems, a well-known congestion collapse called TCP incast (Incast briefly) occurs because many servers almost simultaneously send data to the same client and then many packets overflow the port buffer of the link connecting to the client. Incast leads to throughput degradation in the network. In this paper, we propose three methods to avoid Incast based on the fact that the bandwidth-delay product is small in current data center networks. The first method is a method which completely serializes connection establishments. By the serialization, the number of packets in the port buffer becomes very small, which leads to Incast avoidance. The second and third methods are methods which overlap the slow start period of the next connection with the current established connection to improve throughput in the first method. Numerical results from extensive simulation runs show the effectiveness of our three proposed methods.

    DOI: 10.5121/ijcnc.2016.8406

    Scopus

    researchmap

  • Prototype Development of a Virtual Network Embedding System Using OpenStack

    Itsuho Goda, Kohei Sato, Yukinobu Fukushima, Heung-Gyoon Ryu, Tokumi Yokohira

    The 31st International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2016)   21 - 24   2016年

     詳細を見る

  • Nonlinearity Sensitivity of FBMC and UFMC Modulation System for the 5G Mobile System

    Changyoung An, Heung-Gyoon Ryu, Yukinobu Fukushima, Tokumi Yokohira

    The 31st International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2016)   1 - 4   2016年

     詳細を見る

  • Performance improvement of an AS-friendly peer selection algorithm for P2P live streaming

    Yukinobu Fukushima, Kazuki Kobayashi, Tokumi Yokohira

    International Journal of Computer Networks and Communications   8 ( 1 )   35 - 46   2016年

     詳細を見る

    記述言語:英語   出版者・発行元:Academy and Industry Research Collaboration Center (AIRCC)  

    Minimum Physical Hop (MPH) has been proposed as a peer selection algorithm for decreasing inter-AS (Autonomous System) traffic volume in P2P live streaming. In MPH, a newly joining peer selects a peer whose physical hop count (i.e., the number of ASes traversed on the content delivery path) from it is the minimum as its providing peer. However, MPH shows high inter-AS traffic volume when the number of joining peers is large. In this paper, we propose IMPH that tries to further decrease the inter-AS traffic volume by distributing peers with one logical hop count (i.e., the number of peers or origin streaming servers (OSSes) traversed on the content delivery path from an OSS to the peer) to many ASes and encouraging the following peers to find their providing peers within the same AS. Numerical examples show that IMPH achieves at the maximum of 64% lower inter-AS traffic volume than MPH.

    DOI: 10.5121/ijcnc.2016.8103

    Scopus

    researchmap

  • Load Modulation Based MIMO Communication for the Low Complexity and Low Power Consumption

    Changyoung An, Heung-Gyoon Ryu, Seung Hwan Lee, Masahiro Umehira, Tokumi Yokohira

    2016 IEEE International Conference on Consumer Electronics (ICCE 2016)   558 - 561   2016年

  • Candidate Path Selection Method for TCP Performance Improvement in Fixed Robust Routing

    Yukinobu Fukushima, Takashi Matsumura, Kazutaka Urushibara, Tokumi Yokohira

    IEIE Transactions on Smart Processing & Computing   5 ( 6 )   445 - 453   2016年

     詳細を見る

  • Modification of an Energy-Efficient Virtual Network Mapping Method for a Load-Dependent Power Consumption Model

    Shigeyuki Osada, Ryo Miyayama, Yukinobu Fukushima, Tokumi Yokohira

    WSEAS Transactions on Communications   15   240 - 250   2016年

     詳細を見る

  • A trail multi-splitting method for throughput improvement in light trail networks

    Yukinobu Fukushima, Wenjie Chen, Tokumi Yokohira

    PHOTONIC NETWORK COMMUNICATIONS   30 ( 2 )   178 - 189   2015年10月

     詳細を見る

    記述言語:英語   出版者・発行元:SPRINGER  

    Light trail networks have been proposed as an extension of lightpath networks in order to enable sub-wavelength bandwidth allocation in WDM networks. The networks need a medium access control (MAC) method to avoid collisions of data transmissions. We have proposed a MAC method which adopts a token-passing mechanism. The method splits one trail into two trails: one upstream trail and one downstream trail and permits independent data transmissions on the trails. However, the method leaves bandwidths of links upstream from the token-holding node idle because the method only splits the original trail into two trails and leaves the upstream trail unsplit. In this paper, we propose a novel token-passing MAC method for further improving trail throughputs. Our proposed method recursively splits the upstream trail, and consequently the original trail can be split into more than two trails. In the proposed method, an appropriate setting of upstream/downstream token-holding times of all nodes is a key factor to successfully accommodate an input traffic. Therefore, we tackle a problem (called a token-holding time decision problem) where we optimize token-holding times of all nodes so that input traffic is successfully accommodated. We formulate the problem as a linear programming model. Numerical examples on maximum effective throughput show that the proposed method is more superior as the ratio of short-hop traffic is higher in input traffic patterns.

    DOI: 10.1007/s11107-015-0509-z

    Web of Science

    researchmap

  • Strict application execution control with hierarchical group management using digital certificates on educational windows PCs

    Daisuke Okamoto, Keita Kawano, Nariyoshi Yamai, Tokumi Yokohira

    Journal of Information Processing   23 ( 4 )   449 - 457   2015年7月

     詳細を見る

    記述言語:英語   出版者・発行元:Information Processing Society of Japan  

    We have developed a system (traditional system) to flexibly provide the requested applications environment on educational Windows PCs. The traditional system dynamically controls the execution of applications installed on each educational PC depending on the rules defined by teachers as well as by administrators. The traditional system, however, has a low tolerance for malicious attacks. If the execution file of a certain application is falsified, the corresponding rules already applied become invalid. In addition, though the traditional system has a function to define groups of controlled applications, it does not support hierarchical groups. This reduces the usability of the traditional system. In order to address these issues, this paper proposes a control method of application execution using digital certificates. The proposed method has a high tolerance for the falsification of execution files by controlling their executions based on the reliability of the corresponding digital certificates. It also improves its usability by introducing hierarchical group management utilizing hierarchical structure for digital certificates.

    DOI: 10.2197/ipsjjip.23.449

    Scopus

    researchmap

  • Performance Evaluation of an Energy Efficient Virtual Network Mapping Method-In the case of load-dependent power consumption model-

    Yuta Hoshino, Yukinobu Fukushima, Tutomu Murase, Tokumi Yokohira, Tatsuya Suda

    The International Conference on Electronics and Software Science 2015 (ICESS 2015)   134 - 144   2015年

     詳細を見る

  • An On-line Algorithm to Determine the Location of the Server in a Server Migration Service

    Yuta Hoshino, Yukinobu Fukushima, Tutomu Murase, Tokumi Yokohira, Tatsuya Suda

    2015 12TH ANNUAL IEEE CONSUMER COMMUNICATIONS AND NETWORKING CONFERENCE   740 - 745   2015年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    In IaaS cloud services, QoS of network applications (NW-Apps) may degrade due to location factors such as significant distance between a server-side application (server) of a NW-App at a data center and a client-side application (client) of the NW-App at a client terminal. In order to shorten the distance and to improve the QoS, server migration services (SMSes) have been proposed. In SMSes, servers may migrate between different computers (called work places, WPs) on a network to prevent QoS degradation caused by the changes of client locations. Although server migrations can improve QoS of NW-Apps, they also generate a huge amount of traffic (server migration traffic) in the network. This paper focuses on a server location decision problem where the location of a server is decided in an on-line manner so that QoS of a NW-App is improved under the constraint that the server migration traffic has to be suppressed below an acceptable level. For the problem, we propose a practical on-line algorithm. The key idea behind the proposed algorithm is that the location of the server is decided with consideration of the QoS degradation in the future. The algorithm defines the averagely good location for the server where the QoS is expected to be relatively good for various client locations. Then, it keeps the range of the server's migration within the returnable range where the server can soon come back to the averagely good location. As a result, the QoS can be always kept as good as the one under the averagely good location. Simulation results show that the proposed algorithm improves QoS of the NW-App by up to 30% compared to a greedy algorithm.

    DOI: 10.1109/CCNC.2015.7158070

    Web of Science

    researchmap

  • Performance Improvement of SCTP Communication Using Selective Bicasting on Lossy Multihoming Environment

    Koki Okamoto, Nariyoshi Yamai, Kiyohiko Okayama, Keita Kawano, Motonori Nakamura, Tokumi Yokohira

    2014 IEEE 38TH ANNUAL INTERNATIONAL COMPUTERS, SOFTWARE AND APPLICATIONS CONFERENCE (COMPSAC)   551 - 557   2014年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    In recent years, with proliferation of smart phones and tablet PCs, speedup of wireless LAN communication is required for dealing with increase of traffic in wireless networks. However, transmission speed through a wireless network often slows down in comparison with that through a wired network since packets of wireless networks frequently drop due to the influence of surrounding environment such as electromagnetic noise. In this paper, we propose a method to mitigate the impacts caused by packet loss by virtue of SCTP bicasting in lossy multihoming environment with two or more wireless networks. This method bicasts not all packets but only important packets concerning retransmission for efficiency since bicasting all packets would cause congestion. We also implemented a prototype system based on the proposed method. According to the result of performance evaluation experiment, we confirmed the effectiveness of the proposed method by the fact that the prototype system performed faster transmission than normal SCTP transmission even in high packet loss rate environment.

    DOI: 10.1109/COMPSAC.2014.78

    Web of Science

    researchmap

  • Power Efficiency Evaluation of Medium Access Control Methods in Light Trail Networks

    Ryo Fukuyama, Yukinobu Fukushima, Tokumi Yokohira

    The 29th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2014)   338 - 341   2014年

     詳細を見る

  • Performance Evaluation of Overlay Construction Algorithms in Mesh-pull P2P Live Streaming

    Yukinobu Fukushima, Tokumi Yokohira

    The 29th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2014)   334 - 337   2014年

     詳細を見る

  • Power Consumption Evaluation of Light-trail Networks

    Yukinobu Fukushima, Tokumi Yokohira

    The 29th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2014)   289 - 292   2014年

     詳細を見る

  • AS-friendly Peer Selection Algorithm for P2P Live Streaming

    Yukinobu Fukushima, Tokumi Yokohira

    International Journal of Multimedia Technology   4 ( 2 )   63 - 73   2014年

     詳細を見る

  • Throughput Improvement of TCP Proxies in Network Environment with Wireless LANs

    Wang Hui, Yukinobu Fukushima, Tokumi Yokohira

    2014 IEEE Region 10 Technical Symposium (TENSYMP 2014)   86 - 91   2014年

     詳細を見る

  • A Reroute Method to Recover Fast from Network Failure

    Yasuhiro Harada, Wang Hui, Yukinobu Fukushima, Tokumi Yokohira

    2014 INTERNATIONAL CONFERENCE ON INFORMATION AND COMMUNICATION TECHNOLOGY CONVERGENCE (ICTC)   903 - 908   2014年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    The demand for high Internet availability has increased. As routing methods to recover fast from a single network component (link or node) failure, methods using multiple routing tables have been proposed. In the methods, when a component failure occurs, packets which are supposed to pass through the component in the failure-free state are rerouted using a routing table (backup table) which does not use the component for packet forwarding. Thus, it is important to decrease the increased routing cost (for example, the number of increased hops of rerouted packets if every link cost is one) due to the reroute as much as possible. In this paper, we propose a new routing method to decrease the increased routing cost. In the conventional methods, there are many components that do not fail but are not used for packet forwarding in a backup table. In our proposed method, we use such components as much as possible, and consequently we try to decrease the increased routing cost. Numerical examples show the effectiveness of our proposed method.

    DOI: 10.1109/ICTC.2014.6983329

    Web of Science

    researchmap

  • Optimization of Maximum Timeout Value in TCP with a Fine-grained Timer for Data Center Networks

    Ryo Miyayama, Shigeyuki Osada, Yukinobu Fukushima, Tokumi Yokohira

    2014 INTERNATIONAL CONFERENCE ON INFORMATION AND COMMUNICATION TECHNOLOGY CONVERGENCE (ICTC)   433 - 437   2014年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    When the standard TCP implementation is used in distributed. le systems in data center, a well-known throughput degradation called TCP Incast occurs. In order to avoid TCP Incast, a TCP implementation using a specialized. fine-grained timer is proposed. However, the throughput still decreases in the implementation when the number of servers in distributed. le systems is large. In this paper, we clarify that the cause of the decreasing is that maximum timeout value is too large and optimize the value.

    DOI: 10.1109/ICTC.2014.6983174

    Web of Science

    researchmap

  • A Multi-splitting Method for Light-trail Networks

    Yukinobu Fukushima, Tokumi Yokohira

    The 28th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2013)   803 - 806   2013年

     詳細を見る

  • A Wavelength and Converter Assignment Scheme using Converter Usage History in Wavelength-Routed Networks

    Yukinobu Fukushima, Takahiro Ooishi, Tokumi Yokohira

    International Journal of Computer Networks & Communicationsd   5 ( 4 )   63 - 73   2013年

     詳細を見る

  • Optimization of Server Locations in Server Migration Service

    Yukinobu Fukushima, Tutomu Murase, Tokumi Yokohira, Tatsuya Suda

    The Ninth International Conference on Networking and Services (ICNS 2013)   200 - 206   2013年

     詳細を見る

  • A Per-burst Traffic Distribution Method for TCP Performance Improvement in Fixed Robust Routing

    Yu Sezaki, Yukinobu Fukushima, Takahiro Nabeta, Tokumi Yokohira

    The 28th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2013)   819 - 822   2013年

     詳細を見る

  • Improvement of a TCP Incast Avoidance Method for Data Center Networks

    Kazutoshi Kajita, Shigeyuki Osada, Yukinobu Fukushima, Tokumi Yokohira

    International Conference on ICT Convergence 2013 (ICTC 2013)   459 - 464   2013年

  • A Reroute Method Using Multiple Routing Configurations for Fast IP Network Recovery

    Daiki Imahama, Yukinobu Fukushima, Tokumi Yokohira

    The 19th Asia-Pacific Conference on Communications (APCC 2013)   439 - 444   2013年

  • TCP Incast Avoidance Based on Connection Serialization in Data Center Networks

    Shigeyuki Osada, Kazutoshi Kajita, Yukinobu Fukushima, Tokumi Yokohira

    The 19th Asia-Pacific Conference on Communications (APCC 2013)   120 - 125   2013年

  • Decreasing of the Number of Backup Tables in Multiple Routing Table Method for Fast IP Network Recovery

    Daiki Imahama, Yukinobu Fukushima, Tokumi Yokohira

    The 28th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2013)   823 - 826   2013年

     詳細を見る

  • An Architecture and a MAC Protocol for Throughput Improvement in Light Trail Networks

    Wenjie Chen, Yukinobu Fukushima, Tokumi Yokohira

    IEICE TRANSACTIONS ON COMMUNICATIONS   E95B ( 7 )   2330 - 2343   2012年7月

     詳細を見る

    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    Light trail architecture is attracting attention as a new optical wavelength-division multiplexing network architecture that can be built with currently available devices and can achieve bandwidth allocation with granularity finer than a wavelength. Because a light trail is a shared medium, we need a medium access control (MAC) protocol to prevent collisions. Although MAC protocols using token passing can prevent collisions, the bandwidths of links that are located upstream of the token holding node are kept idle. We first propose a dynamic light trail splitting method for increasing throughput of a light trail by using such idle bandwidths. Our method splits a trail into upstream and downstream trails at the token holding node, and independent data transmission on the two trails are permitted. As a result, we expect that the split trail architecture will achieve higher throughput than the original non-split trail architecture. The degree of performance improvement with the split trail architecture depends on how appropriately we determine the upstream and downstream token holding times of every transmission node. Thus, we formulate a problem in which we optimize the token holding times to accommodate requested traffic volume as a linear programming problem. We then derive the throughput of the split trail architecture by solving the problem using the NUOPT solver and investigate the degree of improvement over the original architecture. In addition, we evaluate the end-to-end delay of the split trail architecture by simulation. According to numerical examples, the split trail architecture achieves 1) almost the same throughput as the original one for the worst-case traffic pattern where every transmission node sends data to the terminating node of the trail only, 2) about 1.6 times higher throughput for a uniform traffic pattern where every node pair requests the same traffic volume and an extremely unbalanced traffic pattern where only a few node pairs request huge traffic volume, 3) about 1.9 time higher throughput for the split trail architecture's good-case traffic pattern where every transmission node sends data to its adjacent downstream node only, and 4) the end-to-end delay enough to satisfy any application's QoS requirement according to ITU-T Recommendation Y.1541.

    DOI: 10.1587/transcom.E95.B.2330

    Web of Science

    researchmap

  • Throughput Improvement for TCP with a Performance Enhancing Proxy Using a UDP-Like Packet Sending Policy

    Hui Wang, Yuichi Nishida, Yukinobu Fukushima, Tokumi Yokohira, Zhen Wu

    IEICE TRANSACTIONS ON COMMUNICATIONS   E95B ( 7 )   2344 - 2357   2012年7月

     詳細を見る

    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    To improve TCP throughput even if the maximum receiving window size is small, a TCP performance enhancing proxy (PEP) using a UDP-like packet sending policy with error control has been proposed. The PEP operates on a router along a TCP connection. When the PEP receives a data packet from the source host, it transmits the packet to the destination host, copies the packet into the local buffer (PEP buffer) in case the packets need to be transmitted and sends a premature ACK acknowledging receipt of the packet to the source host. In the PEP, the number of prematurely acknowledged packets in the PEP buffer is limited to a fixed threshold (watermark) value to avoid network congestion. Although the watermark value should be adjusted to changes in the network conditions, watermark adjusting algorithms have not been investigated. In this paper, we propose a watermark adjusting algorithm the goal of which is to maximize the throughput of each connection as much as possible without excessively suppressing the throughputs of the other connections. In our proposed algorithm, a newly established connection uses the initial watermark value of zero to avoid drastic network congestion and increases the value as long as its throughput increases. In addition, when a new connection is established, every already-established connection halves its watermark value to allow the newly established connection to use some portion of the bandwidth and increases again as long as its throughput increases. We compare the proposed algorithm (CW method) with other methods: the FW method that uses a fixed large watermark value and the NP method that does not use the PER Numerical results with respect to throughput and fairness showed that the CW method is generally superior to the other two methods.

    DOI: 10.1587/transcom.E95.B.2344

    Web of Science

    researchmap

  • Hybrid Fixed Robust Routing Taking Account of TCP Performance

    Takahiro Nabeta, Yukinobu Fukushima, Tokumi Yokohira

    The 27th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2012), CD-ROM (4 pages)   2012年

     詳細を見る

  • Optimal TCP Receive Buffer Size under Packet Loss Environment

    Kazutoshi Kajita, Takumi Shinkai, Naohiro Honda, Yukinobu Fukushima, Tokumi Yokohira

    The 27th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2012), CD-ROM (4 pages)   2012年

     詳細を見る

  • Inter-AS Traffic Volume Reduction by Localizing Delivery for P2P Live Streaming

    Kazuki Kobayashi, Yukinobu Fukushima, Tokumi Yokohira

    2012 THIRD INTERNATIONAL CONFERENCE ON NETWORKING AND COMPUTING (ICNC 2012)   156 - 161   2012年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    In recent years, there is a big demand for live streaming service over the Internet. As one of the service model, peer-to-peer (P2P) live streaming has been utilized. In the system, it is important to decrease inter-AS (Autonomous System) traffic volume and content delivery delay because the larger volume leads to higher transit cost of ASes and this system treats the live contents, respectively. Therefore, as a conventional peer selection algorithm that tries to decrease them, Minimum Physical Hop (MPH) has been proposed. In MPH, to decrease inter-AS traffic volume, a newly joining peer selects a providing peer with the minimum physical hop count, which is the minimum number of ASes between the providing peer and the newly joining peer. Furthermore, to decrease content delivery delay, if there are several such candidates, it selects a providing peer with the minimum logical hop count, which is the number of Origin Streaming Servers (OSS) or peers passed from an OSS to the peer, from the candidates. However, MPH shows high inter-AS traffic volume when the number of joining peers is large. When we use MPH, candidates for providing peer with large logical hop count tend to swarm in ASes without an OSS while those with small logical hop count do in ASes with an OSS because of the peer selection policy of MPH. As the number of joining peers becomes large, the logical hop counts of the candidates for providing peer in every AS increase. As a result, in the former ASes, the logical hop counts of all the candidates for providing peer reach the upper bound frequently, and the newly joining peer cannot often find its providing peer in the AS, and consequently have to select providing peers in different ASes. In this paper, we improve MPH in order to further decrease the inter-AS traffic volume. In the improved algorithm called Improved Minimum Physical Hop (IMPH), we try to decrease the volume by distributing providing peers with one logical hop count to many ASes. As a result of the evaluation, we show that IMPH achieves to reduce the inter-AS traffic volume by at a maximum of 38% compared to MPH under uniform peer generation distributions.

    DOI: 10.1109/ICNC.2012.31

    Web of Science

    researchmap

  • A Solution to Transmission Halting In a New Flow Control Method TCP-fox

    Takumi Shinkai, Wang Hui, Hiroyuki Ishihara, Yuichi Nishida, Yukinobu Fukushima, Tokumi Yokohira

    18TH ASIA-PACIFIC CONFERENCE ON COMMUNICATIONS (APCC 2012): GREEN AND SMART COMMUNICATIONS FOR IT INNOVATION   806 - 811   2012年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    TCP-fox is a new flow control method for TCP (Transmission Control Protocol) which allows the sender of a connection to send packets over the receive window advertised by the receiver to obtain higher throughput. However, TCP-fox has the problem that it halts sending packets when the receiver uses a receive buffer auto tuning mechanism. In this paper, we investigate the cause of the halting and present a way to avoid it.

    DOI: 10.1109/APCC.2012.6388193

    Web of Science

    researchmap

  • Improvement of an ACK Returning Method of TCP Proxies in Network Environment with Wireless LANs

    Naohiro Honda, Wang Hui, Yuichi Nishida, Yukinobu Fukushima, Tokumi Yokohira

    The 1st IEEE Global Conference on Consumer Electronics (GCCE 2012)   715 - 719   2012年

  • Destination selection algorithm in a server migration service

    Asato Yamanaka, Yukinobu Fukushima, Tokumi Yokohira, Tutomu Murase, Tatsuya Suda

    Proceedings of the 7th International Conference on Future Internet Technologies, CFI'12   15 - 20   2012年

     詳細を見る

    記述言語:英語  

    Using network virtualization technologies for network applications (NW-Apps) consisting of server and clients, we can implement a server migration service where there are many server running environments (working places: WPs) inside a network and servers onWPs can migrate to otherWPs when communication QoSs in some NW-Apps fall off. Because server size is large, the traffic for server migration causes QoS degradation of its background traffic. Thus, it is important to decrease the degree (network impact) of the QoS degradation. In this paper, we propose three destination selection algorithms, MIA (Minimum Impact Algorithm), MRA (Maximum Remaining space Algorithm) and MCA (Maximum Covering Algorithm) that try to decrease the impact while increasing the number of NW-Apps' clients whose SLA (service level agreement) are satisfied. When a server migration is triggered, MIA, MRA and MCA move the server in the WP with the minimum impact, the WP with the maximum remaining space for servers and the WP with the maximum coverage, which is the number of routers under which the corresponding clients can communicate with the server while satisfying the SLA, respectively. Numerical examples show that when the number of accommodatable servers in full-cover WP (a full-cover WP is such WP that communicates with an arbitrary client while satisfying the SLA) is small or there is no full-cover WP, MIA outperforms the others, otherwise MCA outperforms the others. Copyright © 2012 by the Association for Computing Machinery, Inc.

    DOI: 10.1145/2377310.2377315

    Scopus

    researchmap

  • Multi-stage change-point detection scheme for large-scale simultaneous events

    Yukinobu Fukushima, Tutomu Murase, Masayoshi Kobayashi, Hiroki Fujiwara, Ryohei Fujimaki, Tokumi Yokohira

    COMPUTER COMMUNICATIONS   34 ( 15 )   1810 - 1821   2011年9月

     詳細を見る

    記述言語:英語   出版者・発行元:ELSEVIER SCIENCE BV  

    Change-point detection schemes, which represent one type of anomaly detection schemes, are a promising approach for detecting network anomalies, such as attacks and epidemics by unknown viruses and worms. These events are detected as change-points. However, the schemes generally also detect false-positive change-points caused by other events, such as improper parameter setting of detectors. Therefore there is a requirement for a scheme that detects only true-positive change-points caused by attacks and epidemics by unknown viruses and worms. The true-positive change-points tend to occur simultaneously and intensively in very large numbers, while the false-positive change-points tend to occur independently. Therefore, we expect that the multi-stage change-point detection scheme, which performs change-point detection in a distributed manner and takes account of the correlation among multiple change-points, can exclude false-positive change-points by neglecting those that occur independently. In this paper, we propose the multi-stage change-point detection scheme and introduce a weighting function that gives smaller weight to LDs with higher false-positive rate inferred by GD in order to avoid a set of false-positive alerts generated by the low-accuracy detectors from causing high false-positive rate of the scheme. We evaluate the performance of the scheme by a simulation using the parameter values obtained in an experiment using real random scan worms. In the evaluation, we modify AAWP (Analytical Active Worm Propagation) model so that it can derive the number of infected hosts (i.e., attack hosts) more accurately by considering a failure of infection behavior by random scan worms. The simulation results show that our scheme can achieve an optimal performance (detection rate of 1.0 and false-positive rate of 0) while the stand-alone change-point detection scheme, which does not use the correlation among multiple change-points, cannot attain such optimal performance, and our scheme with alert weighting always shows better detection performance than the scheme without alert weighting. (C) 2011 Elsevier B.V. All rights reserved.

    DOI: 10.1016/j.comcom.2011.05.001

    Web of Science

    researchmap

  • Optimization of Token Holding Times in Split Light Trail Networks

    Wenjie Chen, Yukinobu Fukushima, Tokumi Yokohira

    IEEE Globecom 2011   2011年

  • Performance Evaluation of TCP over Multiple Paths in Fixed Robust Routing

    Wenjie Chen, Yukinobu Fukushima, Takashi Matsumura, Yuichi Nishida, Tokumi Yokohira

    IEEE Communications Society Communications Quality and Reliability Workshop 2011 (CQR 2011)   2011年

     詳細を見る

  • Early Detection of Increasing Traffic with Distributed Traffic Measurement

    Yukinobu Fukushima, Mamoru Niboshi, Tutomu Murase, Ryohei Fujimaki, Shunsuke Hirose, Tokumi Yokohira

    TENCON 2010: 2010 IEEE REGION 10 CONFERENCE   809 - 814   2010年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    With the spread of broadband access lines, many bandwidth-consuming services such as video streaming have appeared. The popularity of these services can cause problems such as the shortage of the Internet backbone capacity, so it is important to detect increasing traffic caused by these services early. Conventional detection method called aggregation method tries to detect increasing traffic by predicting its future traffic volume with linear approximation. However, the aggregation method may not cope with increasing traffic whose growth is more rapid than linear growth. In this paper, we propose an early detection method (partial aggregation method) of increasing traffic under per-subnet based distributed traffic measurement. The method predicts 1) future traffic volume for each address in each subnet and 2) the number of subnets having increasing traffic in the future with a linear approximation. Then, the method estimates future traffic volume for each address as a product of the predicted future traffic volume in each subnet and the predicted subnet number. As a result, the method is expected to cope with rapid growth in traffic volume. Simulation results show that the partial aggregation method can detect increasing traffic earlier than the aggregation method by a maximum of 90 days.

    DOI: 10.1109/TENCON.2010.5686580

    Web of Science

    researchmap

  • Performance Evaluation of Multi-stage Change-point Detection Scheme with Alert Weighting

    Mari Nakagawa, Yukinobu Fukushima, Tutomu Murase, Ryohei Fujimaki, Shunsuke Hirose, Tokumi Yokohira

    TENCON 2010: 2010 IEEE REGION 10 CONFERENCE   785 - 790   2010年

     詳細を見る

    記述言語:英語   出版者・発行元:IEEE  

    As a detection method of large-scale simultaneous events (e.g., DDoS attack), a multi-stage change-point detection scheme with alert weighting was proposed. In the scheme, local detectors (LDs), which are deployed on each monitored subnet, try to detect an event by change-point detection. If they do, they send an alert to global detector (GD). Then GD judges whether an event is occurring by comparing the weight sum of the received alerts with an predetermined threshold value. The weight of an alert is set lower for LDs with higher false-positive rate (FPR). Conventional evaluation results only showed that alert weighting improves the performance for particular combination of two kinds of LDs with different FPRs. In this paper, we investigate the effectiveness of alert weighting for various combinations of two kinds of LDs with different FPRs in detail. We first consider the situation where detection rates (DRs) of all LDs are identical. Then, we consider the situation where high-FPR LDs show higher DR than low-FPR LDs, which is more realistic. Simulation results show that 1) alert weighting does not lead to degradation of detection performance and 2) alert weighting is most effective when event scale is moderate in our numerical examples.

    DOI: 10.1109/TENCON.2010.5686586

    Web of Science

    researchmap

  • TCP-fox: A New Flow Control Method for Improving TCP Throughput in Large Bandwidth-Delay Product Networks

    Yuichi Nishida, Hiroyuki Ishihara, Wang Hui, Yukinobu Fukushima, Tokumi Yokohira

    International Symposium on Broadband Communication (ISBC) 2010   2010年

     詳細を見る

  • Performance Evaluation of TCP Proxies in Network Environment Including Wireless LANs

    Yuichi Nishida, Wang Hui, Yukinobu Fukushima, Tokumi Yokohira

    The 25th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2010)   1231 - 1234   2010年

     詳細を見る

  • AS-friendly Peer Selection Algorithms without AS Topology Information in P2P Live Streaming

    Yukinobu Fukushima, Yin Tao, Kazuya Inada, Tokumi Yokohira

    The Eighth Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT 2010)   2010年

     詳細を見る

  • Throughput Improvement of TCP using Split-Connection Type Proxies in Network Environment including Wireless LANs

    Yuichi Nishida, Wang Hui, Hiroaki Matsumoto, Hiroyuki Ishihara, Tokumi Yokohira, Yukinobu Fukushima

    The 24th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2009   1360 - 1363   2009年

     詳細を見る

  • Accuracy Improvement of Multi-Stage Change-Point Detection Scheme by Weighting Alerts based on False-Positive Rate

    Yukinobu Fukushima, Tutomu Murase, Ryohei Fujimaki, Syunsuke Hirose, Tokumi Yokohira

    IEEE Communications Society Communications Quality and Reliability Workshop 2009 (CQR 2009)   2009年

     詳細を見る

  • Performance Evaluation of Medium Access Control Methods in Light Trail Networks

    Yukinobu Fukushima, Kota Tanaka, Tokumi Yokohira

    11TH INTERNATIONAL CONFERENCE ON ADVANCED COMMUNICATION TECHNOLOGY, VOLS I-III, PROCEEDINGS,   1421 - 1425   2009年

     詳細を見る

    記述言語:英語   出版者・発行元:ELECTRONICS TELECOMMUNICATIONS RESEARCH INST  

    We evaluate performance of two medium access control methods with token passing, LT-FA MAC and ART MAC, in light trail networks. LT-FA MAC aims at coping with bursty packet arrivals while ART MAC aims at decreasing transmission delay. Simulation evaluation is performed in terms of the number of the maximum transmission nodes accommodated on a light trail and the maximum communication distance under the constraints that the bandwidth utilization rate of 90% and the average transmission delay of 100 ms must be achieved. Simulation results show that ART MAC permits about 500-1500km longer communication distance than LT-FA MAC with the same number of transmission nodes on a light trail and ART MAC accommodates about 15-25 more nodes than LT-FA MAC with the same communication distance.

    Web of Science

    researchmap

  • Performance evaluation of AS-friendly peer selection algorithms for P2P live streaming

    Yukinobu Fukushima, Kazuya Inada, Yin Tao, Yasuyuki Fujiwara, Tokumi Yokohira

    2009 15th Asia-Pacific Conference on Communications, APCC 2009   866 - 870   2009年

     詳細を見る

    記述言語:英語  

    In this paper, we evaluate the performance of peer selection algorithms: MLH (Minimum Logical Hop) and MPH (Minimum Physical Hop) to increase the number of joining peers and to decrease inter-AS traffic volume in P2P live streaming, where we assume that every peer's logical hop count (the number of providing peers between an origin streaming server and the peer) is limited by a predetermined value in order to keep real-time property of live streaming. In MLH, a newly joining peer selects such providing peers that the logical hop count is minimum to increase the number of joining peers. And then if there are several such providing peers, the newly joining peer selects such providing peers that the number (physical hop count) of ASs between the newly joining peer and each of the providing peers is minimum to decrease the inter-AS traffic volume. In MPH, a newly joining peer selects providing peers in the reverse order of MLH. Simulation results show that MLH achieves about from 20% to 60% more maximum joining peers than MPH, and MPH shows smaller inter-AS traffic volume than MLH when the number of joining peers is small while MLH shows smaller inter-AS traffic volume when the number of joining peers is large. ©2009 IEEE.

    DOI: 10.1109/APCC.2009.5375467

    Scopus

    researchmap

  • A Burst Assembly Methodto Reduce End-to-End Packet Delay in Optical Burst Switching Networks

    Yukinobu Fukushima, Wengie Chen, Yasuyuki Fujiwara, Tokumi Yokohira

    WSEAS Transactions on Communications   8 ( 8 )   894 - 903   2009年

     詳細を見る

  • Dynamic splitting of light trails for increasing throughput in light trail networks

    Yukinobu Fukushima, Kota Tanaka, Wenjie Chen, Tokumi Yokohira

    The 24th International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2009)   1370 - 1373   2009年

     詳細を見る

  • Performance Evaluation of Multi-Stage Change-Point Detection Scheme against DDoS Attacks by Random Scan Worms

    Tutomu Murase, Yukinobu Fukushima, Masayoshi Kobayashi, Sakiko Nishimoto, Ryohei Fujimaki, Tokumi Yokohira

    IEEE Communications Society Communications Quality and Reliability Workshop 2008 (CQR 2008)   2008年

     詳細を見る

  • Performance Evaluation of a Multi-stage Network Event Detection Scheme against DDoS Attacks

    Tutomu Murase, Yukinobu Fukushima, Masayoshi Kobayashi, Hiroki Fujiwara, Ryouhei Fujimaki, Tokumi Yokohira

    The Seventh Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT 2008)   118 - 123   2008年

  • Retransmission Control in a TCP with a Performance Enhancing Proxy

    Yuichi Nisida, Hui Wang, Hiroaki Matsumoto, Tokumi Yokohira, Yuinobu Fukushima

    International Conference on Advanced Communication Technology 2008 (ICACT 2008)   1881 - 1886   2008年

  • Detection of CMOS open node defects by frequency analysis

    Hiroyuki Michinishi, Tokumi Yokohira, Takuji Okamoto, Toshifumi Kobayashi, Tsutomu Hondo

    IEICE TRANSACTIONS ON INFORMATION AND SYSTEMS   E90D ( 3 )   685 - 687   2007年3月

     詳細を見る

    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    A method to detect open node defects that cannot be detected by the conventional IDDQ test method has previously been proposed employing a sinusoidal wave superposed on the DC supply voltage. The present paper proposes a strategy to improve the detectability of the test method by means of frequency analysis of the supply current. In this strategy. defects are detected by determining whether secondary harmonics of the sinusoidal wave exist in the supply current. The effectiveness of the method is confirmed by experiments on two CMOS NAND gate packages (SSIs).

    DOI: 10.1093/ietisy/e90-d.3.685

    Web of Science

    researchmap

  • Effect of premature ACK transmission timing on throughput in TCP with a performance enhancing proxy

    Hui Wang, Shigeyuki Osada, Tokumi Yokohira, Kiyohiko Okayama, Nariyoshi Yamai

    IEICE TRANSACTIONS ON COMMUNICATIONS   E90B ( 1 )   31 - 41   2007年1月

     詳細を見る

    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    In order to improve TCP performance, the use of a PEP (Performance Enhancing Proxy) has been proposed. The PEP operates on a router along a TCP connection. When a data packet arrives at the PEP, it forwards the packet to the destination host, transmits the corresponding ACK (premature ACK) to the source host on behalf of the destination host, and stores a copy of the packet in a local buffer (PEP buffer) in case the packet needs to be retransmitted. In this paper, in accordance with a strategy that keeps the number of prematurely acknowledged packets in the PEP buffer below a fixed threshold (watermark) value, we investigate the relation between the watermark value and the average throughput. Extensive simulations show that the results can be roughly classified into two cases. In the first case, the average throughput becomes larger for larger watermark values and becomes a constant value when the watermark value is over a certain value. In the second case, although the average throughput becomes larger for lager watermark value in the same way, it decreases when the watermark value is over a certain value. We also show that the latter (former) case can occur more easily as the propagation delay in the input side network of the PEP becomes smaller (larger) and the propagation delay in the output side network of the PEP becomes larger (smaller), and also show that the latter (former) case can occur more easily as the transmission speed in the input side network becomes larger (smaller) and the transmission speed in the output side network becomes smaller (larger) while the PEP buffer capacity becomes smaller (larger).

    DOI: 10.1093/ietcom/e90-b.1.31

    Web of Science

    researchmap

  • A Wavelength and Converter Assignment Scheme for Decreasing Blocking Probability in Wavelength-Routed Networks

    Yukinobu Fukushima, Takahiro Ooishi, Tokumi Yokohira

    The 12th OptoElectronics and Communication Conference and The 16th International Conference on Integrated Optics and Optical Fiber Communication (OECC/IOCC 2007)   454 - 455   2007年

     詳細を見る

  • Performance Evaluation of a Multi-Stage Network Event Detection Scheme for Decreasing the False-Positive Rate against a Large Number of Simultaneous, Unknown Events

    Tutomu Murase, Hiroki Fujiwara, Yukinobu Fukushima, Masayoshi Kobayashi, Tokumi Yokohira

    The Sixth International Conference of Networking (ICN 2007)in the Conference CD-ROM (6 pages)   2007年

     詳細を見る

  • A Throughput Optimization Algorithm for TCP Connections with Different Routes in Long-Delay Satellite Environments

    Nobuto Watanabe, Wang Hui, Shigeyuki Osada, Tokumi Yokohira, Yukinobu Fukushima

    The 25th AIAA International Communications Satellite Systems Conference (ICSSC 2007), Paper No. AIAA 2007-3208 in the Conference CD-ROM (12 pages)   2007年

     詳細を見る

  • High-speed calculation of worst-case link delays in the EDD connection admission control scheme

    Tokumi Yokohira, Kiyohiko Okayama

    IEICE TRANSACTIONS ON COMMUNICATIONS   E89B ( 7 )   2012 - 2022   2006年7月

     詳細を見る

    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    The EDD connection admission control scheme has been proposed for supporting real-time communication in packet-switched networks. In the scheme, when a connection establishment request occurs, the worst-case link delay in each link along the connection is calculated to determine whether the request can be accepted or not. In order to calculate the worst-case link delay, we must perform a check called the point schedulability check for each of some discrete time instants (checkpoints). Therefore when there are many checkpoints, the worst-case link delay calculation is time-consuming. We have proposed a high-speed calculation method. The method finds some checkpoints for which the point schedulability check need not be performed and removes such unnecessary checkpoints in advance before a connection establishment request occurs, and the check is performed for each of the remaining checkpoints after the request occurs. However, the method is not so effective under the situation that the maximum packet length in networks is large, because the method can find few unnecessary checkpoints under the situation. This paper proposes a new high-speed calculation method. We relax the condition which determines whether or not the point schedulability check need not be performed for each checkpoint in our previous method and derive a new condition for finding unnecessary checkpoints. Using the proposed method based on the new condition, we can increase the number of unnecessary checkpoints compared to our previous method. Numerical examples which are obtained by extensive simulation show that the proposed method can attain as much as about 50 times speedup.

    DOI: 10.1093/ietcom/e89-b.7.2012

    Web of Science

    researchmap

  • Throughput Optimization for TCP with an Active Proxy in Long-Delay Satellite Environments

    Wang Hui, Shigeyuki Osada, Tokumi Yokohira, Yukinobu Fukushima, Deng Chaolong, Kiyohiko Okayama, Nariyoshi Yamai

    2006 Joint Conference on Satellite Communications (JC-SAT 2006)   2006年

     詳細を見る

  • Throughput Optimization in TCP with a Performance Enhancing Proxy,

    Shigeyuki Osada, Wang Hui, Tokumi Yokohira, Yukinobu Fukushima, Kiyohiko Okayama, Nariyoshi Yamai

    International Conference on Communication Technology (ICCT 2006)   2006年

  • A Burst Assembly Method for Decreasing End-to-end Packet Delays in Optical Burst Switching Networks

    Yukinobu Fukushima, Tokumi Yokohira, Yasuhiro Noine, Kazuteru Nagahara

    International Conference on Communication Technology (ICCT 2006)   2006年

  • Node placement algorithms in the case that routes are design variables in shuffle-like multihop lightwave networks

    T Yokohira, K Okayama

    IEICE TRANSACTIONS ON COMMUNICATIONS   E88B ( 12 )   4578 - 4587   2005年12月

     詳細を見る

    記述言語:英語   出版者・発行元:IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

    The shuffle-like network (SL-Net) is known as a logical topology for WDM-based multihop packet-switched networks. Even if we fix the logical topology to an SL-Net, we can still reposition nodes in the SL-Net by re-tuning wavelengths of transmitters and/or receivers. In conventional node placement algorithms, routes between nodes are assumed to be given. In this paper, we propose two heuristic node placement algorithms for the SL-Net to decrease the average end-to-end packet transmission delay under a given traffic matrix in the case that routes are design variables. The principal idea is to prevent too many traffic flows from overlapping on any link. To attain the idea, in one of the algorithms, a node is selected one by one in a decreasing order of the sums of sending and receiving traffic requirements in nodes, and its placement and routes between the node and all the nodes already placed are simultaneously decided so that the maximum of the amounts of traffic on links at the moment is minimum. In the other algorithm, a node is selected in the same way, and first it is placed so that the average distance between the node and all the nodes already placed is as large as possible, and then routes between the node and all the nodes already placed are decided so that the maximum of the amounts of traffic on links at the moment is minimum. Numerical results for four typical traffic matrices show that either of the proposed algorithms has better performance than conventional algorithms for each matrix, and show that the proposed algorithms, which are based on a jointed optimization approach of node placement and routing, are superior to algorithms which execute node placement and routing as two isolated phases.

    DOI: 10.1093/ietcom/e88-b.12.4578

    Web of Science

    researchmap

  • A Framework for Mobile Agent Systems with the Capability of Preceding and Following Users

    Tokumi Yokohira, Kiyohiko Okayama, Takashi Murakami, Kayo Takarako

    Proceedings of The Sixth Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT 2005)   2005年

     詳細を見る

  • Performance Improvement of TCP using Performance Enhancing Proxies --- Effect of Premature ACK Transmission Timing on Throughput ---

    Shigeyuki Osada, Tokumi Yokohira, Wang Hui, Kiyohiko Okayama, Nariyoshi Yamai

    Proceedings of The Sixth Asia-Pacific Symposium on Information and Telecommunication Technologies (APSITT 2005)   2005年

     詳細を見る

  • CMOS Floating Gate Defect Detection Using Supply Current Test with DC Power Supply Superposed by AC Component

    Hiroyuki Michinishi, Tokumi Yokohira, Takuji Okamoto, Toshifumi Kobayashi, Tsutomu Hondo

    The IEICE Transactions on Information and Systems   2004年

     詳細を見る

  • Improvement of Detectability for CMOS Floating Gate Defects in Supply Current Test

    Hiroyuki Michinishi, Tokumi Yokohira, Takuji Okamato, Toshifumi Kobayashi, Tsutomu Hondou

    12th Asian Test Symposium   2003年

  • 描画時合成方式と表示時合成方式の併用によるスムーズ操作が可能なマルチウィンドウシステム

    佐藤洋一郎, 横平徳美, 籠谷裕人, 岡本卓爾, 茅野功

    電子情報通信学会論文誌   2003年

     詳細を見る

  • シャッフル型波長分割多重方式パケット交換網におけるノード配置アルゴリズム

    横平徳美, 岡本卓爾

    電子情報通信学会論文誌   2003年

     詳細を見る

  • 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

    米津政隆, 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   2003年

     詳細を見る

  • An Optimal Path Selection Algorithm for Static and Mobile Multicast Routing Problems

    S.Tajima, M.Fujii, N.Funabiki, T.Yokohira, K.Tsunemura, T.Higashino

    International Conference on Information Networking 2002   2002年

     詳細を見る

  • A Proposal of a Quasi-Solution State Evolution Algorithm for Channel Assignment Problems

    N.Funabiki, T.Nakanishi, T.Yokohira, S.Tajima, T.Higashino

    International Conference on Information Networking 2002   2002年

     詳細を見る

  • CMOS Floating Gate Defect Detection Using IDDQ Test with DC Power Supply Superposed by AC Component

    H.Michinishi, T.Yokohira, T.Okamoto, T.Kobayashi, T.Hondo

    11th Asian Test Symposium   2002年

  • EDDコネクション受付制御方式における最悪リンク遅延の高速導出法

    横平徳美, 岡本卓爾

    電子情報通信学会論文誌   2002年

     詳細を見る

  • 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 Science   2002年

     詳細を見る

  • 静的及びモバイルマルチキャストルーチ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   2002年

     詳細を見る

  • EDDコネクション受付制御方式における遅延余裕の一割当法 - 最悪リンク遅延に比例した割当て -

    横平徳美, 岡本卓爾

    電子情報通信学会論文誌   2001年

     詳細を見る

  • LAN,MANにおける波長分割多重パケット交換網の最適化

    横平徳美, 岡本卓爾

    電子情報通信学会論文誌   2000年

     詳細を見る

  • Quantitative Analysis of Knee-Joint Spasticity by Pendulum Test

    Kazuaki Jikuya, Tokumi Yokohira, Takuji Okamoto, Ken Akashi

    Proc. The 4th Asia-Pacific Conference on Medical and Biological Engineering   1999年

     詳細を見る

  • ルーチングマトリクスを有するFPGAの配線領域の検査法

    道西博行, 横平徳美, 岡本卓爾

    電子情報通信学会論文誌   1999年

     詳細を見る

  • Testing for the Programming Circuit of SRAM-Based FPGAs

    Hiroyuki Michinishi, Tokumi Yokohira, Takuji Okamoto, Tomoo Inoue, Hideo Fujiwara

    IEICE Transactions   1999年

     詳細を見る

  • Fault Tolerant Packet-Switched Network Design and Its Sensitivity

    Tokumi Yokohira, Masashi Okayama

    IEEE Transactions on Reliability   40 ( 4 )   452 - 460   1991年

     詳細を見る

    記述言語:英語  

    Reliability and performance for telecommunication networks have been traditionally investigated separately in spite of their close relation. A design method integrating them for a reliable packet switched network, called a proofing method, was discussed in previous papers. This paper first presents the proofing method in detail. Then two heuristic design approaches (max-average, max-delay-link) for optimizing network cost in the proofing method are described. In order to verify their effectiveness and applicability, they are compared numerically for three example network topologies. Finally, the sensitivity of these two methods is examined with respect to changes in traffic demand and in link reliability. Numerical results show that the max-delay-link method provides a lower minimum network-cost than does the max-average method, for both a small and a large example network. The answers obtained by these two methods are not highly sensitive to changes either in traffic demand or in link reliability. Thus a network designed by these two methods is robust to a system change which is not considered at a design stage. The max-average method is superior to the max-delay-link method in terms of the sensitivity. Many other sources of failures must be considered in our failure model, eg, node and software faults. Only statistically independent failures are considered. Statistical dependence effects must be included to make the model more realistic. The max-average and max-delay-link methods cannot prevent a state where there are no routes between a particular source and destination node pair. To cope with this, a topological design method must be added to these methods. The computational complexity of these methods needs to be clarified to identify how large a practical problem can be solved using them. © 1991 IEEE.

    DOI: 10.1109/24.93767

    Scopus

    researchmap

▼全件表示

講演・口頭発表等

  • 仮想網マッピングシステムの機能拡張-仮想リンク単位での経路選択の実現-

    電気・情報関連学会中国支部第69回連合大会  2018年 

     詳細を見る

  • マルチパスTCPにおける輻輳制御方式のスループット公平性の検討

    電気・情報関連学会中国支部第69回連合大会  2018年 

     詳細を見る

  • IP高速迂回法における想定外故障の迂回可能性の検討

    電気・情報関連学会中国支部第69回連合大会  2018年 

     詳細を見る

  • Link Capacity Provisioning and Server Location Decision in Server Migration Service

    IEEE International Conference on Cloud Networking (CloudNet 2018)  2018年 

     詳細を見る

  • The Effect of Using Attribute Information in Network Traffic Prediction with Deep Learning

    International Conference on ICT Convergence 2018 (ICTC 2018)  2018年 

     詳細を見る

  • Backoff Algorithms to Avoid TCP Incast in Data Center Networks

    International Conference on ICT Convergence 2018 (ICTC 2018)  2018年 

     詳細を見る

  • マルチパスTCPのスループット公平性の 検討

    電子情報通信学会2018年総合大会  2018年 

     詳細を見る

  • Workplace Capacity Design Using the Minimum Dominating Set in Server Migration Services

    The 9th IFIP International Conference on New Technologies, Mobility and Security (NTMS 2018)  2018年 

     詳細を見る

  • データセンターネットワークにおけるTCPインキャスト回避法の性能改善

    電子情報通信学会2017年総合大会  2017年 

     詳細を見る

  • Improvement of a TCP Incast Avoidance Method using a Fine-grained Kernel Timer

    International Conference on ICT Convergence 2017 (ICTC 2017)  2017年 

     詳細を見る

  • 多重ルーティング形態法における予備テーブルのエントリ数の低減

    電子情報通信学会2017年総合大会  2017年 

     詳細を見る

  • Load Modulation Based MIMO Communication for the Low Complexity and Low Power Consumption

    2016 IEEE International Conference on Consumer Electronics (ICCE 2016)  2016年 

     詳細を見る

  • Power-Aware Server Lofcation Decision in Server Migration Service

    International Conference on ICT Convergence 2016 (ICTC 2016)  2016年 

     詳細を見る

  • Prototype Development of a Virtual Network Embedding System Using OpenStack

    The 31st International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2016)  2016年 

     詳細を見る

  • Nonlinearity Sensitivity of FBMC and UFMC Modulation System for the 5G Mobile System

    The 31st International Technical Conference on Circuits/Systems, Computers and Communications (ITC-CSCC 2016)  2016年 

     詳細を見る

  • Performance Evaluation of an Energy Efficient Virtual Network Mapping Method -In the case of load-dependent power consumption model-

    The International Conference on Electronics and Software Science 2015 (ICESS 2015)  2015年 

     詳細を見る

  • An On-line Algorithm to Determine the Location of the Server in a Server Migration Service

    The 12th Annual IEEE Consumer Communications & Networking Conference (CCNC 2015)  2015年 

     詳細を見る

  • 多重ルーティング形態法における予備テーブルのエントリ数の低減

    第17回IEEE広島支部学生シンポジウム (HISS 2015)  2015年 

     詳細を見る

  • 消費電力低減を指向した仮想網マッピング手法の性能評価 --機器の消費電力が負荷に応じて変化する場合--

    第17回IEEE広島支部学生シンポジウム (HISS 2015)  2015年 

     詳細を見る

  • マルチパスTCPにおけるスループット公平性の改善

    第17回IEEE広島支部学生シンポジウム (HISS 2015)  2015年 

     詳細を見る

  • サーバ移動トラヒックの背景トラヒック への影響に関する実験的評価

    電気・情報関連学会中国支部第66回連合大会  2015年 

     詳細を見る

  • 複数アプリケーション存在下におけるマルチパスTCPのスループット評価

    電気・情報関連学会中国支部第66回連合大会  2015年 

     詳細を見る

  • Power Consumption Evaluation of Light-trail Networks

    ITC-CSCC  2014年 

     詳細を見る

  • 教育用WindowsPCにおけるデジタル証明書を用いた柔軟かつ堅牢なアプリケーション実行制御システムの設計

    情報処理学会インターネットと運用技術研究会研究報告vol.2014-IOT-26  2014年 

     詳細を見る

  • Throughput Improvement of TCP Proxies in Network Environment with Wireless LANs

    TENSYMP  2014年 

     詳細を見る

  • サーバ移動サービスにおけるサーバ配置決定アルゴリズム

    電子情報通信学会技術研究報告(NS2014-138)  2014年 

     詳細を見る

  • ロバストルーティング方式におけるバースト分配方式

    電子情報通信学会技術研究報告(NS2013-240)  2014年 

     詳細を見る

  • 光トレイルネットワークにおける省電力を指向したトラヒックエンジニアリング手法

    電子情報通信学会技術研究報告(NS2013-235)  2014年 

     詳細を見る

  • 多重ルーティングテーブル法における迂回経路導出法の改良

    電子情報通信学会2014年総合大会  2014年 

     詳細を見る

  • Power Efficiency Evaluation of Medium Access Control Methods in Light Trail Networks

    ITC-CSCC  2014年 

     詳細を見る

  • Performance Evaluation of Overlay Construction Algorithms in Mesh-pull P2P Live Streaming

    ITC-CSCC  2014年 

     詳細を見る

  • リソースとコストを考慮した仮想網マッピング

    第16回IEEE広島支部学生シンポジウム (HISS 2014)  2014年 

     詳細を見る

  • IPネットワークにおける故障からの高速回復のためのルート迂回法

    第16回IEEE広島支部学生シンポジウム (HISS 2014)  2014年 

     詳細を見る

  • 細粒度タイマを用いたTCP におけるバックオフ値の最適化

    第16回IEEE広島支部学生シンポジウム (HISS 2014)  2014年 

     詳細を見る

  • 光トレイルネットワークにおけるメディアアクセス制御方式の電力性能評価

    第16回IEEE広島支部学生シンポジウム (HISS 2014)  2014年 

     詳細を見る

  • メッシュプル型P2Pライブストリーミングにおけるオーバーレイネットワーク構築方式の性能評価

    電気・情報関連学会中国支部第65回連合大会  2014年 

     詳細を見る

  • A Reroute Method to Recover Fast from Network Failure

    International Conference on ICT Convergence 2014 (ICTC 2014)  2014年 

     詳細を見る

  • Optimization of Maximum Timeout Value in TCP with a Fine-grained Timer for Data Center Networks

    International Conference on ICT Convergence 2014 (ICTC 2014)  2014年 

     詳細を見る

  • Performance Improvement of SCTP Communication Using Selective Bicasting on Lossy Multihoming Environment

    2014 IEEE 38th Annual International Computers, Software and Applications Conference (COMPSAC 2014)  2014年 

     詳細を見る

  • TCP Incast の回避手法の改良

    第15回IEEE広島支部学生シンポジウム (HISS 2013)  2013年 

     詳細を見る

  • サーバ移動サービスにおける最適サーバ配置

    電子情報通信学会技術研究報告(NS2012-231)  2013年 

     詳細を見る

  • コネクション直列化によるTCP Incastの回避

    電子情報通信学会技術研究報告(NS2012-208)  2013年 

     詳細を見る

  • A Reroute Method Using Multiple Routing Configurations for Fast IP Network Recovery

    APCC  2013年 

     詳細を見る

  • Decreasing of the Number of Backup Tables in Multiple Routing Table Method for Fast IP Network Recovery

    ITC-CSCC  2013年 

     詳細を見る

  • A Per-burst Traffic Distribution Method for TCP Performance Improvement in Fixed Robust Routing

    ITC-CSCC  2013年 

     詳細を見る

  • A Multi-splitting Method for Light-trail Networks

    ITC-CSCC  2013年 

     詳細を見る

  • Optimization of Server Locations in Server Migration Service

    ICNS  2013年 

     詳細を見る

  • 多重ルーティングテーブル法における予備テーブル数の低減

    電子情報通信学会2013年総合大会  2013年 

     詳細を見る

  • サーバ移動サービスにおける移動先決定アルゴリズム 〜 複数サーバ移動の場合 〜

    電子情報通信学会技術研究報告(NS2012-232)  2013年 

     詳細を見る

  • Improvement of a TCP Incast Avoidance Method for Data Center Networks

    ICTC  2013年 

     詳細を見る

  • ロバストルーティング方式におけるバースト分配方式

    電気・情報関連学会中国支部第64回連合大会  2013年 

     詳細を見る

  • TCP Incast Avoidance Based on Connection Serialization in Data Center Networks

    APCC  2013年 

     詳細を見る

  • マルチパスTCPにおける受信バッファ最適化法のスループットへの影響

    第15回IEEE広島支部学生シンポジウム (HISS 2013)  2013年 

     詳細を見る

  • パケットロス環境下でのTCPの最適受信バッファサイズ

    第14回IEEE広島支部学生シンポジウム (HISS 2012)  2012年 

     詳細を見る

  • TCPの性能を考慮した複合型ロバストルーティング方式

    電子情報通信学会通信方式研究会  2012年 

     詳細を見る

  • P2PライブストリーミングにおけるASフレンドリーなピア選択法の性能改善

    電子情報通信学会2012年総合大会  2012年 

     詳細を見る

  • CAIDA Datasetに基づく国内ASトポロジーの精度検証と改善

    電子情報通信学会2012年総合大会  2012年 

     詳細を見る

  • TCPスループットを考慮した複合型ロバストルーティング方式

    電子情報通信学会2012年総合大会  2012年 

     詳細を見る

  • 光トレイルネットワークにおけるトレイル多重分割方式

    電子情報通信学会ネットワークシステム研究会  2012年 

     詳細を見る

  • Improvement of an ACK Returning Method of TCP Proxies in Network Environment with Wireless LANs

    GCCE  2012年 

     詳細を見る

  • A Solution to Transmission Halting In a New Flow Control Method TCP-fox

    APCC  2012年 

     詳細を見る

  • 多重ルーティングテーブルを用いたルート迂回法

    電気・情報関連学会中国支部第63回連合大会  2012年 

     詳細を見る

  • Destination Selection Algorithm in a Server Migration Service

    CFI  2012年 

     詳細を見る

  • Optimal TCP Receive Buffer Size under Packet Loss Environment

    ITC-CSCC  2012年 

     詳細を見る

  • Hybrid Fixed Robust Routing Taking Account of TCP Performance

    ITC-CSCC  2012年 

     詳細を見る

  • Inter-AS Traffic Volume Reduction by Localizing Delivery for P2P Live Streaming

    ICNC  2012年 

     詳細を見る

  • Performance Evaluation of TCP over Multiple Paths in Fixed Robust Routing

    IEEE CQR Workshop  2011年 

     詳細を見る

  • IaaS 型クラウドサービスにおけるQoSを考慮したサーバ移動アルゴリズム

    電子情報通信学会2011年総合大会  2011年 

     詳細を見る

  • サーバ移動サービスにおけるサーバ追い出しアルゴリズム

    電子情報通信学会情報ネットワーク研究会  2011年 

     詳細を見る

  • Optimization of Token Holding Times in Split Light Trail Networks

    IEEE GLOBECOM  2011年 

     詳細を見る

  • P2PライブストリーミングにおけるAS フレンドリーなピア選択法の性能改善

    第13回IEEE広島支部学生シンポジウム (HISS 2011)  2011年 

     詳細を見る

  • 無線LAN混在環境におけるTCPプロキシのACK返送法の改良

    電気・情報関連学会中国支部第62回連合大会  2011年 

     詳細を見る

  • サーバ移動サービスにおける移動先決定アルゴリズム

    電子情報通信学会ネットワーク研究会  2011年 

     詳細を見る

  • P2Pライブストリーミングにおけるピア選択法の性能評価 -部分的なASトポロジーのみが利用できる場合-

    電気・情報関連学会中国支部第61回連合大会  2010年 

     詳細を見る

  • 分散トラヒック計測に基づく増加トラヒックの早期検出

    電子情報通信学会2010年総合大会  2010年 

     詳細を見る

  • 分割型光トレイルネットワークにおけるトークン保持時間の最適化

    電子情報通信学会ネットワークシステム研究会  2010年 

     詳細を見る

  • 分散トラヒック計測に基づく増加トラヒックの早期検出

    電子情報通信学会情報ネットワーク研究会  2010年 

     詳細を見る

  • 重み付き階層型変化点検出方式の性能評価 -アラートに対する重み付けの有効性の検討-

    コンピュータセキュリティシンポジウム2010  2010年 

     詳細を見る

  • P2Pライブストリーミングにおけるピア選択法の性能評価 -日本国内におけるASトポロジを利用した評価-

    第12回IEEE広島支部学生シンポジウム (HISS 2010)  2010年 

     詳細を見る

  • マルチドメイン光パス網におけるスター型抽象化方式

    第12回IEEE広島支部学生シンポジウム (HISS 2010)  2010年 

     詳細を見る

  • マルチパスルーチングにおけるTCPの性能評価

    電子情報通信学会2010年ソサイエティ大会  2010年 

     詳細を見る

  • 光トレイルネットワークにおけるトレイルの動的分割によるスループットの向上

    電子情報通信学会ネットワークシステム研究会  2010年 

     詳細を見る

  • モバイルエージェントフレームワークにおけるデモンストレーション機能の実装

    電気・情報関連学会中国支部第61回連合大会  2010年 

     詳細を見る

  • 無線LAN混在環境におけるスプリット型TCPプロキシの性能評価

    電気・情報関連学会中国支部第61回連合大会  2010年 

     詳細を見る

  • 光トレイル網におけるメディアアクセス制御方式の性能評価

    電子情報通信学会2009年総合大会  2009年 

     詳細を見る

  • アラートの重み付けによる階層型変化点検出方式の精度改善

    電子情報通信学会2009年総合大会  2009年 

     詳細を見る

  • P2Pライブストリーミングにおけるピア選択方式の性能評価

    電子情報通信学会技術研究報告,IN2008-203  2009年 

     詳細を見る

  • ユーザ先行・追随型モバイルエージェントフレームワークによるモバイルディレクトリィの実装

    第11回IEEE広島支部学生シンポジウム (HISS 2009)  2009年 

     詳細を見る

  • P2PライブストリーミングにおけるAS間トラヒックの低減を目指したピア選択法

    電気・情報関連学会中国支部第60回連合大会  2009年 

     詳細を見る

  • カットスルー機能を備えた光トレイル網の性能評価

    電子情報通信学会2009年総合大会  2009年 

     詳細を見る

  • TCP性能向上プロキシにおける再送制御の実装,

    第10回IEEE広島支部学生シンポジウム (HISS2008),CD-ROM,C-01,pp.31-34  2008年 

     詳細を見る

  • モバイルエージェントフレームワークにSQLデータベースを用いた移動予測

    電気・情報関連学会中国支部第59回連合大会,pp.187-188  2008年 

     詳細を見る

  • 階層型変化点検出機構における宛先IPアドレス数の変化に基づくワーク拡散の検出

    電子情報通信学会2008年総合大会,pp.S60-S61  2008年 

     詳細を見る

  • 光バースト交換網におけるオフセット期間中の到着パケットもバースト化するバースト生成法の性能比較

    電子情報通信学会2008年総合大会  2008年 

     詳細を見る

  • 性能向上プロキシを用いたTCPにおける再送制御

    電子情報通信学会技術研究報告,NS2007-68,pp.77-82  2007年 

     詳細を見る

  • 同時多発する未知イベントに対する情報集約による偽陽性アラート排除検知方法の性能評価

    電子情報通信学会技術研究報告,ICSS2006-16, pp.37-42  2007年 

     詳細を見る

  • TCP性能改善のための早期ACK返送機能を有するルータの実装

    第9回IEEE広島支部学生シンポジウム (HISS 2007)  2007年 

     詳細を見る

  • モバイルエージェントフレームワークにおける地図情報を用いた移動予測

    第9回IEEE広島支部学生シンポジウム (HISS 2007)  2007年 

     詳細を見る

  • バースト交換網におけるバースト長推定に基づくバースト生成法の性能評価

    第9回IEEE広島支部学生シンポジウム (HISS 2007)  2007年 

     詳細を見る

  • 同時多発イベント検出を目的とした階層型変化点検出機構の性能評価

    電気・情報関連学会中国支部第58回連合大会,pp.379-380  2007年 

     詳細を見る

  • モバイルエージェントフレームワークにおける地図情報データベースの作成

    電気・情報関連学会中国支部第58回連合大会,pp.334-335  2007年 

     詳細を見る

  • OBSネットワークにおける複数のヘッダパケットの使用による性能改善

    電子情報通信学会技術研究報告,NS2005-183,pp.101-104  2006年 

     詳細を見る

  • 同時多発する未知イベントに対する情報集約による偽陽性アラート排除検知方法の性能評価

    電子情報通信学会技術研究報告,IN2006-89,pp.25-30  2006年 

     詳細を見る

  • ユーザ先行・追随型モバイルエージェントフレームワークにおけサーバの分散化

    第8回IEEE広島支部学生シンポジウム (HISS 2006),pp.139-142  2006年 

     詳細を見る

  • 性能向上プロキシを用いたTCPの性能評価 -パケットロスが生起する場合-

    第8回IEEE広島支部学生シンポジウム (HISS 2006), pp.97-100  2006年 

     詳細を見る

  • 性能改善プロキシを用いたTCPにおける公平性の検討

    電気・情報関連学会中国支部第57回連合大会,pp.532-533  2006年 

     詳細を見る

  • 光バースト交換網におけるエンド間遅延の低減を目指したバースト生成法

    電気・情報関連学会中国支部第57回連合大会,pp.530-531  2006年 

     詳細を見る

  • 性能向上プロクシを用いたTCPにおけるスループットの最適化

    電子情報通信学会技術研究報告,NS2006-96,pp.145-150  2006年 

     詳細を見る

  • インテリジェントマークとモバイルエージェントの融合によるユーザ支援手法の構築

    ヒューマンインターフェースシンポジウム2006 (HIS 2006), pp.1181-1184  2006年 

     詳細を見る

  • ユーザ先行・追随型モバイルエージェントフレームワークにおけるユーザエージエント消失からの回復法

    第7回IEEE広島支部学生シンポジウム,pp.337-340  2005年 

     詳細を見る

  • 早期ACKパケットの返送によるTCPの性能改善 -複数コネクションが存在する状況での性能評価-

    電子情報通信学会ネットワークシステム研究会,信学技報NS2005-129,pp.87-90  2005年 

     詳細を見る

  • ユーザ先行・追随型モバイルエージェントフレームワークにおけるサービス断絶状態からの回復法

    電気・情報関連学会中国支部第56回連合大会,pp.227-228  2005年 

     詳細を見る

  • 早期ACKパケットの返送によるTCPの性能改善

    電子情報通信学会ネットワークシステム研究会,信学技報NS2005-67,pp.25-28  2005年 

     詳細を見る

  • 長期的なリンクダウン状態に対するTCP通信の維持

    情報処理学会シンポジウムシリーズ(マルチメディア,分散,協調とモバイルシンポジウム (DICOMO 2005)),Vol.2005,No.6,pp.345-348  2005年 

     詳細を見る

  • EDDコネクション受付制御方式における最悪リンク遅延導出法の改良

    電子情報通信学会ネットワークシステム研究会,信学技報NS2005-37,pp.53-56  2005年 

     詳細を見る

  • PEPによるTCPの性能改善 --- 早期ACKパケットの返送タイミングがスループットに及ぼす影響 ---

    電子情報通信学会ネットワークシステム研究会,信学技報NS2004-264,pp.103-106  2005年 

     詳細を見る

  • 長期的なリンクダウン状態に対するTCP通信の維持

    第7回IEEE広島支部学生シンポジウム,pp.357-360  2005年 

     詳細を見る

  • EDDコネクション受付制御方式における最悪リンク遅延の高速導出法 -許容遅延の大きいコネクションが多数設定される場合-

    電子情報通信学会ネットワークシステム研究会,信学技報NS2005-141,pp.33-36  2005年 

     詳細を見る

  • EDDコネクション受付制御方式における最悪リンク遅延の高速導出法 --- 負荷が中程度以下の場合

    電子情報通信学会ネットワークシステム研究会  2004年 

     詳細を見る

  • ユーザ先行・追随型モバイルエージェントシステム構築のためのフレームワーク

    第6回IEEE広島支部学生シンポジウム  2004年 

     詳細を見る

  • バーストスイッチングにおける波長パス要求保留時間の性能への影響

    電気・情報関連学会中国支部第54回連合大会  2004年 

     詳細を見る

  • シャッフル型WDMネットワークにおけるノード配置アルゴリズム --- 経路を設計変数とした場合 ---

    電子情報通信学会ネットワークシステム研究会  2004年 

     詳細を見る

  • EDDコネクション受付制御方式における遅延余裕割当法 -必要が生じたときに割り当てる方法-

    電子情報通信学会ネットワークシステム研究会  2003年 

     詳細を見る

  • シャッフル型WDMネットワークにおけるノード配置アルゴリズム -経路を設計変数とした場合-

    電気・情報関連学会中国支部第54回連合大会  2003年 

     詳細を見る

  • EDDコネクション受付制御方式における最悪リンク遅延導出法の高速化

    電子情報通信学会ネットワークシステム研究会  2003年 

     詳細を見る

  • ネットワーク技術の最新動向(特別講演)

    計測自動制御学会中国支部計測制御シンポジウム2002予稿集  2002年 

     詳細を見る

  • EDDコネクション受付制御方式における最悪リンク遅延の高速導出法 -パケット長の最大値がコネクションによらず一定の場合-

    電子情報通信学会ネットワークシステム研究会  2002年 

     詳細を見る

  • ペンドラムテストによる痙縮の定量化手法

    第41回日本エム・イー学会大会論文集  2002年 

     詳細を見る

  • ペンドラムテストシミュレータによる痙縮の定量化手法

    第17回中国四国リハビリテーション医学研究会  2002年 

     詳細を見る

  • 相動性筋紡錘モデルの提案

    第25回日本ME学会中国四国支部大会  2002年 

     詳細を見る

  • シャッフル型波長分割多重方式パケット交換網におけるノード配置アルゴリズム

    電子情報通信学会ネットワークシステム研究会  2002年 

     詳細を見る

  • CMOSオープン故障の検出に関する研究

    電気・情報関連学会中国支部第53回連合大会  2002年 

     詳細を見る

  • モジュール化による機能独立を指向したテレビ会議システムの設計

    電気・情報関連学会中国支部第53回連合大会  2002年 

     詳細を見る

  • ジョセフソン素子による3変数論理関数の一構成法

    電気・情報関連学会中国支部第53回連合大会  2002年 

     詳細を見る

  • 筋粘弾性におる筋トーヌス低下の評価

    第16回中国四国リハビリテーション医学研究会  2001年 

     詳細を見る

  • 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

    電子情報通信学会コンピュテーション研究会  2001年 

     詳細を見る

  • 膝関節反射評価装置の改良 -評価値算出時間の評価-

    第24回日本ME学会中国四国支部大会  2001年 

     詳細を見る

  • EDDコネクション受付制御方式における最悪リンク遅延の高速導出法 -コネクション設定要求の発生前における処理の高速化-

    電気・情報関連学会中国支部第52回連合大会  2001年 

     詳細を見る

  • EDDコネクション受付制御方式における最悪リンク遅延の高速導出法

    電子情報通信学会ネットワークシステム研究会  2001年 

     詳細を見る

  • ペンドラムテストによる痙縮の定量化 -測定系の改良-

    第40回日本エム・イー学会大会  2001年 

     詳細を見る

  • ペンドラムテストにおける反射の評価 -評価手続き簡略化のための測定系の改良-

    第23回日本ME学会中国四国支部大会  2000年 

     詳細を見る

  • シャッフル形ネットワークにおけるノード配置アルゴリズム -トラヒック分散を指向したアルゴリズム-

    電気・情報関連学会中国支部第51回連合大会  2000年 

     詳細を見る

  • 描画時合成方式と表示時合成方式とを併用した高速マルチウィンドウシステム -ウィンドウ親子関係の実現に関する検討-

    電気・情報関連学会中国支部第51回連合大会  2000年 

     詳細を見る

  • EDDコネクション設定制御方式における遅延余裕の一割当法 -最悪リンク遅延に比例した割当て-

    電子情報通信学会交換システム研究会  2000年 

     詳細を見る

  • EDDコネクション設定制御方式における遅延余裕の一割当法

    2000年電子情報通信学会総合大会(通信2)  2000年 

     詳細を見る

  • 膝関節反射評価装置の開発 -ペンドラムテストによる反射評価法の実用化に向けて-

    第15回中国四国リハビリテーション医学研究会  2000年 

     詳細を見る

  • EDDコネクション設定制御方式における最悪リンク遅延導出法の高速化

    電気・情報関連学会中国支部第50回連合大会  1999年 

     詳細を見る

  • ペンドラムテスト用チェアーの開発

    第14回中国四国リハビリテーション医学研究会  1999年 

     詳細を見る

  • ペンドラムテスト時の筋電発火と膝関節加速度波形 -α系亢進とγ系亢進による相違について-

    第22回日本ME学会中国四国支部大会  1999年 

     詳細を見る

  • 描画時合成方式と表示時合成方式とを併用した高速マルチウィンドウシステム -ウィンドウ操作時間の評価-

    電気・情報関連学会中国支部第50回連合大会  1999年 

     詳細を見る

▼全件表示

受賞

  • 電子情報通信学会ネットワークシステム研究専門委員会活動功労賞

    2018年  

     詳細を見る

    受賞国:日本国

    researchmap

  • IEICE ESS貢献賞 (電子情報通信学会 基礎境界ソサイエティ 貢献賞)

    2016年  

     詳細を見る

    受賞国:日本国

    researchmap

  • 2014 IEEE Region 10 Technical Symposium (TENSYMP 2014) best paper award

    2014年  

     詳細を見る

  • 第10回HISS記念論文賞受賞

    2008年  

     詳細を見る

    受賞国:日本国

    researchmap

 

担当授業科目

  • コンピュータネットワークA (2021年度) 第4学期  - 月1,月2,木5,木6

  • コンピュータネットワークB (2021年度) 第2学期  - 月3,月4,木3,木4

  • コンピュータネットワークⅡ (2021年度) 第2学期  - 月3,月4,木3,木4

  • コンピュータネットワークI (2021年度) 第4学期  - 月1,月2,木5,木6

  • セキュリティ概論 (2021年度) 3・4学期  - 水7,水8

  • データ構造とアルゴリズム (2021年度) 第3学期  - 月1,月2,木5,木6

  • ネットワークアーキテクチャⅠ (2021年度) 前期  - 水3~4

  • ネットワークアーキテクチャⅡ (2021年度) 前期  - 水3~4

  • ネットワーク性能評価論 (2021年度) 後期  - その他

  • ビッグデータ構築・解析学 (2021年度) 後期  - 金1~2

  • ヘルスシステム統合科学アドバンストインターンシップ (2021年度) 通年  - その他

  • ヘルスシステム統合科学専門英語 (2021年度) 後期  - その他

  • ヘルスシステム統合科学専門英語 (2021年度) 後期  - その他

  • ヘルスシステム統合科学特別研究 (2021年度) 通年  - その他

  • ヘルスシステム統合科学特別研究 (2021年度) 通年  - その他

  • 分散データ管理演習 (2021年度) 夏季集中  - その他

  • 医療機器材料学概論 (2021年度) 前期  - その他

  • 医療機器材料学概論 (2021年度) 前期  - 水1~2

  • 情報セキュリティ演習 (2021年度) 通年  - その他

  • 技術表現発表学 (2021年度) 後期  - その他

  • 技術表現発表学 (2021年度) 後期  - その他

  • 通信プロトコルⅡ (2021年度) 第2学期  - 月3,月4,木3,木4

  • 通信プロトコルI (2021年度) 第4学期  - 月1,月2,木5,木6

  • クロスサイトスクリプティング対策演習 (2020年度) 夏季集中  - その他

  • コンピュータネットワークA (2020年度) 第4学期  - 月1,月2,木5,木6

  • コンピュータネットワークB (2020年度) 第2学期  - 月3,月4,木3,木4

  • コンピュータネットワークⅡ (2020年度) 第2学期  - 月3,月4,木3,木4

  • コンピュータネットワークI (2020年度) 第4学期  - 月1,月2,木5,木6

  • セキュリティ総論E (2020年度) 3・4学期  - 水7,水8

  • データ構造とアルゴリズム (2020年度) 第3学期  - 月1,月2,木5,木6

  • ネットワークアーキテクチャⅠ (2020年度) 前期  - 水3,水4

  • ネットワークアーキテクチャⅡ (2020年度) 前期  - 水3,水4

  • ネットワーク性能評価論 (2020年度) 後期  - その他

  • ビッグデータ構築・解析学 (2020年度) 後期  - 金1,金2

  • ヘルスシステム統合科学アドバンストインターンシップ (2020年度) 通年  - その他

  • ヘルスシステム統合科学専門英語 (2020年度) 後期  - その他

  • ヘルスシステム統合科学特別研究 (2020年度) 通年  - その他

  • 医療機器材料学概論 (2020年度) 前期  - 水1,水2

  • 安全性評価のための衝突型暗号攻撃演習 (2020年度) 夏季集中  - その他

  • 技術表現発表学 (2020年度) 後期  - その他

  • 暗号ハードウェアセキュリティ演習 (2020年度) 第4学期  - その他

  • 通信プロトコルⅡ (2020年度) 第2学期  - 月3,月4,木3,木4

  • 通信プロトコルI (2020年度) 第4学期  - 月1,月2,木5,木6

▼全件表示