Updated on 2023/03/28

写真a

 
TEI, Kenji
 
Scopus Paper Info  
Paper Count: 72  Citation Count: 389  h-index: 11

Click to view the Scopus page. The data was downloaded from Scopus API in March 27, 2023, via http://api.elsevier.com and http://www.scopus.com .

Affiliation
Faculty of Science and Engineering, Global Center for Science and Engineering
Job title
Associate Professor(without tenure)
Degree
2008/03 Waseda University Ph.D (Engineering)
Profile

Kenji Tei is an associate professor at Faculty of Science and Engineering in Waseda University.

Dr. Kenji Tei received the B.E and D.E degrees in information and computer science from Waseda University, Japan, in 2003, and 2005, respectively, and he received Ph.D. in Engineering from Waseda University, Japan in 2008. He joined the Department of Information and Computer Science at Waseda University as a research assistant. From 2008 to 2010, he was an assistant professor at Media Network Center in Waseda University and a project assistant professor at National Institute of Informatics. From 2010 to 2015, he was an assistant professor at National Institute of Informatics and SOKENDAI. From 2015 to 2018, he was an associate professor at National Institute of Informatics and SOKENDAI. From 2018, he was an associate professor at Waseda University.

He is interested in self-adaptive software, software architecture, model-driven engineering, and software verification. He is a member of the IEEE Computer Society (IEEE CS), Association for Computing Machinery (ACM), Information Processing Society of Japan (IPSJ), and Institute of Electronics, Information and Communication Engineers (IEICE). He currently serves as Associate Editor of ACM Transactions on Autonomous and Adaptive Systems (TAAS). He has served as Steering Committee Member of International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS) and Program co-Chair of SEAMS ’19.

 

Research Experience

  • 2019.09
    -
    Now

    Waseda University   Faculty of Science and Engineering, Global Center for Science and Engineering   Associate Professor

  • 2018.04
    -
    2019.09

    Waseda University   Waseda Research Institute for Science and Engineering   Associate Professor / Researcher

  • 2015.04
    -
    2018.03

    National Institute of Informatics   Information Systems Architecture Science Research Division   Associate Professor

  • 2010.04
    -
    2015.03

    National Institute of Informatics   Information Systems Architecture Science Research Division   Assistant Professor

  • 2008.04
    -
    2010.03

    Waseda University   Media Network Center   Assistant Professor

  • 2008.04
    -
    2010.03

    Media Network Center, Waseda University   Assistant Professor

  • 2006.04
    -
    2008.03

    Faculty of Science and Engineering, Waseda University   Research associate

  • 2018.04
    -
    2022.09

    National Institute of Informatics   GRACE Center   Associate Professor by Special Appointment

  • 2015.04
    -
    2018.03

    SOKENDAI   associate professor

  • 2010.04
    -
    2015.03

    SOKENDAI   associate professor

  • 2008.04
    -
    2010.03

    National Institute of Informatics   National Institute of Informatics

  • 2008.04
    -
    2010.03

    Information Systems Architecture Science Research Division, National Institute of Informatics   Project Assistant Professor

  • 2007.04
    -
    2008.03

    Waseda University   School of Fundamental Science and Engineering

  • 2005.04
    -
    2008.03

    National Institute of Informatics

  • 2006.04
    -
    2007.03

    Waseda University   School of Science and Engineering

▼display all

Committee Memberships

  • 2021
    -
    Now

    IEEE International Conference on Autonomic Computing and Self-Organizing Systems (ACSOS)  Program Committee

  • 2021
    -
    Now

    ACM Transactions on Autonomous and Adaptive Systems (TAAS)  Associate Editor

  • 2021
     
     

    ACM/IEEE 24th International Conference on Model Driven Engineering Languages and Systems (MODELS2021)  Tool and Demonstration Track Chair

  • 2018
    -
    2021

    International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS)  Steering Committee

  • 2019
     
     

    No.153 NII Shonan Meeting on The 3rd Controlled Adaptation of Self-adaptive Systems (CASaS2020)  Organizer

  • 2018
     
     

    No.118 NII Shonan Meeting on Modelling and Analysing Resilient Cyber-Physical Systems  Organizer

  • 2018
     
     

    International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS2019)  Program co-Chair

  • 2017
     
     

    No.110 NII Shonan Meeting on The 2nd Controlled Adaptation of Self-adaptive Systems (CASaS2017)  Organizer

  • 2015
     
     

    No.077 NII Shonan Meeting on Controlled Adaptation of Self-adaptive Systems (CASaS)  Organizer

  • 2016
    -
    Now

    International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS)  Program Committee

  • 2023
     
     

    4th IEEE International Conference on Autonomic Computing and Self-Organizing Systems (ACSOS 2023)  Demo & Poster Chair

  • 2022
     
     

    The IEEE Technical Community on Software Engineering (TCSE)  TCSE Distinguished Service Award Chair

  • 2020
     
     

    IEEE International Requirements Engineering Conference (RE)  Program Committee

  • 2018
     
     

    IEEE International Conference on Self-Adaptive and Self-Organizing Systems (SASO)  Program Committee

  • 2017
    -
    2018

    International Conference on Engineering of Complex Computer Systems (ICECCS)  Program Committee

▼display all

Professional Memberships

  •  
     
     

    ACM

  •  
     
     

    IEEE Computer Society

  •  
     
     

    情報処理学会

Research Areas

  • Software

Research Interests

  • Software Engineering

  • Self-adaptive System

  • Model-driven Engineering

  • Requirement Engineering

  • Software Architecture

  • Internet of Things

  • Cyber-Physical System

  • Software Pattern

  • Wireless Sensor Network

  • Distributed Computing

  • Mobile Agent

▼display all

Awards

  • 情報処理学会 卓越研究賞 (SE研究会)

    2022.09   情報処理学会 ソフトウェア工学研究会   Towards scalable model checking of reflective systems via labeled transition systems

    Winner: Kenji Tei, Yasuyuki Tahara, Akihiko Ohsuga

  • Best Presentation Award

    2022.06   2nd IEEE International Conference on Software Engineering and Artificial Intelligence (SEAI2022)  

    Winner: Nianzhao Zheng, Jialong Li, Zhenyu Mao, Kenji Tei

  • WASEDA e-Teaching Award

    2022.02   Waseda University   C Programming (3)

    Winner: Kenji Tei

  • Waseda University Presidential Teaching Awards

    2022.02   Waseda University   C Programming (3)

    Winner: Kenji Tei

  • ICIEA‘ 2021 Excellent Oral Presentation

    2021.05   ICIEA‘ 2021   Differential Controller Synthesis at Runtime Using Changed Parts of Environment Model

    Winner: Takanori Hirano, Kenji Tei, Kazuya Aizawa, Shinichi Honiden

  • 科学技術分野の文部科学大臣表彰 科学技術賞

    2021.04   文部科学省   先端スマートシステム技術の普及啓発

    Winner: 鷲崎 弘宜, 本位田 真一, 鄭 顕志, 内平 直志, 深澤 良彰

  • 2019年度情報処理学会SE研究会功績賞受賞

    2019   情報処理学会   トップエスイープロジェクトの推進

    Winner: 本位田 真一, 石川 冬樹, 鄭 顕志

  • 優秀論文賞

    2016.09   合同エージェントワークショップ&シンポジウム2016 (JAWS2016)   自己適応システムのための実行時環境モデル学習手法

    Winner: 田邉萌香, 鄭顕志, 深澤良彰, 本位田真一

  • Best Paper Award

    2016.05   11th International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS 2016)   Assured and Correct Dynamic Update of Controllers

    Winner: Leandro Nahabedian, Victor Braberman, Nicolas D’Ippolito, Shinichi Honiden, Jeff Kramer, Kenji Tei, Sebastian Uchitel

  • SENSORCOMM 2012 Best paper award

    2012.08   International Academy, Research, and Industry Association   Classification of Faults in Sensor Readings withStatistical Pattern Recognition

    Winner: Valentina Baljak, Kenji Tei, Shinichi Honiden

  • DICOMO2007優秀プレゼンテーション賞

    2007.07  

    Winner: 鄭顕志

  • JAWS2006学生奨励賞

    2006.10  

    Winner: 鄭顕志

▼display all

 

Papers

  • Preference Adaptation: user satisfaction is all you need!

    Nianyu Li, Mingyue Zhang, Jialong Li, Eunsuk Kang, Kenji Tei

    18th International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS)    2023.05  [Refereed]  [International journal]  [International coauthorship]

    Authorship:Last author

  • 段階的な部分合成による離散制御器合成の分析空間削減

    山内 拓人, 鄭 顕志

    電子情報通信学会論文誌   J106-D ( 04 ) 1 - 12  2023.04  [Refereed]  [Domestic journal]

    Authorship:Last author

  • Attention-guiding Takeover Requests for Situation Awareness in Semi-autonomous Driving

    Qingxin Chen, Jialong Li, Kenji Tei

    18th ACM/IEEE International Conference on Human-Robot Interaction (HRI)    2023.03  [Refereed]  [International journal]

    Authorship:Last author

  • Efficient Difference Analysis of Guaranteeable Requirements for Fault-tolerant Self-adaptation

    Jialong Li, Kenji Tei

    Journal of Information Processing   31   1 - 11  2023.03  [Refereed]  [Domestic journal]

    Authorship:Last author

  • A Reinforcement Learning Approach for Adaptive Covariance Tuning in Kalman Filter

    Jiajun Gu, Jialong Li, Kenji Tei

    IEEE 5th Advanced Information Management,Communicates,Electronic and Automation Control Conference (IMCEC 2022)    2022.12  [Refereed]  [International journal]

    Authorship:Last author

  • Value Iteration Residual Network with Self-Attention

    Jinyu Cai, Jialong Li, Zhenyu Mao, Kenji Tei

    22nd International Conference on Intelligent Systems Design and Applications (ISDA)    2022.12  [Refereed]  [International journal]

    Authorship:Last author

  • Goal-oriented Knowledge Reuse via Curriculum Evolution for Reinforcement Learning-based Adaptation

    Jialong Li, Mingyue Zhang, Zhenyu Mao, Haiyan Zhao, Zhi Jin, Shinichi Honiden, Kenji Tei

    29th Asia-Pacific Software Engineering Conference (APSEC 2022)    2022.12  [Refereed]  [International journal]  [International coauthorship]

    Authorship:Last author

  • A formulation of MIP train rescheduling at terminals in bidirectional double-track lines with a moving block and ATO

    Kosuke Kawazoe, Takuto Yamauchi, Kenji Tei

    22nd Symposium on Algorithmic Approaches for Transportation Modelling, Optimization, and Systems (ATMOS)     10:1 - 10:18  2022.09  [Refereed]  [International journal]

    Authorship:Last author

    DOI

    Scopus

  • Towards Better Service Personalization: Reinforcement Learning with Guarantee of User Preference

    Zhenyu Mao, Jialong Li, Kenji Tei

    IEEE 20th International Symposium on Intelligent Systems and Informatics (SISY 2022)    2022.09  [Refereed]  [International journal]

    Authorship:Last author

  • Multi-Agent Path Finding with Priority Transfer Accompanied with Moving Obstacles

    Yichen Ding, Jialong Li, Kenji Tei

    IEEE 20th International Symposium on Intelligent Systems and Informatics (SISY 2022)    2022.09  [Refereed]  [International journal]

    Authorship:Last author

  • Done is better than perfect: Iterative Adaptation via Multi-grained Requirement Relaxation

    Jialong Li, Kenji Tei

    the 30th IEEE International Requirements Engineering (RE'22)     288 - 294  2022.08  [Refereed]  [International journal]

    Authorship:Last author

    DOI

    Scopus

  • From Local to Global: A Curriculum Learning Approach for Reinforcement Learning-based Traffic Signal Control

    Nianzhao Zheng, Jialong Li, Zhenyu Mao, Kenji Tei

    2022 IEEE 2nd International Conference on Software Engineering and Artificial Intelligence (SEAI)     253 - 258  2022.06  [Refereed]  [International journal]

    Authorship:Last author

    DOI

  • Towards scalable model checking of reflective systems via labeled transition systems

    Kenji Tei, Yasuyuki Tahara, Akihiko Ohsuga

    IEEE Transactions on Software Engineering (TSE)     1 - 23  2022.05  [Refereed]  [International journal]

    Authorship:Lead author, Corresponding author

     View Summary

    early access

    DOI

    Scopus

  • Safe Reinforcement Learning through Hierarchical Shielding with Self-Adaptive Techniques

    Prasanth Senthilvelan, Jialong Li, Kenji Tei

    IEEE 9th International Conference on Industrial Engineering and Applications (ICIEA 2022)    2022.04  [Refereed]  [International journal]

    Authorship:Last author

     View Summary

    to appear

  • 列車自動運転を伴う運転整理MIPモデルの移動閉塞下への適用

    川添 宏介, 山内 拓人, 鄭 顕志, 富井 規雄, 本位田 真一

    情報処理学会論文誌   63 ( 3 ) 786 - 807  2022.03  [Refereed]  [Domestic journal]

    DOI

  • Towards Personalized Autonomous Driving: An Emotion Preference Style Adaptation Framework

    Jiali Ling, Jialong Li, Kenji Tei, Shinichi Honiden

    The 5th IEEE International Conference on Agents (IEEE ICA2021)     47 - 52  2021.12  [Refereed]  [International journal]

    DOI

    Scopus

  • A Development Method for Safety Node-RED Systems using Discrete Controller Synthesis

    Takuto Yamauchi, Takanori Hirano, Jialong Li, Takafumi Kawasaki, Yin Chen, Akira Tsuge, Tadashi Okoshi, Jin Nakazawa, Nobukazu Yoshioka, Georgios Palaiokrassas, Antonios Litke, Kenji Tei

    The 14th IEEE International Conference on Internet of Things (IEEE iThings-2021)     130 - 137  2021.12  [Refereed]  [International journal]  [International coauthorship]

    Authorship:Last author

    DOI

    Scopus

  • OACAL: Finding Module-consistent Specifications to Secure Systems from Weakened User Obligations

    Pengcheng Jiang, Kenji Tei

    the 2021 IEEE Symposium Series on Computational Intelligence (SSCI 2021)     1 - 9  2021.12  [Refereed]  [International journal]

    Authorship:Last author

    DOI

    Scopus

  • Blockchain-Based Cooperative Incentive System for Emergency Road Right Transferring

    Yichen Ding, Jialong Li, Kenji Tei, Shinichi Honiden

    IEEE 10th Global Conference on Consumer Electronics (GCCE 2021)     736 - 739  2021.10  [Refereed]  [International journal]

    DOI

    Scopus

  • Transfer Learning Method in Reinforcement Learning-based Traffic Signal Control

    Zhenyu Mao, Jialong Li, Nianzhao Zheng, Kenji Tei, Shinichi Honiden

    IEEE 10th Global Conference on Consumer Electronics (GCCE 2021)     304 - 307  2021.10  [Refereed]  [International journal]

    DOI

    Scopus

  • A Meta Reinforcement Learning-based Approach for Self-Adaptive System

    Mingyue Zhang, Jialong Li, Haiyan Zhao, Kenji Tei, Shinichi Honiden, Zhi Jin

    2nd IEEE International Conference on Autonomic Computing and Self-Organizing Systems (ACSOS2021)     1 - 10  2021.09  [Refereed]  [International journal]  [International coauthorship]

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Automated Motion Plan Generation for Service Robot by Discrete Controller Synthesis

    Takara KASAI, Kenji TEI

       2021.06  [Refereed]  [Domestic journal]

    Authorship:Last author

     View Summary

    to appear

  • Towards Better Adaptive Systems by Combining MAPE, Control Theory, and Machine Learning

    Danny Weyns, Bradley Schmerl, Masako Kishida, Alberto Leva, Marin Litoiu, Necmiye Ozay, Colin Paterson, Kenji Tei

    16th International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS2021)     217 - 223  2021.05  [Refereed]  [International journal]  [International coauthorship]

    Authorship:Last author

     View Summary

    to appear

  • Differential Controller Synthesis at Runtime Using Changed Parts of Environment Model

    Takanori Hirano, Kenji Tei, Kazuya Aizawa, Shinichi Honiden

    IEEE 8th International Conference on Industrial Engineering and Applications (ICIEA 2021)     91 - 100  2021.04  [Refereed]  [International journal]

    DOI

    Scopus

  • Self-adaptive Hydroponics Care System for Human-hydroponics Coexistence

    Jialong Li, Zhenyu Mao, Zhen Cao, Kenji Tei, Shinichi Honiden

    IEEE 3rd Global Conference on Life Sciences and Technologies (LifeTech2021)     204 - 206  2021.03  [Refereed]

    DOI

  • Heterogeneous Information Network based Adaptive Social Influence Learning for recommendation and explanation

    Munan Li, Kenji Tei, Yoshiaki Fukazawa

    The 2020 IEEE/WIC/ACM International Joint Conference on Web Intelligence and Intelligent Agent Technology (WI-IAT'20)     137 - 144  2020.12  [Refereed]  [International journal]

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Identifying achievable goals for adaptive replanning against runtime environment change

    Jialong Li, Kenji Tei, Shinichi Honiden

    The 20th International Conference on Intelligent Systems Design and Applications (ISDA)     945 - 955  2020.12  [Refereed]  [International journal]

    DOI

  • Method of Applying Df-pn Algorithm to On-the-fly Controller Synthesis

    Kengo Kuwana, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    IEEE Third International Conference on AI and Knowledge Engineering (AIKE)     168 - 173  2020.12  [Refereed]  [International journal]

    DOI

    Scopus

  • Method for Low-Cost Environment Partitioning Modeling in Dynamic Update

    Takuto Yamauchi, Kenji Tei, Shinichi Honiden

    IEEE Third International Conference on AI and Knowledge Engineering (AIKE)     183 - 187  2020.12  [Refereed]  [International journal]

    DOI

    Scopus

  • Efficient Difference Analysis Algorithm for Runtime Requirement Degradation under System Functional Fault

    Jialong Li, Kazuya Aizawa, Kenji Tei, Shinichi Honiden

    The 18th IEEE International Conference on Embedded and Ubiquitous Computing (IEEE EUC 2020)     33 - 40  2020.12  [Refereed]

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • Dynamic Update of Discrete Event Controllers

    L. Nahabedian, V. Braberman, N. DIppolito, S. Honiden, J. Kramer, K. Tei, S. Uchitel

    IEEE Transactions on Software Engineering (TSE)   46   1220 - 1240  2020.11  [Refereed]  [International coauthorship]

    DOI

    Scopus

    9
    Citation
    (Scopus)
  • Smart SE: Smart Systems and Services Innovative Professional Education Program

    Hironori Washizaki, Kenji Tei, Kazunori Ueda, Hayato Yamana, Yoshiaki Fukazawa, Shinichi Honiden, Shoichi Okazaki, Nobukazu Yoshioka, Naoshi Uchihira

    The 44th IEEE Computer Society Signature Conference on Computers, Software, and Applications (COMPSAC 2020)     1113 - 1114  2020.07  [Refereed]

    DOI

  • Adaptive Control Method Considering Dynamic Characteristics of External Environment by using Model Predictive Control and Discrete Controller Synthesis

    安曽徳康, 小川雅俊, 松塚貴英, 鄭顕志

    情報処理学会シンポジウムシリーズ(CD-ROM)   2020 ( 1 )  2020.06  [Refereed]

    Authorship:Last author

    J-GLOBAL

  • Towards Bridging the Gap between Control and Self-Adaptive System Properties

    Javier Cámara, Alessandro Vittorio Papadopoulos, Thomas Vogel, Danny Weyns, David Garlan, Shihong Huang, Kenji Tei

    15th International Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS2020)     78 - 84  2020.05  [Refereed]

    Authorship:Last author

     View Summary

    to appear

  • 違反状態抽象化による保証可能な安全性特定のための分析空間削減

    相澤和也, 鄭 顕志, 本位田 真一

    電子情報通信学会論文誌 D   J103-D ( 4 ) 238 - 246  2020.04  [Refereed]

  • A game analysis algorithm for identifying safety properties guaranteeable while satisfying a liveness property

    Kazuya Aizawa, Kenji Tei, Shinichi Honiden

      61 ( 4 ) 853 - 862  2020.04  [Refereed]

  • An Efficient Adaptive Attention Neural Network for Social Recommendation

    Munan Li, Kenji Tei, Yoshiaki Fukazawa

    IEEE Access   8   63595 - 63606  2020  [Refereed]

    DOI

  • Minimising Makespan of Discrete Controllers: A Qualitative Approach

    Ezequiel Castellano, Victor Braberman, Nicolas D'Ippolito, Sebastian Uchitel, Kenji Tei

    2019 IEEE 58th Conference on Decision and Control (CDC)     1068 - 1075  2019.12  [Refereed]

    DOI

  • An efficient co-Attention Neural Network for Social Recommendation

    Munan Li, Kenji Tei, Yoshiaki Fukazawa

    IEEE/WIC/ACM International Conference on Web Intelligence (WI'19)     34 - 42  2019.10  [Refereed]

     View Summary

    to appear

  • Updating Environment Model at Runtime for Self-adaptive System

    Moeka Tanabe, Kenji Tei, Shinichi Honiden

    IPSJ Journal   60 ( 10 ) 1617 - 1630  2019.10  [Refereed]

  • Analysis space reduction with state merging for ensuring safety properties of self-adaptive systems

    Kazuya Aizawa, Kenji Tei, Shinichi Honiden

    The 16th IEEE International Conference on Advanced and Trusted Computing (ATC 2019)     1363 - 1370  2019.08  [Refereed]

     View Summary

    to appear

  • A Runtime Monitoring Framework to Enforce Invariants on Reinforcement Learning Agents Exploring Complex Environments

    Piergiuseppe Mallozzi, Ezequiel Gustavo Castellano, Patrizio Pelliccione, Gerardo Schneider, Kenji Tei

    2nd International Workshop on Robotics Software Engineering (RoSE 2019)     5 - 12  2019.05  [Refereed]

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Modelling and Analysing Resilient Cyber-Physical Systems

    Amel Bennaceur, Carlo Ghezzi, Kenji Tei, Timo Kehrer, Danny Weyns, Radu Calinescu, Schahram Dustdar, Zhenjiang Hu, Shinishi Honiden, Fuyuki Ishikawa, Zhi Jin, Jeffrey Kramer, Marin Litoiu, Michele Loreti, Gabriel Moreno, Hausi Muller, Laura Nenzi, Bashar Nuseibeh, Liliana Pasquale, Wolfgang Reisig, Heinz Schmidt, Christos Tsigkanos, Haiyan Zhao

    the 14th Symposium on Software Engineering for Adaptive and Self-Managing Systems (SEAMS2019)     70 - 76  2019.05  [Refereed]

    DOI

    Scopus

    18
    Citation
    (Scopus)
  • 環境変化時に保証可能な安全性を特定するためのゲーム分析アルゴリズム

    相澤和也, 鄭顕志, 本位田真一

    情報処理学会論文誌   60 ( 4 ) 1025 - 1039  2019.04  [Refereed]

  • Identifying safety properties guaranteed in changed environment at runtime

    Kazuya Aizawa, Kenji Tei, Shinichi Honiden

    the 3rd IEEE International Conference on Agents (ICA 2018)     75 - 80  2018.09  [Refereed]

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • Applicability of earned value management for deadline energy constrained applications

    S. Suenaga, K. Tei, S. Honiden

    IEEE International Conference on Industrial Engineering and Engineering Management   2017-   691 - 695  2018.02  [Refereed]

     View Summary

    Earned Value Management (EVM) is a progress management method in project management. EVM is used as metrics to analyze execution statuses of projects that need to be accomplished within deadlines and limited budgets. By replacing budgets used in project management with energy used in applications, we can apply EVM as metrics to analyze execution statuses of Deadline Energy Constrained (DEC) applications that execute tasks within deadlines and limited energy. DEC applications are often seen in applications that need to consume energy within limits, for example, Wireless Sensor Networks (WSNs), Electric Cars (ECs), and Unmanned Aerial Vehicle (UAV). In this paper, we introduce new possibilities of applying EVM by showing that EVM can be used to analyze execution statuses of and make changes to DEC applications.

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • Soft-Goal Approximation Context Awareness of Goal-Driven Self-Adaptive Systems

    Aurelien Vialon, Kenji Tei, Samir Aknine

    Proceedings - 2017 IEEE International Conference on Autonomic Computing, ICAC 2017     233 - 238  2017.08  [Refereed]

     View Summary

    In goal-driven self-adaptive systems, a goal model is used as a requirement model and is held by the system even at runtime. At this moment, the self-adaptive system, which can change its behaviour at runtime, will be able to reason over the variability within the goal model. It will then be able to find the best behaviour to deal with environment evolutions. However, the uncertain nature of the requirements engineering concepts in a real dynamic world is not always rightfully defined. In particular, quality requirements runtime changes are almost never considered in the literacy. Specifically, a problem we highlight here is the lack of context consideration in quality constraint approximation. Our purpose is to clearly define this problem and to propose a first solution. In this paper, we introduce a flexible version of the quality constraints. This new kind of quality constraints can be rewritten at runtime to tackle the context change induced by the environment change. To stick the constraint definition to the context change, we developed a new algorithm which modifies the specification of the quality constraints at runtime.

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • Learning environment model at runtime for self-adaptive systems

    Moeka Tanabe, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    Proceedings of the ACM Symposium on Applied Computing   128005   1198 - 1204  2017.04  [Refereed]

     View Summary

    Self-adaptive systems alter their behavior in response to environmental changes to continually satisfy their requirements. Self-adaptive systems employ an environment model, which should be updated during runtime to maintain consistency with the real environment. Although some techniques have been proposed to learn environment model based on execution traces at the design time, these techniques are time consuming and consequently inappropriate for runtime learning. Herein, a technique using a stochastic gradient descent and the difference in the data acquired during the run-time is proposed as an efficient learning environment model. The computational time and accuracy of our technique are verified through a case study.

    DOI

    Scopus

    8
    Citation
    (Scopus)
  • A comparative analysis of machine learning algorithms for faults detection in wireless sensor networks

    Ehsan Ullah Warriach, Kenji Tei

    INTERNATIONAL JOURNAL OF SENSOR NETWORKS   24 ( 1 ) 1 - 13  2017  [Refereed]

     View Summary

    Wireless sensor networks (WSNs) deployment experiences show that collected data is prone to be faulty. Faults are due to internal and external influences, such as calibration, low battery, environmental interference and sensor aging. In this paper, we focus on faults occurred due to low battery and calibration in WSNs. Machine learning algorithms have been successfully used to identify and classify various types of faults. In this paper, we evaluate and compare the performance of k-nearest neighbour, support vector machine (SVM), and Naive Bayes machine learning algorithms by using the real-world datasets to identify and classify the faults. We present here a comparative study of the above mentioned approaches on experimental datasets. The approach is validated using real data obtained from over one month of samples from motes deployed in an actual living lab. The results show that the k-nearest neighbour (kNN) algorithm obtained a better fault detection rate than other algorithms based on given performance metrics.

    DOI

  • Learning Environment Model at Runtime for Self-Adaptive Systems

    Moeka Tanabe, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    合同エージェントワークショップ&シンポジウム2016 (JAWS2016)     1 - 8  2016.09  [Refereed]

  • Generating Specification for Automated Warehouse System by Hieratical Discrete Controller Synthesis

    Masaki Katae, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    合同エージェントワークショップ&シンポジウム2016 (JAWS2016)     1 - 8  2016.09  [Refereed]

  • Relaxing Requirements with Environment Changes for Graceful Degradation

    Kazuya Aizawa, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    5th Asian Workshop of Advanced Software Engineering    2016.03  [Refereed]

  • Involving End-Users in Web-Based System Development with INTER-Mediator

    Masayuki Nii, Kenji Tei, Fuyuki Ishikawa

    Transactions on Engineering Technologies     79 - 93  2016.03  [Refereed]

    DOI

  • Benchmark Datasets for Fault Detection and Classification in Sensor Data

    Bas de Bruijn, Tuan Anh Nguyen, Doina Bucur, Kenji Tei

    5th International Conference on Sensor Networks (SENSORNETS 2016)     185 - 195  2016.02  [Refereed]

    DOI

    Scopus

    14
    Citation
    (Scopus)
  • Assured and Correct Dynamic Update of Controllers

    L. Nahabedian, V. Braberman, N. D'Ippolito, S. Honiden, J. Kramer, K. Tei, S. Uchitel

    PROCEEDINGS OF 2016 IEEE/ACM 11TH INTERNATIONAL SYMPOSIUM ON SOFTWARE ENGINEERING FOR ADAPTIVE AND SELF-MANAGING SYSTEMS (SEAMS)     96 - 107  2016  [Refereed]

     View Summary

    In many application domains, continuous operation is a desirable attribute for software-intensive systems. As the environment or system requirements change, so the system should change and adapt without stopping or unduly disturbing its operation. There is, therefore, a need for sound engineering techniques that can cope with dynamic change. In this paper we address the problem of dynamic update of controllers in reactive systems when the specification (environment assumptions, requirements and interface) of the current system changes. We present a general approach to specifying correctness criteria for dynamic update and a technique for automatically computing a controller that handles the transition from the old to the new specification, assuring that the system will reach a state in which such a transition can correctly occur. Indeed, using controller synthesis we show how to automatically build a controller that guarantees both progress towards update and safe update. Seven case studies have been implemented to validate the approach.

    DOI

    Scopus

    15
    Citation
    (Scopus)
  • Mesh-based Combination and Expansion Type Cache Management Method for Spatio-Temporal Data

    Hideaki Hirayama, Kenji Tei, Yuichi Sei, Akihiko Ohsuga

        1276 - 1283  2015.07  [Refereed]

  • Earned Value Management Based Adaptation Framework for Deadline Budget Constrained Applications

    Shunichiro Suenaga, Kenji Tei

      56 ( 5 ) 1363 - 1376  2015.05  [Refereed]

  • Model-driven-development-based stepwise software development process for wireless sensor networks

    Kenji Tei, Ryo Shimizu, Yoshiaki Fukazawa, Shinichi Honiden

    IEEE Transactions on Systems, Man, and Cybernetics: Systems   45 ( 4 ) 675 - 687  2015.04  [Refereed]

     View Summary

    To meet future demands for wireless sensor network (WSN) software, both experts and average software developers should be involved in WSN software development. However, WSN software development is difficult for the average software developer because data processing-related design and network-related design are tangled in the software. Here, we propose a software development process for WSN software by stepwise refinement. Our process enables stepwise refinement to separately address data processing-related and network-related concerns, reuse of well-defined designs, and implementations for network-related concerns prepared by the experts, and perform model-driven development to obtain source codes from models by model transformations. Additionally, we used case studies using actual WSN software development and user studies to evaluate how our proposed process can support actual WSN software development.

    DOI

    Scopus

    28
    Citation
    (Scopus)
  • Model-Driven-Development-Based Stepwise Software Development Process for Wireless Sensor Networks

    Kenji Tei, Ryo Shimizu, Yoshiaki Fukazawa, Shinichi Honiden

    IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS   45 ( 4 ) 675 - 687  2015.04  [Refereed]

     View Summary

    To meet future demands for wireless sensor network (WSN) software, both experts and average software developers should be involved in WSN software development. However, WSN software development is difficult for the average software developer because data processing-related design and network-related design are tangled in the software. Here, we propose a software development process for WSN software by stepwise refinement. Our process enables stepwise refinement to separately address data processing-related and network-related concerns, reuse of well-defined designs, and implementations for network-related concerns prepared by the experts, and perform model-driven development to obtain source codes from models by model transformations. Additionally, we used case studies using actual WSN software development and user studies to evaluate how our proposed process can support actual WSN software development.

    DOI

    Scopus

    28
    Citation
    (Scopus)
  • Framework Enabling End-Users to Maintain Web Applications

    Masayuki Nii, Kenji Tei, Fuyuki Ishikawa

    IAENG International Conference on Internet Computing and Web Services (ICICWS'15)     387 - 394  2015.03  [Refereed]

  • A Self-healing Framework for Online Sensor Data

    Tuan Anh Nguyen, Marco Aiello, Takuro Yonezawa, Kenji Tei

    2015 IEEE INTERNATIONAL CONFERENCE ON AUTONOMIC COMPUTING     295 - 300  2015  [Refereed]

     View Summary

    In pervasive computing environments, wireless sensor networks (WSNs) play an important role, collecting reliable and accurate context information so that applications are able to provide services to users on demand. In such environments, sensors should be self-adaptive by taking correct decisions based on sensed data in real-time. However, sensor data is often faulty. Faults are not so exceptional and in most deployments tend to occur frequently. Therefore, the capability of self-healing is important to ensure higher levels of reliability and availability. We design a framework which provides self-healing capabilities, enabling a flexible choice of components for detection, classification, and correction of faults at runtime. Within our framework, a variety of fault detection and classification algorithms can be applied, depending on the characteristics of the sensor data types as well as the topology of the sensor networks. A set of mechanisms for each and every step of the self-healing framework, covering detection, classification, and correction of faults are proposed. To validate the applicability, we illustrate a case study where our solution is implemented as an adaptation engine and integrated seamlessly into the ClouT system. The engine processes data coming from physical sensors deployed in Santander, Spain, providing corrected sensor data to other smart city applications developed in the ClouT project.

    DOI

    Scopus

    5
    Citation
    (Scopus)
  • Supporting Model Transformation Developments with Multi-Level Models: A Wireless Sensor Network Case

    Ryo Shimizu, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    the 11th International Conference Applied Computing 2014 (AC 2014)    2014.10  [Refereed]

  • Data Quality-Centric Development Process in Wireless Sensor Network

    Ryo Shimizu, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    The IEICE transactions on information and systems (Japanese edition)   J97-D ( 3 ) 473 - 487  2014.03  [Refereed]

    CiNii

  • 自己適応ソフトウェアのための自己適応性設計に関する研究動向

    鄭 顕志, 清水 遼, 高橋 竜一, 石川 冬樹

    コンピュータソフトウェア   31 ( 1 ) 49 - 59  2014.02  [Refereed]

    DOI

  • HoppingDuster: Self-adaptive cleaning robot based on aerial vehicle

    Kenji Tei, Shunichiro Suenaga, Shun Lee, Kazuya Aizawa, Ryuichi Takahashi, Yoshiaki Fukazawa

    UbiComp 2014 - Adjunct Proceedings of the 2014 ACM International Joint Conference on Pervasive and Ubiquitous Computing     271 - 274  2014  [Refereed]

     View Summary

    Home cleaning robots have become popular. Most of the home cleaning robots are based on ground vehicles. While the cleaning robots based on ground vehicles can vacuum or wash floors robustly and efficiently, but they only clean on floors, not on stairs or furnitures. In this demo, we show a new concept of cleaning robot, called HoppingDuster. HoppingDuster is based on an aerial vehicle, which can y to stairs or furnitures to be cleaned, and hop or hover to wipe or blow down dust on them toward the floor so that the ground cleaning robot can vacuum the dust. HoppingDuster adapts its behavior to finish it cleaning within designated time and battery capacity.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Project Management Inspired Framework for Action Selection in Wireless Sensor Networks

    Shunichiro Suenaga, Kenji Tei

    2014 IEEE ASIA PACIFIC CONFERENCE ON WIRELESS AND MOBILE     54 - 59  2014  [Refereed]

     View Summary

    Applications in wireless sensor networks (WSNs) sometimes cannot deliver the quality required by users due to packet loss and node leaving. There is a trade-off between energy and quality: increasing quality requires energy, and decreasing energy invites a lack of quality. To adjust the trade-off, actions which make changes to the energy and quality condition are required. There has been previous research on actions to reduce energy and to improve quality, but how to select actions and methods in accordance with the condition has not been established. To overcome this problem, we propose a framework that can select suitable actions from multiple choices based on an analysis of the condition by applying methods found in Project Management. This framework consists of (1) Earned Value Management (EVM) and (2) an Action Table. EVM is a metric that is used to analyze cost and progress, and the Action Table is a method to select appropriate actions in accordance with condition. Simulation results show that the proposed framework can adjust the trade-off more effectively than conventional frameworks by selecting and changing the most suitable actions.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • ClouT : Cloud of Things for Empowering the Citizen Clout in Smart Cities

    Kenji Tei, Levent Guergen

    2014 IEEE WORLD FORUM ON INTERNET OF THINGS (WF-IOT)     369 - +  2014  [Refereed]

    DOI

    Scopus

    45
    Citation
    (Scopus)
  • Toward A Portability Framework with Multi-Level Models for Wireless Sensor Network Software

    Ryo Shimizu, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    2014 INTERNATIONAL CONFERENCE ON SMART COMPUTING (SMARTCOMP)     253 - 260  2014  [Refereed]

     View Summary

    Wireless sensor networks (WSNs) play important roles in systems that interact with the real world (e.g., cyber-physical systems and internet of things). To mitigate the complex nature of WSNs, many platforms at different abstraction levels (e.g., abstraction of hardware, communications, and individual nodes) have been proposed in the last decade. WSNs in different environments might employ different platforms to satisfy nonfunctional requirements (NFRs) because the diversity of platforms results in trade-offs of NFRs and the quality of WSN heavily depends on the environment it runs. Although WSN software should be highly portable, existing approaches only support porting between operating systems and not more abstract middleware. Herein we propose a methodology with a framework to capture various platforms in the WSN domain with platform-independent multi-level models. A case study demonstrates that our framework can port WSN software to platforms at different abstraction levels and adapt the software to the new platform to improve performance.

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • A Decentralized Scheme for Fault Detection and Classification in WSNs

    Tuan Anh Nguyen, Marco Aiello, Kenji Tei

    the 1st International Conference on Cyber-Physical Systems, Networks, and Applications, WIP session     1 - 4  2013.08  [Refereed]

  • Fault detection in wireless sensor networks: A machine learning approach

    Ehsan Ullah Warriach, Kenji Tei

    Proceedings - 16th IEEE International Conference on Computational Science and Engineering, CSE 2013     758 - 765  2013  [Refereed]

     View Summary

    Wireless Sensor Network (WSN) deployment experiences show that collected data is prone to be faulty. Faults are due to internal and external influences, such as calibration, low battery, environmental interference and sensor aging. However, only few solutions exist to deal with faulty sensory data in WSN. We develop a statistical approach to detect and identify faults in a WSN. In particular, we focus on the identification and classification of data and system fault types as it is essential to perform accurate recovery actions. Our method uses Hidden Markov Models (HMMs) to capture the fault-free dynamics of an environment and dynamics of faulty data. It then performs a structural analysis of these HMMs to determine the type of data and system faults affecting sensor measurements. The approach is validated using real data obtained from over one month of samples from motes deployed in an actual living lab. © 2013 IEEE.

    DOI

    Scopus

    29
    Citation
    (Scopus)
  • Applying time series analysis and neighbourhood voting in a decentralised approach for fault detection and classification in WSNs

    Tuan Anh Nguyen, Doina Bucur, Marco Aiello, Kenji Tei

    ACM International Conference Proceeding Series     234 - 241  2013  [Refereed]

     View Summary

    In pervasive computing environments, wireless sensor networks play an important infrastructure role, collecting reliable and accurate context information so that applications are able to provide services to users on demand. In such environments, sensors should be self-adaptive by taking correct decisions based on sensed data in real-time in a decentralised manner
    however, sensed data is often faulty. We thus design a decentralised scheme for fault detection and classification in sensor data in which each sensor node does localised fault detection. A combination of neighbourhood voting and time series data analysis techniques are used to detect faults. We also study the comparative accuracy of both the union and the intersection of the two techniques. Then, detected faults are classified into known fault categories. An initial evaluation with SensorScope, an outdoor temperature dataset, confirms that our solution is able to detect and classify faulty readings into four fault types, namely, 1) random, 2) malfunction, 3) bias, and 4) drift with accuracy up to 95%. The results also show that, with the experimental dataset, the time series data analysis technique performs comparable well in most of the cases, whilst in some other cases the support from neighbourhood voting technique and histogram analysis helps our hybrid solution to successfully detects the faults of all types. Copyright © 2013 ACM.

    DOI

    Scopus

    21
    Citation
    (Scopus)
  • Intention-based automated composition approach for coordination protocol

    Ryuichi Takahashi, Fuyuki Ishikawa, Kenji Tei, Yoshiaki Fukazawa

    Proceedings - IEEE 20th International Conference on Web Services, ICWS 2013     260 - 267  2013  [Refereed]

     View Summary

    In systems that require several services to collaborate, specifying coordination protocols is vital, but costly. Additionally, several properties, which are derived from laws, regulations, requirements, etc., must be satisfied. Coordination protocol composition approaches construct specific protocols in a cost effective manner in accordance with the composition intentions. However, existing composition approaches are insufficient in terms of satisfying properties. Existing approaches use concrete specifications to identify composition intentions and do not consider interference between compositions. Herein we propose a new composition approach in which a developer directly expresses his or her intentions as constraints via metadata, and then the system searches for optimal composition methods based on the constraints. © 2013 IEEE.

    DOI

    Scopus

  • Faults in Sensory Readings: Classification and Model Learning

    Valentina Baljak, Tei Kenji, Shinichi Honiden

    Sensors & Transducers Journal   18   177 - 187  2013.01  [Refereed]

  • Fault Classification and Model Learning from Sensory Readings - Framework for Fault Tolerance in Wireless Sensor Networks

    Valentina Baljak, Kenji Tei, Shinichi Honiden

    2013 IEEE EIGHTH INTERNATIONAL CONFERENCE ON INTELLIGENT SENSORS, SENSOR NETWORKS AND INFORMATION PROCESSING     408 - 413  2013  [Refereed]

     View Summary

    Primary task of wireless sensor networks is to deliver reliable and accurate information about the phenomena of interest. However, faults are a frequent occurrence and their accumulation affects the quality of service significantly. This leads to a shorter effective lifetime of the network. In this work, we propose a framework for the fault tolerance in sensory readings. The main concept is based on the observation of the pattern that faults leave in data behavior. Based on the duration, continuity and the impact, we propose a complete and consistent classification of faults as they can be observed in sensory readings independently of the underlying cause. Further, we propose that network learns a model of a fault for each faulty node from the past behavior. Each phase of the framework can be implemented with the use of different algorithms appropriate for the task. In this paper we present an instance that relies on neighborhood vote, time series analysis and statistical pattern recognition. Results so far confirm that the scheme works well for dense data-centric wireless sensor networks.

    DOI

    Scopus

    7
    Citation
    (Scopus)
  • Classification of Faults in Sensor Readings with Statistical Pattern Recognition

    Valentina Baljak, Kenji Tei, Shinichi Honiden

    The Sixth International Conference on Sensor Technologies and Applications (SENSORCOMM 2012)     270 - 276  2012.08  [Refereed]

     View Summary

    Best Paper Award

  • Meta-Models for Wireless Sensor Network Applications: Data, Group, and Node Views

    Ryo Shimizu, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    GRACE Technical Report   GRACE-TR-2012-01   1 - 9  2012.02

  • S-CLAIM: An Agent-based Programming Language for AmI, A Smart-Room Case Study

    Valentina Baljak, Marius Tudor Benea, Amal El Fallah Seghrouchni, Cedric Herpson, Shinichi Honiden, Thi Thuy Nga Nguyen, Andrei Olaru, Ryo Shimizu, Kenji Tei, Susumu Toriumi

    ANT 2012 AND MOBIWIS 2012   10   30 - 37  2012  [Refereed]

     View Summary

    This paper introduces a declarative agent-oriented language for Ambient Intelligence - S-CLAIM - that allows programming reactive or cognitive mobile agents in a simple, easy-to-use manner while meeting AmI requirements. Based on a hierarchical representation of the agents, the language offers a natural solution to achieve context-sensitivity. S-CLAIM is light-weight and, being transparently underpinned by the JADE framework, allows deployment on mobile devices and easy interoperation with other components by means of web services. The usefulness of the proposed language for AmI is illustrated through a scenario and a demo featuring an AmI application in a Smart Room. (C) 2011 Published by Elsevier Ltd.

    DOI

    Scopus

    12
    Citation
    (Scopus)
  • A Machine Learning Approach for Identifying and Classifying Faults in Wireless Sensor Networks

    Ehsan Ullah Warriach, Marco Aiello, Kenji Tei

    15TH IEEE INTERNATIONAL CONFERENCE ON COMPUTATIONAL SCIENCE AND ENGINEERING (CSE 2012) / 10TH IEEE/IFIP INTERNATIONAL CONFERENCE ON EMBEDDED AND UBIQUITOUS COMPUTING (EUC 2012)     618 - 625  2012  [Refereed]

     View Summary

    Wireless Sensor Network (WSN) deployment experiences show that collected data is prone to be faulty. Faults are due to internal and external influences, such as calibration, low battery, environmental interference and sensor aging. However, only few solutions exist to deal with faulty sensory data in WSN. We develop a statistical approach to detect and identify faults in a WSN. In particular, we focus on the identification and classification of data and system fault types as it is essential to perform accurate recovery actions. Our method uses Hidden Markov Models (HMMs) to capture the fault-free dynamics of an environment and dynamics of faulty data. It then performs a structural analysis of these HMMs to determine the type of data and system faults affecting sensor measurements. The approach is validated using real data obtained from over one month of samples from motes deployed in an actual living lab.

    DOI

    Scopus

    20
    Citation
    (Scopus)
  • A Hybrid Fault Detection Approach for Context-aware Wireless Sensor Networks

    Ehsan Ullah Warriach, Tuan Anh Nguyen, Marco Aiello, Kenji Tei

    9TH IEEE INTERNATIONAL CONFERENCE ON MOBILE AD-HOC AND SENSOR SYSTEMS (MASS 2012)     281 - 289  2012  [Refereed]

     View Summary

    Wireless Sensor Network (WSN) deployment experiences show that data collected is prone to be imprecise and faulty due to internal and external influences, such as battery drain, environmental interference, sensor aging. An early detection of such faults is necessary for the effective operation of the sensor network. We focus on identifying data fault types and their causes. In particular, we propose a hybrid approach to the detection of faults based on three qualitatively different classes of fault detection methods. Rule-based methods leverage domain and expert knowledge to develop heuristic rules for identifying and classifying faults. Estimation methods predict normal sensor behavior by leveraging sensor spatial and temporal correlations, identifying erroneous sensor readings as faults. Finally, learning-based methods are inferred a model for the faulty sensor readings using training data and statistically detect and identify classes of faults. We illustrate the performance of a hybrid approach on data coming from two actual sensor deployments.

    DOI

    Scopus

    6
    Citation
    (Scopus)
  • S-CLAIM: An Agent-based Programming Language for AmI, A Smart-Room Case Study

    Valentina Baljak, Marius Tudor Benea, Amal El Fallah Seghrouchni, Cedric Herpson, Shinichi Honiden, Thi Thuy Nga Nguyen, Andrei Olaru, Ryo Shimizu, Kenji Tei, Susumu Toriumi

    ANT 2012 AND MOBIWIS 2012   10   30 - 37  2012  [Refereed]

     View Summary

    This paper introduces a declarative agent-oriented language for Ambient Intelligence - S-CLAIM - that allows programming reactive or cognitive mobile agents in a simple, easy-to-use manner while meeting AmI requirements. Based on a hierarchical representation of the agents, the language offers a natural solution to achieve context-sensitivity. S-CLAIM is light-weight and, being transparently underpinned by the JADE framework, allows deployment on mobile devices and easy interoperation with other components by means of web services. The usefulness of the proposed language for AmI is illustrated through a scenario and a demo featuring an AmI application in a Smart Room. (C) 2011 Published by Elsevier Ltd.

    DOI

    Scopus

    12
    Citation
    (Scopus)
  • Case studies on the development of wireless sensor network applications using multiple abstraction levels

    Ryo Shimizu, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    2012 3rd International Workshop on Software Engineering for Sensor Network Applications, SESENA 2012 - Proceedings     22 - 28  2012  [Refereed]

     View Summary

    Model-driven development (MDD) facilitates the development of wireless sensor network (WSN) applications because MDD can deal with models at the abstraction level to the concrete level. In the MDD for WSN applications, the developers model the dataflow at the abstract level and model the designs of a communication and task assignment at the concrete level. In our previous work we proposed a MDD process for WSN applications with three domain specific languages (DSLs). However, we did not sufficiently evaluate the description capabilities of our DSLs. For that reason, we report case studies on real-world applications to prove the feasibility of our approach. Our DSL can be used to describe both the application logic and design decisions concerning the quality of data, which are adopted in target applications. Additionally, we demonstrate the effectiveness of the DSLs at multiple abstraction levels. © 2012 IEEE.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Poster Abstract: Fault Detection in Wireless Sensor Networks: A Hybrid Approach

    Ehsan Warriach, Tuan Anh Nguyen, Marco Aiello, Kenji Tel

    IPSN'12: PROCEEDINGS OF THE 11TH INTERNATIONAL CONFERENCE ON INFORMATION PROCESSING IN SENSOR NETWORKS     87 - 88  2012  [Refereed]

     View Summary

    Wireless Sensor Network (WSN) deployment experiences show that data collected is prone to be imprecise and faulty due to internal and external influences, such as battery drain, environmental interference, sensor aging. An early detection of such faults is necessary for the effective operation of the sensor network. In this preliminary work, we propose a hybrid approach to the detection of faults and we illustrate its performance on data coming from a real sensor deployment. The proposal is a first step to have a hybrid method towards automated on-line fault detection and classification in context-aware WSNs middleware framework.

    DOI

    Scopus

    15
    Citation
    (Scopus)
  • A Configurable Sensor Model for Target Tracking in Wireless Sensor Networks

    Kenji Tei, Hikotoshi Nakazato, Yoshiaki Fukazawa, Shinichi Honiden

    The IEICE transactions on communications B   J94-B ( 10 ) 1351 - 1362  2011.10  [Refereed]

    CiNii

  • Autonomic role and mission allocation framework for wireless sensor networks

    Themistoklis Bourdenas, Kenji Tei, Shinichi Honiden, Morris Sloman

    Proceedings - 2011 5th IEEE International Conference on Self-Adaptive and Self-Organizing Systems, SASO 2011     61 - 70  2011  [Refereed]

     View Summary

    Pervasive applications incorporate physical components that are exposed to everyday use and a large number of conditions and external factors that can lead to faults and failures. It is also possible that application requirements change during deployment and the network needs to adapt to a new context. Consequently, pervasive systems must be capable to autonomically adapt to changing conditions without involving users becoming a transparent asset in the environment. In this paper, we present an autonomic mechanism for initial task assignment in sensor networks, an NP-hard problem. We also study on-line adaptation of the original deployment which considers real-time metrics for maximising utility and lifetime of applications and smooth service degradation in the face of component failures. © 2011 IEEE.

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Model driven development for rapid prototyping and optimization of wireless sensor network applications

    Ryo Shimizu, Kenji Tei, Yoshiaki Fukazawa, Shinichi Shinichi

    Proceedings - International Conference on Software Engineering     31 - 36  2011  [Refereed]

     View Summary

    In order to develop Wireless Sensor Network (WSN) applications, it is necessary to develop prototypes in a low-cost way and to optimize application performance. Existing development approaches enable to develop a low-cost prototype by concealing the detail of WSN from the developers. However, there is a trade-off between the development cost of prototype and the description capability needed to optimize the application performance. We propose a Model-Driven Development (MDD) process to enable a low-cost prototyping and detailed optimization. To enable such a development process, we define modeling languages, which describe an application at three abstraction levels, and transformation rules, which transform models described by our modeling language to concrete one. Using our process, in prototyping, the developer describes a model by using the modeling language at the highest abstraction level and automatically obtains an executable model by using transformation rules. In addition, in optimizing, the developer can automatically obtain the models at more concrete abstraction level than the prototype by using transformation rules and modifies them in greater detail by using each modeling language. © 2011 ACM.

    DOI

    Scopus

    26
    Citation
    (Scopus)
  • 組合せによる条件付き品質を考慮したWebサービス選択の高速化手法

    渡辺 敦, 片渕 聡, 高橋 竜一, 鄭 顕志, 石川 冬樹, 深澤 良彰, 本位田 真一

    マルチメディア,分散,協調とモバイル(DICOMO2010)シンポジウム    2010.07  [Refereed]

  • 無線センサネットワークの為のモデル駆動開発に向けたDSL非依存モデルの提案

    清水 遼, 鄭 顕志, 深澤 良彰, 本位田 真一

    マルチメディア,分散,協調とモバイル(DICOMO2010)シンポジウム    2010.07  [Refereed]

  • イベント駆動型Webサービス検索のためのイベントマッチング

    片渕 聡, 鄭 顕志, 高橋 竜一, 深澤 良彰, 石川 冬樹, 本位田 真一

    人工知能学会全国大会(第24回)(JSAI2010)    2010.06  [Refereed]

  • N-ary Sensor Model for Target Tracking in Wireless Sensor Networks

    Kenji Tei, Hikotoshi Nakazato, Yoshiaki Fukazawa, Shinichi Honiden

    In Proceedings of the First International Workshop on Energy Aware Design and Analysis of Cyber Physical Systems (WEA-CPS’10), in conjunction with CPSWEEK    2010.04  [Refereed]

  • 組み合わせQoSを考慮した自動サービス合成に関する研究

    渡辺敦, 片渕聡, 高橋竜一, 鄭顕志, 石川冬樹, 深澤良彰, 本位田真一

    ウィンターワークショップ2010・イン・倉敷    2010.01  [Refereed]

  • サービス設計における付随機能の考慮によるQoSの向上

    高橋 竜一, 鄭 顕志, 石川 冬樹, 本位田 真一, 深澤 良彰

    ウィンターワークショップ2010・イン・倉敷    2010.01  [Refereed]

  • Notification型Webサービス特有のQoSによるサービス選択に向けてのアプローチ

    片渕 聡, 鄭 顕志, 高橋 竜一, 石川 冬樹, 深澤 良彰, 本位田 真一

    ウィンターワークショップ2010・イン・倉敷    2010.01  [Refereed]

  • Coordination Protocol Composition Approach Using Metadata in Multi-agent Systems

    TAKAHASHI Ryuichi, TEI Kenji, ISHIKAWA Fuyuki, HONIDEN Shinichi, FUKAZAWA Yoshiaki

    The IEICE transactions on information and systems   J92-D ( 11 ) 1827 - 1839  2009.11  [Refereed]

    CiNii

  • サービス合成における メタデータを用いた協調プロトコル合成手法

    高橋 竜一, 鄭 顕志, 石川 冬樹, 本位田 真一, 深澤 良彰

    電子情報通信学会情報・システムソサエティサービスコンピューティング時限専門委員会第1回研究会    2009.07  [Refereed]

  • Webサービス 検索のための操作カテゴリ分類手法の提案

    片渕 聡, 鄭 顕志, 高橋 竜一, 石川 冬樹, 深澤 良彰, 本位田 真一

    電子情報通信 学会情報・システムソサエティサービスコンピューティング時限専門委員会第1回研究会    2009.07  [Refereed]

  • 無線センサネットワークにおけるアプリケーション配置を考慮した生存時間延長

    鳥海晋, 清雄一, 末永俊一郎, 鄭顕志, 本位田真一

    マルチメディア,分散,協調とモバイルシンポジウム (DICOMO2009)    2009.07  [Refereed]

  • 無線センサネットワークにおける計測記述言語のための規範モデル導出手法の構築

    鄭顕志, 深澤良彰, 本位田真一

    第15回ソフトウェア工学の基礎ワークショップ(FOSE2008)     69 - 75  2008.11  [Refereed]

  • An Efficient Node Selection Metric for In-network Process Deployment

    Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    The Fourth International Wireless Internet Conference (WICON 2008), November 17-19     1 - 8  2008.11  [Refereed]

  • 協調プロトコル合成における制御構造付与のためのハイレベルオペレーション

    高橋竜一, 鄭顕志, 石川冬樹, 深澤良彰, 本位田真一

    合同エージェントワークショップ&シンポジウム2008 (JAWS-2008)    2008.10  [Refereed]

  • ユビキタスコンピューティングにおけるアプリケーション開発手法に関する研究動向

    鄭顕志, 中川博之, 川俣洋次郎, 吉岡信和, 深澤良彰, 本位田真一

    コンピュータソフトウェア   25 ( 4 ) 121 - 132  2008.10  [Refereed]

  • A Survey of Ubiquitous Computing Middlewares for Adaptable Agents

    TEI Kenji, ISHIKAWA Fuyuki, YOSHIOKA Nobukazu, FUKAZAWA Yoshiaki, HONIDEN Shinichi, Kenji Tei, Fuyuki Ishikawa, Nobukazu Yoshioka, Yoshiaki Fukazawa, Shinichi Honiden, Waseda University:National Institute of Informatics, National Institute of Informatics:the University of Tokyo

      25 ( 4 ) 11 - 19  2008.10  [Refereed]  [Invited]

    DOI CiNii

  • 通信コストと計測精度を考慮したトラッキングのためのセンサモデルの提案

    中里彦俊, 中村善行, 鄭顕志, 深澤良彰, 本位田真一

    マルチメディア, 分散, 協調とモバイルシンポジウム(DICOMO2008)    2008.07  [Refereed]

  • 無線センサネットワークにおける省資源性を考慮したセンサセレクション手法

    中村善行, 鄭顕志, 深澤良彰, 本位田真一

    マルチメディア, 分散, 協調とモバイルシンポジウム(DICOMO2008)    2008.07  [Refereed]

  • 効率の良いネットワーク内処理のための配置ノード選択指標の提案

    鄭顕志, 深澤良彰, 本位田真一

    情報処理学会論文誌   49 ( 6 ) 1872 - 1884  2008.06  [Refereed]

  • A Flexible Protocol Composition for Multi-party Coordination Protocols in Multi-agent Systems

    Ryuichi Takahashi, Kenji Tei, Yoshiaki Fukazawa, Fuyuki Ishikawa, Shinichi Honiden

    2008 IEEE INTERNATIONAL CONFERENCE ON PERVASIVE COMPUTING AND COMMUNICATIONS     609 - +  2008  [Refereed]

     View Summary

    Multi-agent systems need protocols to coordinate among agents implemented by different owners. However specifying coordination protocols for many participating agents is a complex task. A protocol composition approach, which can reduce the complexity of specifying such a coordination protocol, must specify how to compose coordination protocols in a composition configuration. Current protocol compositions cannot sufficiently reduce the complexity because composing a protocol several times requires the specification of too many configurations. We propose a protocol composition approach that can specify composition configurations in an abstract way. We assign metadata to the messages in a coordination protocol and use the metadata to specify the configuration. An abstract configuration using metadata can be applied to various protocol compositions and can reduce the number of specifications required for configuration composition.

    DOI

    Scopus

  • Coordination Protocol Composition Approach Using Metadata in Multi-agent Systems

    Ryuichi Takahashi, Kenji Tei, Yoshiaki Fukazawa, Fuyuki Ishikawa, Shinichi Honiden

    EDOC 2008: 12TH IEEE INTERNATIONAL ENTERPRISE DISTRIBUTED OBJECT COMPUTING, PROCEEDINGS     372 - +  2008  [Refereed]

     View Summary

    In e-Business, agents need to coordinate with each other Coordination protocols that specify the defining orders of message passing are very important. The scale of e-Business grows with the advancement of technology, and the number of agents involved continues to increase. Specifying the coordination protocols for so many participating agents is a complex task. A coordination protocol composition approach reduces the complexity of specifying such a coordination protocol. It treats coordination protocols as individual parts and composes them to construct the intended protocols. However existing approaches do not sufficiently reduce the complexity when a coordination protocol is composed several times, because too many configurations are required to specify a composition. A new approach is proposed that uses metadata to specify the compositions by specifying only one configuration. It can reduce the number of configurations when a coordination protocol is composed several times.

    DOI

    Scopus

    1
    Citation
    (Scopus)
  • Region-based sensor selection for wireless sensor networks

    Yoshiyuki Nakamura, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    Proceedings - IEEE International Conference on Sensor Networks, Ubiquitous, and Trustworthy Computing     326 - 331  2008  [Refereed]

     View Summary

    In a sensor network, the technique that limits the number of sensors used for observation is effective to reduce the energy consumption of each sensor. To limit the number of sensors without sacrificing observation accuracy, an appropriate sensor combination must be selected by evaluating the observation effectiveness of various combinations. However, the computational workload for evaluating all the sensor combinations is quite large. We can define a parameter related to the optimal size of a region around an observation target by making a trade-off between accuracy and the computational workload. In region-based sensor selection, a combination of sensors is selected from that is near the observation target. Accuracy is better in a larger region with a lot of sensors, but the computational workload is heavier. In contrast, a smaller region with fewer sensors has poorer accuracy, but a lighter workload. The size of the region controls the trade-off between accuracy and the computational workload. We define a parameter related to the optimal size of a region, and use it to dynamically adjust the region's size. Our simulations confirmed that region-based sensor selection reduces the computational workload and improves accuracy in comparison to existing techniques. © 2008 IEEE.

    DOI

    Scopus

    4
    Citation
    (Scopus)
  • Real-time POI detection and rating using floating car data

    Osamu Masutani, Hirotoshi Iwasaki, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    14th World Congress on Intelligent Transport Systems    2007.10

  • マルチエージェントシステムにおける柔軟なプロトコル合成言語

    高橋竜一, 鄭顕志, 石川冬樹, 深澤良彰, 本位田真一

    合同エージェントワークショップ&シンポジウム2007 (JAWS2007)    2007.10  [Refereed]

  • ユビキタスコンピューティングにおけるコンテキストのモデル化,管理に関する研究動向

    中村善行, 清家良太, 鄭顕志, 吉岡信和, 深澤良彰, 本位田真一

    合同エージェントワークショップ&シンポジウム2007 (JAWS2007)    2007.10  [Refereed]

  • ユビキタスコンピューティングにおけるアプリケーション開発手法に関する研究動向

    鄭顕志, 中川博之, 川俣洋次郎, 吉岡信和, 深澤良彰, 本位田真一

    合同エージェントワークショップ&シンポジウム2007 (JAWS2007)    2007.10  [Refereed]

  • MANETにおけるコスト基準経路探索プロトコルへのコスト基準拡張リング探索の適用

    河村美嗣, 鄭顕志, 深澤良彰, 本位田真一

    マルチメディア,分散,協調とモバイルシンポジウム (DICOMO2007)     238 - 244  2007.07  [Refereed]

  • 無線センサーネットワークにおける計測処理記述のためのデザインパターンの抽出と適用

    鄭顕志, 深澤良彰, 本位田真一

    マルチメディア,分散,協調とモバイルシンポジウム (DICOMO2007)     506 - 515  2007.07  [Refereed]

  • KAOSによる無線センサーネットワークのための計測処理中間モデルの導出

    鄭顕志, 深澤良彰, 本位田真一

    マルチメディア,分散,協調とモバイルシンポジウム (DICOMO2007)     1168 - 1179  2007.07  [Refereed]

  • A sensor middleware for lightweight relocatable sensing programs

    Makoto Ishiguro, Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    CIMCA 2006: International Conference on Computational Intelligence for Modelling, Control and Automation, Jointly with IAWTIC 2006: International Conference on Intelligent Agents Web Technologies ...    2007  [Refereed]

     View Summary

    Wireless sensor networks (WSNs) have attracted attention in recent years. Many sensors will be equipped in buildings and provide data about the context of buildings in the future. We can provide many kinds of services that use various context information acquired from wireless sensor networks. However, sensing programs may not be able to be executed concurrently on the same sensor node because of sensors' resource restrictions. So, sensing programs sometimes have to relocate to other sensors if necessary. In this paper, we suggest a middleware for the relocation of a sensing program. Considering severe resource restrictions in a wireless sensor network, we can make a sensing program with a small code footprint. © 2006 IEEE.

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Introducing auction scheme to route allocation to prolong the lifetime of ad-hoc networks

    Kenji Tei, Hiromi Muto, Yoshiaki Fukazawa, Shinichi Honiden

    CIMCA 2006: International Conference on Computational Intelligence for Modelling, Control and Automation, Jointly with IAWTIC 2006: International Conference on Intelligent Agents Web Technologies ...    2007  [Refereed]

     View Summary

    Prolonging a network lifetime is one of crucial issues of message routing protocol in mobile ad-hoc networks (MANETs), because MANETs consist of mobile devices powered by batteries. Previous routing protocols focus on route selection by a message sender to balance message forwarding load. However, in this approach, message routes determined by different senders cannot be coordinated, because each sender selects its message route independently. In this paper, we propose an auction-based route allocation scheme where message routes are determined by auctions between message senders and forwarders, and apply the route allocation scheme to the Dynamic Source Routing protocol. Simulation results show the DSR protocol with our allocation scheme can prolong the network lifetime comparing with the routing protocol proposed in the previous works. © 2006 IEEE.

    DOI

    Scopus

    3
    Citation
    (Scopus)
  • Applying design patterns to wireless sensor network programming

    Kenji Tei, Yoshiaki Fukazawa, Shinichi Honiden

    PROCEEDINGS - 16TH INTERNATIONAL CONFERENCE ON COMPUTER COMMUNICATIONS AND NETWORKS, VOLS 1-3     1099 - +  2007  [Refereed]

     View Summary

    Middleware for wireless sensor network (WSN) abstracts a network as an entity and hides programming difficulties from programmers. Many middlewares have been proposed, but they use different programming languages to manipulate functions in WSNs. This inhibits usability when manipulating multiple WSNs managed by different middlewares, because the primitives of each language have different descriptive capabilities. In this paper, we propose and apply design patterns in WSN programming to complement the capabilities of language primitives, and discuss the effectiveness of these design patterns. First, we discuss major middleware languages and compare the capabilities of their primitives. Second, we extract design patterns from the representative middlewares to cover the missing capabilities identified in the comparison. Finally, we discuss the effectiveness of design patterns for WSN programming. The discussion indicates that design patterns improve the usability of manipulating multiple WSNs.

    DOI

    Scopus

    8
    Citation
    (Scopus)
  • Energy Efficient Location-Specific Data Retrieval in Mobile Ad-Hoc Networks

    TEI Kenji, FUKAZAWA Yoshiaki, HONIDEN Shinichi

    The IEICE transactions on information and systems   89 ( 12 ) 2625 - 2636  2006.12  [Refereed]

    CiNii

  • 無線センサーネットワークミドルウェアの研究動向とエージェント技術の適用可能性

    鄭顕志, 深澤良彰, 本位田真一

    合同エージェントワークショップ&シンポジウム2006 (JAWS2006)    2006.10  [Refereed]

  • コンテンツ流通エージェントのための強化学習メカニズム

    片岡慧, 吉岡信和, 石川冬樹, 鄭顕志, 本位田真一

    合同エージェントワークショップ&シンポジウム2006 (JAWS2006)    2006.10  [Refereed]

  • センサーの資源制約を考慮したセンシングプログラムの退避行動手法の提案

    石黒真, 鄭顕志, 深澤良彰, 本位田真一

    合同エージェントワークショップ&シンポジウム2006 (JAWS2006)    2006.10  [Refereed]

  • MANETにおける送信遅延と電力消費を考慮したルーティングプロトコルの提案

    河村美嗣, 鄭顕志, 深澤良彰, 本位田真一

    マルチメディア,分散,協調とモバイルシンポジウム (DICOMO2006)     265 - 268  2006.07  [Refereed]

  • センシングプログラムの軽量な退避行動を実現するセンサーミドルウェア開発

    石黒真, 鄭顕志, 深澤良彰, 本位田真一

    マルチメディア,分散,協調とモバイルシンポジウム (DICOMO2006)     797 - 800  2006.07  [Refereed]

  • MANETにおける情報収集プログラム再配備手法の提案と評価

    鄭顕志, 深澤良彰, 本位田真一

    マルチメディア,分散,協調とモバイルシンポジウム (DICOMO2006)     133 - 136  2006.07  [Refereed]

  • Adaptive geographically bound mobile agents

    K. Tei, Ch. Sommer, Y. Fukazawa, S. Honiden, P. -L. Garoche

    MOBILE AD-HOC AND SENSOR NETWORKS, PROCEEDINGS   4325   353 - +  2006  [Refereed]

     View Summary

    With the spread of mobile phones, the use of Mobile Adhoc NETworks (MANETs) for disaster recovery finally becomes feasible. Information retrieval from the catastrophic place is attended in an energy-efficient manner using the Geographically Bound Mobile Agent (GBMA) model. The GBMA, which is a mobile agent on MANETs that retrieves geographically bound data, migrates to remain in a designated region to maintain low energy consumption for data retrieval, and provides location based migration scheme to eliminate needless migration to reduce energy consumption. In the data retrieval using the GBMA model, survivability of the agent is important. In a MANET, a GBMA with retrieved data may be lost due to its host's death. The lost of the agent causes re-execution of the retrieval process, which depraves energy efficiency. We propose migration strategies of the GBMA to improve its survivability. In the migration strategies, the selection of the next host node is parameterized by node location, speed, connectivity, and battery level. Moreover, in the strategies, multiple migration trigger policies are defined to escape from a dying node. We present the implementation of migration strategies and confirm the achievements with several simulations. This finally leads to the adaptive Geographically Bound Mobile Agent model, which consumes even less energy.

    DOI

    Scopus

    2
    Citation
    (Scopus)
  • 位置に束縛されたモバイルエージェントによる位置依存情報の収集

    鄭 顕志, 深澤 良彰, 本位田 真一

    合同エージェントワークショップ&シンポジウム2005 (JAWS2005)     421 - 428  2005.11  [Refereed]

  • アドホックネットワークのルーティングへの市場原理の適用

    武藤 宏美, 鄭 顕志, 深澤 良彰, 本位田 真一

    合同エージェントワークショップ&シンポジウム2005 (JAWS2005)     227 - 233  2005.11  [Refereed]

  • A Flexible Wireless Sensor Network for Deploying Multiple Services

    ISHIGURO Makoto, TEI Kenji, FUKAZAWA Yoshiaki, HONIDEN Shinichi

    IPSJ SIG technical reports   2005 ( 113 ) 121 - 128  2005.11

     View Summary

    A sensor network attracts much attention in recent years. We expect that many services using sensors are to be provided in various places in the future. However, it is difficult to use a sensor simultaneously by many sensing programs because of the poorness of the computational performance of a sensor. So, in this research, we propose a sensor middleware named "SemiFloA" that supports evacuation of sensing programs. This middleware enables the sensing programs to continue its own work in the application specific manner.

    CiNii

  • Geographically bound mobile agent in MANET

    K Tei, N Yoshioka, Y Fukazawa, S Honiden

    PROCEEDINGS OF MOBIQUITOUS 2005     516 - 518  2005  [Refereed]

     View Summary

    A location-specific data retrieval, which is data retrieval from nodes in a designated region at the time, is an attractive application in a Mobile Ad-hon Network (MANET). However, almost all nodes in a MANET are powered by batteries, the location-specific data retrieval should involve a small number of messages. In this paper, we use a mobile agent to retrieve the location-specific data. A mobile agent migrates to a node in a designated region, and retrieves data from nodes in this region. Since, after migration, the agent can communicate with nodes in the designated region through low overhead short length hops, the mobile agent can retrieve data at low message cost for long periods, even if the owner of this agent moves around. However, even after migrating to node in the designated region, in order to stay near this region, a mobile agent should migrate to other nodes in response to the movement of the node hosting this agent. In this paper, we propose the Geographically Bound Mobile Agent (GBMA) which is a mobile agent that periodically migrates in order to always be located in a designated region. In order to clarify where the GBMA should be located and when the GBMA starts to migrate, two geographic zones are set to the GBMA: required zone and expected zone. The required zone ease tracking of the GBMA, and the expected zone ease adjustment of the GBMA migration timing.

    DOI

    Scopus

    6
    Citation
    (Scopus)
  • Using mobile agent for location-specific data retrieval in MANET

    K Tei, N Yoshioka, Y Fukazawa, S Honiden

    INTELLIGENCE IN COMMUNICATION SYSTEMS   190   157 - 168  2005  [Refereed]

     View Summary

    Location-specific data retrieval is an attractive application in a Mobile Ad-hoc Network (MANET). Simple solution for it is that an observer retrieves the data by geocasting from an observer node, but its overhead highly depends on location of the observer and the designated region. We propose a mobile agent approach. A mobile agent migrates from the observer node to a node in the designated region, retrieves data from there, and summarizes, filters, and compresses the retrieved data, This data is sent back to the observer, when the observer request. Since the data is retrieved by the mobile agent located near the data Sources, the data retrieval in the mobile agent approach would involve low overhead, even if the observer is far from the target region or moves around. In the MANET, however, even after the first migration; to stay near data Sources, a mobile agent should migrate to another node in response to node movements.. In this paper, we propose the Geographically Bound Mobile Agent (GBMA) which is a mobile agent that migrates to always be located in a designated region. Moreover, to clarify where the GBMA should be located and when the GBMA starts to migrate, we introduce two geographic zones: required zone and expected zone, Compared with the conventional methods with geocast or with a conventional mobile agent, the GBMA with these zones for retrieving location-specific data can reduce the total number of messages.

  • P2Pグリッドにおけるモバイルエージェントを用いた生存性の高いサービスの構築

    鄭 顕志, 吉岡 信和, 深澤 良彰, 本位田 真一

    第11回 ソフトウェア工学の基礎ワークショップ (FOSE2004)     49 - 60  2004.12  [Refereed]

  • ホットスポットにおけるリソースレンタルシステムの提案と評価

    武藤宏美, 鄭顕志, 田原康之, 深澤良彰, 本位田真一

    合同エージェントワークショップ&シンポジウム(JAWS2004)     27 - 34  2004.10  [Refereed]

  • P2P グリッドにおけるサービスの効率的障害退避

    鄭 顕志, 吉岡 信和, 深澤 良彰, 本位田 真一

    合同エージェントワークショップ&シンポジウム2004 (JAWS2004)     197 - 204  2004.10  [Refereed]

  • モバイルエージェントを用いた小規模Grid構築

    鄭 顕志, 吉岡 信和, 本位田 真一, 深澤 良彰

    合同エージェントワークショップ&シンポジウム (JAWS2003)     25 - 32  2003.10  [Refereed]

  • PCクラスタ対応マルチエージェントフレームワーク

    吉岡信和, 鄭顕志, 深澤良彰, 本位田真一

    合同エージェントワークショップ&シンポジウム(JAWS2002)     119 - 130  2002.11  [Refereed]

  • PCクラスタに対応したマルチエージェントシステムの提案

    吉岡信和, 鄭顕志, 深澤良彰, 本位田真一

    エージェント合同シンポジウム (JAWS 2002)論文集     353 - 363  2002.03  [Refereed]  [Invited]

▼display all

Presentations

  • An experience riding the IoT wave

    Kenji Tei  [Invited]

    IEEE 8th World Forum on Internet of Things (WF-IoT2022), Young Professional Forum  (Yokohama) 

    Presentation date: 2022.11

  • ニュース映像における縦動画への自動変換ツール

    水門 菜花, 山内 拓人, 鄭 顕志

    2022年度 人工知能学会全国大会(第36回) 

    Presentation date: 2022.06

  • 再利用制御器合成を用いた自己適応システムにおける実行時の離散制御器合成時間削減手法

    有岡 勇紀, 山内 拓人, 鄭 顕志

    2022年度 人工知能学会全国大会(第36回) 

    Presentation date: 2022.06

  • 離散制御器合成におけるメイクスパン比較時間削減のための部分問題化アルゴリズム

    清水 優希, 山内 拓人, 鄭 顕志

    2022年度 人工知能学会全国大会(第36回) 

    Presentation date: 2022.06

  • ドメイン依存性の低い画像分類モデルを活用したゼロショットインスタンスセグメンテーション手法

    及川 雅哉, 山内 拓人, 鄭 顕志

    2022年度 人工知能学会全国大会(第36回) 

    Presentation date: 2022.06

  • 色及び位置情報を用いたアニメキャラクタの目と口の抽出

    鈴木 絵理, 山内 拓人, 鄭 顕志

    2022年度 人工知能学会全国大会(第36回) 

    Presentation date: 2022.06

  • Automation in MDE, the good, the bad, and the ugly

    Lionel C. Briand, John Grundy, Bran Selic, Kenji Tei  [Invited]

    ACM/IEEE 24th International Conference on Model Driven Engineering Languages and Systems (MODELS2021) 

    Presentation date: 2021.10

  • Towards Personalized Autonomous Driving: Deep Reinforcement Learning from Human Feedback

    Jiali Ling, Jialong Li, Kenji Tei, Shinichi Honiden

    Symposium on Multi Agent Systems for Harmonization 2021 (SMASH21 SUMMER SYMPOSIUM) 

    Presentation date: 2021.09

  • Models@run.time入門

    鄭 顕志

    ソフトウェアエンジニアリングシンポジウム2021 

    Presentation date: 2021.09

  • 離散制御器合成によるサービスロボット向け行動計画自動生成手法

    笠井 栄良, 鄭 顕志

    マルチメディア、分散、協調とモバイルシンポジウム(DICOMO2021) 

    Presentation date: 2021.07

  • 離散制御器合成における設計誤りを特定するための反例出力手法

    李 家隆, 相澤 和也, 鄭 顕志, 本位田 真一

    IPSJ/SIGSEソフトウェアエンジニアリングシンポジウム2020(SES2020) 

    Presentation date: 2020.09

  • Event-Bによるリファインメントのパターン最適化

    荒井 滉平, 本位田 真一, 鄭 顕志

    日本ソフトウェア科学会第37回大会 

    Presentation date: 2020.09

  • Big Data, Cloud and IoT Technologies for Smart Cities: The M-Sec project paradigm – objectives, current status and related future research topics

    Kenji Tei  [Invited]

    the 2nd International Workshop on Big data, cloud, and IoT technologies for smart cities (IWBigDataCity2020) 

    Presentation date: 2020.02

  • 環境変化の差分情報を用いた離散制御器の実行時差分合成アルゴリズム

    平野 貴規, 相澤 和也, 鄭 顕志, 鷲崎 弘宜, 本位田 真一

    マルチメディア、分散、協調とモバイル(DICOMO2019)シンポジウム 

    Event date:
    2019.07
     
     
  • Dynamic Updating Controller自動生成のための環境モデル構築における関心事分離手法

    山内 拓人, 鄭 顕志, 鷲崎 弘宜, 本位田 真一

    マルチメディア、分散、協調とモバイル(DICOMO2019)シンポジウム 

    Event date:
    2019.07
     
     
  • 鉄道制御システムに特化した離散制御器合成における状態削減モデリング手法

    桑名 賢吾, 鄭 顕志, 半田 隆信, 柳井 法貴, 西面 敦義, 深澤 良彰, 本位田 真一

    マルチメディア、分散、協調とモバイル(DICOMO2019)シンポジウム 

    Event date:
    2019.07
     
     
  • 実行時requirement enhancementのためのゲーム空間の差分分析アルゴリズム

    李 家隆, 相澤 和也, 鄭 顕志, 鷲崎 弘宜, 本位田 真一

    マルチメディア、分散、協調とモバイル(DICOMO2019)シンポジウム 

    Event date:
    2019.07
     
     
  • スーパーアーキテクト育成の方法論と実践

    鄭顕志  [Invited]

    JISA ITアーキテクトコミュニティイベント  一般社団法人 情報サービス産業協会

    Presentation date: 2019.04

  • Assured Graceful Degradation by Models@run.time

    Kenji Tei

    Third International Workshop on Software Engineering for Cyber-Physical-Social Systems 2018 in Hakone (CPSS-2018-Hakone) 

    Presentation date: 2018.12

  • Assured Graceful Degradation by Models@run.time

    Kenji Tei

    the 7th Asian-Pacific Workshop of Advanced Software Engineering (AWASE2018)  (Gold Coast, Australia) 

    Presentation date: 2018.10

  • Assured Runtime Graceful Degradation by Models@run.time

    Kenji Tei

    OU-NII-Lero-Khalifa-LYON1 Workshop on Software Engineering for Cyber-Physical-Social Systems CPSS 2018  (Lyon, France) 

    Presentation date: 2018.08

  • IoT時代のソフトウェアシステムのための実行時モデリング技術 -機械学習と制御理論を応用したシステムの自動更新-

    鄭 顕志  [Invited]

    2017年度 情報処理学会東海支部 講演会  (名古屋大学)  情報処理学会東海支部

    Presentation date: 2018.01

  • Models@Run.Time for Self-adaptive Reactive Systems

    Kenji Tei

    Joint SMA/LIP6-NII WorkShop on Multi-Agent and Distributed Systems  (Paris, France) 

    Presentation date: 2018.01

  • Qualitative Analysis for Adaptation Strategies

    Kenji Tei

    No.110 The 2nd Controlled Adaptation of Self-adaptive Systems (CASaS2017) 

    Presentation date: 2017.09

  • Learning Environment Model at Runtime for Self-Adaptive Systems

    Kenji Tei

    6th Asian Workshop of Advanced Software Engineering (AWASE2017)  (Chongqing, China) 

    Presentation date: 2017.05

  • Learning Environment Model at Runtime for Self-adaptive Systems

    Kenji Tei

    OU-NII-Khalifa Workshop on SE for Cyber-Physical-Social Systems (CPSS2017)  (Abu Dhabi, UAE) 

    Presentation date: 2017.04

  • IoT時代のソフトウェアシステムのための最新モデリング・検証技術

    鄭 顕志  [Invited]

    Embeded Technology (ET) 2016  JASA

    Presentation date: 2016.11

  • Assured and Correct Dynamic Update of Controllers

    Kenji Tei with Leandro Nahabedian, Victor Braberman, Nicolas D’Ippolito, Shinichi Honiden, Jeff Kramer, Sebastian Uchitel  [Invited]

    Workshop on Formal and Model-Driven Techniques for Developing Trustworthy Systems (FM&MDD)  (Tokyo, Japan) 

    Presentation date: 2016.11

  • ClouT/BigClouT Project

    Kenji Tei, ClouT/BigClouT Consortium  [Invited]

    10th International Symposium on Intelligent Distributed Computing (IDC2016)  (Paris, France) 

    Presentation date: 2016.10

  • Qualitative Analysis for Adaptation Strategies

    Kenji Tei  [Invited]

    No.77 NII Shonan Meeting on Controlled Adaptation of Self-adaptive Systems (CASaS) 

    Presentation date: 2016.04

  • Assured Graceful Degradation with Discrete Controller Synthesis

    Kenji Tei

    5th Asian Workshop on Advanced Software Engineering (AWASE2016)  (Nara, Japan) 

    Presentation date: 2016.03

  • TopSE : Intellectual Manufacturing Education Program based on Science

    Kenji Tei

    World Engineering Conference and Convention 2015 (WECC2015) 

    Presentation date: 2015.12

  • ClouT project, Cloud of Things for empowering the citizen clout in smart cities

    Kenji Tei

    3rd International Workshop on Self-Aware Internet of Things (Self-IoT 2015) 

    Presentation date: 2015.07

  • Quality Analysis for Self-adaptive Systems with Multiple Adaptation Loops

    Kenji Tei

    GRACE Workshop on Adaptive and Evolve Software Systems  (Tokyo, Japan) 

    Presentation date: 2015.01

  • A Development Process of Adaptation Engine for Control-loop-based Adaptable Software

    Kenji Tei

    4th Asian Workshop of Advanced Software Engineering (AWASE2014)  (Beijing, China) 

    Presentation date: 2014.10

  • Is This Configuration Management Still Right?

    Kenji Tei

    10th International Joint NII-LIP6 Seminar on Multi-Agent and Distributed Systems  (Paris, France) 

    Presentation date: 2014.09

  • Cloud of Things for empowering the citizen clout in smart cities - ClouT Project

    Kenji Tei  [Invited]

    Japan-EU Collaboration Workshop on Cloud Computing 

    Presentation date: 2014.07

  • ClouT: Cloud of Things for Empowering the Citizen Clout in Smart Cities

    Kenji Tei

    the Ninth joint NII-LIP6 WorkShop on Multi-Agent and Distributed Systems  (Tokyo, Japan) 

    Presentation date: 2013.11

  • Supporting Multi-Level Design Changes in Adaptive Software Maintenance

    Kenji Tei

    the 3rd Asian Workshop on Advanced Software Engineering (AWASE2013)  (Singapore, Singapore) 

    Presentation date: 2013.07

  • Towards a Software Development Process for Self-Adaptive (Evolvable) Control System: Control-loop Based Approach

    Kenji Tei

    the Eighth joint NII-LIP6 WorkShop on Multi-Agent and Distributed Systems  (Paris, France) 

    Presentation date: 2013.06

▼display all

Research Projects

  • 想定に漏れた環境変化にしなやかに耐える実行時モデルフレームワーク

    文部科学省  科学研究費補助金: 基盤研究(B)

    Project Year :

    2018.04
    -
    2022.03
     

    鄭 顕志

  • Multi-layered Security technologies to ensure hyper connected smart cities with Blockchain, BigData, Cloud and IoT (M-Sec)

    NICT/H2020  EUJ-01-2018 Advanced technologies (Security/Cloud/IoT/BigData) for a hyper-connected society in the context of Smart City

    Project Year :

    2018.07
    -
    2021.06
     

    Worldline Iberia SA, NTT East

  • Big data meeting Cloud of Things for empowering the citizen clout in smart cities(BigClouT)

    NICT/H2020 

    Project Year :

    2016.07
    -
    2019.06
     

    NTT EAST

  • ClouT: Cloud of Things for empowering the citizen clout in smart cities

    FP7/NICT  FP7-ICT-2013-EU-Japan

    Project Year :

    2013.04
    -
    2016.03
     

  • センサネットワークにおけるセンサデータの自己修復に関する研究

    文部科学省  科学研究費補助金(基盤研究(C))

    Project Year :

    2014
    -
    2016
     

    鄭 顕志

  • 対象追跡システムのための無線センサーネットワーク感度調整に関する研究

    科学研究費補助金  若手研究(B)

    Project Year :

    2011
    -
    2013
     

    鄭 顕志

     View Summary

    本研究では,無線センサネットワークを用いた対象追跡システムのためのセンサモデルを提案する.無線センサネットワークには厳しい資源制約があるため,ネットワークを長期に維持するには,対象追跡システムは期待される感度を満たしつつ,通信量を低減することが求められる.しかし,感度と通信量は一般にトレードオフであり,期待されるより高い感度で観測を行うと不必要に通信量が増大してしまう.
    そこで,本研究では,システム全体に期待される感度を最小限度で満たすことを目的とし,ネットワークを構成する各ノードの観測感度をソフトウェアによって調整可能とするセンサモデルとその調整手法を提案する.

  • 想定に漏れた環境変化に対して最大限の機能を維持する実行時モデルフレームワーク

    MEXT  KAKENHI Scientific Research (B)

    Project Year :

    2023.04
    -
    2027.03
     

    Kenji Tei

  • IoT向け自律協調自己適応機構とその形式検証手法の研究

    文部科学省  科学研究費補助金: 基盤研究(B)

    Project Year :

    2018.04
    -
    2022.03
     

    田原 康之

  • 行動の意図を把握するソーシャルセンサ~物理センサ融合マイニング基盤

    文部科学省  科学研究費補助金: 基盤研究(B)

    Project Year :

    2018.04
    -
    2022.03
     

    大須賀 昭彦

  • しなやかなシステムを実現するマルチビュー実行時モデルフレームワーク

    文部科学省  科学研究費補助金: 基盤研究(A)

    Project Year :

    2017.04
    -
    2022.03
     

    本位田真一

  • 想定に漏れた環境変化に耐えるソフトウェアを実現する実行時モデル更新技術

    文部科学省  科学研究費補助金(挑戦的萌芽研究)

    Project Year :

    2016.04
    -
    2018.03
     

    本位田 真一

  • センサーソフトウェア工学の確立に関する研究

    文部科学省  科学研究費補助金(基盤研究(B))

    Project Year :

    2013
    -
    2017
     

    深澤 良彰

  • 想定外に備えた空間制御ソフトウェアの分析・設計・検証手法

    文部科学省  科学研究費補助金(基盤研究(A))

    Project Year :

    2012
    -
    2014
     

    本位田 真一

  • オープン無線センサーネットワークのためのミドルウェアに関する研究

    科学研究費補助金  基盤研究(A)

    Project Year :

    2007
    -
    2009
     

    本位田真一

▼display all

Misc

  • Introduction to Self-adaptive Systems

    Kenji Tei

    Journal of the Robotics Society of Japan   40 ( 3 ) 195 - 198  2022.03  [Invited]  [Domestic journal]

    Authorship:Lead author, Last author, Corresponding author

    Article, review, commentary, editorial, etc. (scientific journal)  

    DOI

  • ICSE 2018 参加報告

    吉岡信和, 鵜林尚靖, 石川冬樹, 鄭顕志, 鷲崎弘宜

    コンピュータソフトウェア     1 - 8  2019  [Refereed]

    Article, review, commentary, editorial, etc. (scientific journal)  

     View Summary

    In Printing

  • 機械学習工学研究会キックオフシンポジウム参加報告

    鵜林 尚靖, 鷲崎 弘宜, 鄭 顕志

    コンピュータソフトウェア   35 ( 3 ) 96 - 101  2018.10

    Meeting report  

    DOI

  • Frontiers of Software Engineering - The Era of Software-Defined Everything -:10. Self-adaptive Software in Era of IoT

      58 ( 8 ) 702 - 704  2017.07  [Invited]

    Article, review, commentary, editorial, etc. (trade magazine, newspaper, online media)  

  • ClouT: Cloud of Things for Empowering Citizen's Clout in Smart Cities

    Kenji Tei, Levent Gürgen, Takuro Yonezawa

    Enablers for Smart Cities     107 - 126  2016.07  [Refereed]

    Other  

    DOI

  • Shared Wireless Sensor Networks as Enablers for a Context Management System in Smart Cities

    Kenji Tei

    Enablers for Smart Cities     1 - 21  2016.07  [Refereed]

    Other  

    DOI

  • Qualitative Analysis for Multiple Adaptation Loops

    Kenji Tei, Ryuichi Takahashi, Nicolas D’Ippolito Hiroyuki Nakagawa, Shinichi Honiden

    GRACE Technical Report     1 - 29  2015.06

    Internal/External technical report, pre-print, etc.  

  • Study about Mashup of the Services which are Provided by IoT Systems Built Individually

    IPSJ SIG Notes   2015 ( 37 ) 1 - 6  2015.02

     View Summary

    Recently, M2M (Machine to Machine) or IoT (Internet of Things) is attracting attention. It connects everything in the real world to the Internet without operator's assistance. M2M or IoT has become familiar, because of miniaturization and connectivity of sensor devices. Then it is generating Big Data and becoming the driving force of realization of Smart City or Smart Community. If we can mashup the services of several M2M or IoT systems, we will be able to develop the systems which are producing greater value. But there are various problems to mashup the M2M or IoT systems. In this paper, we select an application domain of this mashup system and study its problems and solutions.

    CiNii

  • EASSy2013参加報告

    石川 冬樹, 日高 宗一郎, 鄭 顕志

    日本ソフトウェア科学会論文誌コンピュータソフトウェア    2014.05  [Refereed]  [Invited]

    Article, review, commentary, editorial, etc. (scientific journal)  

     View Summary

    to appear

  • Model-Based Software Development

    Kenji Tei

    Systems, Control and Information   56 ( 7 ) 389 - 390  2012.07  [Refereed]  [Invited]

    Article, review, commentary, editorial, etc. (scientific journal)  

  • XAC project: Towards a middleware for open wireless sensor networks

    Kenji Tei, Shunichiro Suenaga, Yoshiyuki Nakamura, Yuichi Sei, Hikotoshi Nakazato, Yoichi Kaneki, Nobukazu Yoshioka, Yoshiaki Fukazawa, Shinichi Honiden

    Designing Solutions-Based Ubiquitous and Pervasive Computing: New Issues and Trends     214 - 231  2010  [Refereed]

     View Summary

    In pervasive computing environment (Satyanarayanan, 2001), common context management system, that make context of the real world be shared among the context-aware applications, is required to reduce development cost of each context-aware applications. A wireless sensor network (WSN) will be a key infrastructure for the context management system. Towards pervasive computing, a WSN integrated into context management system should be open infrastructure. In an open WSN should (1)handle various kinds of tasks, (2)manage tasks at runtime, (3)save resource consumption, and (4)adapt to changes of environments. To develop such an open WSN, middleware supports are needed, and our XAC project tries to develop a middleware for the open WSN. The XAC project is a research project to develop a middleware for open WSN. In this chapter, the auhors show research issues related to open WSN from the viewpoints of task description language, runtime task management, self-adaptability, and security. © 2010, IGI Global.

    DOI

▼display all

Other

  • ACM International Collegiate Programming Contest Asia Regional Contest 2010 in Tokyo, Vice director (2010)

  • International Workshop on Software Patterns and Quality(SPAQu) Program Committee (2007~2008)

  • 合同エージェントワークショップ&シンポジウム プログラム委員(2007〜現在)

  • 第69回情報処理学会全国大会 現地実行委員 (2007)

  • 21st IEEE/ACM International Conference on Automated Software Engineering 現地実行委員 (2007)

  • ETロボコン本部審査委員(2009~現在)

▼display all

 

Syllabus

▼display all

Teaching Experience

  • Algorithms and Data Structures

    Waseda University  

    2020
    -
    Now
     

  • Autonomous Agent System

    Waseda University  

    2019
    -
    Now
     

  • Computer Science and Communications Engineering Laboratory A

    Waseda University  

    2019
    -
    Now
     

  • Logic Circuit

    Waseda University  

    2019
    -
    Now
     

  • Computer Architecture

    Waseda University  

    2019
    -
    Now
     

  • C Programming

    Waseda University  

    2019
    -
    Now
     

  • ソフトウェア工学入門

    国立情報学研究所,トップエスイー  

  • インターネットサーバ管理

    早稲田大学,メディアネットワークセンター  

  • UNIX入門

    早稲田大学,メディアネットワークセンター  

  • アスペクト指向

    国立情報学研究所,トップエスイー  

  • ソフトウェアパターン

    国立情報学研究所,トップエスイー  

  • コンポーネントベース開発

    国立情報学研究所,トップエスイー  

  • Javaプログラミング入門

    早稲田大学,基幹理工学部  

  • ソフトウェア開発技術

    早稲田大学,メディアネットワークセンター  

▼display all

 

Sub-affiliation

  • Faculty of Political Science and Economics   School of Political Science and Economics

  • Faculty of Science and Engineering   Graduate School of Fundamental Science and Engineering

Research Institute

  • 2022
    -
    2024

    Waseda Research Institute for Science and Engineering   Concurrent Researcher

Internal Special Research Projects

  • センサーネットワークにおけるアプリケーション開発手法に関する研究

    2009  

     View Summary

     無線センサーネットワークにおけるアプリケーション開発では,ネットワークの詳細を隠蔽し,複数のノードで実行すべきマクロな振る舞いを記述可能とするDomain Specific Language(DSL)を用いた開発が主流となっている.しかし,現在は,抽象化の度合いが異なるDSLが乱立しており,記述したアプリケーションを他のDSLに移植するコストが増大している.そこで本研究では,モデル駆動開発に基づき,アプリケーションをDSL非依存のモデルで記述し,変換ルールによってDSL依存のモデルを自動生成する,開発プロセスを目指す. このようなモデル駆動開発では,DSL非依存のモデルを記述するモデリング言語と,各DSL依存のモデルに変換する変換ルールが必要となる.しかし,DSL非依存モデルのモデリング言語を設計する場合,その記述の抽象度が課題となる.既存のDSLは,計測したいデータに関する性質のみを宣言的に記述するDSLや,分散ネットワーク上での分散計測処理を手続き的に記述するDSLなど,DSL上で記述される抽象度が異なる.DSL非依存のモデルの抽象度をある抽象度にあわせた場合,他の抽象度で記述するDSLに変換する場合,記述の抜け漏れ・重複が生じてしまい,開発工数の増加,保守性の低下などを招いてしまう. そこで本研究では,DSLを抽象度毎のカテゴリに分け,各カテゴリの抽象度に合わせたDSL非依存モデリング言語と,抽象度毎の非依存モデル間を変換する変換ルールを提案した.抽象度に基づいたカテゴリに応じて非依存モデルを記述することで,複数のセンサーネットワークに移植する際に生じる冗長な作業工程を排除し,開発工数低減,保守性の向上することができる. 本研究では,提案した開発手法に基づき,火災検知アプリケーションを抽象度の異なる2つのDSLに移植する事例で開発工数に関する評価を行い,従来の開発手法と比較し,開発工数を低減できることを確認した.