Performance information

• Evaluation of Transformer-Based Encoder on Conditional Graph Generation　　　　　　　　　　　　　　　
  Thamila Abeywickrama; Sho Tsugawa; Akiko Manada; Kohei Watabe
  in Proceedings of the 48th IEEE International Conference on Computers, Software, and Applications (COMPSAC 2024) Fast Abstract, Jul. 2024, [Reviewed]
  IEEE, English
• Effect of Retraining Graph Generative Models with Generated Graphs　　　　　　　　　　　　　　　
  Takeru Inada; Sho Tsugawa; Akiko Manada; Kohei Watabe
  in Proceedings of the 48th IEEE International Conference on Computers, Software, and Applications (COMPSAC 2024) Fast Abstract, Jul. 2024, [Reviewed]
  IEEE, English
• Wireless Link Quality Estimation Using LSTM Model　　　　　　　　　　　　　　　
  Yuki Kanto; Kohei Watabe
  in Proceedings of 2024 IEEE/IFIP Network Operations and Management Symposium (NOMS 2024), May 2024, [Reviewed]
  IEEE, English
• Impact of Graph-to-Sequence Conversion Methods on the Accuracy of Graph Generation for Network Simulations　　　　　　　　　　　　　　　
  Kazuhiro Yasuda; Sho Tsugawa; Kohei Watabe
  in Proceedings of 2024 IEEE/IFIP Network Operations and Management Symposium (NOMS 2024) Workshop, May 2024, [Reviewed]
  IEEE, English
• Evolution and Future Prospects of Graph Generation Models　　　　　　　　　　　　　　　
  Kohei Watabe
  in Proceedings of 2023 International Conference on Emerging Technologies for Communications (ICETC 2023), Nov. 2023, [Invited]
  IEICE, English
• Effectiveness of Link Deletion Methods Using History of Information Diffusion Cascades for Limiting Their Future Spread on Social Media　　　　　　　　　　　　　　　
  Shiori Furukawa; Sho Tsugawa; Kohei Watabe
  in Proceedings of the 2023 International Symposium on Nonlinear Theory and Its Applications (NOLTA 2023), Sep. 2023, [Reviewed]
  IEICE NOLTA Society, English
• An Accurate Graph Generative Model with Tunable Features　　　　　　　　　　　　　　　
  Takahiro Yokoyama, Yoshiki Sato, Sho Tsugawa, and Kohei Watabe
  in Proceedings of the 32nd International Conference on Computer Communications and Networks (ICCCN 2023) Poster Session, Jul. 2023, [Reviewed]
  International conference proceedings
• Identifying Influential Brokers on Social Media from Social Network Structure　　　　　　　　　　　　　　　
  Sho Tsugawa and Kohei Watabe
  in Proceedings of the 17th International AAAI Conference on Web and Social Media (ICWSM 2023), Jun. 2023, [Reviewed]
  International conference proceedings
• A Method for Network Intrusion Detection Using Flow Sequence and BERT Framework　　　　　　　　　　　　　　　
  Loc Gia Nguyen and Kohei Watabe
  in Proceedings of 2023 IEEE International Conference on Communication (ICC 2023), May 2023, [Reviewed]
  International conference proceedings
• GraphTune: A Learning-Based Graph Generative Model With Tunable Structural Features　　　　　　　　　　　　　　　
  Kohei Watabe, Shohei Nakazawa, Yoshiki Sato, Sho Tsugawa, and Kenji Nakagawa
  IEEE Transactions on Network Science and Engineering, Feb. 2023, [Reviewed]
  Generative models for graphs have been actively studied for decades, and they have a wide range of applications. Recently, learning-based graph generation that reproduces real-world graphs has been attracting the attention of many researchers. Although several generative models that utilize modern machine learning technologies have been proposed, conditional generation of general graphs has been less explored in the field. In this paper, we propose a generative model that allows us to tune the value of a global-level structural feature as a condition. Our model, called GraphTune, makes it possible to tune the value of any structural feature of generated graphs using Long Short Term Memory (LSTM) and a Conditional Variational AutoEncoder (CVAE). We performed comparative evaluations of GraphTune and conventional models on a real graph dataset. The evaluations show that GraphTune makes it possible to more clearly tune the value of a global-level structural feature better than conventional models.
  Scientific journal
  DOI：https://doi.org/10.1109/TNSE.2023.3244590
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85149375786&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85149375786&origin=inward
  DOI ID：10.1109/TNSE.2023.3244590, eISSN：2327-4697, SCOPUS ID：85149375786
• Flow-based Network Intrusion Detection Based on BERT Masked Language Model　　　　　　　　　　　　　　　
  Loc Gia Nguyen and Kohei Watabe
  in Proceedings of the 18th International Conference on emerging Networking EXperiments and Technologies (CoNEXT 2022) Student Workshop, First page：7, Last page：8, Dec. 2022
  A Network Intrusion Detection System (NIDS) is an important tool that identifies potential threats to a network. Recently, different flow-based NIDS designs utilizing Machine Learning (ML) algorithms have been proposed as potential solutions to detect intrusions efficiently. However, conventional ML-based classifiers have not seen widespread adoption in the real-world due to their poor domain adaptation capability. In this research, our goal is to explore the possibility of improve the domain adaptation capability of NIDS. Our proposal employs Natural Language Processing (NLP) techniques and Bidirectional Encoder Representations from Transformers (BERT) framework. The proposed method achieved positive results when tested on data from different domains.
  International conference proceedings
  DOI：https://doi.org/10.1145/3565477.3569152
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85145884584&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85145884584&origin=inward
  DOI ID：10.1145/3565477.3569152, SCOPUS ID：85145884584
• Accurate Parallel Flow Monitoring for Loss Measurements　　　　　　　　　　　　　　　
  Kohei Watabe, Norinosuke Murai, Shintaro Hirakawa, and Kenji Nakagawa
  IEICE Transactions on Communications, Volume：E105-B, Number：12, First page：1530, Last page：1539, Dec. 2022, [Reviewed]
  End-to-end loss and delay are both fundamental metrics in network performance evaluation, and accurate measurements for these end-to-end metrics are one of the keys to keeping delay/loss-sensitive applications (e.g., audio/video conferencing, IP telephony, or telesurgery) comfortable on networks. In our previous work [1], we proposed a parallel flow monitoring method that can provide accurate active measurements of end-to-end delay. In this method, delay samples of a target flow increase by utilizing the observation results of other flows sharing the source/destination with the target flow. In this paper, to improve accuracy of loss measurements, we propose a loss measurement method by extending our delay measurement method. Additionally, we improve the loss measurement method so that it enables to fully utilize information of all flows including flows with different source and destination. We evaluate the proposed method through theoretical and simulation analyses. The evaluations show that the accuracy of the proposed method is bounded by theoretical upper/lower bounds, and it is confirmed that it reduces the error of loss rate estimations by 57.5% on average.
  Scientific journal
  DOI：https://doi.org/10.1587/transcom.2021EBP3160
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85144621685&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85144621685&origin=inward
  DOI ID：10.1587/transcom.2021EBP3160, ISSN：0916-8516, eISSN：1745-1345, SCOPUS ID：85144621685
• Development of the Patent Values Evaluation Method Considering Growth of Technical Community　　　　　　　　　　　　　　　
  Yuta Yamamoto, Asahi Hentona, Koji Marusaki, Kohei Watabe, Seiya Kawano, Tokimasa Goto, Yutaka Hada, Kazuhisa Fukuzawa, and Hirofumi Nonaka
  in Proceedings of IEEE Symposium Series on Computational Intelligence (SSCI 2021), Dec. 2021, [Reviewed]
  Patent value quantification methods are in great demand in formulating intellectual property, development, and investment strategies. Various methods have been studied to date. Among them, a method using citation information has been proposed because patent citations have a significant impact on the market value of a company. However, conventional methods are based on static models using PageRank, etc., and do not reflect the growth potential of the technical community that a patent belongs to. In this study, we developed a patent value evaluation method that considers the technical community's growth potential. Furthermore, we compared the patent value calculated by our method with company sales. We investigated the necessity and effectiveness of considering the growth potential of technical fields.
  International conference proceedings
  DOI：https://doi.org/10.1109/SSCI50451.2021.9660168
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85125803108&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85125803108&origin=inward
  DOI ID：10.1109/SSCI50451.2021.9660168, SCOPUS ID：85125803108
• Analysis of the Convergence Speed of the Arimoto-Blahut Algorithm by the Second-Order Recurrence Formula
  Kenji Nakagawa, Yoshinori Takei, Shin-ichiro Hara, and Kohei Watabe
  IEEE Transactions on Information Theory, Volume：67, Number：10, First page：6810, Last page：6831, Oct. 2021, [Reviewed]
  In this paper, we investigate the convergence speed of the Arimoto-Blahut algorithm. For many channel matrices, the convergence speed is exponential, but for some channel matrices it is slower than exponential. By analyzing the Taylor expansion of the defining function of the Arimoto-Blahut algorithm, we will make the conditions clear for the exponential or slower convergence. The analysis of the slow convergence in this paper is new. Based on this analysis, we will compare the convergence speeds of the Arimoto-Blahut algorithm numerically with the values obtained in our theorems for several channel matrices. The purpose of this paper is to obtain a complete understanding of the convergence speed of the Arimoto-Blahut algorithm.
  Institute of Electrical and Electronics Engineers (IEEE), Scientific journal
  DOI：https://doi.org/10.1109/TIT.2021.3095406
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85112619726&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85112619726&origin=inward
  DOI ID：10.1109/TIT.2021.3095406, ISSN：0018-9448, eISSN：1557-9654, SCOPUS ID：85112619726
• A Tunable Model for Graph Generation Using LSTM and Conditional VAE　　　　　　　　　　　　　　　
  Shohei Nakazawa, Yoshiki Sato, Kenji Nakagawa, Sho Tsugawa, and Kohei Watabe
  in Proceedings of the 41st IEEE International Conference on Distributed Computing Systems (ICDCS 2021) Poster Track, Volume：2021-July, First page：1126, Last page：1127, Jul. 2021, [Reviewed]
  With the development of graph applications, generative models for graphs have been more crucial. Classically, stochastic models that generate graphs with a pre-defined probability of edges and nodes have been studied. Recently, some models that reproduce the structural features of graphs by learning from actual graph data using machine learning have been studied. However, in these conventional studies based on machine learning, structural features of graphs can be learned from data, but it is not possible to tune features and generate graphs with specific features. In this paper, we propose a generative model that can tune specific features, while learning structural features of a graph from data. With a dataset of graphs with various features generated by a stochastic model, we confirm that our model can generate a graph with specific features.
  International conference proceedings
  DOI：https://doi.org/10.1109/ICDCS51616.2021.00119
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85117113369&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85117113369&origin=inward
  DOI ID：10.1109/ICDCS51616.2021.00119, SCOPUS ID：85117113369
• Model-less Approach for an Accurate Packet Loss Simulation　　　　　　　　　　　　　　　
  Kohei Watabe, Masahiro Terauchi, and Kenji Nakagawa
  in Proceedings of 2020 IEEE International Conference on Communications (ICC 2020), Volume：2020-June, Jun. 2020, [Reviewed]
  In network evaluation through simulations, accurately modeling traffic of real networks is difficult. Even if accurate traffic modeling is achieved, it is also difficult to accurately estimate a rate of rare packet loss events. For accurate estimations of rare events, Importance Sampling (IS) based on the change-of-measure technique using traffic models has been investigated. However, these studies are inapplicable for traffic traces of real networks since the applicable traffic models are extremely limited. In this paper, we propose a model-less approach to accurately estimate a packet loss rate through a simulation without directly modeling traffic. The change-ofmeasure is achieved based on traffic traces of networks in our model-less approach. We evaluated the applicability of the modelless approach on a G/M/1/K system with a traffic trace of a real network and confirmed that the model-less approach achieves up to 145 times accurate than normal a trace-driven Monte Carlo (MC) simulation.
  International conference proceedings
  DOI：https://doi.org/10.1109/ICC40277.2020.9149066
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85089471041&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85089471041&origin=inward
  DOI ID：10.1109/ICC40277.2020.9149066, ISSN：1550-3607, SCOPUS ID：85089471041
• Accurate Loss Estimation Technique Utilizing Parallel Flow Monitoring　　　　　　　　　　　　　　　
  Kohei Watabe, Norinosuke Murai, Shintaro Hirakawa, and Kenji Nakagawa
  in Proceedings of 15th International Conference on Network and Service Management (CNSM 2019) Short paper, Oct. 2019, [Reviewed]
  For the design of delay/loss sensitive applications (e.g., audio/video conferencing, IP telephony, or telesurgery), it is important to accurately measure metrics along an end-to-end path. To improve the accuracy of end-to-end delay measurements, in our previous work, we have proposed a parallel flow monitoring technique. In this technique, delay samples of a target flow increase by utilizing the observation results of other flows sharing the source/destination with the target flow. In this paper, we extend this delay measurement technique to loss measurements and enable it to fully utilize information of all flows including flows with different source and destination. We confirmed that the proposed method reduces the error of loss rate estimations by 57.5% on average in ns-3 simulations.
  International conference proceedings
  DOI：https://doi.org/10.23919/CNSM46954.2019.9012665
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85081954648&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85081954648&origin=inward
  DOI ID：10.23919/CNSM46954.2019.9012665, SCOPUS ID：85081954648
• Accurate Measurement Technique of Packet Loss Rate in Parallel Flow Monitoring　　　　　　　　　　　　　　　
  Kohei Watabe, Norinosuke Murai, Shintaro Hirakawa, and Kenji Nakagawa
  in Proceedings of the 28th International Conference on Computer Communications and Networks (ICCCN 2019) Poster Session, Volume：2019-July, Jul. 2019, [Reviewed]
  In our previous research, we have proposed a parallel flow monitoring method in which the end-to-end delay is accurately measured. The method increases delay samples of a target flow by utilizing the observation results of other flows sharing the source/destination with the target flow. In this paper, we extend this method to loss measurement, and enable it to fully utilize information of all flows including flows with different source and destination. Through NS-3 simulations, we confirmed that the proposed method reduces error of loss rate estimations by 57.5% on average.
  International conference proceedings
  DOI：https://doi.org/10.1109/ICCCN.2019.8847064
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85073164452&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85073164452&origin=inward
  DOI ID：10.1109/ICCCN.2019.8847064, ISSN：1095-2055, SCOPUS ID：85073164452
• A Parallel Flow Monitoring Technique That Achieves Accurate Delay Measurement　　　　　　　　　　　　　　　
  Kohei Watabe, Shintaro Hirakawa, and Kenji Nakagawa
  IEICE Transactions on Communications, Volume：E102-B, Number：4, First page：865, Last page：875, Apr. 2019, [Reviewed]
  In this paper, a parallel flow monitoring technique that achieves accurate measurement of end-to-end delay of networks is proposed. In network monitoring tasks, network researchers and practitioners usually monitor multiple probe flows to measure delays on multiple paths in parallel. However, when they measure an end-to-end delay on a path, information of flows except for the flow along the path is not utilized in the conventional method. Generally, paths of flows share common parts in parallel monitoring. In the proposed method, information of flows on paths that share common parts, utilizes to measure delay on a path by partially converting the observation results of a flow to those of another flow. We perform simulations to confirm that the observation results of 72 parallel flows of active measurement are appropriately converted between each other. When the 99th-percentile of the end-to-end delay for each flow are measured, the accuracy of the proposed method is doubled compared with the conventional method.
  English, Scientific journal
  DOI：https://doi.org/10.1587/transcom.2018EBP3155
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85063980448&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85063980448&origin=inward
  DOI ID：10.1587/transcom.2018EBP3155, ISSN：0916-8516, eISSN：1745-1345, SCOPUS ID：85063980448
• Measuring Lost Packets with Minimum Counters in Traffic Matrix Estimation　　　　　　　　　　　　　　　
  Kohei Watabe, Toru Mano, Takeru Inoue, Kimihiro Mizutani, Osamu Akashi, and Kenji Nakagawa
  IEICE Transactions on Communications, Volume：E102-B, Number：1, First page：76, Last page：87, Jan. 2019, [Reviewed]
  Traffic matrix (TM) estimation has been extensively studied for decades. Although conventional estimation techniques assume that traffic volumes are unchanged between origins and destinations, packets are often lost on a path due to traffic burstiness, silent failures, etc. Counting every path at every link, we could easily get the traffic volumes with their change, but this approach significantly increases the measurement cost since counters are usually implemented using expensive memory structures like a SRAM. This paper proposes a mathematical model to estimate TMs including volume changes. The method is established on a Boolean fault localization technique; the technique requires fewer counters as it simply determines whether each link is lossy. This paper extends the Boolean technique so as to deal with traffic volumes with error bounds that requires only a few counters. In our method, the estimation errors can be controlled through parameter settings, while the minimum-cost counter placement is determined with submodular optimization. Numerical experiments are conducted with real network datasets to evaluate our method.
  English, Scientific journal
  DOI：https://doi.org/10.1587/transcom.2018EBP3072
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85059987674&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85059987674&origin=inward
  DOI ID：10.1587/transcom.2018EBP3072, ISSN：0916-8516, eISSN：1745-1345, SCOPUS ID：85059987674
• On Accurate Packet Loss Estimation for Networks Without Traffic Models　　　　　　　　　　　　　　　
  Masahiro Terauchi, Kohei Watabe, and Kenji Nakagawa
  in Proceedings of Internet Conference 2018 (IC 2018) Poster, Nov. 2018, [Reviewed]
  International conference proceedings
• Analysis for the Slow Convergence in Arimoto Algorithm　　　　　　　　　　　　　　　
  Kenji Nakagawa, Yoshinori Takei, and Kohei Watabe
  in Proceedings of 2018 International Symposium on Information Theory and its Applications (ISITA 2018), First page：732, Last page：736, Oct. 2018, [Reviewed]
  In this paper, we investigate the convergence speed of the Arimoto algorithm. By analyzing the Taylor expansion of the defining function of the Arimoto algorithm, we will clarify the conditions for the exponential or 1=N order convergence and calculate the convergence speed. We show that the convergence speed of the 1=N order is evaluated by the derivatives of the Kullback-Leibler divergence with respect to the input probabilities. The analysis for the convergence of the 1=N order is new in this paper. Based on the analysis, we will compare the convergence speed of the Arimoto algorithm with the theoretical values obtained in our theorems.
  English, International conference proceedings
  DOI：https://doi.org/10.23919/ISITA.2018.8664307
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85063898503&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85063898503&origin=inward
  DOI ID：10.23919/ISITA.2018.8664307, DBLP ID：journals/corr/abs-1809-00752, SCOPUS ID：85063898503
• Reduction of Response Time by Data Placement Reflecting Co-Occurrence Structures in Structured Overlay Networks　　　　　　　　　　　　　　　
  Yusuke Koizumi, Kohei Watabe, and Kenji Nakagawa
  PLOS ONE, Volume：12, Number：10, First page：e0205757, Oct. 2018, [Reviewed], ［International magazine］
  We propose a method to accelerate a response of structured overlay networks by reducing the number of hops required to answer multi-queries. In the proposed method, by copying data items to the redundant storage spaces in other storages, a good data placement reflecting co-occurrence structures in the structured overlay network is achieved. We formulate the optimization problem of the data placement in the limited redundant space of the storages as an integer programming. A greedy approach to solve the optimization problem is also proposed. Through several simulations, it is confirmed that the proposed method can reduce the average number of hops required to answer multi-queries by about 30% at the maximum in our simulation settings. The reduction rate of the average number of hops depends on the level of co-occurrence. Further, the reduction of the computation time to solve the optimization problem with the greedy approach is evaluated. We also confirm that the proposed method does not affect load balancing of structured overlay networks.
  English, Scientific journal
  DOI：https://doi.org/10.1371/journal.pone.0205757
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85054889203&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85054889203&origin=inward
  DOI ID：10.1371/journal.pone.0205757, eISSN：1932-6203, PubMed ID：30312337, PubMed Central ID：PMC6185839, SCOPUS ID：85054889203
• Model-Less Approach of Network Traffic for Accurate Packet Loss Simulations　　　　　　　　　　　　　　　
  Masahiro Terauchi, Kohei Watabe, and Kenji Nakagawa
  in Proceedings of the 26th IEEE International Conference on Network Protocols (ICNP 2018) Poster session, Volume：2018-September, First page：251, Last page：252, Sep. 2018, [Reviewed]
  It is important to accurately model network traffic when we evaluate Quality of Service (QoS) of networks through simulations. However, for traffic in real networks, it is a tough task to select an appropriate traffic model and tune its parameters. Even if the accurate traffic modeling is achieved, it is also difficult to accurately estimate QoS regarding rare events, such as a packet loss rate in the modern Internet. In this paper, we propose a model-less approach to accurately estimate a packet loss rate through a simulation without directly modeling traffic including real network traffic. We also show the effectiveness of the approach in a simple queueing system as a first step in our development.
  International conference proceedings
  DOI：https://doi.org/10.1109/ICNP.2018.00038
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85058107324&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85058107324&origin=inward
  DOI ID：10.1109/ICNP.2018.00038, ISSN：1092-1648, SCOPUS ID：85058107324
• Accurate Delay Measurement for Parallel Monitoring of Probe Flows　　　　　　　　　　　　　　　
  Kohei Watabe, Shintaro Hirakawa, and Kenji Nakagawa
  in Proceedings of 2017 13th International Conference on Network and Service Management (CNSM 2017), Volume：2018-January, First page：1, Last page：9, Nov. 2017, [Reviewed]
  In this paper, we propose an accurate parallel flow monitoring method using active probe packets. Although multiple probe flows are monitored to measure delays on multiple paths in parallel for most measurement applications, information of only one probe flow of the multiple probe flows is utilized to measure an end-to-end delay on a path in conventional active measurement. In addition to information observed by the flow along the path, information of other flows is also utilized for the measurement in the proposed method. Delays on a flow are accurately measured by partially converting the observation results of a flow to those of another flow. Simulations are performed to confirm that the observation results of 72 parallel flows of active measurement are appropriately converted between each other in the proposed method. When the 99th-percentile of an end-to-end delay for each flow are measured, the proposed method achieves up to 95 % reduction of the error, and the error of the worst flow among all flows are reduced by 28%.
  International conference proceedings
  DOI：https://doi.org/10.23919/CNSM.2017.8256029
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85046670396&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85046670396&origin=inward
  DOI ID：10.23919/CNSM.2017.8256029, SCOPUS ID：85046670396
• Improving Fairness in Wireless Ad Hoc Networks by Channel Access Sensing at Link Layer and Packet Rate Control　　　　　　　　　　　　　　　
  Minh Tuan Nguyen, Kohei Watabe, Thanh Giang Pham, and Kenji Nakagawa
  IEICE Transactions on Communications, Volume：E100-B, Number：10, First page：1818, Last page：1826, Oct. 2017, [Reviewed]
  Wireless Ad hoc networks have been rapidly developed in recent years since they promise a wide range of applications. However, their structures, which are based on the IEEE 802.11 standard, cause a severe unfairness problem in bandwidth sharing among different users. This is an extreme drawback because in wireless ad hoc networks, all users need to be treated fairly regardless of their geographical positions. In this paper, we propose a method to improve the fairness among flows by sensing channel access of other nodes based on the information obtained at the link layer and then, controlling the packet sending rate from the link layer to the MAC layer and the dequeue rate from the queue. Simulation results show that the proposed method achieves a better fairness with a good total throughput compared to conventional methods.
  Institute of Electronics, Information and Communication, Engineers, IEICE, English, Scientific journal
  DOI：https://doi.org/10.1587/transcom.2016EBP3359
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85030454233&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85030454233&origin=inward
  DOI ID：10.1587/transcom.2016EBP3359, ISSN：1745-1345, eISSN：1745-1345, SCOPUS ID：85030454233
• Packet Delay Estimation That Transcends a Fundamental Accuracy Bound Due to Bias in Active Measurements　　　　　　　　　　　　　　　
  Kohei Watabe and Kenji Nakagawa
  IEICE Transactions on Communications, Volume：E100-B, Number：8, First page：1377, Last page：1387, Aug. 2017, [Reviewed]
  For network researchers and practitioners, active measurement, in which probe packets are injected into a network, is a powerful tool to measure end-to-end delay. It is, however, suffers the intrusiveness problem, where the load of the probe traffic itself affects the network QoS. In this paper, we first demonstrate that there exists a fundamental accuracy bound of the conventional active measurement of delay. Second, to transcend that bound, we propose INTrusiveness-aware ESTimation (INTEST), an approach that compensates for the delays produced by probe packets in wired networks. Simulations of M/M/1 and MMPP/M/1 show that INTEST enables a more accurate estimation of end-to-end delay than conventional methods. Furthermore, we extend INTEST for multi-hop networks by using timestamps or multi-flow probes.
  IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English, Scientific journal
  DOI：https://doi.org/10.1587/transcom.2016EBP3364
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85026655357&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85026655357&origin=inward
  DOI ID：10.1587/transcom.2016EBP3364, ISSN：0916-8516, eISSN：1745-1345, SCOPUS ID：85026655357, Web of Science ID：WOS:000410752500022
• A Proposal of an Efficient Traffic Matrix Estimation Under Packet Drops　　　　　　　　　　　　　　　
  Kohei Watabe, Toru Mano, Kimihiro Mizutani, Osamu Akashi, Kenji Nakagawa, and Takeru Inoue
  in Proceedings of the 37th IEEE International Conference on Distributed Computing Systems (ICDCS 2017) Poster Track, First page：2636, Last page：2637, Jun. 2017, [Reviewed]
  Traffic matrix (TM) estimation has been extensively studied for decades. Although conventional estimation techniques assume that traffic volumes are unchanged between origins and destinations, packets are often discarded on a path due to traffic burstiness, silent failures, etc. This paper proposes a novel TM estimation method that works correctly even under packet drops. The method is established on a Boolean fault localization technique; the technique requires fewer counters though it only determines whether each link is healthy. This paper extends the Boolean technique so as to deal with traffic volumes with error bounds just by a small number of counters. Along with submodular optimization for the minimum counter placement, we evaluate our method with real network datasets.
  International conference proceedings
  DOI：https://doi.org/10.1109/ICDCS.2017.169
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85027254880&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85027254880&origin=inward
  DOI ID：10.1109/ICDCS.2017.169, SCOPUS ID：85027254880
• On Spatio-Temporal Message Diffusion in Epidemic Broadcasting　　　　　　　　　　　　　　　
  Kohei Watabe and Hiroyuki Ohsaki
  Ad Hoc & Sensor Wireless Networks, Volume：33, Number：1-4, First page：53, Last page：80, Nov. 2016, [Reviewed]
  Although there have been many analyses of the effects of node mobility on communication performance of DTNs (Delay/Disruption-Tolerant Networks), to the best of our knowledge, there is no research investigating the impact of local positional distributions of nodes. In this paper, we analyze the effect of locality of node mobility on the spatio-temporal message diffusion in epidemic broadcasting in DTNs. We assume that each node has its own anchor point and that each node tends to move around the anchor point. By representing the strength of locality of node mobility through the shape of the positional distributions of nodes, we derive the dynamics of the spatio-temporal message diffusion in epidemic broadcasting. Through numerical examples, we show that communication performance is significantly affected by the tail of the pdf (probability density function) of node position. We derive a positional distribution for the Homesick Levy Walk mobility model, which is a representative model with locality of node mobility, and derive the delivery time in epidemic broadcasting.
  OLD CITY PUBLISHING INC, English, Scientific journal
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84996605805&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84996605805&origin=inward
  ISSN：1551-9899, eISSN：1552-0633, SCOPUS ID：84996605805, Web of Science ID：WOS:000389653700003
• On the Search Algorithm for the Output Distribution That Achieves the Channel Capacity　　　　　　　　　　　　　　　
  Kenji Nakagawa, Kohei Watabe, and Takuto Sabu
  in Proceedings of 2016 International Symposium on Information Theory and its Applications (ISITA 2016), Volume：63, Number：2, First page：443, Last page：447, Oct. 2016, [Reviewed]
  We consider a search algorithm for the output distribution that achieves the channel capacity of a discrete memoryless channel. We will propose an algorithm by iterated projections of an output distribution onto affine subspaces in the set of output distributions. The problem of channel capacity has a similar geometric structure as that of smallest enclosing circle for a finite number of points in the Euclidean space. The metric in the Euclidean space is the Euclidean distance and the metric in the space of output distributions is the Kullback-Leibler divergence. We consider these two problems based on Amari's a-geometry. Then, we first consider the smallest enclosing circle in the Euclidean space and develop an algorithm to find the center of the smallest enclosing circle. Based on the investigation, we will apply the obtained algorithm to the problem of channel capacity.
  IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, English, International conference proceedings
  DOI：https://doi.org/10.1109/TIT.2016.2636847
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85015164966&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85015164966&origin=inward
  DOI ID：10.1109/TIT.2016.2636847, ISSN：0018-9448, eISSN：1557-9654, SCOPUS ID：85015164966, Web of Science ID：WOS:000394667700014
• A Method at Link Layer to Improve the Fairness in Multi-Hop Wireless Ad Hoc Networks　　　　　　　　　　　　　　　
  Minh Tuan Nguyen, Kenji Nakagawa, and Kohei Watabe
  in Proceedings of the 6th International Symposium on Information and Communication Technology (SoICT 2015), Volume：03-04-December-2015, First page：135, Last page：142, Dec. 2015, [Reviewed]
  Using the protocol IEEE 802.11, multi-hop wireless ad hoc networks yield only a poor performance, especially in throughput and fairness. When the offered load becomes large, i.e. the system is in saturation state, long-distance flows suffer a high degree of throughput deterioration. These problems not only come from medium contention at the MAC layer but are due to the link layer. In this paper, we propose a method to solve the throughput degradation and unfairness problem by providing fair treatment between flows at the link-layer. In our proposed method, a fair scheduling algorithm using round robin queue and the estimation for the average interval of packet enqueueing is applied to alleviate the unfairness problem at both MAC layer and link layer. The simulation results reveal that our proposed method is able to achieve better throughput and fairness compared to the standard IEEE 802.11.
  International conference proceedings
  DOI：https://doi.org/10.1145/2833258.2833277
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84959299914&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84959299914&origin=inward
  DOI ID：10.1145/2833258.2833277, SCOPUS ID：84959299914
• Contact Duration-Aware Epidemic Broadcasting in Delay/Disruption-Tolerant Networks　　　　　　　　　　　　　　　
  Kohei Watabe and Hiroyuki Ohsaki
  IEICE Transactions on Communications, Volume：E98-B, Number：12, First page：2389, Last page：2399, Dec. 2015, [Reviewed]
  DTNs (Delay/Disruption-Tolerant Networks) composed of mobile nodes in low node-density environments have attracted considerable attention in recent years. In this paper, we propose a CD-BCAST (Contact Duration BroadCAST) mechanism that can reduce the number of message forwardings while maintaining short message delivery delays in DTNs composed of mobile nodes. The key idea behind CD-BCAST is to increase the probability of simultaneous forwarding by intentionally delaying message forwarding based on the contact duration distribution measured by each node. Through simulations, we show that CD-BCAST needs substantially less message forwardings than conventional mechanisms and it does not require parameter tuning under varieties of communication ranges and node densities.
  IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English, Scientific journal
  DOI：https://doi.org/10.1587/transcom.E98.B.2389
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84948743643&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84948743643&origin=inward
  DOI ID：10.1587/transcom.E98.B.2389, ISSN：0916-8516, eISSN：1745-1345, SCOPUS ID：84948743643, Web of Science ID：WOS:000368901200005
• Intrusiveness-Aware Estimation for High Quantiles of a Packet Delay Distribution　　　　　　　　　　　　　　　
  Kohei Watabe and Kenji Nakagawa
  in Proceedings of 2015 IEEE International Conference on Communications (ICC 2015), Volume：2015-September, First page：6169, Last page：6174, Jun. 2015, [Reviewed]
  The active measurement of network quality, in which probe packets are injected into a network, is hindered by the intrusiveness problem, where the load of the probe traffic itself affects network quality. In this paper, we first demonstrate that there exists a fundamental bound on the accuracy of the conventional active measurement of delay. Second, to transcend that bound, we propose INTEST (INTrusiveness-aware ESTimation), an approach that compensates for delays produced by probe packets for wired networks. We show that INTEST enables an accurate high quantile estimation of delay. We do so through two simulations: a single-hop network composed of a router modeled by M/M/1 queuing, and a realistic multi-hop network modeled by a network simulator.
  International conference proceedings
  DOI：https://doi.org/10.1109/ICC.2015.7249306
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84953791474&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84953791474&origin=inward
  DOI ID：10.1109/ICC.2015.7249306, ISSN：1550-3607, SCOPUS ID：84953791474
• On Optimal Magnitude of Fluctuations in Probe Packet Arrival Intervals　　　　　　　　　　　　　　　
  Kohei Watabe and Masaki Aida
  IEICE Transactions on Communications, Volume：E96-B, Number：12, First page：3028, Last page：3040, Dec. 2013, [Reviewed]
  Active measurement is an end-to-end measurement technique that can estimate network performance. The active measurement techniques of PASTA-based probing and periodic-probing are widely used. However, for the active measurement of delay and loss, Baccelli et al. reported that there are many other probing policies that can achieve appropriate estimation if we can assume the non-intrusive context (the load of the probe packets is ignored in the non-intrusive context). While the best policy in terms of accuracy is periodic-probing with fixed interval, it suffers from the phase-lock phenomenon created by synchronization with network congestion. The important point in avoiding the phase-lock phenomenon is to shift the cycle of the probe packet injection by adding fluctuations. In this paper, we analyse the optimal magnitude of fluctuations corresponding to the given autocovariance function of the target process. Moreover, we introduce some evaluation examples to provide guidance on designing experiments to network researchers and practitioners. The examples yield insights on the relationships among measurement parameters, network parameters, and the optimal fluctuation magnitude.
  IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG, English, Scientific journal
  DOI：https://doi.org/10.1587/transcom.E96.B.3028
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84889646561&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84889646561&origin=inward
  DOI ID：10.1587/transcom.E96.B.3028, ISSN：0916-8516, eISSN：1745-1345, SCOPUS ID：84889646561, Web of Science ID：WOS:000329008200010
• Modeling Fluctuations in the Quasi-Static Approach Describing the Temporal Evolution of Retry Traffic　　　　　　　　　　　　　　　
  Kohei Watabe and Masaki Aida
  WSEAS Transactions on Communications, Volume：12, Number：9, First page：488, Last page：498, Sep. 2013, [Reviewed]
  In previous work, we introduced the quasi-static retry traffic model, which describes the behavior of retry traffic generated by users who are impatient when waiting for a response from the system. In other words, the model describes interactions between users and the system. This interaction can be described in a simple form if it is assumed that the system offers infinitely fast (ideal) processing. Moreover, we proposed a performance evaluation technique called the quasi-static approach that replicates the temporal evaluation of traffic in finite speed (real-world) systems. In the quasi-static approach, the difference between the behavior of the ideal system and that of the real-world system is expressed as stochastic fluctuation. In this paper, we model the fluctuation for exactly replicating the behavior of retry traffic caused by user impatience using the quasi-static approach, and show the validity of an evaluation of the quasi-static approach by comparing the results of the quasi-static approach and that of conventional Monte Carlo simulation, in M/M/1- and M/M/s-based systems with retry traffic. © 2013. WSEAS Transactions on Communications.
  English, Scientific journal
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84885004041&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84885004041&origin=inward
  ISSN：1109-2742, eISSN：2224-2864, SCOPUS ID：84885004041
• An Epidemic Broadcasting Mechanism in Delay/Disruption-Tolerant Networks Utilizing Contact Duration Distribution　　　　　　　　　　　　　　　
  Kosuke Matsuda, Kohei Watabe, and Hiroyuki Ohsaki
  in Proceedings of the 6th Joint IFIP Wireless and Mobile Networking Conference (WMNC 2013), Apr. 2013, [Reviewed]
  Epidemic broadcasting, in which an infected node repeatedly forwards a copy of a message to other nodes, realizes one-to-many communication in delay/disruption-tolerant networks. In epidemic broadcasting, the key is to control the number of message forwardings among nodes while maintaining a short message delivery time in the network. In this paper, we present a novel idea for improving the performance of epidemic broadcasting: when an infected node encounters a (possibly) susceptible node, the infected node intentionally delays its message forwarding since this may increase the chance of simultaneous transmission to multiple susceptible nodes. On the basis of this idea, we propose HCD-BCAST (History-based Contact Duration aware BroadCAST), which significantly reduces the number of message forwardings. In HCD-BCAST, each node autonomously determines the message forwarding delay based on the contact duration distribution measured by that node. Through simulations, we show that HCD-BCAST achieves a reduction of approximately 10-40% in the number of message forwardings compared with history-based self-adaptive broadcast and k-neighbor broadcast. © 2013 IEEE.
  International conference proceedings
  DOI：https://doi.org/10.1109/WMNC.2013.6549004
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84881433851&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84881433851&origin=inward
  DOI ID：10.1109/WMNC.2013.6549004, SCOPUS ID：84881433851
• Effect of Locality of Node Mobility on Epidemic Broadcasting in DTNs　　　　　　　　　　　　　　　
  Kohei Watabe and Hiroyuki Ohsaki
  in Proceedings of the 6th Joint IFIP Wireless and Mobile Networking Conference (WMNC 2013) Poster session, Apr. 2013, [Reviewed]
  In DTNs (Delay/Disruption-Tolerant Networks) composed of mobile nodes, when the node movement has spatial locality, the nodes repeatedly miss opportunities to forward messages to other nodes, thus lowering communication performance. In this paper, we analyze the effect of locality of node mobility on message dissemination speed in epidemic broadcasting. We represent the locality of node mobility using the positional distribution of nodes in a stationary state, and we present a method for deriving the ratio of infected nodes from the positional distribution. Based on the results of a numerical experiment where the positional distribution of nodes obeys a two-dimensional normal distribution, we show that the message dissemination speed is heavily restricted by the locality of node mobility. Moreover, we clarify that a heavy-tailed positional distribution leads to a low locality of node mobility and entails mostly unrestricted message dissemination speed. © 2013 IEEE.
  International conference proceedings
  DOI：https://doi.org/10.1109/WMNC.2013.6549017
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=84881465972&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=84881465972&origin=inward
  DOI ID：10.1109/WMNC.2013.6549017, SCOPUS ID：84881465972
• On Modeling of Fluctuations in Quasi-Static Approach Describing the Temporal Evolution of Retry Traffic　　　　　　　　　　　　　　　
  Kohei Watabe and Masaki Aida
  in Proceedings of the 23rd International Teletraffic Congress (ITC 2011) Student Poster, First page：308, Last page：309, Sep. 2011, [Reviewed]
  We previously introduced a traffic model that describes the behavior of the retry traffic created by users who are impatient when waiting for a service to be provided. The behavior can be described in a simple form if it is assumed that the system offers infinitely fast processing (i.e. ideal). Moreover, we proposed the quasi-static approach that replicates the temporal evolution of traffic in finite speed (i.e. actual) systems. In the quasi-static approach, the difference between the behavior of the ideal system and that of the actual system is treated as stochastic fluctuation. However, work presented to date not verified that the quasi-static approach can express the traffic model. This paper calculates the temporal evolution of traffic in the M/M/l based model with retry traffic by traditional Monte-Carlo simulations and the quasi-static approach. The results show that quasi-static approach is as good as the traditional approach in modeling the traffic. © 2011 ITC.
  International conference proceedings
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=80055009923&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=80055009923&origin=inward
  SCOPUS ID：80055009923
• Analysis on the Fluctuation Magnitude in Probe Interval for Active Measurement　　　　　　　　　　　　　　　
  Kohei Watabe and Masaki Aida
  in Proceedings of the 30th IEEE International Conference on Computer Communication (INFOCOM 2011) Mini-Conference, First page：161, Last page：165, Apr. 2011, [Reviewed]
  Active measurement, which can provide end-to-end measurements of network performance, is critical since the Internet is managed by multiple organizations. Recently, on the active measurement of delay and loss, Baccelli et al reported that many probing policies can be used to provide appropriate estimation in addition to the traditional policy based on PASTA property if the volume of probe stream is negligible compared to the traffic stream. Probing schemes with fixed probe packet intervals suffer from the phase-lock phenomenon due to synchronization against the network performance; they do, however, provide superior accuracy. A remaining issue is how to decide the optimal probing policy while taking the phase-lock phenomenon into consideration. In this paper, we propose the probing policy that randomly fluctuates the probe packet interval to avoid the phase-lock phenomenon. We start by clarifying the relationships among the fluctuation magnitude, the properties of the target network, and estimation accuracy, and we discuss the optimal probing policy with regard to the properties of the target network. © 2011 IEEE.
  International conference proceedings
  DOI：https://doi.org/10.1109/INFCOM.2011.5934954
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=79960864213&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=79960864213&origin=inward
  DOI ID：10.1109/INFCOM.2011.5934954, ISSN：0743-166X, SCOPUS ID：79960864213
• Probe Interval Designs That Improve Accuracy of CoMPACT Monitor　　　　　　　　　　　　　　　
  Kohei Watabe, Yudai Honma, and Masaki Aida
  Simulation Modelling Practice and Theory, Volume：19, Number：1, First page：56, Last page：68, Jan. 2011, [Reviewed]
  We have proposed the CoMPACT monitor It achieves the scalable measurement of the one-way delay distribution for each flow CoMPACT monitor transforms the one-way delay data obtained by active measurement by using the passively monitored traffic data of the target flow A recent study reported that using an inter-probe time with Gamma distribution can improve the accuracy of simple active measurements The improvement is in terms of the ensemble mean of the stationary stochastic process In this paper to improve accuracy of CoMPACT monitor we apply Gamma-probing as the active measurement component of CoMPACT monitor The significant issue in this application is in the difference between objects targeted for measurement CoMPACT monitor estimates the time average of sample path rather than the ensemble mean We investigate the characteristics of CoMPACT monitor and Gamma-probing and verify the improved accuracy of CoMPACT monitor through simulations (C) 2010 Elsevier B V All rights reserved
  ELSEVIER SCIENCE BV, English, Scientific journal
  DOI：https://doi.org/10.1016/j.simpat.2010.06.019
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=78049371679&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=78049371679&origin=inward
  DOI ID：10.1016/j.simpat.2010.06.019, ISSN：1569-190X, eISSN：1878-1462, SCOPUS ID：78049371679, Web of Science ID：WOS:000284987900006
• Quasi-Static Approach for Retry Traffic with Different Service Time　　　　　　　　　　　　　　　
  Yoshiyuki Ishii, Kohei Watabe, and Masaki Aida
  in Proceedings of the 2nd International Symposium on Aware Computing (ISAC 2010), First page：122, Last page：127, Nov. 2010, [Reviewed]
  We proposed the "Quasi-static approach" as a method that can analyze the stability of a telecommunication system experiencing retry traffic. This method considers human interaction with the system, and use the difference of timescale between humans and system. Our recent studies evaluated the stability when all traffic including retry traffic has the same holding-time distribution as calls in the data plane. However, it is not natural to assume that all the calls including retries have the same holding-time distribution as those in the data plane. In this report, we consider a generalization of the quasi-static approach for retry traffic with different holding-time distributions. ©2010 IEEE.
  International conference proceedings
  DOI：https://doi.org/10.1109/ISAC.2010.5670462
  Scopus：https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=78651508328&origin=inward
  Scopus Citedby：https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=78651508328&origin=inward
  DOI ID：10.1109/ISAC.2010.5670462, SCOPUS ID：78651508328
• Design of Probe Intervals to Improve Accuracy of CoMPACT Monitor　　　　　　　　　　　　　　　
  Kohei Watabe, Yudai Honma, and Masaki Aida
  in Proceedings of International Conference on Intelligent Networking and Collaborative Systems (INCoS 2009) Workshop, First page：335, Last page：340, Nov. 2009, [Reviewed]
  International conference proceedings
  DOI：https://doi.org/10.1109/INCOS.2009.42
  DOI ID：10.1109/INCOS.2009.42
• Accuracy Improvement of CoMPACT Monitor by Using New Probing Method　　　　　　　　　　　　　　　
  Kohei Watabe, Yudai Honma, and Masaki Aida
  in Proceedings of the 12th Asia-Pacific Network Operations and Management Symposium (APNOMS 2009), First page：31, Last page：40, Sep. 2009, [Reviewed]
  International conference proceedings
  DOI：https://doi.org/10.1007/978-3-642-04492-2_4
  DOI ID：10.1007/978-3-642-04492-2_4
• Verification of Accuracy Improvement for CoMPACT Monitor Due to Suboptimal Inter-Probe Time　　　　　　　　　　　　　　　
  Kohei Watabe, Yudai Honma, and Masaki Aida
  in Proceedings of the 9th Annual International Symposium on Applications and the Internet (SAINT 2009) Short paper, First page：133, Last page：136, Jul. 2009, [Reviewed]
  International conference proceedings
  DOI：https://doi.org/10.1109/SAINT.2009.30
  DOI ID：10.1109/SAINT.2009.30

• ネットワーク内コンピューティングを応用したインターネット アーキテクチャーの継続的な進化に向けて　　　　　　　　　　　　　　　
  小泉 佑揮; 武政 淳二; 長谷川 亨; 日下 卓也; 渡部 康平
  2023年 電子情報通信学会 総合大会, 24 Mar. 2025
  電子情報通信学会
• データセットを用いずに任意の特徴量を満たすグラフを生成するDeep Learning手法に関する研究　　　　　　　　　　　　　　　
  井脇 蒼葉; 津川 翔; 眞田 亜紀子; 渡部 康平
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 124, no. 139, First page：77, Last page：82, 30 Jul. 2024
  電子情報通信学会
• Twitterにおける経路不明なリポストの発生理由の考察とその後の情報拡散への影響分析　　　　　　　　　　　　　　　
  田村 雄登; 津川 翔; 渡部 康平
  電子情報通信学会 コミュニケーションクオリティ研究会, 信学技報, vol. 000, no. 000, 28 Jun. 2024
  電子情報通信学会
• LSTMモデルを用いた無線リンク品質推定　　　　　　　　　　　　　　　
  関東 悠樹; 渡部 康平
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 123, no. 398, First page：13, Last page：18, 29 Feb. 2024
  電子情報通信学会
• ソーシャルネットワークからの情報媒介者の特定　　　　　　　　　　　　　　　
  津川 翔; 渡部 康平
  第3回 計算社会科学会大会 (CSSJ 2024), 19 Feb. 2024
  計算社会科学会
• ソーシャルメディア上の拡散経路が推定できない再投稿が情報拡散に及ぼす影響に関する一考察　　　　　　　　　　　　　　　
  田村 雄登; 津川 翔; 渡部 康平
  電子情報通信学会 革新的無線通信技術に関する横断型研究会 (MIKA 2023), 10 Oct. 2023
  電子情報通信学会
• ユーザ間距離に着目した拡散経路が推定できないリツイートの発生パターン分析　　　　　　　　　　　　　　　
  田村 雄登; 津川 翔; 渡部 康平
  第4回コミュニケーションクオリティ(CQ)学生ワークショップ, 30 Aug. 2023
  電子情報通信学会
• 拡散予測を用いたリンク削除によるソーシャルメディア上の情報拡散抑制効果の検証　　　　　　　　　　　　　　　
  古川 栞; 津川 翔; 渡部康平
  電子情報通信学会 コミュニケーションクオリティ研究会, 信学技報, vol. 122, no. 438, First page：13, Last page：18, 15 Mar. 2023
  電子情報通信学会
• グラフ生成モデルの発展と今後の展望 〜統計的生成モデルからDeep Graph Generatorsまで〜　　　　　　　　　　　　　　　
  渡部 康平
  2023年 電子情報通信学会 総合大会, 07 Mar. 2023
  電子情報通信学会
• フローシーケンスによる侵入検知システムのドメイン適応能力の向上　　　　　　　　　　　　　　　
  グエン ザ ロック; 渡部 康平
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 122, no. 342, First page：7, Last page：12, 19 Jan. 2023
  Ieice
• LSTMと条件付きVAEを用いた構造的特徴を高精度に指定可能なグラフ生成モデル　　　　　　　　　　　　　　　
  横山 昂大; 佐藤 良紀; 津川 翔; 渡部 康平
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 122, no. 342, First page：1, Last page：6, 19 Jan. 2023
  Ieice
• LSTMを用いた任意パラメータ指定可能なネットワークトラヒック生成　　　　　　　　　　　　　　　
  栗山 海渡; 渡部 康平
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 122, no. 146, First page：27, Last page：32, 05 Aug. 2022
  電子情報通信学会
• 日本におけるマルチビーム衛星通信システムの帯域と電力の配分量について　　　　　　　　　　　　　　　
  奥浜 駿; 渡部 康平; 中平 勝也
  電子情報通信学会 衛星通信研究会, 信学技報, vol. 121, no. 379, First page：57, Last page：61, 17 Feb. 2022
  電子情報通信学会
• ソーシャルネットワークにおける情報拡散者の特定に関する一検討　　　　　　　　　　　　　　　
  津川 翔; 渡部 康平
  電子情報通信学会 コミュニケーションクオリティ研究会, 信学技報, vol. 121, no. 357, First page：100, Last page：105, 20 Jan. 2022
  電子情報通信学会
• インポータンスサンプリング法を用いたネットワークシミュレーション　　　　　　　　　　　　　　　
  宮田 将; 渡部 康平; 眞田 亜紀子; 中川 健治
  2021年 電子情報通信学会 信越支部大会, 25 Sep. 2021
  電子情報通信学会
• End-to-Endにおける可用帯域の推定に関する研究　　　　　　　　　　　　　　　
  後藤 隆輔; 渡部 康平; 眞田 亜紀子; 中川 健治
  2021年 電子情報通信学会 信越支部大会, 25 Sep. 2021
  電子情報通信学会
• 帯域重畳伝送を適用した無線LAN高効率チャネル割り当て方式の効果　　　　　　　　　　　　　　　
  荷川取 大; 津波 琉; 渡部 康平; 中平 勝也
  2021年 電気学会 全国大会, 09 Mar. 2021
  電気学会
• LSTMと条件付きVAEを用いた構造的特徴を指定可能なグラフ生成モデル　　　　　　　　　　　　　　　
  中沢 昇平; 佐藤 良紀; 中川 健治; 津川 翔; 渡部 康平
  電子情報通信学会 ネットワークシステム研究会, 信学技報, vol. 120, no. 413, First page：214, Last page：219, 05 Mar. 2021
  電子情報通信学会
• 機械学習による通信データ生成へのアプローチ　　　　　　　　　　　　　　　
  渡部 康平
  電子情報通信学会 コミュニケーションクオリティ研究会, 信学技報, vol. 120, no. 314, First page：57, Last page：57, 20 Jan. 2021
  電子情報通信学会
• 無線アドホックネットワークにおける総スループット及び公平性向上に関する研究　　　　　　　　　　　　　　　
  チュオン ヴァン ニャット ミン; 中川 健治; 渡部 康平
  電子情報通信学会 ネットワークシステム研究会, 信学技報, vol. 120, no. 297, First page：103, Last page：107, 18 Dec. 2020
  電子情報通信学会
• 機械学習による実トポロジの特徴を捉えた生成モデルに関する研究　　　　　　　　　　　　　　　
  中沢昇平; 渡部康平; 中川健治
  2020年 電子情報通信学会 信越支部大会, 27 Sep. 2020
  電子情報通信学会
• 機械学習を用いた複数のネットワーク間の時系列データの補間に関する研究　　　　　　　　　　　　　　　
  會澤 一輝; 渡部 康平; 中川 健治
  2020年 電子情報通信学会 信越支部大会, First page：77, Last page：77, 26 Sep. 2020
  電子情報通信学会
• LSTMを用いたGANによる疑似トラヒックの生成に関する－考察　　　　　　　　　　　　　　　
  栗山海渡; 渡部康平; 中川健治
  2020年 電子情報通信学会 信越支部大会, First page：70, Last page：70, 26 Sep. 2020
  電子情報通信学会
• マルチキャスト通信におけるL1ノルム最小化によるパケット損失率推定法とパスの選択法　　　　　　　　　　　　　　　
  吉川 泰司; 中川 健治; 渡部 康平
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 119, no. 342, First page：51, Last page：55, 19 Dec. 2019
  Ieice
• MACD指標を用いた可用帯域推定法　　　　　　　　　　　　　　　
  齋藤 綾太; 中川 健治; 渡部 康平
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 119, no. 342, First page：57, Last page：61, 19 Dec. 2019
  Ieice
• 敵対的生成ネットワークを用いた類似ネットワーク生成モデルに関する一考察　　　　　　　　　　　　　　　
  中沢 昇平; 渡部 康平; 中川 健治
  電子情報通信学会 革新的無線通信技術に関する横断型研究会 (MIKA2019), 04 Oct. 2019
  電子情報通信学会
• 敵対的生成ネットワークによる擬似トラヒックデータ生成手法に関する一考察　　　　　　　　　　　　　　　
  山際 哲哉; 渡部 康平; 中川 健治
  2019年 電子情報通信学会 信越支部大会, 29 Sep. 2019
  電子情報通信学会
• 並列アクティブ計測による遅延推定におけるクラスタリングの最適化による高精度化　　　　　　　　　　　　　　　
  和久井 直樹; 渡部 康平; 中川 健治
  2019年 電子情報通信学会 信越支部大会, 29 Sep. 2019
  電子情報通信学会
• マルチキャスト通信におけるL1ノルム最小化によるパケット損失率推定　　　　　　　　　　　　　　　
  吉川 泰司; 中川 健治; 渡部 康平
  2019年 電子情報通信学会 信越支部大会, 29 Sep. 2019
  電子情報通信学会
• トラヒックモデルを用いないパケット廃棄率推定法におけるトラヒック生成の改善　　　　　　　　　　　　　　　
  梶浦 天佑; 寺内 将大; 渡部 康平; 中川 健治
  2019年 電子情報通信学会 信越支部大会, 29 Sep. 2019
  電子情報通信学会
• インターネットにおける可用帯域幅の推定法に関する研究　　　　　　　　　　　　　　　
  齊藤 綾太; 中川 健治; 渡部 康平
  2019年 電子情報通信学会 信越支部大会, 29 Sep. 2019
  電子情報通信学会
• 敵対的生成ネットワークを利用した疑似トラヒックデータ生成手法　　　　　　　　　　　　　　　
  山際 哲哉; 渡部 康平; 中川 健治
  2019年 電子情報通信学会 ソサイエティ大会, First page：71, Last page：71, 10 Sep. 2019
  電子情報通信学会
• 敵対的生成ネットワークを利用した疑似トラヒック生成に関する一考察　　　　　　　　　　　　　　　
  山際 哲哉; 渡部 康平; 中川 健治
  電子情報通信学会 コミュニケーションクオリティ研究会, 信学技報, vol. 119, no. 125, First page：27, Last page：29, 18 Jul. 2019
  Ieice
• 未知のトラヒック特性を持つネットワークの高精度なパケット廃棄率推定手法　　　　　　　　　　　　　　　
  寺内 将大; 渡部 康平; 中川 健治
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 118, no. 466, First page：283, Last page：288, 05 Mar. 2019
  電子情報通信学会 情報ネットワーク研究会
• 並列パスアクティブ測定によるパケット廃棄率推定　　　　　　　　　　　　　　　
  村井 啓之介; 渡部 康平; 中川 健治
  電子情報通信学会 情報ネットワーク研究会, 信学技報, vol. 118, no. 466, 01 Mar. 2019
  電子情報通信学会 情報ネットワーク研究会
• Arimotoアルゴリズムにおける遅い収束についての解析　　　　　　　　　　　　　　　
  中川 健治; 武井 由智; 渡部 康平
  Dec. 2018
  Japanese, Summary national conference
• パスの選択・統合の併用によるネットワーク故障箇所特定の最適化　　　　　　　　　　　　　　　
  中沢 昇平; 小嶋 真矢; 渡部 康平; 中川 健治
  Sep. 2018
  Japanese, Summary national conference
• 未知のトラヒック特性を持つネットワークのパケット廃棄率におけるIS法を利用した推定手法　　　　　　　　　　　　　　　
  寺内 将大; 渡部 康平; 中川 健治
  Sep. 2018
  Japanese, Summary national conference
• 複数フローアクティブ計測におけるパケット廃棄率推定の高精度化　　　　　　　　　　　　　　　
  村井 啓之介; 渡部 康平; 中川 健治
  Sep. 2018
  Japanese, Summary national conference
• ネットワーク障害におけるパスの統合・分割による障害箇所の推定　　　　　　　　　　　　　　　
  堤 陽祐; 渡部 康平; 中川 健治
  Mar. 2018
  Japanese, Summary national conference
• L1ノルム最小化によるパケット損失率推定の高速化　　　　　　　　　　　　　　　
  手崎 達也; 渡部 康平; 中川 健治
  Mar. 2018
  Japanese, Summary national conference
• 複数プローブフローの並列測定による高精度遅延推定　　　　　　　　　　　　　　　
  平川 槙太郎; 渡部 康平; 中川 健治
  Jan. 2018
  Japanese, Summary national conference
• 未知のトラヒック特性を持つネットワークにおけるIS法を利用したパケット廃棄率推定に関する一考察　　　　　　　　　　　　　　　
  寺内 将大; 渡部 康平; 中川 健治
  Jan. 2018
  Japanese, Summary national conference
• 計測パスの最適化によるネットワーク障害原因の推定　　　　　　　　　　　　　　　
  堤 陽祐; 渡部 康平; 中川 健治
  Oct. 2017
  Japanese, Summary national conference
• バースト遅延の相互補完におけるクラスタリングを用いた高精度化　　　　　　　　　　　　　　　
  平川 槙太郎; 渡部 康平; 中川 健治
  Oct. 2017
  Japanese, Summary national conference
• アクティブ計測とパッシブ計測を用いたL1ノルム最小化によるパケット損失率推定　　　　　　　　　　　　　　　
  手崎 達也; 渡部 康平; 中川 健治
  Oct. 2017
  Japanese, Summary national conference
• 未知のトラヒック特性を持つネットワークにおける IS 法を利用したパケット廃棄率の推定法に関する一考察　　　　　　　　　　　　　　　
  寺内 将大; 渡部 康平; 中川 健治
  Oct. 2017
  Japanese, Summary national conference
• 無線アドホックネットワークにおけるキューレート制御による QoS 特性向上に関する研究　　　　　　　　　　　　　　　
  グエン フー カイン; 渡部 康平; 中川 健治
  Oct. 2017
  Japanese, Summary national conference
• バースト遅延の相互補完におけるクラスタリングを用いた高精度化　　　　　　　　　　　　　　　
  平川 槙太郎; 渡部 康平; 中川 健治
  Sep. 2017
  Japanese, Summary national conference
• ネットワーク故障におけるパスの統合・分割による故障単位の推定　　　　　　　　　　　　　　　
  堤 陽祐; 渡部 康平; 井上 武; 水谷 后宏; 間野 暢; 明石 修; 中川 健治
  Mar. 2017
  Japanese, Summary national conference
• 構造化オーバーレイにおける関係性に基づくデータ複製によるマルチクエリに対する応答の高速化　　　　　　　　　　　　　　　
  小泉 悠介; 渡部 康平; 中川 健治
  Mar. 2017
  Japanese, Summary national conference
• 複数フローアクティブ計測におけるバースト遅延時系列の相互補完　　　　　　　　　　　　　　　
  平川 槙太郎; 渡部 康平; 中川 健治
  Mar. 2017
  Japanese, Summary national conference
• 通信路容量を達成する出力分布の射影アルゴリズムによる探索について　　　　　　　　　　　　　　　
  中川 健治; 渡部 康平; 佐武 拓斗
  Feb. 2017
  Japanese, Summary national conference
• ネットワークの多重故障におけるパスの統合・分割による故障原因の推定　　　　　　　　　　　　　　　
  堤 陽祐; 渡部 康平; 井上 武; 水谷 后宏; 間野 暢; 明石 修; 中川 健治
  Jan. 2017
  Japanese, Summary national conference
• 通信路容量を計算する新しいアルゴリズムの研究　　　　　　　　　　　　　　　
  佐武 拓斗; 渡部 康平; 中川 健治
  Dec. 2016
  Japanese, Summary national conference
• パスの統合・分割によるネットワーク故障箇所推定の最適化　　　　　　　　　　　　　　　
  堤 陽祐; 渡部 康平; 井上 武; 水谷 后宏; 間野 暢; 明石 修; 中川 健治
  Oct. 2016
  Japanese, Summary national conference
• 構造化オーバーレイにおけるデータの複製によるマルチクエリに対する応答の高速化　　　　　　　　　　　　　　　
  小泉 悠介; 渡部 康平; 中川 健治
  Oct. 2016
  Japanese, Summary national conference
• 重い裾の分布におけるISシミュレーションの研究　　　　　　　　　　　　　　　
  佐藤 敏希; 中川 健治; 渡部 康平
  Oct. 2016
  Japanese, Summary national conference
• 通信路容量を計算する新しいアルゴリズムの研究　　　　　　　　　　　　　　　
  佐武 拓斗; 渡部 康平; 中川 健治
  Oct. 2016
  Japanese, Summary national conference
• バースト遅延時系列の補完による複数フローアクティブ計測の高精度化　　　　　　　　　　　　　　　
  平川 慎太郎; 渡部 康平; 中川 健治
  Oct. 2016
  Japanese, Summary national conference
• 無線アドホックネットワークにおける公平性向上の研究　　　　　　　　　　　　　　　
  グエン フー カイン; 渡部 康平; 中川 健治
  Oct. 2016
  Japanese, Summary national conference
• 確率分布に関する凸最適化問題の最適解探索アルゴリズム　　　　　　　　　　　　　　　
  中川 健治; 渡部 康平; 佐武 拓斗
  Jul. 2016, [Invited]
  Japanese, Summary national conference
• active計測によるネットワークQoS過程のサンプリングとQoS推定精度について　　　　　　　　　　　　　　　
  渡部 康平
  Apr. 2016, [Invited]
  Japanese, Summary national conference
• 構造化オーバーレイにおけるデータ間の関係性に基づくマルチクエリに対する応答の高速化　　　　　　　　　　　　　　　
  小泉 悠介; 渡部 康平; 中川 健治
  Mar. 2016
  Japanese, Summary national conference
• Network-wide Packet Behaviorに基づくパケット分類を用いたネットワーク故障箇所の推定法　　　　　　　　　　　　　　　
  渡部 康平; 井上 武; 水谷 后宏; 間野 暢; 明石 修; 中川 健治
  Mar. 2016
  Japanese, Summary national conference
• 通信路容量を達成する出力分布の射影アルゴリズムによる探索について　　　　　　　　　　　　　　　
  中川 健治; 渡部 康平
  Nov. 2015
  Japanese, Summary national conference
• 構造化オーバーレイにおけるデータ間の関連性によるマルチクエリに対する応答の高速化　　　　　　　　　　　　　　　
  小泉 悠介; 渡部 康平; 中川 健治
  Oct. 2015
  Japanese, Summary national conference
• 重い裾のキュー長分布におけるパケット廃棄率推定に対する ISシミュレーションの検討　　　　　　　　　　　　　　　
  佐藤 敏希; 中川 健治; 渡部 康平
  Oct. 2015
  Japanese, Summary national conference
• 多次元空間における最小包含円のアルゴリズムに関する研究　　　　　　　　　　　　　　　
  佐武 拓斗; 渡部 康平; 中川 健治
  Oct. 2015
  Japanese, Summary national conference
• 遅延のバースト性を利用したプローブ送出の動的制御によるパケット損失率推定　　　　　　　　　　　　　　　
  伊藤 峻; 渡部 康平; 中川 健治
  Oct. 2015
  Japanese, Summary national conference
• 複数フローのアクティブ計測によるバースト遅延時系列の推定　　　　　　　　　　　　　　　
  広川 将吾; 渡部 康平; 中川 健治
  Oct. 2015
  Japanese, Summary national conference
• 通信路容量を達成する出力分布の射影アルゴリズムによる探索について　　　　　　　　　　　　　　　
  中川 健治; 渡部 康平; 佐武 拓斗
  Sep. 2015
  Japanese, Summary national conference
• Improvement for Throughput and Fairness in Multi-hop Wireless Ad Hoc Networks (ネットワークシステム)　　　　　　　　　　　　　　　
  ミン トゥアン グェン; 中川 健治; 渡部 康平
  Volume：115, Number：159, First page：159, Last page：164, 30 Jul. 2015
  English
  ISSN：0913-5685, CiNii Articles ID：40020559000, CiNii Books ID：AA11546431
• マルチホップ無線アドホックネットワークにおけるスループットとその 公平性の改善に関する研究　　　　　　　　　　　　　　　
  グェン ミン トゥアン; 中川 健治; 渡部 康平
  Jul. 2015
  English, Summary national conference
• 無線通信環境におけるアクティブ計測のバイアスを補正するアクセス遅延推定法の提案　　　　　　　　　　　　　　　
  渡部 康平; 中川 健治
  Jul. 2015
  Japanese, Summary national conference
• 周期的変動を伴うネットワーク遅延の圧縮センシングを利用したアクティブ計測　　　　　　　　　　　　　　　
  広川 将吾; 渡部 康平; 中川 健治
  Mar. 2015
  Japanese, Summary national conference
• 裾の重いキュー長分布におけるパケット廃棄率のIS推定　　　　　　　　　　　　　　　
  島崎 沢; 渡部 康平; 中川 健治
  Mar. 2015
  Japanese, Summary national conference
• 遅延のバースト性を利用したプローブ送出の動的制御手法の提案　　　　　　　　　　　　　　　
  伊藤 峻; 渡部 康平; 中川 健治
  Mar. 2015
  Japanese, Summary national conference
• 通信路容量を達成する入力シンボルについての一考察　　　　　　　　　　　　　　　
  中川 健治; 渡部 康平
  Dec. 2014
  Japanese, Summary national conference
• A Proposal of Intrusiveness-aware Estimation for a Packet Delay Distribution　　　　　　　　　　　　　　　
  WATABE Kohei; NAKAGAWA Kenji
  IEICE technical report, Volume：114, Number：297, First page：47, Last page：52, 13 Nov. 2014
  The intrusiveness problem that the load of the probe traffic itself affects network quality hinders the active measurement of network quality. In this paper, we demonstrate that there exists a fundamental bound on the accuracy of the conventional active measurement of delay. Moreover, to transcend that bound, we propose INTEST(INTrusiveness-aware ESTimation), an approach that compensates for delays produced by probe packets.
  The Institute of Electronics, Information and Communication Engineers, English
  ISSN：0913-5685, CiNii Articles ID：110009971239, CiNii Books ID：AA11546431
• 試験パケット負荷によるパス品質劣化を考慮した高精度遅延計測の提案　　　　　　　　　　　　　　　
  渡部 康平; 中川 健治
  Nov. 2014
  English, Summary national conference
• CoMPACT Monitorによるパケット遅延推定の精度向上の研究　　　　　　　　　　　　　　　
  菅野 彰人; 渡部 康平; 中川 健治
  Oct. 2014
  Japanese, Summary national conference
• パケットネットワークにおける遅延ジッタレギュレータの特性改善　　　　　　　　　　　　　　　
  白井 孝幸; 渡部 康平; 中川 健治
  Oct. 2014
  Japanese, Summary national conference
• 試験パケット負荷によるパス品質劣化を考慮した高精度遅延計測　　　　　　　　　　　　　　　
  渡部 康平; 中川 健治
  Oct. 2014
  Japanese, Summary national conference
• 裾の重いキュー長分布におけるパケット廃棄率推定　　　　　　　　　　　　　　　
  島崎 沢; 渡部 康平; 中川 健治
  Oct. 2014
  Japanese, Summary national conference
• 無線アドホックネットワークにおける公平性向上手法の提案　　　　　　　　　　　　　　　
  野口 隼人; 渡部 康平; 中川 健治
  Oct. 2014
  Japanese, Summary national conference
• 遅延耐性ネットワークにおけるエピデミックブロードキャストの時間的・空間的メッセージ拡散特性の解析　　　　　　　　　　　　　　　
  渡部 康平; 大崎 博之
  Mar. 2014
  Japanese, Summary national conference
• ノードの移動の局所性がエピデミックブロードキャストに与える影響　　　　　　　　　　　　　　　
  渡部 康平; 大崎 博之
  Aug. 2013
  Japanese, Summary national conference
• 遺伝的プログラミングを用いたネットワークサービス処理時間のモデル化　　　　　　　　　　　　　　　
  林田 龍一; 渡部 康平; 大崎 博之
  May 2013
  Japanese, Summary national conference
• マイクロロボットによる被災地の要救護者探索においてマイクロロボットの性能や機能が目標発見に与える影響の評価　　　　　　　　　　　　　　　
  原田 稔; 小泉 佑揮; 渡部 康平; 大崎 博之; 今瀬 真
  Feb. 2013
  Japanese, Summary national conference
• ノードの接触時間分布を利用したエピデミックブロードキャスト方式　　　　　　　　　　　　　　　
  松田 浩輔; 渡部 康平; 大崎 博之
  Sep. 2012
  Japanese, Summary national conference
• ノードの接触時間分布を利用したエピデミックブロードキャスト方式の提案　　　　　　　　　　　　　　　
  松田 浩輔; 渡部 康平; 大崎 博之
  Jul. 2012
  Japanese, Summary national conference
• 拡散型フロー制御のスケーラビリティ向上のためのフロー集約方式の検討　　　　　　　　　　　　　　　
  日下 蘭子; 渡部 康平; 会田 雅樹
  Sep. 2011
  Japanese, Summary national conference
  CiNii Articles ID：20000936864
• 動作時間スケールによる階層アーキテクチャの構成に向けた準静的アプローチのくりこみ群的シナリオ　　　　　　　　　　　　　　　
  会田 雅樹; 渡部 康平; 高山 裕紀; 高野 知佐
  Jun. 2011
  Japanese, Summary national conference
• 再試行トラヒックの振舞いを解析する準静的アプローチにおけるゆらぎのモデル化方法に関する考察　　　　　　　　　　　　　　　
  渡部 康平; 田邊 槙子; 会田 雅樹
  Mar. 2011
  Japanese, Summary national conference
• 社会ネットワークにおけるハブユーザ探索範囲の検討　　　　　　　　　　　　　　　
  本村 昭太郎; 刈谷 博和; 渡部 康平; 会田 雅樹
  Mar. 2011
  Japanese, Summary national conference
• active計測の試験パケット送出時刻における揺らぎ量の分析　　　　　　　　　　　　　　　
  渡部 康平; 会田 雅樹
  Sep. 2010
  Japanese, Summary national conference
• 自律分散制御の階層化を実現する為の時間スケール分離技術の検討　　　　　　　　　　　　　　　
  佐々木 亮; 渡部 康平; 会田 雅樹
  Sep. 2010
  Japanese, Summary national conference
• B-7-34 Search Range for Finding Hub Users in Social Networks　　　　　　　　　　　　　　　
  MOTOMURA Shotaro; KARIYA Hirokazu; WATABE Kohei; AIDA Masaki
  Proceedings of the Society Conference of IEICE, First page：111, Last page：111, Sep. 2010
  The Institute of Electronics, Information and Communication Engineers, Japanese, Summary national conference
  CiNii Articles ID：110008139245, CiNii Books ID：AN10489017
• active試験パケット送出時刻に与える揺らぎ量の最適化　　　　　　　　　　　　　　　
  渡部 康平; 会田 雅樹
  Mar. 2010
  Japanese, Summary national conference
• 再試行トラヒックが異なるサービス時間を持つ場合の準静的アプローチ適用可能性の研究　　　　　　　　　　　　　　　
  石井 良幸; 渡部 康平; 本間 裕大; 会田 雅樹
  Mar. 2010
  Japanese, Summary national conference
• 測度変換型品質計測技術における試験パケット送出規則と計測誤差の考察　　　　　　　　　　　　　　　
  渡部 康平; 本間 裕大; 会田 雅樹
  Jul. 2009
  Japanese, Summary national conference
• 再試行トラヒックが異なるサービス時間を持つ場合の準静的アプローチ適用可能性の研究　　　　　　　　　　　　　　　
  石井 良幸; 渡部 康平; 本間 裕大; 会田 雅樹
  Mar. 2009
  Japanese, Summary national conference
• 測度変換型品質計測技術の精度向上のための試験パケット間隔設計法　　　　　　　　　　　　　　　
  渡部 康平; 本間 裕大; 会田 雅樹
  Mar. 2009
  Japanese, Summary national conference
• 準最適な試験パケット間隔の適用による測度変換型品質計測技術の精度向上効果の検証　　　　　　　　　　　　　　　
  渡部 康平; 本間 裕大; 会田 雅樹
  Mar. 2009
  Japanese, Summary national conference

• Apr. 2022 - Present
  情報通信理論
• Apr. 2023 - Mar. 2024
  情報通信ネットワーク特論
• Apr. 2022 - Mar. 2024
  電気電子情報工学実験 I
• Apr. 2021 - Mar. 2024
  ネットワークシステム特論
• Apr. 2021 - Mar. 2024
  デジタル信号処理
• Apr. 2021 - Mar. 2024
  データベースと応用システム
• Apr. 2021 - Mar. 2022
  フーリエ解析
• Apr. 2021 - Mar. 2022
  微分積分II
• Apr. 2014 - Mar. 2022
  電気電子情報工学実践演習Ｂ
• Apr. 2014 - Mar. 2021
  電気工学基礎実験
• Apr. 2014 - Mar. 2021
  数学演習１

• IEEE
• IEICE

• 通信データの生成技術から開く想定外の事象を検出・予測可能なシステムの構築　　　　　　　　　　　　　　　
  01 Apr. 2023 - 31 Mar. 2027
  Grant amount(Total)：18330000, Direct funding：14100000, Indirect funding：4230000
  Grant number：23H03379
• 通信データ独占を克服するための疑似データ生成プラットフォームの構築　　　　　　　　　　　　　　　
  01 Apr. 2020 - 31 Mar. 2024
  Grant amount(Total)：17810000, Direct funding：13700000, Indirect funding：4110000
  Grant number：20H04172
• Grant Number JP18K18035　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, KAKENHI Early-Career Scientists, Apr. 2018 - Mar. 2021
  Kohei Watabe, Principal investigator
  Competitive research funding
• Grant Number JP17K00008　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research(C), Apr. 2017 - Mar. 2020
  Kenji Nakagawa
  Competitive research funding
• ネットワークの保守・運用作業の自動化のためのネットワークモデル化技術の開発　　　　　　　　　　　　　　　
  Japan Prize Foundation, Research Grant, Apr. 2017 - Mar. 2018
  Kohei Watabe, Principal investigator
  Competitive research funding
• Research Grant　　　　　　　　　　　　　　　
  The Telecommunications Advancement Foundation, Apr. 2017 - Mar. 2018
  Kohei Watabe, Principal investigator
  Competitive research funding
• Establishment of Lightweight and Accurate Measurement Techniques on Wired/wireless Network Environment　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Grant-in-Aid for Research Activity Start-up, 29 Aug. 2014 - 31 Mar. 2016
  Watabe Kohei, Nagaoka University of Technology
  Grant amount(Total)：2080000, Direct funding：1600000, Indirect funding：480000
  To establish lightweight and accurate measurement on wired/wireless network environment, we developed the following techniques: 1) Dynamic control of probe rate; 2) Active measurement using compressive sensing for periodic delay; 3) Burst delay estimation with multiple probe flow; 4) A modification technique of measurement bias on wireless networks; 5) Intrusiveness-aware estimation of network delay.
  Grant number：26880008
• Grant Number JP26880008　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, KAKENHI Grant-in-Aid for Research Activity Start-up, Apr. 2014 - Mar. 2015
  Kohei Watabe, Principal investigator
  Grant amount(Total)：910000, Direct funding：700000, Indirect funding：210000
  Competitive research funding
• Grant Number JP12J03184　　　　　　　　　　　　　　　
  Japan Society for the Promotion of Science, KAKENHI Grant-in-Aid for JSPS Research Fellow, Apr. 2012 - Mar. 2014
  Kohei Watabe, Principal investigator
  Competitive research funding, Grant number：12J03184

• ＳＤＧｓ基礎／ＳＤＧｓが目指す未来　　　　　　　　　　　　　　　
  lecturer
  15 Dec. 2020
• やさしい科学技術セミナー ネットが遅いのは誰のせい? -インターネットの地図を描こう-　　　　　　　　　　　　　　　
  lecturer
  09 Dec. 2017