Naoki Yonezawa
| Faculty of Interdisciplinary and Co-creative Innovation,Department of Digital Innovation | Associate Professor |
| Faculty of Humanities and Social Sciences,Department of Business,Management Information Course | Associate Professor |
| Graduate School of Information Sciences,Major of Information Sciences | Associate Professor |
Last Updated :2026/08/07
■Researcher basic information
■Career
Career
- Apr. 2026 - Present
Teikyo Heisei University - Apr. 2022 - Mar. 2026
Teikyo Heisei University, Associate Professor - Apr. 2017 - Mar. 2022
Teikyo Heisei University, Associate Professor - Apr. 2014 - Mar. 2017
Teikyo Heisei University, Faculty of Modern Life Department of Business Management, Senior Lecturer - Apr. 2013 - Mar. 2014
Department of Information Science, Faculty of Science, Kanagawa University, Assistant Professor - Apr. 2009 - Mar. 2013
Department of Information Science, Faculty of Science, Kanagawa University, Assistant Professor - Apr. 2003 - Mar. 2009
Kanagawa University, Faculty of Science, Department of Information Sciences, Research Associate - Apr. 1999 - Mar. 2003
University of Tsukuba, Institute of Information Sciences and Electronics, Research Associate
Educational Background
■Research activity information
Paper
- Proof of Team Sprint: A Collaborative Consensus Algorithm for Reducing Energy Consumption in Blockchain Systems
Naoki Yonezawa
IET Blockchain, Feb. 2026, [Reviewed]
This paper introduces proof of team sprint (PoTS), a novel consensus algorithm designed to address the significant energy inefficiencies inherent in traditional proof of work (PoW) systems. PoTS shifts the consensus mechanism from an individual competition model to a collaborative team-based approach. Participants are organized into groups, with each group collaboratively working to solve cryptographic puzzles required to validate transactions and add new blocks to the blockchain. This collaborative approach aims to reduce redundant computation and improve overall energy efficiency. While PoTS is designed to preserve key aspects of security and decentralization, a full evaluation of these properties depends on deployment-specific factors. Under idealized conditions, our model suggests that PoTS can reduce energy consumption by up to a factor of 1/N, , where N is the number of participants per team, compared to PoW. Furthermore, PoTS incorporates a team-based reward mechanism that promotes more balanced participation. While this approach encourages inclusivity, its long-term effects on engagement and network stability require further empirical validation. The paper also discusses the scalability, security implications, and potential challenges of adopting PoTS, positioning it as a promising alternative for sustainable blockchain technology. - Empirical Evaluation and Scalability Analysis of Proof of Team Sprint (PoTS): Reward Fairness, Energy Efficiency, and System Stability
Naoki Yonezawa
IEEE Access, 2025, [Reviewed]
This paper presents a comprehensive empirical evaluation of the Proof of Team Sprint (PoTS) consensus algorithm, focusing on its impact on reward fairness, energy efficiency, system stability, and scalability. To assess these factors, we conducted large-scale simulations comparing PoTS with conventional Proof of Work (PoW) under various computational environments and team configurations. Our results demonstrate that PoTS significantly mitigates reward disparities caused by heterogeneous computational capabilities. In PoW, the highest-performing node secured the top ranking in 100 out of 100 trials, leading to extreme centralization. In contrast, under PoTS, the dominance of high-performance nodes was reduced, with the strongest node ranking first only 55 times out of 100, ensuring a fairer distribution of rewards among participants. The skewness and kurtosis of the reward distribution decreased as team size increased, confirming that PoTS fosters a more equitable allocation of mining rewards. Energy efficiency analysis revealed that PoTS exhibits a near 1/N scaling trend in computational workload, where N is the team size. Total active computation time in PoTS (team size 64) was reduced by a factor of 64 compared to PoW, demonstrating a drastic reduction in energy consumption while maintaining the same level of security and consensus reliability. Furthermore, system stability and scalability evaluations confirmed that PoTS maintains statistical consistency across multiple simulation runs, ensuring robust performance regardless of network size. The correlation between participant performance and reward allocation increased with team size, peaking at 0.898 when N=16 , before stabilizing, highlighting the controlled balance between computational power and fairness. These findings suggest that PoTS is a viable alternative to traditional PoW, offering a more decentralized, fair, and energy-efficient approach to achieving blockchain consensus. This study provides empirical validation for PoTS’s ability to improve the sustainability and fairness of decentralized networks, positioning it as a promising consensus mechanism for future blockchain applications. - Generative AI and Software Development : An Analysis of Human-ChatGPT Communication in Medium-Scale Projects
Naoki Yonezawa
Mar. 2024, [Reviewed] - PROBABILISTIC ANALYSIS OF LOAD-IMBALANCED PARALLEL APPLICATIONS WITH PARTIALLY ELIMINATED BARRIERS
Naoki Yonezawa; Ken'ichi Katou; Issei Kino; Koichi Wada
Journal of the Operations Research Society of Japan, Apr. 2015, [Reviewed] - Probabilistic Analysis of Barrier Eliminating Method Applied to Load-Imbalanced Parallel Application
Naoki Yonezawa; Ken'ichi Katou; Issei Kino; Koichi Wada
Lecture Notes in Computer Science, 2014, [Reviewed] - Probabilistic analysis of parallel program with partially eliminated barriers
N. Yonezawa; K. Katou; I. Kino; K. Wada
Proceedings of the 5th IEEE International Workshop on Multicore and Multithreaded Architectures and Algorithms (M2A2 2013, with ISPA-13), Jul. 2013, [Reviewed] - Distributed Shared Memory Based on Offloading to Cluster Network
K. Wada; S. Kawaguchi; M. Ono; N. Yonezawa
2011 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, Aug. 2011, [Reviewed] - Probabilistic analysis of time reduction by eliminating barriers in parallel programmes
Naoki Yonezawa; Issei Kino; Koichi Wada
International Journal of Communication Networks and Distributed Systems, Jun. 2011, [Reviewed] - A Probabilistic Analysis of a Barrier Eliminating Algorithm
N. Yonezawa; I. Kino; K. Wada
2009 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, Aug. 2009, [Reviewed] - なし
Aug. 2008, [Reviewed] - Reducing Idle Times on Matrix Programs by Eliminating Barrier Synchronizations
Apr. 2008, [Reviewed] - Barrier Elimination Based on Access Dependency Analysis for OpenMP
Naoki Yonezawa; Koichi Wada; Takahiro Aida
Lecture Notes in Computer Science, Dec. 2006, [Reviewed] - Eliminating Barrier Synchronizations in OpenMP Programs for PC Clusters
N. Yonezawa; K. Wada
Proceedings of 2005 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, Aug. 2005, [Reviewed] - quad: an Array Section Descriptor for Parallel Computing
Naoki Yonezawa; Koichi Wada
May 2005, [Reviewed] - Quaver: OpenMP Compiler for Clusters Based on Array Section Descriptor
Naoki Yonezawa; Koichi Wada; Takahiro Ogura
Proceedings of the IASTED International Conference on Parallel and Distributed Computing and Networks, Feb. 2005, [Reviewed] - An Implementation of OpenMP Compiler for PC Clusters Based on Array Section Descriptor
N. Yonezawa; K. Wada
2003 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, Aug. 2003, [Reviewed] - quad: an Array Section Descriptor for Parallel Computing
N. Yonezawa; K. Wada
Proceedings of IASTED International Conference on Networks, Parallel and Distributed Processing, and Applications, Oct. 2002, [Reviewed] - Design and Implementation of Message Passing Library for PC Cluster Maestro
P. Kulkasem; S. Yamagiwa; N. Ito; N. Yonezawa; K. Wada
Proceedings of IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, Aug. 1999, [Reviewed] - Scheduling a Reservation Primitive for Effective Latency Hiding in DSM
M. Hirota; T. Yamazaki; N. Yonezawa; K. Wada
Proceedings of IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, Aug. 1999, [Reviewed] - SVCP: A Cache Coherency Protocol with Explicit Update Subscription
T. Yamazaki; N. Yonezawa; P. Kulkasem; S. Yamagiwa; M. Ono; A. Al-Khoury N.M.; K. Wada
Proceedings of the International Conference on Parallel and Distributed Processing Techniques and Applications (PDPTA '98), Jul. 1998, [Reviewed] - Fine-Grain Update Control Protocol for a Distributed Shared Memory System
A. Al-Khoury N. M.; T. Yamazaki; N. Yonezawa; S. Yamagiwa; P. Kulkasem; M. Ono; K. Wada
Proceedings of 1997 IEEE Pacific Rim Conference on Communications, Computers and Signal Processing, Aug. 1997, [Reviewed] - なし
May 1997, [Reviewed] - Implementation and Evaluation of Distributed Shared Data Objects on a Workstation Cluster
N. Yonezawa; K. Wada; M. Obata
Proceedings of IEEE Pacific Rim Conference on Communications, Computers, and Signal Processing, May 1995, [Reviewed]
MISC
- なし
Oct. 2013
Books and other publications
- Computer Architecture: A Quantitative Approach, Fourth Edition
Joint translation, John L. Hennessy; David A. Patterson
Feb. 2008
9784798114408
Lectures, oral presentations, etc.
- クリティカルな処理を持つ並列計算のモデル化と解析
Sep. 2013
Research Themes
- Multiple-layered human interface for safety control and sharing of situation awareness in dynamical environments with risks
Grant-in-Aid for Scientific Research (B)
University of Tsukuba
2002 - 2004
This research project has investigated design of human interface to support human-machine collaborations under dynamically changing environment in which allotted time. may be limited for situation recognition, decision making, and action selection and implementation. Function allocation needs to be dynamic and situation-adaptive to support humans appropriately. Machines have thus been given various types of intelligence. Intelligent machines can now sense and analyze situations, decide what must be done, and implement control actions. It is true, however, humans working with such smart machines often suffer negative consequences of automation, such as the out-of-the-loop performance problem, loss of situation awareness, complacency or over-trust, and automation-induced surprises. By taking the adaptive cruise control (ACC) system as a real-world example of adaptive systems, this research project has developed the concept of multi-layered human interface in which information is provided with human drivers so that they can share situation recognition and intentions with automated systems and authority may be traded dynamically in an emergency to assure system safety. The efficacy of the human interface has been analyzed and evaluated through series of cognitive experiments with various types of scenarios. Furthermore, computer simulation methods have been developed to investigate degree of safety degradation due to drivers' over-trust in automation, in which conventional cognitive experimental approach may not be applicable or feasible. It has been proven that an effective strategy for function allocation between humans and automation assuring system safety can lie within the category that does not fulfill conditions assumed for a conventional human-centered automation. - 計算機クラスタでの実行を可能とするOpenMPコンパイラに関する研究
2002 - 2003
