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Yasushi Nakabayashi

    Department of Information Sciences and Arts　Professor
    Research Institute of Industrial Technology　Researcher
    Center for Computational Mechanics Research　Researcher
    Course of Information Sciences and Arts　Professor
Last Updated :2024/04/23

Researcher Information

Degree

  • Ph.D. in Engineering（The University of Tokyo）

Research funding number

  • 00349937

J-Global ID

Research Interests

  • 計算力学システム   ネットワーク・コンピューティング   数値流体力学   CAE System   Network Computing   Computational Fluid Dynamics   

Research Areas

  • Manufacturing technology (mechanical, electrical/electronic, chemical engineering) / Fluid engineering
  • Informatics / Computational science
  • Informatics / Information theory

Academic & Professional Experience

  • 2017/04 - Today  Toyo UniversityFaculty of Information Sciences and Arts教授
  • 2010/04 - 2017/03  Toyo UniversityFaculty of Information Sciences and Arts准教授
  • 2009/04 - 2010/03  Toyo UniversityFaculty of Information Sciences and Arts講師
  • 2002/04 - 2009/03  Toyo University工学部講師
  • 1999/04 - 2002/03  東京大学大学院新領域創成科学研究科リサーチ・アソシエイト
  • 1999 - 2002  Research Associate, Institute of Frontier
  • 2002  - Lecturer, Toyo University
  • 1996/04 - 1999/03  日本学術振興会特別研究員
  • 1996 - 1999  JSPS Research Fellow

Education

  • 1996/04 - 1999/03  東京大学大学院  工学系研究科  情報工学専攻（博士課程）
  •        - 1999  The University of Tokyo  Graduate School, Division of Engineering  Information Engineering
  • 1994/04 - 1996/03  東京大学大学院  工学系研究科  システム量子工学専攻（修士課程）
  •        - 1994/03  The University of Tokyo  The Faculty of Engineering  システム量子工学科
  •        - 1994  The University of Tokyo  Faculty of Engineering  Quantum Engineering and Systems Science

Association Memberships

  • JAPAN SOCIETY FOR SIMULATION TECHNOLOGY   JAPAN SOCIETY FOR COMPUTATIONAL ENGINEERING AND SCIENCE   THE JAPAN SOCIETY OF MECHANICAL ENGINEERS   

Published Papers

Books etc

  • 有限要素法流れ解析
    (Joint work)朝倉書店 1998

Conference Activities & Talks

  • NAGAOKA Shinsuke; NAKABAYASHI Yasushi; TAMURA Yoshiaki; YAGAWA Genki
    The Computational Mechanics Conference  2014/11 
    Fluid-structure interaction problem is becoming a very important issue in numerical analysis field. A lot of methods to solve this phenomenon are proposed by many researchers. Our proposed new method to solve fluid-structure interaction problem is combined the Enriched Free Mesh Method and the SUPG/PSPG stabilized Finite Element Method. This method is using only linear element but it can be obtained fine analysis result. On the other hand, no crucial benchmark test for fluid structure interaction problems is also available. Therefore, we also proposed new experiment for fluid structure interaction problem to establish a new benchmark test. In this paper, we described comparison between experimental result and analysis result to prove effectiveness of our proposed method.
  • Masuda Masato; Nakabayashi Yasushi; Tamura Yoshiaki
    The Computational Mechanics Conference  2014/11
  • MASUDA Masato; NAKABAYASHI Yasushi; TAMURA Yoshiaki
    The Computational Mechanics Conference  2013/11
  • NAGAOKA Shinsuke; NAKABAYASHI Yasushi; YAGAWA Genki
    Mechanical Engineering Congress, Japan  2013/09 
    We have been already proposed a new analysis method for fluid-structure coupled problem, which has nodal consistency at the fluid-structure interface and its calculation efficiency and accuracy are high. Our proposed method is using Enriched Free Mesh Method and SUPG/PSPG stabilized FEM. Enriched Free Mesh Method and SUPG/PSPG stabilized EFM have a very good chemistry because both methods are using linear tetrahedral element. However, Enriched Free Mesh Method has a shortcoming that is difficult to apply adaptive parallel analysis. So, in this paper, we describe a new treatment to apply Enriched Free Mesh Method into parallel analysis. Finally, verification result of our new treatment is also described.
  • MASUDA Masato; NAKABAYASHI Yasushi; YAGAWA Genki
    Transactions of the Japan Society for Computational Engineering and Science  2013 
    In this paper, the authors propose the Free-Kick Support System, which solves the inverse problem of the free-kick simulator. The free-kick simulator is the system which physically computes the motion of soccer ball by the information of ball position, velocity, rotating angle, rotating speed and the aerodynamic properties of soccer ball. Using the Neural Network (NN) and the Self-Organizing Map (SOM), the Free-Kick Support System solves the inverse problem of the free-kick simulator and the output is available for the practice of the free-kick and making a strategic plan of real soccer games. Furthermore, the authors propose the evaluation method of the modular network SOM (mnSOM) for quantitatively evaluating the learning effects, and show that the mnSOM is useful for the Free-Kick Support System.
  • NAGAOKA Shinsuke; NAKABAYASHI Yasushi; YAGAWA Genki
    NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan  2013 
    This paper proposes a new analysis method for fluid-structure coupled problem, which has nodal consistency at the fluid-structure interface and its calculation efficiency and accuracy are high.   Our proposed method is using a EFMM as a structure analysis method and SUPG/PSPG stabilized FEM as a fluid analysis method.These method have a very good chemistry in coupled analysis field. However our proposed method is difficult to introduce into parallel method. This is a problem due to the characteristics of the EFMM. In this paper, we also describe special handling for the introduction to parallel analysis of our proposed method.
  • NAGAOKA Shinsuke; NAKABAYASHI Yasushi; YAGAWA Genki
    The Computational Mechanics Conference  2011/10 
    Since majority of phenomena which occur around us are coupled ones, the necessity for coupled analysis is well-known. In many computational mechanics studies, however, the coupled effect is disregarded because of the difficulty to consider it in a numerical computation. In other words, the coupled analyses are much complicated as compared with the non-coupled ones. We have employed the EFMM for this class of problems as this method has various advantages, for example, analysis accuracy improves sharply as compared with the FEM. In the present paper, we aim at conducting efficient coupled analysis, which does not use a middle-point node by using the present method.
  • Nakabayashi Yasushi; TOMIYAMA Jun
    The Computational Mechanics Conference  2010/09
  • 長岡 慎介; 中林 靖; 矢川 元基
    計算工学講演会論文集 = Proceedings of the Conference on Computational Engineering and Science  2010/05
  • NAGAOKA Shinsuke; NAKABAYASHI Yasushi; YAGAWA Genki
    The Computational Mechanics Conference  2009/10 
    Since majority of phenomena which occur around us are coupled ones, the necessity for coupled analysis is well-known. In many computational mechanics studies, however, the coupled effect is disregarded because of the difficulty to consider it in a numerical computation. In other words, the coupled analyses are much complicated as compared with the non-coupled ones. We have employed the EFMM for this class of problems as this method has various advantages, for example, analysis accuracy improves sharply as compared with the FEM. In the present paper, we aim at conducting efficient coupled analysis, which does not use a middle-point node by using the present method.
  • OSAKI Hiroaki; NAKABAYASHI Yasushi; YAGAWA Genki; KIM Young Jin
    The Computational Mechanics Conference  2009/10
  • Ochiai Kazuaki; Nakabayashi Yasusi
    The Computational Mechanics Conference  2009/10 
    Recently, the computational performance of GPU is improving rapidly. The technology which uses the GPU for not visualization but general purpose calculation is called GPGPU, and the research using it are performed actively. In this paper, the authors use GPU for the CFD code for improving computational performance. The bottleneck point of CFD code is the calculation of matrix-vector products. Therefore, the authors use CUDA for improving the bottleneck. After some numerical tests, the performance of the CUDA based code is compared with the original CPU based code.
  • MASUDA Masato; NAKABAYASHI Yasushi
    The Computational Mechanics Conference  2009/10
  • OSAKI Hiroaki; NAKABAYASHI Yasushi; YAGAWA Genki; KIM Yong Ji
    M&M材料力学カンファレンス  2009/07 
    It is well known that the crack propagation in a structure is a serious problem from the structural integrity point of view. In order to prevent serious crack propagation, a circular hole is using as a crack arrester. This paper describes the application of a hierarchical neural network to the estimation of a crack arrester position in a solid with the FEM. We solve the 2D crack propagation problem in three point bending model. NN is used as a method of asking for a crack arrester position. It was shown that NN is very effective in prediction of crack arrester position.
  • NAGAOKA Shinsuke; NAKABAYASHI Yasushi; YAGAWA Genki
    日本シミュレーション学会大会発表論文集 : シミュレーション・テクノロジー・コンファレンス・計算電気・電子工学シンポジウム  2009/06
  • Osaki Hiroaki; Nakabayashi Yasushi; Yagawa Genki
    NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan  2009 
    The crack propagation arrestability by circular hole is clarified using the Free Mesh Method analysis. In three point bending analysis, the case where a crack stops is clarified and a crack and circular hole relationship are examined.
  • Nagaoka Shinsuke; Nakabayashi Yasushi; Yagawa Genki
    NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan  2009 
    Many of Phenomena which occur around us are Coupled ones. The necessity for Coupled analysis is very important, but in many cases, the Coupled effect is disregarded because of the difficulty in the numerical computation. In other words, the coupled analysis is much complicated as compared with the conventional analysis. In this research, we introduce the EFMM for this class of problems as this method has various advantages. For example, analysis accuracy improves sharply as compared with the FEM. We aim at conducting efficient coupled analysis which does not use a middle-point node by using the present method.
  • Nakabayashi Yasushi; Masuda Masato; Yoshimura Shinobu
    The Computational Mechanics Conference  2008/11
  • Osaki Hiroaki; NAKABAYASHI Yasushi; YAGAWA Genki
    The Computational Mechanics Conference  2008/11
  • Ochiai Kazuaki; Nakabayashi Yasusi
    The Computational Mechanics Conference  2008/11
  • MASUDA Masato; NAKABAYASHI Yasushi
    The Computational Mechanics Conference  2008/11
  • Osaki Hiroaki; NAKABAYASHI Yasushi; YAGAWA Genki
    M&M材料力学カンファレンス  2008/09 
    本研究では,き裂が進展する事により起こる破壊防止の為に,円孔によりき裂進展を阻止できるかどうか調べる事を目的としている。き裂進展解析としては円孔無し2次元試験片と円孔付き2次元試験片の3点曲げ解析を行った。き裂進展位置をニューラルネットワークで学習し,き裂進展位置の予測において、ニューラルネットワークが有効かどうか評価・検討した。
  • OSAKI Hiroaki; NAKABAYASHI Yasushi; YAGAWA Genki
    日本機械学会関東支部総会講演会講演論文集  2008/03 
    The purpose of this study is to prevent the destruction by crack propagation. The computational fracture mechanics requires frequent re-meshing as the crack propagating. In order to show the effectiveness of the Free Mesh Method (FMM) in crack propagation analysis, we solve the 2D crack propagation problems with the FMM. The method to predict the crack propagation direction will be proposed using Neural Network.
  • Osaki Hiroaki; Nakabayashi Yasushi; Yagawa Genki
    NCTAM papers, National Congress of Theoretical and Applied Mechanics, Japan  2008 
    The purpose of this study is to prevent the destruction of a structure by the crack propagation. The computational fracture mechanics requires frequent re-meshing as the crack propagating. In order to show the effectiveness of the Free Mesh Method (FMM) in crack propagation analysis, we solve the 2D crack propagation problems with the FMM. The method to predict the crack propagation direction will be proposed using Neural Network.
  • OSAKI Hiroaki; NAKABAYASHI Yasushi; YAGAWA Genki
    The Computational Mechanics Conference  2007/11 
    This paper describes the 2D crack propagation analysis using the Free Mesh Method (FMM). The computational fracture mechanics involves frequent re-meshing as the crack propagating. In order to show the effectiveness of the FMM in crack propagation analysis, we solve the 2D crack propagation problems with the FMM. The method controlling the crack propagation will be proposed using Neural Network.
  • MASUDA Masato; NAKABAYASHI Yasushi
    The Computational Mechanics Conference  2007/11 
    The Free-kick Support System is the system that raises the score efficiency at the free kick. However, this system treated the aerodynamic properties as the constant so far. In this study, large scale fluid analysis around soccer ball are performed for evaluating aerodynamic properties of soccer ball. As a result, the Free-kick Support System will become more accurate for evaluating trajectory of soccer ball.
  • OSAKI Hiroaki; NAKABAYASHI Yasushi; YAGAWA Genki
    M&M材料力学カンファレンス  2007/10 
    This paper describes the 2D complicated crack propagation analysis using the Free Mesh Method(FMM). The computational fracture mechanics involves frequent re-meshing as the crack propagates. In order to show the effectiveness of the FMM in crack propagation analysis, we study the 2D complicated crack propagation problems with the FMM. In order to show the effectiveness of the neural network in control of crack propagation analysis result.
  • 中林 靖; 布施 一穂
    Proceedings of the conference on computational engineering and science  2007/05
  • 増田 正人; 中林 靖
    Proceedings of the conference on computational engineering and science  2007/05
  • YAMAMOTO Masaaki; YOSHIMURA Shinobu; NAKABAYASHI Yasushi
    The Computational Mechanics Conference  2005/11
  • MIYAMURA Tomoshi; Bunya Shintaro; Nakabayashi Yasushi; Yoshimura Shinobu
    The Computational Mechanics Conference  2005/11
  • NAKABAYASHI Yasushi; MASUDA Masato; YOSHIMURA Shinobu
    The Computational Mechanics Conference  2005/11
  • NAKABAYASHI Yasushi; ASANO Masahiro
    The Computational Mechanics Conference  2005/11
  • YAMAMOTO Masaaki; YOSHIMURA Shinobu; NAKABAYASHI Yasushi
    年次大会講演論文集 : JSME annual meeting  2005/09 
    Aggravation of air pollution containing suspended particle matter (SPM) discharged from various sources is one of serious environmental problems. The simulation of diffusion behavior of SPM is performed, using the multilevel simulation of combining random walk of particles and parallel finite element air flow analysis.
  • NAKABAYASHI Yasushi
    The Computational Mechanics Conference  2003/11 
    The author is developing an incompressible viscous fluid analysis system (ADVENTURE_Fluid) which contains the Q1-P0 hexahedral element solver with the BTD method and matrix storage free technique and the P1-P1 tetrahedral element solver with the SUPG/PSPG stabilization method. In this paper, the author demonstrates a coupled analysis of incompressible fluid and hard sphere using the ALE method. Three mesh control strategies are compared for evaluating the efficiency and the suitability for parallel processing.
  • NAKABAYASHI Yasushi
    The Computational Mechanics Conference  2002/10 
    In this paper, the author investigates efficient parallelizeation methods on SMP clu7ster. At first, the author compares the performance of three communication libraries, MPICH, LAM and MPICH-GM. Then, the efficiency of OpenMP is tested using some numerical examples. Finally, the author shows the best approach for the parallelization of the finite element flow analysis. code.
  • IMAI Yoichi; YOSHIMURA Shinobu; NAKABAYASHI Yasushi
    The Computational Mechanics Conference  2001/11 
    Diffusion of dioxin class into the environment has become one of serious social problems. More than 80% of such dioxin class is estimated to be discharged from trash incinerators and factories. There are several ways to solve the problems, In this study, we focus on the quantitative understanding of dioxin class diffusing from trash incinerators and factories into the atmosphere. Here incompressible fluid flow in the atmosphere is first calculated using the 3D finite element method. Then the diffusing process of contaminant particles with different weight is traced within the time dependent finite element solutions, and visualized.
  • NAKABAYASHI Yasushi; YOSHIMURA Shinobu; YAGAWA Genki
    計算工学講演会論文集  2001/05
  • NAKABAYASHI Yasushi; YAGAWA Genki; YOSHIMURA Shinobu
    The Computational Mechanics Conference  2000/11 
    In the paper, an efficient computational strategy for ultra large scale finite element fluid analysis on PC clusters was shown. The authors have developed the incompressible viscous fluid analysis system, which is suitable for Massively Parallel Processors and apply it to the PC cluster system. using the efficient parallel domain decomposition tool based on METIS and ParMETIS and the efficient parallel I/O method, high parallel performance was achieved on PC cluster environment. Some numerical examples were shown for estimating the parallel efficiency of the developed analysis system.
  • NAKABAYASHI Yasushi; TANAKA Shinya; MIYAMURA Tomoshi; YOSHIMURA Shinobu; YAGAWA Genki
    年次大会講演論文集 : JSME annual meeting  2000/07 
    The authors are developing an advanced general-purpose computational mechanics system (ADVENTURE System) which can analyze a model of arbitrary shape with 10 to 100 million DOFs within 1 hour to 1 day using the fastest computer. In this project, the authors developed the framework of distributed CAE system for large scale problems and heterogeneous network topology (ADVENTURE Framework). To demonstrate fundamental performance of the framework, structure-fluid coupled analysis was performed.
  • ISHIHARA Daisuke; YOSHIMURA Shinobu; NAKABAYASHI Yasushi; YAGAWA Genki
    年次大会講演論文集 : JSME annual meeting  2000/07 
    This paper describes a flamework for coupling analysis of micromachine behavior using blackboard airchitecture. To estimate micromachine's dynamic behaviors, its is required to simulate coupling phenomena among deformation, fluid flow, electromagnetics and heat conduction. The proposed flamework is designed to treate all of them. To prove its fundamental performance, the flamewark is applied to a simple structure-fluid coupling problem.
  • YOSHIMURA S; TANAKA S; WADA Y; MIYAMURA T; NAKABAYASHI Y; YAGAWA G
    計算工学講演会論文集  2000/05
  • NAKABAYASHI Yasushi; YAGAWA Genki; YOSHIMURA Sinobu
    Proceedings of the conference on computational engineering and science  1999/05

Works

  • ADVENTYURE Project
    1997 -2002

MISC

Awards & Honors

  • 2009/05 人工知能学会 人工知能学会賞
     RoboCup Japan Open 2009 サッカーシミュレーションリーグ2D 
    受賞者: 中林 靖
  • 2006/05 人工知能学会 人工知能学会賞
     RoboCup Japan Open 2006 サッカーシミュレーションリーグ2D 
    受賞者: 中林 靖

Research Grants & Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/04 -2019/03 
    Author : Nakabayashi Yasushi; Masuda Masato
     
    The AR camera is a new camera system that has the following functions. First, we use image recognition technology, which is a field of AI, to extract only the structure that appears in the center from the image taken with a smartphone. Next, the structural analysis by voxel finite element method is performed on the extracted structure in real time, and the distribution of stress applied to the structure and the state of displacement, etc. are superimposed and displayed on the finder screen of the camera . We have developed a stress camera that allows us to see the distribution of forces that can not be seen by nature and the situation of fine displacement, and there are some limitations in terms of functionality, but We have completed a system that enables extraction and real-time structural analysis.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2005 -2007 
    Author : YOSHIMURA Shinobu; HORI Muneo; SHIOYA Ryuji; YAMAD Tomonori; BUNYA Shintaro; SUGIMOTO Shin-ichiro
     
    Recently importance of nuclear energy has been recognized again due to serious concerns of global warming and energy security. It is one of the critical issues to verify safety capability of ageing nuclear power plants subjected to big earthquake. In this research, we develop a simulator of quantitatively predicting actual function limit of nuclear power plants. In this research, a Boiled Water Reactor (BWR) model that is offered by Tokyo Electric Power Company and Hitachi, Ltd. is considered. The finite element model contains 200 million DOE The system that seismic analyses and visualizations for large scale models are performed efficiently on the Earth Simulator was developed. Furthermore, 1. Development of a method by which to incorporate a set of linear multipoint constraints (MPC) into the Balancing Domain Decomposition method 2. Development of tools to support the simulation of assembly structures with MPC 3. Introduction of moving boundary condition to the program of incompressible flow analysis 4. Introduction of thermal analysis to the program of incompressible flow analysis 5. Improvement of the explicit dynamics solver for elastic stress analysis 6. Development of a method for a numerical analysis of brittle fractures 7. Research and development of an iterative partitioned coupling algorithm 8. Development of coupled analysis engine with coupler were done. Development of the system that supports design and development of BWR was completed.
  • ADVENTYURE－ITBL Project
    Cooperative Research
    Date (from‐to) : 2002 -2007
  • Development of Stress/Stream Camera using Real Time Simulation Technique
    Grant-in-Aid for Scientific Research
    Date (from‐to) : 2003 -2006
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 2003 -2005 
    Author : 中林 靖
     
    17年度の研究計画としては、昨年度までにほぼ完成した2つの要素技術である「2次元画像認識技術の研究」、「イメージベースシミュレーション技術の研究」を応用し、実際に応力カメラを開発することであった。 まず、これらのうち「2次元画像認識技術の研究」については、本年度さらなる改良を加えて、よりロバストで効率の良い手法が確立された。具体的には、画像処理技術により対象物を二値化する際に、これまで用いてきた判別分析法ではなくて、領域成長法を用いることにより、二値化画像が必ず単連結な領域になることが保障される。これにより、イメージベースシミュレーションを実行する際にしばしば問題となる、境界条件が設定されていないボクセル、いわゆる「浮きボクセル」の問題が回避できることが分かった。なお、この手法は再帰呼び出しを用いるアルゴリズムであるため、システムの構築方法次第ではメモリ等の計算機資源を極度に消費してしまうが、これらに対処するためのアルゴリズムの開発も行った。 次に本課題の最終的な目的である「応力カメラの開発」に関しては以下のような成果が得られた。まず、無線LAN機能を内蔵したデジタルカメラと上記に上げた個々の技術を結びつけることにより、デジタルカメラで撮影した画像を約1秒後にPC画面上に無線送信し、さらに約1秒後に二値化した画像を表示し、さらに5秒〜30秒後に応力分布を表示するシステムが完成した。応力解析する部分の時間が長いため、必ずしもリアルタイムシミュレーションとは言い切れないが、デジタルカメラで撮影した対象物の応力分布を最短5秒程度で表示するシステムはこれまでに類を見ない画期的な成果であると言える。 現在、上記の研究成果を論文としてまとめ投稿する準備を進めている段階である。

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