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Hachimori Masahiro

Faculty of Engineering, Information and Systems
Official title
Associate Professor
Research fields
Foundations of mathematics/Applied mathematics
Research keywords
topological combinatorics
simplicial complex
discrete structure
discrete geometry
Research projects
Topological Combinatorics and Topological Methods in Combinatorics -- (current)/
Studies on Combinatorial Structure -- (current)/
錐最適化における半正定値錐の多面錐近似の理論の構築とその応用2019-04 -- 2023-03吉瀬章子日本学術振興会/科学研究費補助金 基盤研究(B)
Analysis of the structure of simplicial complexes based on the homogeneity of substructures2013 -- 2017Masahiro HachimoriJapan Society of for the Promotion of Science/Grant-in-Aid for Scientific Research (C)4,550,000Yen
Optimization problems on networks with time axes and their applications2016-04 -- 2020-03Maiko ShigenoJapan Society of for the Promotion of Science/Scientific Research Basic B
錐最適化技術の実社会における利活用を加速させる基礎理論の整備と深化2015-04 -- 2019-03Akiko YoshiseJapan Society of for the Promotion of Science/Grant-in-Aid for Scientific Research (B)
Developing network optimization algorithms and methods of analyzing the structures capable for practical problems2013 -- 2015Maiko ShigenoJapan Society of for the Promotion of Science/Grant-in-Aid for Scientific Research (C)
International comparison of the WoM efects on the internet2013 -- 2014Ushio SumitaJapan Society of for the Promotion of Science/Grant-in-Aid for Scientific Research (B)
(A new paradigm for cone optimization: optimization on doubly-nonnegative cones and development of software)2011 -- 2013Akiko YoshiseJapan Society of for the Promotion of Science/Grant-in-Aid for Scientific Research (B)
Topological combinatorics in the view of substructures and minimal counterexamples of simplicial complexes2009 -- 2012Masahiro HachimoriJapan Society of for the Promotion of Science/Grant-in-Aid for Young Scientists (B)4,160,000Yen
Career history
1997-04 -- 2000-03Japan Society for the Promotion of Science Research Fellow (DC1)
2000-10 -- 2002-03Japan Science and Technology Corporation ERATO Quantum Computation and Information Project Researcher
2002-04 -- 2004-03University of Tsukuba Instutute of Policy and Planning Science Assistant Professor
2004-04 -- 2008-07Univsersity of Tsukuba Graduate School of Systems and Information Engineering Assistant Professor
2008-07 -- 2011-09Univsersity of Tsukuba Graduate School of Systems and Information Engineering Associate Professor
2011-10 -- (current)University of Tsukuba Faculty of Engineering, Information and Systems, Associate Professor
Academic background
1991-04 -- 1995-03The University of Tokyo College of Arts and Sciences Department of Natural and Artificial SystemsGraduated
1995-04 -- 2000-03The University of Tokyo Graduate School of Arts and Sciences Department of Systems Science (Master Course & PhD Course)Completed
2000-03-31Doctor of PhilosophyThe University of Tokyo
Academic societies
1999 -- (current)The Mathematical Society of Japan
2003 -- 2009Mathematical Programming Society
2010 -- 2012Mathematical Optimization Society
  • Pure-strategy Nash equilibria on competitive diffusion games
    Enomoto Hikoe; Hachimori Masahiro; Nakamura Shun; Shigeno...
    Discrete Applied Mathematics/244(31)/pp.1-19, 2018-07
  • Hereditary properties and obstructions of simplicial complexes (Designs, Codes, Graphs and Related Areas)
    Masahiro Hachimori
    RIMS Kokyuroku/1986/pp.71-85, 2016-04
  • A comment on pure-strategy Nash equilibria in competitive diffusion games
    Reiko Takehara; Masahiro Hachimori; Maiko Shigeno
    Information Processing Letters/112(3)/p.59-60, 2012-01
  • Obstructions to shellability, partitionability, and sequential Cohen-Macaulayness
    Masahiro Hachimori; Kenji Kashiwabara
    Journal of Combinatorial Theory, Series A/118(5)/pp.1608-1623, 2011-07
  • Decompositions of two-dimensional simplicial complexes
    Masahiro Hachimori
    Discrete Mathematics/308(11)/pp.2307-2312, 2008-06
  • A note on shellability and acyclic orientations
    Masahiro Hachimori; Sonoko Moriyama
    Discrete Mathemaics/308(12)/pp.2379-2381, 2008-06
  • On the topology of the free complexes of convex geometries
    Mashairo Hachimori; Kenji Kashiwabara
    Discrete Mathematics/307(2)/pp.274-279, 2007-01
  • A factorization theorem of characteristic polynomials of convex geometries
    Masahiro Hachimori; Masataka Nakamura
    Annals of Combinatorics/11(1)/pp.39-46, 2007-01
  • The max-flow min-cut property of two-dimensional affine convex geometries
    Masahiro Hachimori; Masataka Nakamura
    Discrete Mathematics/308(9)/pp.1674-1689, 2008-05
  • h-Assignments of simplicial complexes and reverse search
    Sonoko Moriyama; Masahiro Hachimori
    Discrete Applied Mathematics/154(3)/pp.594-597, 2006-03
  • Tangle sum and constructible spheres
    Masahiro Hachimori; Koya Shimokawa
    Journal of Knot Theory and Its Ramifications/13(3)/pp.373-383, 2004-05
  • Deciding constructibility of 3-balls with at most two interior vertices
    Masahiro Hachimori
    Discrete Mathematics/232(1-3)/p.47-58, 2001-04
  • Non-constructible complexes and the bridge index
    Richard Ehrenborg; Masahiro Hachimori
    European Journal of Combinatorics/22(4)/p.475-491, 2001-05
  • Decompositions of balls and spheres with knots consisting of few edges
    Masahiro Hachimori; Günter M. Ziegler
    Mathematische Zeitschrift/235(1)/p.159-171, 2000-09
  • Nonconstructible balls and a way of testing constructibility
    Masahiro Hachimori
    Discrete & Computational Geometry/22(2)/p.223-230, 1999-09
  • Constructible complexes and recursive division of posets
    Masahiro Hachimori
    Theoretical Computer Science/235(2)/p.225-237, 2000-03
  • セル複体に付随するグラフの向き付けとその最適解
    RIMS Kokyuroku/1629/pp.214-224, 2009-02
  • 核付アフィン点配置の根付サーキット系の性質について
    RIMS Kokyuroku/1349/pp.187-203, 2004-01
  • Combinatorial decomposition of simplicial 3-spheres and bridge indices of knots
    RIMS Kokyuroku/1175/p.31-50, 2000-10
  • 組合せ数学の雑記帳:マッチングと交互サイクルとモース関数
    八森 正泰
    数学セミナー2020年2月号, 日本評論社, pp.56-61, 2020-03
  • 組合せ数学の雑記帳:シェリングと分割とh-列
    八森 正泰
    数学セミナー2020年2月号, 日本評論社, pp.62-67, 2020-02
  • 組合せ数学の雑記帳:シェラブルでない単体的複体
    八森 正泰
    数学セミナー2020年1月号, 日本評論社, pp.58-63, 2020-01
  • 組合せ数学の雑記帳:シェラブルな単体的複体
    八森 正泰
    数学セミナー2019年12月号, 日本評論社, pp.64-69, 2019-12
  • 組合せ数学の雑記帳:ハム・サンドイッチとネックレス
    八森 正泰
    数学セミナー2019年11月号, pp.48-53, 2019-11
  • 組合せ数学の雑記帳:ボルスク-ウラムの定理とグラフの彩色
    八森 正泰
    数学セミナー2019年10月号, pp.53-57, 2019-10
  • 組合せ数学の雑記帳:組合せ的な構造の中の単体的複体
    八森 正泰
    数学セミナー2019年9月号, pp.52-57, 2019-09
  • 組合せ数学の雑記帳:曲がったものをまっすぐにすること
    八森 正泰
    数学セミナー2019年8月号, pp.52-57, 2019-08
  • 組合せ数学の雑記帳:グラフのON/OFFゲームと計算量の話
    八森 正泰
    数学セミナー2019年7月号, pp.54-59, 2019-07
  • 組合せ数学の雑記帳:マトロイドと有向マトロイド
    八森 正泰
    数学セミナー2019年6月号, pp.50-54, 2019-06
  • 組合せ数学の雑記帳:包除原理,半順序集合,そして再び超平面配置
    八森 正泰
    数学セミナー2019年5月号, pp.54-58, 2019-05
  • 組合せ数学の雑記帳:超平面の切り分ける領域の個数はいくつ?
    八森 正泰
    数学セミナー2019年4月号, pp.50-54, 2019-04
  • Optimization problems on acyclic orientations of graphs, shellability of simplicial complexes, and acyclic partitions
    八森 正泰
    Mathematical Programming and Game Theory, Springer-Verlag, pp.49-66, 2018
  • 応用数理ハンドブック
    八森 正泰
    応用数理ハンドブック, 朝倉書店, 2013-11
  • 格子の幾何学から広がる数学のダイナミズム(「格子から見える数学」書評)
    八森 正泰
    数学セミナー2013年12月号, 日本評論社, pp.96-96, 2013-12
  • Lecturecs on Polytopes (Japanese Translation)
    ギュンター・M・ツィーグラー; +八森 正泰; 岡本 吉央
    Lecturecs on Polytopes (Japanese Translation), Maruzen (formerly from Springer-Verlag Tokyo), 2003-03
  • Combinatorics from convex polytopes
    Suugaku Seminar, 2006/11, Nippon-Hyoron-sha, pp.21-25, 2006-11
  • Topology and quantum computation
    八森正泰; 由良文孝
    Operations Research 47, The Operations Research Society of Japan, pp.453-458, 2002-07
  • 父娘の会話から始まる数学入門, あるいは数学を巡る散文的モノローグ(ドゥニ・ゲジ著「娘と話す 数学ってなに?」書評)
    Suugaku Seminar, 2011/11, pp.99-99, 2011-11
  • 複雑ネットワークを厳密な数学で(リック・デュレット著「ランダムグラフダイナミクス」書評)
    八森 正泰
    Suugaku Seminar, 2012/8, pp.88-88, 2012-08
  • 四次元の世界ってどうなってるの?(根上生也著「四次元が見えるようになる本」書評)
    八森 正泰
    Suugaku Seminar, 2013/3, pp.92-92, 2013-03
  • 新入生のための数学書ガイド(R.J.ウィルソン著「グラフ理論」、伊藤大雄、宇野裕之編著「離散数学のすすめ」、J.マトウシェク著「離散幾何学講義」 紹介)
    Suugaku Seminar, 2013/4, p.14,24,28, 2013-04
Conference, etc.
  • グラフの向き付けと出次数に関する最適化問題
    八森 正泰
  • Partitioning simplicial complexes and their h-triangles
    Hachimori Masahiro
    Indian Statistical Institute, Delhi Centre/2018-01-09--2018-01-11
  • Nonpureな単体的複体におけるマトロイド構造の考察
    Japanese Conference on Combinatorics and its Applications (JCCA-2017)/2017-08-17--2017-08-19
  • 単体的複体、shellingと分割
  • Optimization on acyclic orientations of graphs, shellability of simplicial complexes, and related topics
    Hachimori Masahiro
    2017 Symposium on Mathematical Programming and Game Theory/2017-01-09--2017-01-11
  • 単体的複体の分割可能性とh-triangle
    八森 正泰
  • Hereditary properties of simplicial complexes and h-triangles
    Masahiro Hachimori
    Japanese Conference on Combinatorics and its Applications 2016 (JCCA2016)/2016-05-21--2016-05-25
  • 単体的複体の分割、h-triangleとhereditary property
    八森 正泰
  • 単体的複体の遺伝的性質とh-vectorの非負性
    八森 正泰
  • 単体的複体におけるhereditary propertyとobstruction
    八森 正泰
  • マトロイドの拡張としてのhereritary property
    八森 正泰
  • Poset matroidとshellability
    八森 正泰; 佐野良夫
  • Hereditary-shellable simplicial complexes and extendability of shellings
    八森 正泰; 柏原賢二
    Japan Conference on Combinatorics and its Applications (JCCA2014)/2014-08-25--2014-08-29
  • Hereditary-shellability and vertex decomposability of simplicial complexes
    八森 正泰; 柏原賢二
  • Hereditary-shellable simplicial complexes and extendability of shellings
    Masahiro Hachimori; Kenji Kashiwabara
    25th Workshop on Topological Graph Theory (TGT25)/2013-11-18--2013-11-22
  • 任意の制限がシェラブルな単体的複体とシェリングの拡張性
    八森 正泰; 柏原賢二
  • 任意の制限がシェラブルである単体的複体とシェリングの拡張可能性
  • 任意の制限がシェラブルな単体的複体におけるシェリングの拡張可能性
    八森正泰; 柏原賢二
  • グラフ上の離散ボロノイゲームと関連するゲームのナッシュ均衡
    八森正泰; 繁野麻衣子; 竹原令依子
  • 任意の制限がシェラブルな単体的複体と純骨格
    八森正泰; 柏原賢二
  • 直径2のグラフ上の離散ボロノイゲーム
    八森正泰; 繁野麻衣子; 竹原令依子
  • グラフ上の離散ボロノイゲームとナッシュ均衡
    八森正泰; 繁野麻衣子; 竹原令依子
  • グラフ上の離散ボロノイゲームにおけるナッシュ均衡
    八森正泰; 竹原令依子; 繁野麻衣子
  • 直径2のグラフ上の離散ボロノイゲーム
  • 任意の制限がシェラブルな単体的複体とオブストラクション
2019-10 -- 2020-02Information Technology Laboartory (undergraduate)University of Tsukuba
2020-01 -- 2020-02Linear Algebra 3 (undergraduate)University of Tsukuba
2019-10 -- 2020-01Linear Algebra 2 (undergraduate)University of Tsukuba
2019-10 -- 2020-01Foster Thinking Skills through Go GamesUniversity of Tsukuba
2019-10 -- 2020-01Discrete Mathematics (graduate)University of Tsukuba
2019-04 -- 2019-07Discrete Mathematics (undergraduate)University of Tsukuba
2018-04 -- 2018-07Mathematical Analysis (undergraduate)University of Tsukuba
2018-10 -- 2018-12Discrete Mathematics (graduate)University of Tsukuba
2018-10 -- 2018-12Information Technology Laboratory (undergraduate)University of Tsukuba
2018-10 -- 2018-12Foster Thinking Skills through Go GamesUniversity of Tsukuba
Professional activities
2017-10 -- 2019-10The Mathematical Society of Japan応用数学分科会 分科会委員
2015-01 -- (current)Graphs and CombinatoricsManaging Editor
University Management
2019-04 -- 2020-03論文委員会(社会工学専攻)
2019-04 -- 2020-03カリキュラム委員会(社会工学類)
2018-04 -- 2019-03全学学群教職課程委員
2018-04 -- 2019-03コンピュータ委員会(社会工学専攻)
2018-04 -- 2019-03カリキュラム委員会(社会工学類)
2018-04 -- 2019-03論文委員会(社会工学専攻)
2018-04 -- 2019-03コンピュータ委員会(社会工学専攻)
This system contains many errors of data that caused by the system design and cannot be corrected by my own access privilege. (Especially, the name of myself is mis-printed. First name and Family name is printed conversely.) So, DO NOT REFER my publication list, etc. from this system. Right data can be found in my web pages linked from the URL written above. For the e-mail address, at first I filled by my message ``my e-mail address is not here because of the buggy system can not display it correctly. Please refer my homepage from the URL above.'' But after that it was replaced by blank without any noticing. I notice it recently and also I found the bug was fixed, so I entered my email address for the place. The administrators of this system is too dishonest that they do not inform me about the changing of the status the system at all, though I sent request to fix the bug long ago with information that I can not fill the data of my email address until the bug is fixed.

(Last updated: 2020-03-03)