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Study of several problems related cut locus and aimed its new applications

Research Project

Project/Area Number 17K05222
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeMulti-year Fund
Section一般
Research Field Geometry
Research InstitutionSugiyama Jogakuen University

Principal Investigator

Itoh Jin-ichi  椙山女学園大学, 教育学部, 教授 (20193493)

Co-Investigator(Kenkyū-buntansha) 清原 一吉  岡山大学, 自然科学研究科, 特命教授 (80153245)
Project Period (FY) 2017-04-01 – 2024-03-31
Project Status Completed (Fiscal Year 2023)
Budget Amount *help
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2020: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Keywords最小跡 / 測地線 / 第一共役跡 / 距離関数 / 多面体 / 全曲率 / 最少跡 / 第1共役跡
Outline of Final Research Achievements

As a comprehensive study on the cut locus, we conducted a well-balanced study in the following five areas. (A) A paper on the generalization of Jacobi's Last Theorem was published. (B) For the study of the structure and properties of cut loci, we defined the minimum traces of general polyhedra and the minimum traces of graphs. (C) Interesting results have been published in the study of problems related to cut locus (farthest point sets, pseudogeodesics, critical points of distance functions, etc.), and new problems and developments have continued. (D) The problem of applying the cut locus was to characterize cells with peculiar shapes. (E) As for the consideration of the cut locus in other related metrics, some time is now needed to obtain the results.

Academic Significance and Societal Importance of the Research Achievements

最小跡の研究は20世紀初頭のポアンカレの論文によって始まり,その後の長い研究の歴史がある.それの進展に貢献するものといえる.また,楕円面上の測地線の挙動からその第一共役跡の特異点に関してはヤコビの最終定理として知られており,それの一般次元への拡張を与えたことになる.
応用面に関しても,多面体の unfolding や Volonoi分割等の計算機科学との関連があり,また,本研究中に始めた,特異形状の細胞を特徴付けるのにも将来的に役立つ可能性があり意義深いと思われる.更に,定義が単純であることから数学教育の分野にもその有用性が期待される.

Report

(8 results)
  • 2023 Annual Research Report   Final Research Report ( PDF )
  • 2022 Research-status Report
  • 2021 Research-status Report
  • 2020 Research-status Report
  • 2019 Research-status Report
  • 2018 Research-status Report
  • 2017 Research-status Report
  • Research Products

    (53 results)

All 2024 2023 2022 2021 2020 2019 2018 2017

All Journal Article (18 results) (of which Int'l Joint Research: 10 results,  Peer Reviewed: 16 results,  Open Access: 10 results) Presentation (35 results) (of which Int'l Joint Research: 7 results,  Invited: 9 results)

  • [Journal Article] Six problems in intuitive geometry2024

    • Author(s)
      S. Honda, N. Horio, J. Itoh, N. Nomura, S. Prasad
    • Journal Title

      Bull. Math. Soc. Sci. Math. Roumanie

      Volume: 67 Pages: 221-227

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Continuous folding of the surface of a regular simplex onto its facet2024

    • Author(s)
      C. Nara, J. Itoh
    • Journal Title

      Bull. Math. Soc. Sci. Math. Roumanie

      Volume: 67 Pages: 251-262

    • Related Report
      2023 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] 大学生による数学探究活動の報告 ー秋山仁先生のメビウスフラワーに関連するいくつかの考察ー2023

    • Author(s)
      伊藤仁一, 田中麻綾,堀内菜智
    • Journal Title

      椙山女学園大学教育学部紀要

      Volume: 16 Pages: 91-97

    • Related Report
      2022 Research-status Report
    • Open Access
  • [Journal Article] Continuous flattening of the 2-dimensional skeleton of a regular 24-cell2021

    • Author(s)
      Itoh Jin-ichi、Nara Chie
    • Journal Title

      Journal of Geometry

      Volume: 112 Issue: 1

    • DOI

      10.1007/s00022-021-00575-6

    • Related Report
      2021 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] Continuously flattening of all polyhedral manifolds using countably infinite creases2021

    • Author(s)
      Z. Abel, E. Demaine, M. Demaine, J. Ku, J. Lynch, J. Itoh, C. Nara
    • Journal Title

      Comput. Geometry: Theory and Appl.

      Volume: 98 Pages: 101773-101773

    • DOI

      10.1016/j.comgeo.2021.101773

    • Related Report
      2021 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Some inequalities for tetrahedra2021

    • Author(s)
      J. Itoh, J. Rouyer, C. Vilcu
    • Journal Title

      Beitrage fur Algebra und Geometrie

      Volume: 62 Pages: 705-715

    • Related Report
      2021 Research-status Report 2020 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] The Structure of the Conjugate Locus of a General Point on Ellipsoids and Certain Liouville Manifolds2021

    • Author(s)
      J. Itoh, K. Kiyohara
    • Journal Title

      Arnold Math. J.

      Volume: 7 Issue: 1 Pages: 31-90

    • DOI

      10.1007/s40598-020-00153-9

    • Related Report
      2020 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] With respect to whom are you critiacal?2020

    • Author(s)
      J. Itoh, C. Vilcu, T. Zamfirescu
    • Journal Title

      Adv. Math.

      Volume: 369

    • Related Report
      2020 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Locating diametrial points2020

    • Author(s)
      J. Itoh, C.Vilcu, L.Yuan, T.Zamfirescu
    • Journal Title

      Results in Math.

      Volume: 75 Issue: 2

    • DOI

      10.1007/s00025-020-01193-5

    • Related Report
      2020 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Some inequalities for tetrahedra2020

    • Author(s)
      Jin-Ichi Itoh, Joel Rouyer, Costin Vilcu
    • Journal Title

      Beitrage fur Algebra und Geometrie

      Volume: ?

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Locating diametrial points2020

    • Author(s)
      Jin-Ichi Itoh, Costin Vilcu, Liping Yuan, Tudor Zamfirescu
    • Journal Title

      Results in Mathematics

      Volume: ?

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Continuous flattening of the 2-dimensional skeletons in regular simplexes and cross-Polytopes2020

    • Author(s)
      Jin-ichi Itoh, Chie Nara
    • Journal Title

      Journal of Geomatry

      Volume: ? Issue: 3

    • DOI

      10.1007/s00022-019-0504-0

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Polyhedra with simple dense geodesic2019

    • Author(s)
      Jin-Ichi Itoh, Joel Rouyer, Costin Vilcu
    • Journal Title

      Differential Geometry and its Applications

      Volume: 66 Pages: 242-252

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] The geometry of a positively curved Zoll surface of revolution2019

    • Author(s)
      K.Kiyohara, Sorin V. Sabau, K.Shibuya
    • Journal Title

      International J. Geometric Methods in Modern Physics

      Volume: 16 Issue: supp02 Pages: 1-29

    • DOI

      10.1142/s0219887819410032

    • Related Report
      2019 Research-status Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Continuous flattening of extended bipyramids with rigid radial edges2018

    • Author(s)
      Chie Nara, Jin-ichi Itoh
    • Journal Title

      The Proceedings from 7th International Meeting on Origami in Science, Mathematics and Education

      Volume: 2 Pages: 561-571

    • Related Report
      2018 Research-status Report
    • Peer Reviewed
  • [Journal Article] The total mixed curvature of open curves in E32018

    • Author(s)
      Kazuyuki Enomoto, Jin-ichi Itoh
    • Journal Title

      Geometriae Dedicata

      Volume: 194 Pages: 131-140

    • Related Report
      2018 Research-status Report
  • [Journal Article] The total mixed curvature of open curves in E^32018

    • Author(s)
      Enomoto, Kazuyuki; Itoh, Jin-ichi
    • Journal Title

      Geometriae Dedicata

      Volume: ? Issue: 1 Pages: 131-140

    • DOI

      10.1007/s10711-017-0269-2

    • Related Report
      2017 Research-status Report
    • Peer Reviewed / Open Access
  • [Journal Article] A natural generalization of regular convex polyhedra2017

    • Author(s)
      Itoh, Jin-ichi; Ohtsuka, Fumiko
    • Journal Title

      Topology and its Appl.

      Volume: 219 Pages: 43-54

    • Related Report
      2017 Research-status Report
    • Peer Reviewed
  • [Presentation] Cut locus and intuitive geometry2023

    • Author(s)
      Jin-ichi Itoh
    • Organizer
      Geometry Seminar at IISER Kolkata
    • Related Report
      2023 Annual Research Report
    • Int'l Joint Research / Invited
  • [Presentation] Continuous Folding of the Surface of a Regular Simplex onto its Facet2023

    • Author(s)
      Chie Nara
    • Organizer
      The 25th Indonesia-Japan Conf. on Discr. and Comput. Geometry, Graphs and Games 2023
    • Related Report
      2023 Annual Research Report
    • Int'l Joint Research
  • [Presentation] 空間曲線の曲率の積分2022

    • Author(s)
      榎本一之
    • Organizer
      第69回幾何学シンポジュウム
    • Related Report
      2022 Research-status Report
    • Invited
  • [Presentation] 誰も知らない多面体の秘密 -直観幾何学への誘い-2022

    • Author(s)
      伊藤仁一
    • Organizer
      確率論と幾何学
    • Related Report
      2021 Research-status Report
    • Invited
  • [Presentation] 球面曲線の曲率の積分2021

    • Author(s)
      榎本一之
    • Organizer
      日本数学会秋季総合分科会
    • Related Report
      2021 Research-status Report
  • [Presentation] 連続的平坦化:正24 胞体の 2 次元スケルトン2021

    • Author(s)
      奈良知惠
    • Organizer
      日本数学会秋季総合分科会
    • Related Report
      2021 Research-status Report
  • [Presentation] 講演「誰も知らない多面体の秘密-直観幾何学への誘い-」2021

    • Author(s)
      伊藤仁一
    • Organizer
      日本数学協会年次大会
    • Related Report
      2021 Research-status Report
    • Invited
  • [Presentation] Cut loci for non-convex polyhedra2021

    • Author(s)
      吉安徹
    • Organizer
      測地線及び関連する諸問題
    • Related Report
      2020 Research-status Report
  • [Presentation] Diametral points2021

    • Author(s)
      C.Vilcu
    • Organizer
      直観幾何学 2021
    • Related Report
      2020 Research-status Report
    • Invited
  • [Presentation] 非凸多面体の最小跡2021

    • Author(s)
      吉安徹
    • Organizer
      直観幾何学 2021
    • Related Report
      2020 Research-status Report
  • [Presentation] 折り紙テントと関連する諸問題2020

    • Author(s)
      伊藤仁一
    • Organizer
      MIMS現象数理学拠点共同研究集会「折紙を基盤とする数理と折紙工学への応用発展」
    • Related Report
      2020 Research-status Report
  • [Presentation] 最小跡に関連する諸問題2020

    • Author(s)
      伊藤仁一
    • Organizer
      応用特異点論ラボ・セミナー
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] 高次元正軸多胞体の三角形面からなる2-スケルトンの連続平坦化2020

    • Author(s)
      奈良知恵
    • Organizer
      日本数学会年会
    • Related Report
      2019 Research-status Report
  • [Presentation] 射影同値のエルミート版とHermite-Liouville多様体2020

    • Author(s)
      清原一吉
    • Organizer
      測地線および関連する諸問題
    • Related Report
      2019 Research-status Report
  • [Presentation] Reversing cube and Origami tent2019

    • Author(s)
      Jin-ichi Itoh
    • Organizer
      International Symposium on Discrete Geometry and Convexity
    • Related Report
      2019 Research-status Report
    • Int'l Joint Research
  • [Presentation] 折り紙テント(パート2)2019

    • Author(s)
      伊藤仁一
    • Organizer
      MIMS現象数理学拠点共同研究集会「折紙を基盤とする数理と折紙工学への応用発展」
    • Related Report
      2019 Research-status Report
  • [Presentation] 直観幾何学への誘い2019

    • Author(s)
      伊藤仁一
    • Organizer
      理工談話会(名城大学)
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] 射影同値と可積分測地流2019

    • Author(s)
      清原一吉
    • Organizer
      北大コロキュウム
    • Related Report
      2019 Research-status Report
    • Invited
  • [Presentation] 発見的幾何教材の事例と教員に必要な幾何的素養2019

    • Author(s)
      伊藤仁一
    • Organizer
      教員養成都城研究会
    • Related Report
      2018 Research-status Report
  • [Presentation] 多面体を裏返す2019

    • Author(s)
      伊藤仁一
    • Organizer
      第26回沼津改め静岡研究会
    • Related Report
      2018 Research-status Report
  • [Presentation] 高次元生多胞体の2次元面上への連続的平坦化(I)2019

    • Author(s)
      奈良知恵
    • Organizer
      第11回直観幾何学
    • Related Report
      2018 Research-status Report
  • [Presentation] 折り紙テント2018

    • Author(s)
      伊藤仁一, 堀尾直文
    • Organizer
      MIMS文科省現象数理学拠点共同研究集会
    • Related Report
      2018 Research-status Report
    • Invited
  • [Presentation] Continuous flattening of the 2-dimensional skeleton in a regular simplex2018

    • Author(s)
      Jin-ichi Itoh, Chie Nara
    • Organizer
      21st Japan Conference on Discrete and Computational Geometry, Graphs and Games
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] On 2-Dimensional Developments of a 4-Dimensional Hypercube and a Regular Pentachoron2018

    • Author(s)
      Takashi Horiyama, Jin-ichi Itoh, Chie Nara
    • Organizer
      21st Japan Conference on Discrete and Computational Geometry, Graphs and Games
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] Continuous flattening of extended bipyramids with rigid radial edges2018

    • Author(s)
      Chie Nara, Jin-ichi Itoh
    • Organizer
      7th International meeting on Origami in Science, Mathematics, and Education
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] Reversing cube with slits2018

    • Author(s)
      Naofumi Horio, Jin-ichi Itoh
    • Organizer
      7th International meeting on Origami in Science, Mathematics, and Education
    • Related Report
      2018 Research-status Report
    • Int'l Joint Research
  • [Presentation] N次元超立方体の正方形面からなる2-スケルトンの連続平坦化2018

    • Author(s)
      奈良知惠, 伊藤仁一
    • Organizer
      日本数学会秋季総合分科会
    • Related Report
      2018 Research-status Report
  • [Presentation] On Finsler surfaces with constant flag curvature,2018

    • Author(s)
      清原一吉
    • Organizer
      幾何学研究会、岡山大学
    • Related Report
      2018 Research-status Report
  • [Presentation] Reversing a polyhedral surface and some topics of Intuitive geometry2018

    • Author(s)
      伊藤仁一
    • Organizer
      研究集会-榎本一之教授退職直前ワークショップ
    • Related Report
      2017 Research-status Report
  • [Presentation] 測地流の可積分性に関する Eisenhardt の一定理のケーラー版2017

    • Author(s)
      清原一吉
    • Organizer
      神戸研究集会
    • Related Report
      2017 Research-status Report
  • [Presentation] Cut locus and Intuitive Geometry2017

    • Author(s)
      Itoh, Jin-ichi
    • Organizer
      Geometry Seminar at Hebei Normal University
    • Related Report
      2017 Research-status Report
  • [Presentation] Total mixed curvature of open curves in E^32017

    • Author(s)
      Itoh, Jin-ichi
    • Organizer
      The 13th Int. Conf. on Discrete Geometry
    • Related Report
      2017 Research-status Report
  • [Presentation] 曲線の混合全曲率2017

    • Author(s)
      榎本一之
    • Organizer
      日本数学会秋季総合分科会
    • Related Report
      2017 Research-status Report
  • [Presentation] Reversing polyhedral surfaces and several topics of Intuitive Geometry2017

    • Author(s)
      伊藤仁一
    • Organizer
      2nd Miyazaki Geometry Seminar
    • Related Report
      2017 Research-status Report
  • [Presentation] 測地流の可積分性に関する Eisenhart の定理のケーラー版2017

    • Author(s)
      清原一吉
    • Organizer
      福岡大研究集会
    • Related Report
      2017 Research-status Report

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Published: 2017-04-28   Modified: 2025-01-30  

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