Jang Yeonhee

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Profile and Settings

• Name (Japanese)

  Jang

• Name (Kana)

  Yeonhee

Degree

• Master of Science, Osaka University
• Ph.D., Hiroshima University

Research Interests

• 3次元多様体論
• 結び目理論
• 3-dimensional manifolds
• Knot Theory

Research Areas

• Natural sciences, Geometry

Research Experience

• Jan. 2019, 9999, Nara Women's University, Faculty, Division of Natural Sciences, 准教授
• Apr. 2013, Dec. 2018, Nara Women's University, Faculty, Division of Natural Sciences, 助教
• 2012, 2013, 日本学術振興会外国人特別研究員
• 2012, 2013, :JSPS Foreign Research Fellow
• 2013, -:Nara Women's University, Assistant Professor
• 2010, 2012, 日本学術振興会特別研究員
• 2010, 2012, :JSPS Research Fellow

Education

• Apr. 2008, Mar. 2011, Hiroshima University, 理学研究科, 数学専攻, Japan
• 2011, Hiroshima University, Graduate School of Sciences, Department of Mathematics
• Apr. 2006, Mar. 2008, Osaka University, 理学研究科, 数学専攻, Japan
• 2008, Osaka University, Graduate School of Sciences, Department of Mathematics
• Mar. 2000, Aug. 2004, 全北大学校, 師範大学, 数学教育学科, Korea, Republic of
• 2004, Chonbuk National University, College of Education, Department of Mathematics Education, Korea, Republic of

Association Memberships

• 日本数学会

Ⅱ．研究活動実績

Published Papers

• Refereed, Adv. Stud. Pure Math., MATH SOC JAPAN, On keen Heegaard splittings, Ayako Ido; Yeonhee Jang; Tsuyoshi Kobayashi, In this paper, we introduce a new concept of strongly keen for Heegaard splittings, and show that, for any integers n > 2 and g > 3, there exists a strongly keen Heegaard splitting of genus g whose Hempel distance is n., Oct. 2018, 78, 293, 311, International conference proceedings
• Refereed, Pacific Journal of Mathematics, University of California, Berkeley, Meridional rank and bridge number for a class of links, Michel Boileau; Yeonhee Jang; Richard Weidmann, We prove that links with meridional rank 3 whose 2-fold branched covers are graph manifolds are 3-bridge links. This gives a partial answer to a question by S. Cappell and J. Shaneson on the relation between the bridge numbers and meridional ranks of links. To prove this result, we also show that the meridional rank of any satellite knot is at least 4., 2018, 292, 1, 61, 80, Scientific journal, 10.2140/pjm.2018.292.61

  DOI URL
• Refereed, TOPOLOGY AND ITS APPLICATIONS, ELSEVIER SCIENCE BV, Meridional rank of knots whose exterior is a graph manifold, Michel Boileau; Ederson Dutra; Yeonhee Jang; Richard Weidmann, We prove for a large class of knots that the meridional rank coincides with the bridge number. This class contains all knots whose exterior is a graph manifold. This gives a partial answer to a question of S. Cappell and J. Shaneson [10, pb 1.11]. (C) 2017 Elsevier B.V. All rights reserved., Sep. 2017, 228, 458, 485, Scientific journal, 10.1016/j.topol.2017.06.008

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• Refereed, JOURNAL OF THE LONDON MATHEMATICAL SOCIETY-SECOND SERIES, OXFORD UNIV PRESS, A knot with destabilized bridge spheres of arbitrarily high bridge number, Yeonhee Jang; Tsuyoshi Kobayashi; Makoto Ozawa; Kazuto Takao, We show that there exists an infinite family of knots, each of which has, for each integer k >= 0, a destabilized (2k + 5)-bridge sphere. We also show that, for each integer n >= 4, there exists a knot with a destabilized 3-bridge sphere and a destabilized n-bridge sphere., Apr. 2016, 93, 2, 379, 396, Scientific journal, 10.1112/jlms/jdw004

  DOI URL
• Refereed, TOPOLOGY AND ITS APPLICATIONS, ELSEVIER SCIENCE BV, Bridge splittings of links with distance exactly n, Ayako Ido; Yeonhee Jang; Tsuyoshi Kobayashi, We show that, for any integers n >= 2, g >= 0 and b >= 1 except for (g, b) = (0,1) and (0, 2), there exists a (g, b)-bridge splitting of a link in some manifold with distance exactly n. (C) 2015 Elsevier B.V. All rights reserved., Dec. 2015, 196, 608, 617, Scientific journal, 10.1016/j.topol.2015.05.028

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• Refereed, PACIFIC JOURNAL OF MATHEMATICS, PACIFIC JOURNAL MATHEMATICS, Distance of bridge surfaces for links with essential meridional spheres, Yeonhee Jang, Bachman and Schleimer gave an upper bound for the distance of a bridge surface of a knot in a 3-manifold which admits an essential surface in the exterior. Here we give a sharper upper bound for the distance of a bridge surface of a link when the manifold admits an essential meridional sphere in the exterior., Jan. 2014, 267, 1, 121, 130, Scientific journal, 10.2140/pjm.2014.267.121

  DOI URL
• Refereed, ALGEBRAIC AND GEOMETRIC TOPOLOGY, GEOMETRY & TOPOLOGY PUBLICATIONS, Heegaard splittings of distance exactly n, Ayako Ido; Yeonhee Jang; Tsuyoshi Kobayashi, In this paper, we show that, for any integers n >= 2 and g >= 2, there exist genus-g Heegaard splittings of compact 3-manifolds with distance exactly n., 2014, 14, 3, 1395, 1411, Scientific journal, 10.2140/agt.2014.14.1395

  DOI URL
• Refereed, Journal of the Mathematical Society of Japan, Classification of 3-bridge spheres of 3-bridge arborescent links, Yeonhee Jang, In this paper, we give an isotopy classification of 3-bridge spheres of 3-bridge arborescent links, which are not Montesinos links. To this end, we prove a certain refinement of a theorem of J. S. Birman and H. M. Hilden [3] on the relation between bridge presentations of links and Heegaard splittings of 3-manifolds. In the proof of this result, we also give an answer to a question by K. Morimoto [23] on the classification of genus-2 Heegaard splittings of certain graph manifolds. © 2013 The Mathematical Society of Japan., 2013, 65, 1, 97, 136, Scientific journal, 10.2969/jmsj/06510097

  DOI URL
• Refereed, Illinois Journal of Mathematics, A G-family of quandles and handlebody-knots, Atsushi Ishii; Masahide Iwakiri; Yeonhee Jang; Kanako Oshiro, 2013, 57, 3, 817, 838
• Refereed, JOURNAL OF KNOT THEORY AND ITS RAMIFICATIONS, WORLD SCIENTIFIC PUBL CO PTE LTD, Symmetric quandle colorings for spatial graphs and handlebody-links, Yeonhee Jang; Kanako Oshiro, In this paper, colorings by symmetric quandles for spatial graphs and handlebody-links are introduced. We also introduce colorings by LH-quandles for LH-links. LH-links are handlebody-links, some of whose circle components are specified, which are related to Heegaard splittings of link exteriors. We also discuss quandle (co)homology groups and cocycle invariants., Apr. 2012, 21, 4, Scientific journal, 10.1142/S0218216511010024

  DOI URL
• Refereed, TOPOLOGY AND ITS APPLICATIONS, ELSEVIER SCIENCE BV, Characterization of 3-bridge links with infinitely many 3-bridge spheres, Yeonhee Jang, In an earlier paper, the author constructed an infinite family of 3-bridge links each of which admits infinitely many 3-bridge spheres up to isotopy. In this paper, we prove that if a prime, unsplittable link L in S-3 admits infinitely many 3-bridge spheres up to isotopy then L belongs to the family. (C) 2011 Elsevier B.V. All rights reserved., Mar. 2012, 159, 4, 1132, 1145, Scientific journal, 10.1016/j.topol.2011.11.033

  DOI URL
• Refereed, HIROSHIMA MATHEMATICAL JOURNAL, HIROSHIMA UNIV, GRAD SCH SCI, Classification of 3-bridge arborescent links, Yeonhee Jang, In this paper, we give a complete classification of 3-bridge arborescent links., Mar. 2011, 41, 1, 89, 136, Scientific journal
• Refereed, TOPOLOGY AND ITS APPLICATIONS, ELSEVIER SCIENCE BV, Three-bridge links with infinitely many three-bridge spheres, Yeonhee Jang, we construct infinitely many three-bridge links each of which admits infinitely many three-bridge spheres up to isotopy. (C) 2009 Elsevier B.V. All rights reserved., Jan. 2010, 157, 1, 165, 172, Scientific journal, 10.1016/j.topol.2009.04.060

  DOI URL
• Refereed, Journal of Knot Theory and Its Ramifications, On 2-twist-spun spherical Montesinos knots, Yeonhee Jang; Misaki Kataoka; Rika Miyakoshi, Dec. 2020, 29, 14, Scientific journal
• Refereed, Geometriae Dedicata, Double branched covers of tunnel number one knots, Yeonhee Jang; Luisa Paoluzzi, Apr. 2021, 211, 1, 129, 143, Scientific journal

MISC

• Not Refereed, RIMS kokyuroku, Extending geodesics in the curve complex, 張 娟姫; Ayako Ido; Tsuyoshi Kobayashi, 2013, 1836, 1, 6
• Not Refereed, RIMS kokyuroku, (1,1)-bridge splitting with distance exactly n, 張 娟姫; Ayako Ido; Tsuyoshi Kobayashi, 2013, 1868, 32, 37
• Not Refereed, 京都大学数理解析研究所講究録, Stabilization of bridge decompositions of knots and bridge positions of knot types, Yeonhee Jang; Tsuyoshi Kobayashi; Makoto Ozawa; Takao Kazuto, 2019, 2135, 23, 28
• Not Refereed, 京都大学数理解析研究所講究録, A note on the paper "A knot with destabilized bridge spheres of arbitrarily high bridge number", Yeonhee Jang; Tsuyoshi Kobayashi; Makoto Ozawa; Takao Kazuto, 2018, 2099, 89, 104
• Not Refereed, 京都大学数理解析研究所講究録, On keen weakly reducible bridge splittings of links, Ayako Ido; Yeonhee Jang; Tsuyoshi Kobayashi, 2023, 2263, 79, 86

Presentations

• Oral presentation
• Women in Mathematics - a Panorama of Contributions, Bridge splittings of links as viewed from the curve complex, 2017
• The 6th TAPU-KOOK Joint Seminar on Knots and Related Topics, Knots with non-minimal dstabilized bridge spheres, 2014
• A Satellite Conference of Seoul ICM 2014: Knots and Low Dimensional Manifolds, Bridge splittings of links with Hempel distance n, 2014
• Yeonhee Jang, The 13th KOOK-TAPU Joint Seminar on Knots and Related Topics, On keen bridge splittings, Invited oral presentation, 27 Jul. 2022, 26 Jul. 2022, 28 Jul. 2022
• Yeonhee Jang, Iberoamerican and Pan Pacific International Conference on Topology and its Applications, On keen bridge splittings of links, Oral presentation, 11 Sep. 2023, 11 Sep. 2023, 14 Sep. 2023
• Yeonhee Jang, Intelligence of Low-dimensional Topology 2023, On keen bridge splittings of links, Oral presentation, 26 May 2023, 24 May 2023, 26 May 2023
• Workshop on topology and geometry of 3-manifolds, Keenness for Heegaard splittings of 3-manifolds and bridge splittings of links, Invited oral presentation, 06 Oct. 2023

Research Projects

• 21K20328, Principal investigator
• 21K20328, Principal investigator
• 基盤研究(C), 01 Apr. 2022, 31 Mar. 2026, 22K03313, 大域構造の空間を基軸とする低次元トポロジーの研究とその応用, 小林 毅; 村井 紘子; 張 娟姫, 日本学術振興会, 科学研究費助成事業, 奈良女子大学, 3250000, 2500000, 750000, kaken

  対象リソースIRI
• 研究活動スタート支援, 30 Aug. 2021, 31 Mar. 2023, 21K20328, ヘガード理論に基づく3次元多様体と絡み目の研究, 張 娟姫, 日本学術振興会, 科学研究費助成事業, 奈良女子大学, 1950000, 1500000, 450000, 本研究の目的は、ヘガード理論の観点を用いて3次元多様体と絡み目の様々な性質やその関係を明確にさせることである。特に、3次元多様体のヘガード分解と絡み目の橋分解の複雑さを表す指標の一つである「Hempel距離」という概念と多様体および絡み目の幾何的性質や対称性等がどう関係しているかを明らかにすることを目標の一つとして設定していた。それに関して、小林毅氏、井戸絢子氏と共同研究を行い、keenおよびstrongly keenな橋分解について調べた結果、任意の自然数nとb、任意の正の整数gに対して、(g,b)=(0,1)または(g,b,n)=(0,3,1)の場合を除き、strongly keenな(g,b)-橋分解で距離nのものが存在することが証明できた。また、(g,b,n)=(0,3,1)の場合については、どんな距離1の(0,3)-橋分解もkeenにはなれないという、興味深い結果を得ることもできた。また、weakly keenであってstrongly keenでないようなHeegaard分解および橋分解を構成する方法についても、現在も研究が継続中である。, kaken

  対象リソースIRI
• Grant-in-Aid for Research Activity Start-up, 30 Aug. 2013, 31 Mar. 2015, 25887039, Research on distances of Heegaard splittings of 3-manifolds and bridge splittings of links, JANG Yeonhee, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research, Nara Women's University, 2730000, 2100000, 630000, We proved that, for any integer n greater than 1, there exist Heegaard splittings of 3-manifolds and bridge splittings of links whose Hempel distance is exactly n. Moreover, we showed the existence of Heegaard splittings for which there is a unique pair of disks realizing the distance. Also, we focused on the fact that relationship between bridge splittings of a knot can be described by a graph, and showed that a new type of graph can describe such relationship of a certain knot, which is an interesting example admitting bridge splittings that are locally minimal but not globally minimal., kaken

  対象リソースIRI