Basic Information

Faculty

• 工学部

Professional Memberships

• The Japan Society for Industrial and Applied Mathematics
• The Operations Research Society of Japan

Academic Degree

• 修士（情報理工学）(東京大学)
• 博士（情報理工学）(東京大学)

Research History

• From Mar. 2020, To Present

  Kyoto University, Graduate School of Informatics Department of Communications and Computer Engineering, 助教
• From Apr. 2019, To Feb. 2020

  Research Fellow of the Japan Society for the Promotion of Science (PD)
• From Apr. 2016, To Mar. 2019

  Research Fellow of the Japan Society for the Promotion of Science (DC1)
• From Jun. 2014, To Feb. 2016

  JST ERATO Kawarabayashi Large Graph Project, The Network Graph Theories and Optimization Group, Research Assistant

Language of Instruction

• Japanese

ID,URL

• ORCID ID

  0000-0002-6794-3543

• J-Global ID

  202001013047262993

• Researcher number

  70854602

• External link

  http://www.lab2.kuis.kyoto-u.ac.jp/iwamasa/

Website(s) (URL(s))

• http://www.lab2.kuis.kyoto-u.ac.jp/iwamasa/

researchmap URL

• https://researchmap.jp/yuni_iwamasa

Research

Research Interests

• Discrete Structure
• Discrete Mathematics
• Combinatorial Optimization

Research Areas

• Informatics, Information theory
• Informatics, Mathematical informatics

Papers

• Basis sequence reconfiguration in the union of matroids

  Tesshu Hanaka; Yuni Iwamasa; Yasuaki Kobayashi; Yuto Okada; Rin Saito

  Proceedings of the 35th International Symposium on Algorithms and Computation (ISAAC 2024), 2024, Peer-reviewed

  
• Finding a maximum restricted $t$-matching via Boolean edge-CSP

  Yuni Iwamasa; Yusuke Kobayashi; Kenjiro Takazawa

  Proceedings of the 32nd Annual European Symposium on Algorithms (ESA 2024), 2024, Peer-reviewed

  
• Characterizations of the set of integer points in an integral bisubmodular polyhedron

  Yuni Iwamasa

  Discrete Mathematics, 2024, Peer-reviewed

  
• Rerouting planar curves and disjoint paths

  Takehiro Ito; Yuni Iwamasa; Naonori Kakimura; Yusuke Kobayashi; Shun-ichi Maezawa; Yuta Nozaki; Yoshio Okamoto; Kenta Ozeki

  Proceedings of the 50th EATCS International Colloquium on Automata, Languages and Programming (ICALP 2023), 2023, Peer-reviewed

  
• Reconfiguration of time-respecting arborescences

  Takehiro Ito; Yuni Iwamasa; Naoyuki Kamiyama; Yasuaki Kobayashi; Yusuke Kobayashi; Shun-ichi Maezawa; Akira Suzuki

  Proceedings of the 18th Algorithms and Data Structures Symposium (WADS 2023), 2023, Peer-reviewed

  
• A combinatorial algorithm for computing the entire sequence of the maximum degree of minors of a generic partitioned polynomial matrix with $$2 \times 2$$ submatrices

  Yuni Iwamasa

  Mathematical Programming, Series A, 2024, Peer-reviewed

  
• Reconfiguration of colorings in triangulations of the sphere

  Takehiro Ito; Yuni Iwamasa; Yusuke Kobayashi; Shun-ichi Maezawa; Yuta Nozaki; Yoshio Okamoto; Kenta Ozeki

  Proceedings of the 39th International Symposium on Computational Geometry (SoCG 2023), 2023, Peer-reviewed

  
• Reconfiguring (non-spanning) arborescences

  Takehiro Ito; Yuni Iwamasa; Yasuaki Kobayashi; Yu Nakahata; Yota Otachi; Kunihiro Wasa

  Theoretical Computer Science, 2023, Peer-reviewed

  
• Algorithms for coloring reconfiguration under recolorability digraphs

  Soichiro Fujii; Yuni Iwamasa; Kei Kimura; Akira Suzuki

  Proceedings of the 33rd International Symposium on Algorithms and Computation (ISAAC 2022), 2022, Peer-reviewed

  
• Monotone edge flips to an orientation of maximum edge-connectivity à la Nash-Williams

  Takehiro Ito; Yuni Iwamasa; Naonori Kakimura; Naoyuki Kamiyama; Yusuke Kobayashi; Shun-Ichi Maezawa; Yuta Nozaki; Yoshio Okamoto; Kenta Ozeki

  ACM Transactions on Algorithms, 2023, Peer-reviewed

  
• Independent set reconfiguration on directed graphs

  Takehiro Ito; Yuni Iwamasa; Yasuaki Kobayashi; Yu Nakahata; Yota Otachi; Masahiro Takahashi; Kunihiro Wasa

  Proceedings of the 47th International Symposium on Mathematical Foundations of Computer Science (MFCS 2022), 2022, Peer-reviewed

  
• Reforming an envy-free matching

  Takehiro Ito; Yuni Iwamasa; Naonori Kakimura; Naoyuki Kamiyama; Yusuke Kobayashi; Yuta Nozaki; Yoshio Okamoto; Kenta Ozeki

  Proceedings of the 36th AAAI Conference on Artificial Intelligence (AAAI 2022), 2022, Peer-reviewed

  
• Monotone edge flips to an orientation of maximum edge-connectivity à la Nash-Williams

  Takehiro Ito; Yuni Iwamasa; Naonori Kakimura; Naoyuki Kamiyama; Yusuke Kobayashi; Shun-ichi Maezawa; Yuta Nozaki; Yoshio Okamoto; Kenta Ozeki

  Proceedings of the 2022 ACM-SIAM Symposium on Discrete Algorithms (SODA 2022), 2022, Peer-reviewed

  
• A combinatorial algorithm for computing the rank of a generic partitioned matrix with $2 \times 2$ submatrices

  Hiroshi Hirai; Yuni Iwamasa

  Mathematical Programming, Series A, 2022, Peer-reviewed

  
• Quantaloidal Approach to Constraint Satisfaction

  Soichiro Fujii; Yuni Iwamasa; Kei Kimura

  Electronic Proceedings in Theoretical Computer Science, 2022, Peer-reviewed

  
• Optimal matroid bases with intersection constraints: valuated matroids, M-convex functions, and their applications

  Yuni Iwamasa; Kenjiro Takazawa

  Mathematical Programming, Series A, 2022, Peer-reviewed

  
• Reconfiguring Directed Trees in a Digraph

  Takehiro Ito; Yuni Iwamasa; Yasuaki Kobayashi; Yu Nakahata; Yota Otachi; Kunihiro Wasa

  Proceedings of the 27th International Computing and Combinatorics Conference (COCOON 2021), 2021, Peer-reviewed

  
• A Combinatorial Algorithm for Computing the Degree of the Determinant of a Generic Partitioned Polynomial Matrix with $2 \times 2$ Submatrices

  Yuni Iwamasa

  Proceedings of the 22nd Conference on Integer Programming and Combinatorial Optimization (IPCO 2021), 2021, Peer-reviewed

  
• Optimal Matroid Bases with Intersection Constraints: Valuated Matroids, M-convex Functions, and Their Applications

  Yuni Iwamasa; Kenjiro Takazawa

  Proceedings of the 16th Annual Conference on Theory and Applications of Models of Computation (TAMC 2020), 2020, Peer-reviewed

  
• A Combinatorial Algorithm for Computing the Rank of a Generic Partitioned Matrix with $2 \times 2$ Submatrices

  Hiroshi Hirai; Yuni Iwamasa

  Proceedings of the 21st Conference on Integer Programming and Combinatorial Optimization (IPCO 2020), 2020, Peer-reviewed

  
• A tractable class of binary VCSPs via M-convex intersection

  Hiroshi Hirai; Yuni Iwamasa; Kazuo Murota; Stanislav Živný

  ACM Transactions on Algorithms, 2019, Peer-reviewed

  
• Reconstructing Phylogenetic Tree From Multipartite Quartet System

  Hiroshi Hirai; Yuni Iwamasa

  Proceedings of the 29th International Symposium on Algorithms and Computation (ISAAC 2018), 2018, Peer-reviewed

  
• Beyond JWP: A Tractable Class of Binary VCSPs via M-Convex Intersection

  Hiroshi Hirai; Yuni Iwamasa; Kazuo Murota; Stanislav Živný

  Proceedings of the 35th International Symposium on Theoretical Aspects of Computer Science (STACS 2018), 2018, Peer-reviewed

  
• Discrete convexity in joint winner property

  Yuni Iwamasa; Kazuo Murota; Stanislav Živný

  Discrete Optimization, 2018, Peer-reviewed

  
• The quadratic M-convexity testing problem

  Yuni Iwamasa

  Discrete Applied Mathematics, 2018, Peer-reviewed

  
• On a general framework for network representability in discrete optimization

  Yuni Iwamasa

  Journal of Combinatorial Optimization, 2018, Peer-reviewed

  
• On a General Framework for Network Representability in Discrete Optimization

  Yuni Iwamasa

  Proceedings of the 4th International Symposium on Combinatorial Optimization (ISCO 2016), 2016, Peer-reviewed

  
• On $k$-submodular relaxation

  Hiroshi Hirai; Yuni Iwamasa

  SIAM Journal on Discrete Mathematics, 2016, Peer-reviewed

  
• Threshold influence model for allocating advertising budgets

  Atsushi Miyauchi; Yuni Iwamasa; Takuro Fukunaga; Naonori Kakimura

  Proceedings of the 32nd International Conference on Machine Learning (ICML 2015), 2015, Peer-reviewed

  
• Networks maximizing the consensus time of voter models

  Yuni Iwamasa; Naoki Masuda

  Physical Review E, 2014, Peer-reviewed

  
• Reconstructing phylogenetic trees from multipartite quartet systems

  Hiroshi Hirai; Yuni Iwamasa

  Algorithmica, 2022, Peer-reviewed

  

Presentations

• 離散凸解析の拡張に向けて

  岩政勇仁

  大阪組合せ論セミナー, Jun. 2024, Invited

  
• 制限付き$t$-マッチング問題に対する制約充足的アプローチ

  岩政 勇仁; 小林 佑輔; 高澤 兼二郎

  第195回アルゴリズム研究発表会, Nov. 2023

  
• Reconfiguration of colorings in triangulations of the sphere

  Takehiro Ito; Yuni Iwamasa; Yusuke Kobayashi; Shun-ichi Maezawa; Yuta Nozaki; Yoshio Okamoto; Kenta Ozeki

  The 39th International Symposium on Computational Geometry (SoCG 2023), Jun. 2023

  
• A combinatorial algorithm for computing the entire sequence of the maximum degree of minors of a generic partitioned polynomial matrix with $2 \times 2$ submatrices

  Yuni Iwamasa

  SIAM Conference on Optimization (OP23), Jun. 2023, Invited

  
• A combinatorial algorithm for computing the entire sequence of the maximum degree of minors of a generic partitioned polynomial matrix with $2 \times 2$ submatrices

  Yuni Iwamasa

  The 12th Japanese-Hungarian Symposium on Discrete Mathematics and Its Applications (JH 2023), Mar. 2023

  
• 整数双劣モジュラ多面体の整数点集合の特徴づけ

  岩政 勇仁

  日本応用数理学会 第19回研究部会連合発表会, Mar. 2023

  
• Algorithms for coloring reconfiguration under recolorability digraphs

  Soichiro Fujii; Yuni Iwamasa; Kei Kimura; Akira Suzuki

  The 33rd International Symposium on Algorithms and Computation (ISAAC 2022), Dec. 2022

  
• 球面の三角形分割の彩色遷移

  伊藤 健洋; 岩政 勇仁; 小林 佑輔; 前澤 俊一; 野崎 雄太; 岡本 吉央; 小関 健太

  2022年度応用数学合同研究集会, Dec. 2022

  
• 球面の三角形分割の彩色遷移

  伊藤 健洋; 岩政 勇仁; 小林 佑輔; 前澤 俊一; 野崎 雄太; 岡本 吉央; 小関 健太

  日本オペレーションズ・リサーチ学会 2022年秋季研究発表会, Sep. 2022

  
• 2部マッチング問題の代数的拡張

  岩政 勇仁

  日本オペレーションズ・リサーチ学会 研究部会「最適化手法とアルゴリズム」, Oct. 2021, Invited

  
• $2 \times 2$型分割多項式行列の行列式次数を求める組合せ的多項式時間アルゴリズム

  岩政 勇仁

  日本応用数理学会 2021年度年会, Sep. 2021

  
• A combinatorial algorithm for computing the degree of the determinant of a generic partitioned polynomial matrix with $2 \times 2$ submatrices

  Yuni Iwamasa

  The 22nd Conference on Integer Programming and Combinatorial Optimization (IPCO 2021), May 2021

  
• 2部マッチング理論の代数的一般化について

  岩政 勇仁

  第32回RAMP数理最適化シンポジウム (RAMP 2020), Oct. 2020, Invited

  
• Optimal matroid bases with intersection constraints: Valuated matroids, M-convex functions, and their applications

  Yuni Iwamasa; Kenjiro Takazawa

  The 16th Annual Conference on Theory and Applications of Models of Computation (TAMC 2020), Oct. 2020

  
• 交叉制約下でのマトロイドの最適基とその一般化

  岩政 勇仁; 高澤 兼二郎

  京都大学数理解析研究所 共同研究（グループ型） 数理最適化の理論・アルゴリズム・応用, Aug. 2020

  
• A combinatorial algorithm for computing the rank of a generic partitioned matrix with $2 × 2$ submatrices

  Hiroshi Hirai; Yuni Iwamasa

  The 21st Conference on Integer Programming and Combinatorial Optimization (IPCO 2020), Jun. 2020

  
• $2 \times 2$型分割行列のランクを求める組合せ的多項式時間アルゴリズム

  平井 広志; 岩政 勇仁

  日本応用数理学会 第16回研究部会連合発表会, Mar. 2020

  
• $2 \times 2$型分割行列のランクを求める組合せ的多項式時間アルゴリズム

  平井 広志; 岩政 勇仁

  日本オペレーションズ・リサーチ学会 研究部会「超スマート社会のシステムデザインのための理論と応用」, Nov. 2019, Invited

  
• Reconstructing phylogenetic tree from multipartite quartet system

  Hirai Hiroshi; Yuni Iwamasa

  The 29th International Symposium on Algorithms and Computation (ISAAC 2018), Dec. 2018

  
• 完全多部四点木システムからの系統樹復元

  平井 広志; 岩政 勇仁

  日本応用数理学会 2018年度年会, Sep. 2018

  
• Discrete convexity in binary VCSPs

  Hiroshi Hirai; Yuni Iwamasa; Kazuo Murota; Stanislav Živný

  The 23rd International Symposium on Mathematical Programming (ISMP 2018), Jul. 2018

  
• Beyond JWP: A tractable class of binary VCSPs via M-convex intersection

  Hiroshi Hirai; Yuni Iwamasa; Kazuo Murota; Stanislav Živný

  The 35th International Symposium on Theoretical Aspects of Computer Science (STACS 2018), Mar. 2018

  
• A tractable class of binary VCSPs via M-convex intersection

  Hiroshi Hirai; Yuni Iwamasa; Kazuo Murota; Stanislav Živný

  電子情報通信学会2018年（平成30年）総合大会 COMP-ELC学生シンポジウム, Mar. 2018

  
• 値付き制約充足問題と離散凸性：2次値付き制約充足問題のM凸交叉による多項式時間可解なクラス

  平井 広志; 岩政 勇仁; 室田 一雄; Stanislav Živný

  日本オペレーションズ･リサーチ学会 研究部会「離散アルゴリズムの応用と理論」, Feb. 2018, Invited

  
• Discrete convexity in joint winner property

  Yuni Iwamasa; Kazuo Murota; Stanislav Živný

  日本応用数理学会 2017年度年会, Sep. 2017

  
• Discrete convexity in valued constraint satisfaction problems: M-convexity and joint winner property

  岩政 勇仁; 室田 一雄; Stanislav Živný

  Japanese Conference on Combinatorics and its Applications (JCCA 2017)・離散数学とその応用研究集会2017, Aug. 2017, Invited

  
• Discrete convexity in joint winner property

  Yuni Iwamasa; Kazuo Murota; Stanislav Živný

  The 19th Conference on Integer Programming and Combinatorial Optimization (IPCO 2017), Jun. 2017

  
• The quadratic M-convexity testing problem

  Yuni Iwamasa

  The 10th Japanese-Hungarian Symposium on Discrete Mathematics and Its Applications (JH 2017), May 2017

  
• 2次関数のM凸性判定問題

  岩政 勇仁

  日本オペレーションズ・リサーチ学会 2017年春季研究発表会（創立60周年記念大会）, Mar. 2017

  
• On a general framework for network representability in discrete optimization

  Yuni Iwamasa

  The 4th International Symposium on Combinatorial Optimization (ISCO 2016), May 2016

  
• M${}^\natural$-convex completion problem

  岩政 勇仁; 室田 一雄

  日本オペレーションズ・リサーチ学会 研究部会「最適化の基盤とフロンティア—未来を担う若手研究者の集い2016—」, May 2016

  
• 関数のネットワーク表現とその拡張について

  岩政 勇仁

  日本オペレーションズ・リサーチ学会 2016年春季研究発表会, Mar. 2016

  
• On $k$-submodular relaxation

  Hiroshi Hirai; Yuni Iwamasa

  The 9th Hungarian-Japanese Symposium on Discrete Mathematics and Its Applications (HJ 2015), Jun. 2015

  
• On $k$-submodular relaxation

  平井 広志; 岩政 勇仁

  日本オペレーションズ・リサーチ学会 研究部会「最適化の基盤とフロンティア—未来を担う若手研究者の集い2015—」, May 2015

  
• 投票者モデルにおける平均合意時間が最大のグラフ

  岩政 勇仁; 増田 直紀

  日本オペレーションズ・リサーチ学会 研究部会「最適化の理論と応用—未来を担う若手研究者の集い2014—」, Jun. 2014

  

External funds: Kakenhi

• マッチング問題の代数的拡張に対する組合せ的アプローチ

  Grant-in-Aid for Research Activity Start-up

  1001:Information science, computer engineering, and related fields

  Kyoto University

  岩政 勇仁

  From 11 Sep. 2020, To 31 Mar. 2024, Granted

  Edmonds問題;重み付きEdmonds問題;非可換Edmonds問題;重み付き非可換Edmonds問題;線形マトロイド交叉;最大最小定理;マトロイド;組合せ最適化;代数的最適化;マッチング理論;アルゴリズム

  https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-20K23323/
• Development of Combinatorial Reconfiguration by Mathematics Approach: From Examples to New Methods

  Grant-in-Aid for Transformative Research Areas (B)

  Transformative Research Areas, Section (IV)

  The University of Electro-Communications

  岡本 吉央

  From 02 Oct. 2020, To 31 Mar. 2023, Granted

  組合せ遷移;数学;離散数学;アルゴリズム;計算複雑性

  https://kaken.nii.ac.jp/grant/KAKENHI-PLANNED-20H05795/
• Exploring novel discrete convexity in discrete optimization and designing high performance algorithms based on it

  Grant-in-Aid for Scientific Research (C)

  The University of Tokyo

  Hiroshi Hirai

  From 01 Apr. 2017, To 31 Mar. 2021, Project Closed

  離散凸解析;劣モジュラ最適化;多項式時間アルゴリズム;代数的アルゴリズム;CAT(0)空間;組合せ最適化

  https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-17K00029/
• 離散凸解析における双対理論の深化

  Grant-in-Aid for Early-Career Scientists

  Basic Section 60020:Mathematical informatics-related

  Kyoto University

  岩政 勇仁

  From 01 Apr. 2022, To 31 Mar. 2027, Granted

  双劣モジュラ関数;共役性;交換公理;単体的複体;組合せ最適化;双対性;離散凸解析

  https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-22K17854/
• 多面体的手法と離散構造を用いた組合せ最適化問題の解法

  Grant-in-Aid for Scientific Research (B)

  Basic Section 60010:Theory of informatics-related

  Kyoto University

  小林 佑輔

  From 01 Apr. 2024, To 31 Mar. 2029, Granted

  組合せ最適化;アルゴリズム

  https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-24K02901/
• 非正曲率空間上の次世代凸最適化

  Grant-in-Aid for Challenging Research (Pioneering)

  Medium-sized Section 60:Information science, computer engineering, and related fields

  Nagoya University

  平井 広志

  From 28 Jun. 2024, To 31 Mar. 2030, Granted

  凸最適化;非正曲率空間;アルゴリズム

  https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-24K21315/

Education

Teaching subject(s)

• From 01 Apr. 2024, To 31 Mar. 2025

  Mathematics in Practice for Computer Science

  9131, Spring, Faculty of Engineering, 2
• From 01 Apr. 2023, To 31 Mar. 2024

  Mathematics in Practice for Computer Science

  9131, Spring, Faculty of Engineering, 2
• From 01 Apr. 2023, To 31 Mar. 2024

  Computer Science Laboratory and Exercise 2

  9022, Fall, Faculty of Engineering, 2
• From 01 Apr. 2022, To 31 Mar. 2023

  Mathematics in Practice for Computer Science

  9131, Spring, Faculty of Engineering, 2
• From 01 Apr. 2022, To 31 Mar. 2023

  Computer Science Laboratory and Exercise 2

  9022, Fall, Faculty of Engineering, 2
• From Apr. 2020, To Mar. 2021

  Computer Science Laboratory and Exercise 1

  Spring, 工学部
• From Apr. 2020, To Mar. 2021

  Computer Science Laboratory and Exercise 1

  Spring, 工学部
• From Apr. 2020, To Mar. 2021

  Computer Science Laboratory and Exercise 2

  Fall, 工学部
• From Apr. 2021, To Mar. 2022

  Computer Science Laboratory and Exercise 1

  Spring, 工学部
• From Apr. 2021, To Mar. 2022

  Computer Science Laboratory and Exercise 1

  Spring, 工学部
• From Apr. 2021, To Mar. 2022

  Mathematics in Practice for Computer Science

  Spring, 工学部

Academic, Social Contribution

Committee Memberships

• From Mar. 2023, To Present

  庶務幹事, 日本オペレーションズ・リサーチ学会
• From Apr. 2022, To Present

  運営委員, 情報処理学会 アルゴリズム研究会
• From Apr. 2024, To Mar. 2025

  事務局, 2024年度LAシンポジウム

Academic Contribution

• The 34th International Symposium on Algorithms and Computation (ISAAC 2023), Local Organizer

  Planning, management, etc.

  From 03 Dec. 2023, To 06 Dec. 2023