Future Talks
 
Talks in 2018

2018/11/07: 
Lecture at Pusan National University
Graph eigenvalues and graph structure (II)
Place: Pusan National University, Korea

2018/11/06: 
Lecture at Pusan National University
Graph eigenvalues and graph structure (I)
Place: Pusan National University, Korea

2018/10/12-13 (13): 
Open Seminar on Combinatorics and Financial Mathematics
Combinatorial structure and algebraic structure on graphs
Place: Gyeongju, Korea

2018/05/20-24 (21): 
Japanese Conference on Combinatorics and its Applications 2018 (JCCA 2018)
"On the partial order competition dimension and the chromatic number of a graph"
Place: 仙台国際センター

2018/02/12-15 (13): 
2018年軽井沢グラフと解析研究集会
"グラフの固有値と辺着色"
Place: 日本大学軽井沢研修所
 
Talks in 2017
  
2017/12/19-21:  
数学特別講義B2 (集中講義) 15h 
"グラフ・マトロイド・組合せ最適化"
Place: 熊本大学
 
2017/12/07: 
近畿大学数学教室講演会
"グラフの最小固有値とグラフ構造"
Place: 近畿大学
 
Talks in 2016

2016/05/21-25 (22):
The Japanese Conference on Combinatorics and its Applications (JCCA 2016)
"Travel groupoids and combinatorial structures on a graph"
Place: Kyoto University, Japan
 
2016/03/04:
山本芳嗣先生ご退職記念シンポジウム「最適化:新たな価値創造のためのモデルとアルゴリズム」
"マトロイドとマッチング" (in 筑波大教員セッション)
Place: 筑波大学

2016/02/29:
早稲田大学数学若手異分野交流会2016
"Travel groupoids and combinatorial structures on graphs"
"トラベル・グルーポイドとグラフ上の組合せ構造"
Place: Waseda University (早稲田大学), Japan
 
Talks in 2015

2015/09/14-16 (16):
18th Japan Conference on Discrete and Computational Geometry and Graphs (JCDCG^2 2015)
"On the competition numbers of diamond-free graphs"
Place: Kyoto University, Japan

2015/09/13-16 (13):
MSJ Fall Meeting 2015
日本数学会2015年度秋季総合分科会
"On the competition numbers of diamond-free graphs"
"ダイアモンドを含まないグラフの競争数について"
Place: Kyoto Sangyo University (京都産業大学), Japan

2015/09/03-06 (04):
Combinatorics Summer School 2015 (COS 2015)
組合せ論サマースクール2015 (オープンプロブレムセッション)
"On the competition numbers of claw-free graphs"
"クローを含まないグラフの競争数について"
Place: Gumma (群馬、伊香保温泉), Japan

2015/09/03-06 (04):
Combinatorics Summer School 2015 (COS 2015)
組合せ論サマースクール2015
"On the competition numbers of diamond-free graphs"
"ダイアモンドを含まないグラフの競争数について"
Place: Gumma (群馬、伊香保温泉), Japan

2015/06/02-05 (03): 
The 9th Hungarian-Japanese Symposium on Discrete Mathematics and Its Applications
"Fat Hoffman graphs with smallest eigenvalue at least -2.481194304092..."
Place: Fukuoka, Japan
 
2015/03/13-15 (15): 
The Third Workshop on Spectral Graph Theory and Related Topics 
スペクトラルグラフ理論および周辺領域第3回研究集会
"On graphs with smallest eigenvalue bounded from below"
"最小固有値を下から制限したグラフについて"
Place: Hiroshima Institute of Technology (広島工業大学), Japan
 

2015/03/10: 
システム情報系若手融合研究プロジェクト2014年度研究成果発表会
"Decision making and optimization on systems containing gaps between micro and macro levels"
"ミクロとマクロのギャップを内包したシステムにおける意思決定と最適化" 
Place: University of Tsukuba (筑波大学), Japan

2015/03/06-07 (06):
Workshop on Finite Geometry and Combinatorial Design
研究集会「有限幾何と組合せデザイン」
"On gregarious group divisible designs"
Place: Tokyo University of Science (東京理科大学), Japan
 
Talks in 2014
 
2014/12/18-20 (19):
2014年度応用数学合同研究集会
"Combinatorial systems and travel groupoids on graphs"
Place: Ryukoku Univiersity (龍谷大学), Japan
 
2014/09/18:
Colloquium at Department of Mathematics, Pusan National University
"Travel groupoids on graphs"
Place: Pusan National University, Korea

2014/08/22: 
Urban Operations Research (UOR) Summer Seminar 2014
"Graph eigenvalues and graph structure" (in Japanese)
"グラフの固有値とグラフ構造"
Place: University of Tsukuba (筑波大学), Japan

2014/03/15-18 (15):
MSJ Spring Meeting 2014
日本数学会 2014年度年会
"The non-confusing travel groupoids on a finite connected graph"
Place: Gakushuin University (学習院大学), Japan

2014/03/15-18 (15):
MSJ Spring Meeting 2014
日本数学会 2014年度年会
"Travel groupoids on infinite graphs"
Place: Gakushuin University (学習院大学), Japan

2014/02/14:
Osaka Combinatorics Seminar
第21回大阪組合せ論セミナー
"Linear Matroids and Matroid Connectivity"
線形マトロイドとマトロイド連結性
+ "Matroids on convex geometries (cg-matroids)"
Place: Osaka (大阪), Japan

2014/01/23-25 (25):
The 12th Korea-Japan Workshop on Algebra and Combinatorics (KJ2014)
"Travel groupoids on graphs"
Place: KAIST, Korea
 
Talks in 2013

2013/12/06:
Combinatorial Mathematics Seminar
組合せ数学セミナー
"Travel groupoids on graphs" (in Japanese)
グラフ上のトラベル・グルーポイドについて
Place: The University of Tokyo (東京大学), Japan

2013/11/18-22 (19): 
25th Workshop on Topological Graph Theory (TGT25)
"On intersection graphs associated with digraphs and posets"
Place: Yokohama National University, Japan

2013/11/13-15 (14): 
研究集会「組合せ論とその実験計画法への応用」
"Travel groupoids on graphs" (in Japanese)
Place: Kumamoto (熊本), Japan
 
2013/10/26-28 (27):
組合せ最適化セミナー秋合宿
"最近勉強していること(線形代数的グラフ・アルゴリズム)"
Place: Kagoshima (鹿児島), Japan

2013/09/17-19 (19):
The 16th Japan Conference on Discrete and Computational Geometry and Graphs (JCDCG^2 2013)
"The number of travel groupoids on a finite graph"
Place: Tokyo University of Science, Japan
 
2013/09/17-19 (17):
The 16th Japan Conference on Discrete and Computational Geometry and Graphs (JCDCG^2 2013)
"The double multicompetition number of a multigraph"
Place: Tokyo University of Science, Japan

2013/09/10-14 (13):
Graph Theory Conference in honor of Yoshimi Egawa on the occasion of his 60th birthday
"The non-confusing travel groupoids on a finite connected graph"
Place: Tokyo University of Science, Japan

2013/01/05-06 (06):
The First Workshop on Algebraic Graph Theory, Spectral Graph Theory and Related Topics
"On graphs with bounded smallest eigenvalue"
Place: Nagoya University, Japan

Talks in 2012

2012/12/21: 
Mathematical Optimization Seminar
数理最適化院生ゼミ
"Matroids on convex geometries (cg-matroids)" (in Japanese)
Place: University of Tsukuba (筑波大学), Japan

2012/12/06-08 (07): 
"A general model for competition graphs and the competition numbers"
Place: Srinakharinwirot University, Bangkok, Thailand

2012/11/02: 
Combinatorial Mathematics Seminar
組合せ数学セミナー
"On graphs with bounded smallest eigenvalue" (in Japanese)
最小固有値を制限したグラフについて
Place: University of Tokyo (東京大学), Japan

2012/10/23: 
Discrete Optimization Seminar
Place: RIMS, Kyoto University, Japan

2012/06/18-21 (21): 
"Fat Hoffman graphs with smallest eigenvalue at least-1-τ"
Place: Dalhousie University, Halifax, Nova Scotia, Canada

2012/05/18-19 (18): 
"Fat Hoffman graphs with smallest eigenvalue at least-1-τ"
Place: University of Toronto, Canada

2012/05/10: 
Algebraic Combinatorics Seminar 
"On graphs with bounded smallest eigenvalue: Hoffman graphs and generalizations of line graphs"

2012/03/26-29 (27): 
"Fat Hoffman graphs with smallest eigenvalue at least -1-τ"
Place: Tokyo University of Science (東京理科大学), Japan

2012/03/26-29 (27): 
"The non-bipartite integral graphs with spectral radius three"
Place: Tokyo University of Science (東京理科大学), Japan
 
2012/02/22-24 (23): 
"On integral graphs with smallest eigenvalue -2 and generalized signless Laplacians"
Place: Keio University (慶應義塾大学), Japan

2012/01/26-28 (26): 
"Fat Hoffman graphs with smallest eigenvalue at least -1-τ"
Place: POSTECH, Korea

Talks in 2011

2011/10/17: 
NIMS Seminar (invited talk)
"Matroids on convex geometries"

2011/09/19: 
"On integral generalized line graphs and generalized signless Laplacians"
Place: Shanghai Jiao Tong University, China 

2011/09/15-18 (18): 
"The competition number of a graph and the holes in the graph"
Place: Shanghai Jiao Tong University, China 

2011/08/14-19 (19): 
"On integral graphs with smallest eigenvalue -2 and generalized signless Laplacians"
Place: Oisterwijk, Netherlands 

2011/07/31-08/02 (1): 
Workshop on Discrete Mathematics and its Applications 2011 
"The competition number of a graph and the holes in the graph" (in Japanese)
Place: Nara, Japan

2011/06/13: 
The 46th KNU-PNU-PMI Combinatorics Seminar (invited talk)
"On the configuration algebra associated with colored graphs, Part 2"
Place: Kyungpook National University, Korea

2011/05/07: 
The 45th KNU-PNU-PMI Combinatorics Seminar (invited talk)
"On the configuration algebra associated with colored graphs"
Place: POSTECH, Korea

2011/04/27: 
Matsue Seminar
松江セミナー 
"On the competition numbers of graphs" (in Japanese)
グラフの競争数について
Place: Shimane University (島根大学), Matsue, Japan 

2011/01/24-25 (24): 
"The non-bipartite integral graphs with spectral radius three"
Place: Tohoku University (東北大学), Sendai, Japan 

2011/01/17: 
Oberseminar Diskrete Optimierung (invited talk)
"Matroids on convex geometries"

Talks in 2010

2010/11/20: 
6th Logic and Calculus & 4th Combinatorial Mathematics Joint Seminar
第6回論理と計算セミナー&2010年度第4回組合せ数学セミナー・合同セミナー
"On the competition numbers of graphs" (in Japanese)
グラフの競争数
Place: Kyushu University (九州大学), Japan

2010/09/29: 
POSTECH T-Seminar
"On the second $\Gamma$-cones of a path $\Gamma$"
Place: POSTECH, Korea

2010/09/22-25 (22): 
"On the CCE graphs of digraphs satisfying Conditions C(p) and C'(p)" (in Japanese)
Place: Nagoya University (名古屋大学), Japan

2010/07/12-16 (13): 
"On the second $\Gamma$-cones of a path $\Gamma$"
Place: Gyeongju Concorde Hotel, Korea

2010/05/14: 
KAIST Discrete Math Seminar (invited talk)
"Matroids on convex geometries"
Place: KAIST, Korea

2010/05/01: 
"Matroids on convex geometries: Subclasses, operations, and optimization"
Place: Pohang University of Science and Technology (POSTECH), Korea

2010/03/16-18 (17): 
Mini-Workshop on Algebraic Combinatorics 
"The competition-common enemy graphs of digraphs satisfying the conditions C(p) and C'(p)" (in Japanese)
Place: Kobe Gakuin University (神戸学院大学), Japan

2010/03/08-12 (10): 
"The competition-common enemy graphs of digraphs satisfying the conditions C(p) and C'(p)"
Place: Florida Atlantic University, USA

Talks in 2009

2009/11/19: 
The 17th GCOE tea time
"Matroids and optimization" (in Japanese)
マトロイドと最適化
Place: Kyoto University (京都大学), Japan

2009/10/30: 
Seminar on Combinatorial Optimization
"A talk on cg-matroids, and a talk on the competition numbers of graphs" (in Japanese)
Place: Aoyama Gakuin University (青山学院大学), Japan

2009/09/24-27 (24): 
"Cycles and p-competition graphs" (in Japanese)
サイクルとp-競争グラフ
Place: Osaka University (大阪大学), Japan

2009/09/24-27 (24): 
"The competition numbers of regular polyhedra" (in Japanese)
正多面体の競争数
Place: Osaka University (大阪大学), Japan

2009/08/01-13 (9): 
"Graphical Arrangements and Braid Arrangements"
Place: Hokkaido University (北海道大学), Japan

2009/07/22-24 (22): 
"On the rank functions of H-matroids" (in Japanese)
Hマトロイドの階数関数について
Place: RIMS, Kyoto University (京都大学), Japan

2009/05/30-31 (30): 
SCOPE for young researchers, The Operations Research Society of Japan 
"Restriction and contraction on matroids defined on convex geometries" (in Japanese)
凸幾何上に定義されたマトロイドにおける制限と縮約
Place: University of Tsukuba (筑波大学), Japan

2009/05/16-19 (17): 
"Subclasses of cg-matroids"
Place : Budapest, Hungary 

2009/04/25: 
2009 Spring, Korean Mathematical Society
"The Competition Numbers of Regular Polyhedra"
Place : Ajou University, Korea

2009/03/26-29 (26): 
2009 Spring, Mathematical Society of Japan
日本数学会 2009年度年会
"On the structure of matroids defined on convex geometries II" (in Japanese)
凸幾何上に定義されたマトロイド構造について II
Place : The University of Tokyo (東京大学), Japan

2009/03/26-29 (26): 
2009 Spring, Mathematical Society of Japan
日本数学会 2009年度年会
"On the competition number of a graph and the number of induced cycle of length at least 4" (in Japanese)
グラフの競争数と長さ4以上の誘導サイクルの数について
Place : The University of Tokyo (東京大学), Japan

2009/03/14: 
Kagawa Seminar
"Matroids, Convexity, Discrete Optimization" (in Japanese)
マトロイド・凸・離散最適化
Place : Kagawa University (香川大学), Japan

2009/03/02-06 (03): 
"The Competition Numbers of Regular Polyhedra"
Place : Florida Atlantic University, USA

2009/02/16-17 (17): 
The 6th RIMS-Kyoto U. and SNU Joint Symposium on Mathematics : Poster session
"The competition numbers of complete multipartite graphs"
Place : Seoul National University, Korea

2009/02/16-17 (16): 
The 6th RIMS-Kyoto U. and SNU Joint Symposium on Mathematics : Presentation
"The competition numbers of complete multipartite graphs"
Place : Seoul National University, Korea

2009/02/09-11 (11): 
The 6th Japan-Korea Workshop on Algebra and Combinatorics, 
The 1st Kumjung Seminar (a satellite seminar)
"The competition number of a graph in the aspects of the number of holes"
Place : Pusan National University, Korea

2009/02/03-05 (04): 
The 5th Combinatorics Workshop for Young Researchers
第5回組合せ論若手研究集会
"On the competition number of a graph and the number of induced cycle of length at least 4" (in Japanese)
Place : Keio University (慶應義塾大学), Japan

2009/01/05-16 (08): 
"The competition numbers of complete multipartite graphs"
Place : The University of Western Australia, Perth, Australia

Talks in 2008

2008/12/07-13 (11): 
"On the rank functions of H-matroids"
Place : Oaxaca, Mexico

2008/11/14: 
Combinatorial Mathematics Seminar (invited talk) 
組合せ数学セミナー
"On the competition number of a graph" (in Japanese)
グラフの競争数について
Place : The University of Tokyo, Japan

2008/10/23-25 (23): 
"On the rank functions of H-matroids"
Place : Jeju International Convention Center, Jeju Island, Korea

2008/10/11-12 (11): 
KSMAP meeting for young researchers in Asuka village
KSMAP, The Operations Research Society of Japan
若手研究交流会(KSMAP合宿 in 明日香村)
日本OR学会「若手によるOR横断研究」研究部会
"On the rank functions of H-matroids" (poster session)
Place : Asuka Institute of Kansai University Ueda Memorial Hall, Japan 

2008/09/29-10/03 (30): 
RIMS joint research; Analysis and Geometry on Graphs -degree conditions and factors-
RIMS共同研究 「次数条件と因子が支配するグラフの幾何と解析」
"On the competition numbers of complete multipartite graphs" (in Japanese)
完全多部グラフの競争数について
Place : RIMS, Kyoto University, Japan

2008/09/24-27 (24): 
2008 Fall, Mathematical Society of Japan
日本数学会 2008年度秋季総合分科会
"On the structure of matroids defined on convex geometries" (in Japanese)
凸幾何上に定義されたマトロイド構造について
Place : Tokyo Institute of Technology (東京工業大学), Japan

2008/09/24-27 (24): 
2008 Fall, Mathematical Society of Japan
日本数学会 2008年度秋季総合分科会
"The competition numbers of complete tripartite graphs" (in Japanese)
完全3部グラフの競争数
Place : Tokyo Institute of Technology (東京工業大学), Japan

2008/09/18-20 (18) : 
The 5th Japan-Korea Workshop on Algebra and Combinatorics,
Young Seminar on Algebra and Combinatorics 2008 (a satellite seminar)
"On the competition numbers of complete multipartite graphs"
Place : Kyushu University (九州大学), Japan

2008/09/07-10 (10) : 
組合せ論サマースクール2008
"Competition graphs and the competition numbers of graphs" (in Japanese)
競争グラフとグラフの競争数
Place : Culture Resort Festone, Okinawa, Japan

2008/07/23-25 (23): 
"Matroids on convex geometries and the greedy algorithm" (in Japanese)
凸幾何上のマトロイドと貪欲アルゴリズム
Place : RIMS, Kyoto University (京都大学), Japan

2008/05/31-06/01 (31): 
Seminar on Advanced Computation and Optimization (S@CO) for young researchers 
"Competition graphs and the competition numbers of graphs" (in Japanese)
競争グラフとグラフの競争数
Place : University of Tsukuba (筑波大学), Japan

2008/02/25-29 (25): 
"Matroids on convex geometries"

Talks in 2007

2007/10/01-12 (12): 
DAAD Summer School 2007 (students' presentation)
"Optimal Graph Realizations of Distances"

2007/08/06-08 (08): 
"The greedy algorithm for strict cg-matroids"
Place: KAIST, Korea

2007/07/26: 
"The greedy algorithm for strict cg-matroids"
Place: Pusan National University, Korea

2007/04/21: 
2007 Spring, Korean Mathematical Society
"Weighted Competition Graphs"
Place: Inha University, Korea

2007/04/03-05 (04): 
"The greedy algorithm for strict cg-matroids"
Place: Tohoku University, Japan

2007/02/13-14 (13): 
The 4th RIMS-SNU Joint Symposium : Poster session
"Weighted Competition Graphs"
Place : Seoul National University, Korea

2007/02/10-11 (10): 
The 2nd Korea-Japan Workshop : Algebra and Combinatorics (invited talk)
"Weighted Competition Graphs"
Place: Pusan National University, Korea

2007/01/26-29 (27): 
Scale-free networks and Random Graphs (impromptu talk)
"Competition graphs and Opsut's conjecture" (in Japanese)
Place: Kyoto Keihanna Plaza, Japan

Talks in 2006

2006/09/23: 
"Matroids on convex geometries"
Place: Pusan National University, Korea

2006/05/27-28 (27): 
Seminar on Advanced Computation and Optimization (S@CO) for young researchers 
"Matroids on convex geometries" (in Japanese)
Place: University of Tsukuba (筑波大学), Japan

2006/05/06: 
"Cones of Graphs"
Place: Pohang University of Science and Technology (POSTECH), Korea

2006/02/21-22 (21): 
The 3rd RIMS-SNU Joint Symposium : Poster session
"$\Gamma$-cones and Enumeration"
Place: Kyoto University (京都大学), Japan

The number of my talks

 
Talks in 2018: 5
Talks in 2017: 2
Talks in 2016: 3
Talks in 2015: 8
Talks in 2014: 7
Talks in 2013: 8
Talks in 2012: 11
Talks in 2011: 10
Talks in 2010: 8
Talks in 2009: 18
Talks in 2008: 12
Talks in 2007: 8
Talks in 2006: 4

Total: 104