2013

• April 14, 2013: Vortrag im Seminar Diskrete Mathematik und Optimierung, Institut für Optimierung und Diskrete Mathematik, Technische Universität Graz, Graz, Austria.
  • Even cycle decompositions of graphs with no odd K₄ minor
• March 20, 2013: Dagstuhl workshop “Bidimensional Structures: Algorithms, Combinatorics and Logic” (March 17-22), Scholss Dagstuhl, Dagstuhl, Germany.
  • Forbidden vertex-minors for graphs of linear rank-width at most k
• January 30, 2013: グラフ・ネットワークにおける理論と最適化グループセミナー (Graph Network Theory and Optimization Group Seminar), National Institute of Informatics, Tokyo, Japan.
  • Well-quasi-ordering conjecture for pivot-minors
• January 22, 2013: KAIST 글로벌 사이언스 리더 캠프 (2012학년도 부산광역시 과학영재교육원 겨울집중수업), KAIST 영재교육센터.
  • 짝지우기, 그래프 이론, 수학

2012

• December 7, 2012: KAIST 일반전형 창의인성면접자 합격생 워크샵 및 멘토링 프로그램, KAIST.
  • KAIST 선배의 경험담
• November 15, 2012: 자연과학강좌, Chungbuk National University, Cheongju.
  • 4색 정리 이야기 (Story on Four Color Theorem)
• October 27, 2012: 2012 International Conference on Graph Theory, Combinatorics and Applications (October 27-30), Zhejiang Normal University, Jinhua, China.
  • Even cycle decomposition of graphs with no odd K₄ minor
• October 18, 2012: Discrete Convexity and Optimization (October 15-18), RIMS Workshop, Kyoto, Japan.
  • Even cycle decomposition of graphs with no odd K₄ minor
• October 5, 2012: Invited talk, 2012 KMS Fall Meeting (October 5-6), Daejeon.
  • Even cycle decomposition of graphs with no odd K₄ minor
• August 20, 2012: Invited session on structural graph theory and methods, 21st International Symposium on Mathematical Programming (August 19-24), Berlin, Germany.
  • Vertex-minors and pivot-minors of graphs
• July 24, 2012: 젊은 지성과의 만남, 영스타클럽(Korean Science and Technology Young Stars Club) 포럼 (July 24-25, 2012), KAIST
• August 3, 2012: Third workshop on graphs and matroids (July 29-August 4), Maastricht, The Netherlands
  • Even cycle decomposition of graphs with no odd K₄ minor
• June 19, 2012: SIAM Conference on Discrete Mathematics(June 18-21), Dalhousie University, Halifax, Nova Scotia, Canada.
  • Rank-Width and Well-Quasi-Ordering of Skew-Symmetric Or Symmetric Matrices
• June 1-7, 2012: Mini-school on Widths-Minors-Matroids, Department of Informatics, University of Bergen, Bergen, Norway.
  • June 1: Relation of rank-width with clique-width
  • June 4: Rank-width and vertex-minors; their relations to binary matroid minors
  • June 5: Branch-width of symmetric submodular functions and their recognition algorithms
  • June 6: Excluded pivot-minors for rank-width
  • June 7: Isotropic systems and vertex-minors; how to write C2MS logic formula for testing vertex-minors
• May 9, 2012: Graph Theory @ Georgia Tech, Conference Honoring the 50th Birthday of Robin Thomas (May 7-11), Georgia Tech, Atlanta, USA.
  • Graphs of small rank-width is a pivot-minor of graphs of small tree-width
• April 12, 2012: Colloquium, Department of Mathematics, Chonbuk National University, Jeonju, Korea.
  • Survey on vertex-minors and pivot-minors

2011

• December 14, 2011: The Second Bertinoro Workshop on Algorithms and Graphs, Bertinoro, Italy.
  • Rank-width and well-quasi-ordering of skew-symmetric or symmetric matrices
• November 8, 2011: Robin Thomas Fest, Charles University, Prague, Czech.
  • Rank-width and well-quasi-ordering of skew-symmetric or symmetric matrices
• October 18, 2011: Seminar, Department of Computer Science and Engineering, Seoul National University, Seoul.
  • Vertex-minors, Monadic Second-Order Logic, and a Conjecture by Seese
• September 2, 2011: European Conference on Combinatorics, Graph Theory, and Applications (Eurocomb), Budapest, Hungary.
  • Rank-width and well-quasi-ordering of skew-symmetric or symmetric matrices
• August 18, 2011: Combinatorics Workshop (2011 조합론 학술대회), Kangwon National University, Chuncheon.
  • Computing Rank-width Exactly
• August 4, 2011: 2011 초등 수학과학 영재교사 직무연수, 충남대학교 과학영재교육원, Choongnam National University, Daejeon.
  • 4색 정리 이야기 (Story on Four Color Theorem)
• June 28, 2011: Noon Lecture, Department of Applied Mathematics (KAM), Charles University, Prague.
  • Vertex-minors and pivot-minors of graphs
• June 10, 2011: Special Department Seminar, Department of Mathematics, Yeungnam University, Kyoungsan.
  • A survey on vertex-minors and pivot-minors
• April 29, 2011: Special Session on Graph Theory, Korean Mathematical Society Spring Meeting, Korea University, Seoul.
  • Rank-width and Well-quasi-ordering of Skew-symmetric or Symmetric Matrices
• April 19, 2011: 자연과학대학 대중강연 (Public Lecture of College of Natural Science), KAIST.
  • 4색정리 이야기 (Story on Four Color Theorem)
• April 11, 2011: 유학준비생을 위한 강연, KAIST.
• February 16, 2011: Graph Algorithm and Combinatorial Optimization, NII Shonan Meeting, Shonan Village Center, Japan.
  • Rank-width and Well-quasi-ordering of Skew-symmetric or Symmetric Matrices

2010

• December 3, 2010: Public Lecture, 금요일에 과학터치, 대전교육과학연구원, Daejeon.
  • Mathematics of Matchings (짝지우기의 수학)
• November 17, 2010: Kyoto Prize Satellite Workshop in Tokyo in honor of Professor László Lovász, Tokyo Institute of Technology, Tokyo.
  • Hyperbolic surface subgroups of doubles of free groups
• September 9, 2010: New trends on structural graph theory, Banff Workshop, Banff, Canada.
  • Hyperbolic surface subgroups of doubles of free groups
• August 25, 2010: 대구과학고 아카데미 강연, Daegu Science High School, Daegu.
• August 23, 2010: Robot Vision 연구회 세미나, Samsung 생산기술연구소, Suwon.
  • 그래프이론 소개 (Introduction to Graph Theory)
• August 20, 2010: Invited Talk, 2010 Combinatorics Workshop, Yeungnam University, Gyeongsan
  • Hyperbolic surface subgroups of one-ended doubles of free groups
• August 13, 2010: Invited Lecture, KAIST 수학문제연구회 영재캠프, KAIST, Daejeon
  • Mathematics of Matchings (짝지우기의 수학)
• June 21, 2010: 40th Algebraic Combinatorics Seminar, Kyungpook National University, Daegu.
  • Well-quasi-ordering conjecture for pivot-minors
• June 16, 2010: Minisymposium on Structural Graph Theory, SIAM Conference on Discrete Mathematics, Austin, Texas, USA.
  • Perfect matchings in claw-free cubic graphs
• April 24, 2010: Lecture for KMS Excellent Paper Award, KMS Spring Meeting, Korean Mathematical Society, Choongnam National University, Daejeon.
  • Vertex-minors, monadic second-order logic, and a conjecture by Seese
• April 24, 2010, Invited Public Lecture, Korean Women in Mathematical Society (한국여성수리과학회), Choongnam National University, Daejeon.
  • Mathematics of Matchings (짝지우기의 수학)
• April 17, 2010: The 3rd Annual Meeting of the Asian Association for Algorithms and Computation (AAAC2010), POSTECH, Pohang.
  • Computing rank-width exactly
• March 24, 2010: Invited Seminar, National Institute of Mathematical Sciences (NIMS), Daejeon.
  • Rank-width of Random Graphs
• February 15-19, 2010: One-Week Workshop on New Development of Discrete Algorithms, Tokyo Institute of Technology, Tokyo, Japan.
  • (2/15) Testing branch-width at most k for fixed k or non-fixed k
• February 10, 2010: The First Wednesday Multidisciplinary Forum (첫수융합포럼), KAIST.
  • Matchings
• January 11-13, 2010: Winter School on Algorithms and Combinatorics, Jochiwon, Korea.
  • (1/12) Parameterized Complexity
  • (1/13) Width Parameters of Graphs

2009

• December 19, 2009: Special session on combinatorial matrix theory, Joint Meeting of the Korean Mathematical Society and the American Mathematical Society, Ewha Womans University, Seoul.
  • Perfect matchings in claw-free cubic graphs
• December 17, 2009: Parameterized complexity and approximation algorithms, Dagstuhl, Germany.
  • Algorithms on Rank-width
• December 10, 2009: Bertinoro Workshop on Graphs and Algorithms, Bertinoro, Italy.
  • Perfect matchings in claw-free cubic graphs
• October 20, 2009: Informatics Colloquium, Faculty of Informatics, Masaryk University, Brno, Czech Republic.
  • Maximum number of complete subgraphs in a certain graph
• October 16, 2009: Fourth workshop on Graph Classes, Optimization, and Width Parameters (GROW 2009), Bergen, Norway.
  • Computing rank-width exactly
• September 17, 2009: Colloquium, Department of Mathematics, Sungkyunkwan University, Suwon, South Korea.
  • Vertex-minors and pivot-minors of graphs
• June 8, 2009: 첨단과학세미나, Korea Science Academy (한국과학영재학교), Pusan, South Korea.
  • Planar graphs and circle graphs
• June 4, 2009: 2009 ASARC Workshop, Muju resort, South Korea.
  • A survey on vertex-minors and pivot-minors
• May 9, 2009: DIMACS Workshop on Graph Colouring and Structure, Princeton University, Princeton, New Jersey, USA.
  • A survey on vertex-minors and pivot-minors
• April 25, 2009: 2009 KMS Spring Meeting, Department of Mathematis, Ajou University, Suwon, South Korea.
  • Maximum number of complete subgraphs in a certain graph
• February 4, 2009: KAIST Combinatorics Seminar, Department of Mathematical Sciences, KAIST, Daejeon, South Korea.
  • Maximum number of complete subgraphs in a certain graph
• January 30, 2009: 2009 ASARC Workshop at Daecheon, Daecheon, South Korea.
  • Maximum number of complete subgraphs in a certain graph
• January 9, 2009: Seminar, Department of informatics, University of Bergen, Bergen, Norway.
  • Maximum number of complete subgraphs in a certain graph
• January 8, 2009: Department Seminar, Department of informatics, University of Bergen, Bergen, Norway.
  • Introduction to Rank-width

2008

• December 22, 2008: Kyoto RIMS Winter School on Graphs and Algorithms, RIMS, Kyoto University, Kyoto, Japan.
  • Survey on Rank-width and Clique-width
• November 5, 2008: Math Club, Department of Mathematics, POSTECH
  • Seese’s conjecture on the decidability of the monadic second-order theory
• November 1, 2008: 수학문제연구회 20주년 기념행사 (20th year anniversary event of KAIST Mathematical Problem Solving Group), KAIST Mathematical Problem Solving Group, KAIST.
  • 그래프 집합 위에서의 단항이차논리식의 결정가능성에 관한 Seese의 추론
• October 16, 2008: Colloquium, Department of Mathematics, Ajou University, Suwon, Korea.
  • Seese’s conjecture on the decidability of the monadic second-order theory
• September 30, 2008: Graph minors, Banff International Research Station, Banff, Canada.
  • Tree-width and rank-width of H-minor-free graphs
• August 7, 2008: 2008 Combinatorics Workshop, Sungkyungkwan University, Suwon, Korea.
  • Finding branch-decompositions and rank-decompositions.
• July 20, 2008: The Netherlands Workshop on Graphs and Matroids, Sittard, the Netherlands.
  • Graphic delta-matroids
• June 24, 2008: Fudan-KAIST Joint Workshop on Applied Mathematics, School of Mathematical Sciences, Fudan University, Shanghai, China.
  • Chain theorems for 4-prime graphs
• June 16, 2008: SIAM Conference on Discrete Mathematics, University of Vermont, Burlington, Vermont, USA.
  • Chain theorems for 4-prime graphs
• June 12, 2008: Kyoto RIMS Workshop on Combinatorial Optimization and Discrete Algorithms, Research Institute for Mathematical Sciences (RIMS), Kyoto University, Kyoto, Japan.
  • Graphic delta-matroids
• Apr. 7, 2008: Workshop on Graph Decomposition: Theoretical, Algorithmic and Logical Aspects, CIRM, Luminy, France.
  • Finding branch-decompositions and rank-decompositions
• Apr. 3, 2008: Combinatorics Seminar, LaBRI, Bordeaux, France.
  • Line graphs of large rank-width
• Mar. 28, 2008: Special session on Structural graph theory, AMS sectional meeting, Baton Rouge, Lousiana, USA.
  • Chain theorems for 4-prime graphs
• Feb. 21, 2008: Undergraduate Colloquium (학부생 콜로퀴엄), Department of Mathematical Sciences, KAIST.
  • Four Color Theorem
• Feb. 1, 2008: 4th Korea-Japan Workshop on Algebra and Combinatorics, POSTECH, Pohang, Korea.
  • Well-quasi-ordering of skew-symmetric matrices of bounded rank-width

2007

• Dec. 3, 2007: Colloquium, Department of Computational and Applied Mathematics, Rice University, Houston, Texas, USA.
  • Introduction to Rank-wdth
• Nov. 27, 2007: Combinatorial Optimization Seminar, University of Waterloo, Waterloo, Ontario, Canada.
  • Finding Branch-decompositions and Rank-decompositions
• Nov. 16, 2007: Joint Combinatorics – Theory Seminar, University of Toronto, Toronto, Canada.
  • Introduction to Rank-width
• Oct. 19, 2007: The Third Workshop on Graph Classes, Optimization, and Width Parameters, Eugene, Oregon, USA.
  • Introduction to Rank-width
• Aug. 6-8, 2007: 2007 Combinatorics Workshop, KAIST, Daejeon, Korea.
  • Circle graphs obstructions under pivoting (Aug. 6)
  • Excluding a bipartitie circle graph from line graphs (Aug. 7)
  • Rank-width and well-quasi-ordering (Aug. 8 )
• Jul. 25, 2007: Structure Theory and FPT Algorithms for Graphs, Digraphs and Hypergraphs, Dagstuhl workshop 07281, Germany.
  • Finding Branch-decompositions and Rank-decompositions
• May 28, 2007: 1st Canadian Discrete and Algorithmic Mathematics Conference (CanaDAM 2007), Banff, Alberta, Canada.
  • Circle graph obstructions under pivoting
• May 10, 2007: Colloquium, Department of Mathematics, Yonsei University, Seoul, Korea.
  • Survey on rank-width and clique-width
• May 8, 2007: Special Lecture, Department of Mathematics, POSTECH, Pohang, Korea.
  • Survey on rank-width and clique-width
• May 2, 2007: Colloquium, Department of Mathematical Sciences, KAIST, Daejeon, Korea.
  • Survey on rank-width and clique-width
• Mar. 28, 2007: Oberwolfach Workshop Graph Theory, Oberwolfach, Germany.
  • Excluded pivot-minor characterization of circle graphs
• Jan. 23, 2007: Combinatorial Optimization Seminar, University of Waterloo, Canada.
  • Circle graph obstructions under pivoting

2006

• Nov. 16, 2006: Graph Theory Seminar, Georgia Institute of Technology, USA.
  • Circle graph obstructions under pivoting
• Aug. 4, 2006: Tutte Seminar, University of Waterloo, Canada.
  • Survey on rank-width and clique-width
• Jul. 21, 2006: Horizon of Combinatorics, Lake Balaton, Hungary.
  • Excluding a bipartite circle graph from line graphs
• Jul. 11, 2006: Sixth Czech-Slovak International Symposium on Combinatorics, Graph Theory, Algorithms and Applications, Prague, Czech Republic.
  • Excluding a bipartite circle graph from line graphs
• Jun. 25, 2006: SIAM Conference on Discrete Mathematics, Victoria, British Columbia, Canada.
  • Towards a Grid Theorem for Rank-width and Clique-width
• May 20, 2006: The XXVIIIth Ohio State-Denison Mathematics Conference, Columbus, OH, USA.
  • Towards a Grid Theorem for Rank-width and Clique-width
• Apr. 27, 2006: Graph Theory Seminar, Georgia Institute of Technology, USA.
  • Towards a Grid Theorem for Rank-width and Clique-width
• Feb. 9, 2006: Graph Theory Seminar, Georgia Institute of Technology, USA.
  • Testing Branch-width
• Jan. 23, 2006: ACM/SIAM Conference on Discrete Algorithms (SODA), Miami, FL, USA.
  • Testing Branch-width

2005

• Dec. 27, 2005: Combinatorics Seminar, Department of Mathematics, KAIST, Daejeon, Korea.
  • Testing Branch-width
• Nov. 24, 2005: Combinatorics and Optimization Seminar, University of Waterloo, Waterloo, Canada.
  • Testing Branch-width
• Oct. 18, 2005: Workshop on Graph Classes, Width Parameters and Optimization, Prague, Czech.
  • Recognizing Rank-width Quickly
• Oct. 13, 2005: Graph Theory Seminar, Georgia Institute of Technology, USA.
  • Graphs of Bounded Rank-width II
• Oct. 12, 2005: Combinatorics Seminar, Georgia Institute of Technology, USA.
  • Rank-width and Well-quasi-ordering of Skew-symmetric Matrices
• Oct. 6, 2005: Graph Theory Seminar, Georgia Institute of Technology, USA.
  • Graphs of Bounded Rank-width
• Sep. 24, 2005: The 41st Midwest Graph Theory Conference, Middle Tennessee State University, Murfreesboro, TN, USA.
  • Approximating Rank-width and Clique-width Quickly
• Sep. 13, 2005: 7th International Colloquium on Graph Theory (ICGT ’05), Hyères, France.
  • Rank-width and well-quasi-ordering of skew-symmetric matrices
• Jul. 26, 2005: Exact Algorithms and Fixed-Parameter Tractability, Dagstuhl workshop, Germany.
  • Graphs of Bounded Rank-width
• Jul. 3, 2005: Princeton-Oxford Workshop, Oxford, UK.
  • Rank-width and Well-quasi-ordering of Skew-symmetric Matrices
• Jun. 23, 2005: 31st International Workshop on Graph-Theoretic Concepts in Computer Science, Metz, France.
  • Approximating Rank-width and Clique-width Quickly
• Jun. 20, 2005: Seminar on graphs and logic, University of Bordeaux 1, Bordeaux, France.
  • Graphs of Bounded Rank-width
• Jun. 16, 2005: Séminaire de Combinatoire Algébrique et Géométrique, Combinatoire et Optimisation, Université Pierre et Marie Curie (Paris 6), Paris, France
  • Well-quasi-ordering of skew-symmetric matrices of bounded rank-width by using isotropic systems on arbitrary fields (abstract)
• Jan. 19, 2005: Oberwolfach Workshop “Graph Theory“, Oberwolfach, Germany
  • Recognizing Rank-width

2004

• Dec. 17, 2004: Workshop “Graph and Hypergraph Decompositions – Methods and Applications in Computer Science“, Vienna, Austria
  • Recognizing graphs of rank-width at most k
• Nov. 19, 2004: PACM Graduate Student Seminar, Princeton University
  • Rank-width and Well-quasi-ordering
• Nov. 15, 2004: Discrete Mathematics and Optimization Seminar, McGill University, Montreal, Quebec, Canada
  • Rank-width and Well-quasi-ordering
• Oct. 29, 2004: Graph Theory Seminar, Georgia Institute of Technology
  • Rank-width and Well-quasi-ordering
• Oct. 1-2, 2004: two talks were given at the Satellite Workshop Logic, Graph Transformations, Finite and Infinite Structures of the 2nd International Conference on Graph Transformations (IGCT) in Rome, Italy. Titles are
  • Rank-width, Clique-width and Vertex-minors.
  • An algorithm for recognizing rank-width at most k and the well-quasi-ordering of the vertex-minor relation.
• May. 23, 2004: Robust and Approximative Algorithms on Particular Graph Classes, a Dagstuhl seminar
  • Replace Clique-width With Rank-width
• Mar. 10, 2004: Princeton Discrete Mathematics Seminar
  • From binary matroids to graphs
• Feb. 27, 2004: PACM Graduate Student Seminar
  • From binary matroids to graphs

2003

• Dec. 13, 2003: Advances in Graph and Matroid Theory, A conference in honour of Neil Robertson’s 65^th birthday
  • Approximating Clique-width in O(n⁹ log(n)) Time
• Jun. 25-28, 2003: Oxford/Princeton Workshop
  • Approximating Clique-width
• Mar. 28, 2003: PACM Graduate Student Seminar
  • Polynomial-time Approximation Algorithm for the Clique-Width of graphs