기초과학연구원 이산수학그룹
On August 11, 2020, Yunbum Kook (국윤범) from KAIST presented his work on the existence of a connectivity-c mimicking network, which is a graph preserving the size of all minimum edge-cuts between any partition of a given set of terminals up to a constant c and an efficient algorithm to find one. The title of his talk was “Vertex Sparsification for Edge Connectivity”.
On August 5, 2020, Robert Ganian from Technische Universität Wien gave an online talk giving an overview of recent approaches to the integer linear programming based on the structural analysis of graphs associated with the instances at the Virtual Discrete Math Colloquium. The title of his talk was “Solving Integer Linear Programs by Exploiting Variable-Constraint Interactions“.
On August 4, 2020, June Huh (허준이) from Institute of Advanced Study presented several conjectures on Kazhdan-Lusztig polynomials of graphs and matroids and recent progress towards them at the Discrete Math Seminar. The title of his talk was “Kazhdan-Lusztig polynomials of graphs and matroids“.
On July 29, 2020, Akanksha Agrawal from Ben-Gurion University of the Negev gave the second talk of the online seminar series called the Virtual Discrete Math Colloquium. The title of her talk was “Polynomial Kernel for Interval Vertex Deletion“.
On July 28, 2020, Eun Jung Kim (김은정) from CNRS, LAMSADE gave a talk on a new tool called the flow augmentation, that is useful to design fixed-parameter algorithms for various graph cut problems on undirected graphs. The title of her talk was “Solving hard cut problems via flow-augmentation“.
Due to the COVID-19 pandemic, we decided to start a new series of talks given online under the name “Virtual Discrete Math Colloquium” so that we can invite speakers abroad online. On July 22, 2020, its first talk was given by Paloma T. Lima from University of Bergen, Norway. She talked about the problem of deciding whether a given input graph G is a square of some graph H with some restrictions on H. The title of her talk was “Graph Square Roots of Small Distance from Degree One Graphs“.
On July 21, 2020, Ilkyoo Choi (최일규) from Hankuk University of Foreign Studies gave a talk on the flexibility of planar graphs, a concept related to extending a a precoloring at the Discrete Math Seminar. The title of his talk was “Flexibility of Planar Graphs“.
On July 14, 2020, Casey Tompkins from IBS Discrete Mathematics Group gave a talk on inverse Turán problems at the Discrete Math Seminar. The goal is for a fixed graph H and an integer k to find the minimum number of edges of a graph G such that that every subgraph of G with at least k edges has a subgraph isomorphic to H. The title of his talk is “Inverse Turán Problems“.
On July 7, 2020, Seog-jin Kim (김석진) from Konkuk University presented his work on the online DP-coloring of graphs, a common generalization of the online coloring and the DP coloring, both generalizing the list coloring of graphs. The title of his talk was “Online DP-coloring of graphs“. He will stay at the IBS discrete mathematics group until the end of this week.
On June 30, 2020, Dennis Wong from SUNY Korea gave a talk on algorithms to generate Gray codes and universal cycles for weak orders at the Discrete Math Seminar. At the end of the talk, his student, Fabio Calero from SUNY Korea, gave a sketch about another work on Gray codes for ballot sequences. The title of his talk is “Generating Gray codes and universal cycles for weak orders“.
