报 告 人：董峰明（新加坡南洋理工大学）
报告时间：2023年12月14日下午3:30
报告地点：章辉楼442
联 系 人：晏卫根教授
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报告摘要：Graph coloring is one of the most important and long-standing topics in graph theory. Not only does it tie many concepts in graph theory in surprising ways, but it also has a wide range of real-world applications. This talk will focuses on the colorability of bi-hypergraphs. A mixed hypergraph 
consists of the vertex set 
and two families of subsets of 
: the family 
of co-edges and the family 
of edges. 
is said to be colorable if there is a mapping 
from to the set of positive integers such that 
for each 
and 
for each 
. There exist mixed hypergraphs which are uncolorable, and quite little about these mixed hypergraphs is known. A mixed hypergraph is called a bi-hypergraph if its co-edge set and edge set are the same. In this talk, I will introduce our recent research on the size of minimal uncolorable bi-hypergraphs.
This is a joint work with Meiqiao Zhang and Ruixue Zhang.
报告人简介：董峰明，现为新加坡南洋理工大学副教授、博士生导师。1997年新加坡国立大学博士。主要研究兴趣为图论，特别是图和拟阵的结构与多项式的关系。和他人合作，已出版专著和其他书籍四本,发表论文近100篇，其中约60篇发表在JCTA, JCTB, JGT, SIAM DM, EJC, CPC, AAM等国际组合数学重要学术刊物上。解决了若干公开问题及猜想，包括牛津大学的Welsh和Bartel提出的“Shameful Conjecture”。2008年他被剑桥大学聘为客座研究员，参与剑桥大学牛顿数学研究所的组合学与统计物理的研究工作。2015年他被邀请参与《The CRC Handbook on the Tutte Polynomial and Related Topics》手册的撰写工作，是该书的亚洲区唯一作者。
理学院
2023年12月8日
