报告题目：Digraph Clustering and Some Minimax Properties in Digraphs

报告摘要：Given a digraph $D$, how do we know if $D$ contains a highly connected subdigraph? This research investigates the maximum subdigraph arc strong connectivity. Extremal and minimax properties related to the maximum subdigraph arc strong connectivity are studied. A digraph $D$ is $k$-strength maximal if every subdigraph of $D$ has arc strong connectivity at most $k$ but adding any arc will result in a subdigraph with arc strong connectivity at least $k+1$. We obtained best possible upper and lower bounds of the size of a $k$-strength maximal digraphs. A minimax property related to investigate the maximum subdigraph arc strong connectivity is found, leading to an algorithm that determines the maximum subdigraph arc strong connectivity in polynomial time.

报告时间：2017年6月5日（周一）上午9：00-10：00

报告地点：长清湖校区B434伟德国际1946源自英国报告厅

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报告人简介：赖虹建教授是美国弗吉尼亚大学数学系主任 、现任Graph and Comninatorics 以及Journal of Discrete Mathematics等杂志编委。赖虹建是国际著名图论与组合优化专家，在国际期刊、杂志发表学术论文180余篇，出版学术专著三部。其中多篇发表在图论与组合的顶级期刊 Journal of Combinatorical Theory Series B, Journal of Graph Theory, SIAM. Discrete Math.等。