学术报告

报告题目：Local bases of primitive non-powerful signed digraphs

报告人：苗正科 教授     江苏师范大学

报告时间：2016 年 11 月 14 日（星期一）上午 10:00-11:00

报告地点：创新园大厦 A1101

报告校内联系人：王毅  教授     联系电话：84708351-8128

报告摘要:  A signed graph S is a digraph (permit loop but no multiple are) where

each are of S is assigned a sign 1 or -1. For a primitive non-powerful signed digraph S of order n, the              local base of S, denoted by             , is denoted by Wang, Miao and Yan [Discrete Math. 309(2009), 748-754]. It is proved that              for             . A nature problem is that for all primitive and non-powerful signed digraphs of order n, how their              local base distribute in [             ]. From [Discrete Math. 309(2009), 748-754], it also follows that there is no sign digraph of order              such that its              local base is in             . We call such interval a “gap” for the              local base, where              and             . In this paper we consider the local base of a primitive and non-powerful signed digraph. More “gaps” for for the              local base are shown, and the primitive non-powerful signed digraphs with the              local base in [             ] are completely characterized.

报告人简介：苗正科，江苏师范大学数学教授、博士生导师。长期从事组合矩阵论和图的着色等方面的研究工作。先后主持3项国自然科学基金面上项目，在国内外学术期刊上发表80余篇文章。

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2016年11月10日