extremal digraphs whose walks with the same initial and terminal vertices have distinct lengths-凯发平台登录
发布者：系统管理员发布时间：2012-04-12浏览次数：458
| 报告题目： | extremal digraphs whose walks with the same initial and terminal vertices have distinct lengths |
| 报 告 人： | 詹兴致教授 博士生导师 |
| | 华东师范大学数学系 |
| 报告时间： | 2012年4月16日（周一） 14：30-15：30 |
| 报告地点： | 九龙湖校区数学系第一报告厅 |
| 相关介绍： | let d be a digraph of order n in which any two walks with the same initial vertex and the same terminal vertex have distinct lengths. we prove that d has at most (n 1)^2/4 arcs if n is odd and n(n 2)/4 arcs if n is even. the digraphs attaining this maximum size are determined. the results have equivalent versions for 0-1 matrices.
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