摘要
设G=(V,E)是简单连通图,简单连通图G的离心率总和定义为图G中所有顶点的离心率总和。若树T中某个顶点的度大于等于3,则称这个点为T的分支点。刻画了给定分支点数为r顶点数为n的树的离心率总和的上界和下界。
Let G=(V,E)be a simple connected graph,the total eccentricity of a simple and connected graph G isdefined as the sum of eccentricities of all vertices in G.A vertex of a tree T with3or greater is called abranching vertex of T.That the upper bound and the lower bound of the total eccentricity of an n-vertex tree with rbranching vertices are determined.
作者
江玲瑶
汤自凯
Jiang Lingyao;Tang Zikai(College of Mathematics and Computer Science, Hunan Normal University, Changsha 410081, China)
出处
《湖南文理学院学报（自然科学版）》
CAS
2017年第2期5-8,共4页
Journal of Hunan University of Arts and Science(Science and Technology)
基金
晓庄学院优秀青年项目(ET13101)
关键词
离心率总和
分支点
树
极值图
the total eccentricity
the branching vertex
tree
extremal graph
