三圈图的最小离心距离指标

为进一步研究离心距离指标（EDS）数学性质，通过研究3种移边变换对离心距离指标的影响，利用移边变换和数学归纳得出了三圈图离心距离指标的最小值及其对应图的结构。本文方法为研究更一般图的离心距离指标提供了一种简单有效的思路。
Abstract：The eccentric distance sum (EDS) has been widely used in the fields of chemistry and biology. In order to study its mathematical properties further, a new method has been used in this paper. Firstly, three transformations of edge-grafting on the eccentricity distance sum of a connected graph were studied. Then by using these transformations and induction, we obtained the minimum eccentric distance sum among all tricyclic graphs with order n, and also characterized the structure of the corresponding tricyclic graphs. The results demonstrate that our method is simple and effective, and offers a new way of studying the eccentric distance sum of general graphs.