连通图G的孤立断裂度isc(G)=max{i(G—S)-|S|=S∈C(G)),其中i(G—S)是G—S中的孤立点数,C(G)是G的点割集.本文研究了孤立断裂度和图的其它一些参数的关系.讨论了孤立断裂度取特殊值的一些图,证明了圈、连通二部图、连通二部图的联图以及树和圈的补图的孤立断裂度都达到最小.给出了具有给定阶数和最大度的树的最大、最小孤立断裂度.
The isolated scattering number isc(G) = max{i(G - S) - ISI : S ∈ C(G)},where G is a connected graph, i(G - S) is the number of isolated vertices of G - S and C(C) is the set of vertex cuts of C. In this paper, we investigate the relationships between the isolated scattering number and other parameters of a graph C, and discuss the graphs with special isolated scattering numbers. We prove that the isolated scattering numbers of a cycle, a connected bipartite graph, the join of connected bipartite graphs and the complement of a tree and a cycle are minimal, and give the maximum and minimum isolated scattering numbers of trees with given order and maximum degree.