图的符号k-控制

On Signed k-subdomination Numbers of Graphs

设G(V,E)为一个图,k为任意的正整数且k不超过|G|,若有一个函数f:V{1,-1}满足:V中至少有k个点满足f[v]1,则称f为图G的一个符号k-控制函数,图G的符号k-控制数定义为γ-ks11(G)=min{f(V)|f为图G的一个符号k-控制}.给出了图的符号k-控制数的下界的一个改进的结论,并确定了轮图的符号k-控制数.

Suppose G（ V, E） is a graph, k is a random positive integer less than I GI. If a function f： V{ 1 ,-1} satisfy： there are at least k vertices satisfied with f[ v] 1, then f is a signed k-subdomination function of G. We denote the signed k-subdomination numbers by γks^-11（G） ,which is the minimum signed k-subdomination function of G. In this paper, we give a improved low bound of the signed k-subdomination number of a graph G, finally the signed k-subdomination num- bers of wheels are determined.