如果图G的一个集合X中任两个点不相邻,则称X为独立集合.如果N[X]=V(G),则称X是一个控制集合.i(G)(β(G))分别表示所有极大独立集合的最小(最大)基数.γ(G)(Г(G))表示所有极小控制集合的最小(最大)基数.在这篇论文中,作者证明如下结论:(1)如果G∈R且G是n阶3-正则图,则γ(G)=i(G),β(G)=n/3.(2)每个n阶连通无爪3-正则图G,如果G(G≠K4)且不含诱导子图K4-e,则β(G)=n/3.
A set X is independent if no two vertices of X are adjacent. A set X is dominating if N[X] = V(G). A dominating set X is minimal if no set X / {x} with x ∈ X is dominating. The independence number i(G)(β(G)) is the minimum (maximum) cardinality of a maximal independent set of G. The domination number γ(G) (the upper domination number Г(G)) is the minimum (maximum) cardinality of a minimal dominating set of G. In this paper, we prove that: (1) if G ∈R and G is a cubic graph of order n, then γ(G) = i(G), β(G) = n/3; (2) for every connected claw-free cubic graph G of order n, if G(G ≠ K4) contains no K4 - e as induced subgraph, then β(G) = n/3.