منابع مشابه
Bounds on the restrained Roman domination number of a graph
A {em Roman dominating function} on a graph $G$ is a function$f:V(G)rightarrow {0,1,2}$ satisfying the condition that everyvertex $u$ for which $f(u) = 0$ is adjacent to at least one vertex$v$ for which $f(v) =2$. {color{blue}A {em restrained Roman dominating}function} $f$ is a {color{blue} Roman dominating function if the vertices with label 0 inducea subgraph with no isolated vertex.} The wei...
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the noncommuting graph $nabla (g)$ of a group $g$ is asimple graph whose vertex set is the set of noncentral elements of$g$ and the edges of which are the ones connecting twononcommuting elements. we determine here, up to isomorphism, thestructure of any finite nonabeilan group $g$ whose noncommutinggraph is a split graph, that is, a graph whose vertex set can bepartitioned into two sets such t...
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For a graph G = (V , E), a subset D V ðGÞ is said to be distance two-dominating set in G if for each vertex u 2 V D, there exists a vertex v 2 D such that dðu; vÞ 2. The minimum cardinality of a distance two-dominating set in G is called a distance twodomination number and is denoted by c2ðGÞ. In this note we obtain various upper bounds for c2ðGÞ and characterize the classes of graphs attaining...
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ژورنال
عنوان ژورنال: Open Mathematics
سال: 2015
ISSN: 2391-5455
DOI: 10.1515/math-2015-0027