A subset D of V is called a dom strong dominating set if for every v V – D, there exists u1, u2 D such that u1v, u2v  E(G) and deg (u1 ) ≥ deg (v). The minimum cardinality of a dom strong dominating set is called dom strong domination number and is denoted by γdsd. In this paper, we introduce the concept of nonsplit dom strong domination number of a graph. A dom strong dominating set D of a ...

In order to increase the paired-domination number of a graph G, minimum edges that must be subdivided (where each edge in G can no more than once) is called subdivision sdγpr(G) G. It well known sdγpr(G+e) smaller or larger for some e∉E(G). this note, we show that, if an isolated-free different from mK2, then, every e∉E(G), sdγpr(G+e)≤sdγpr(G)+2Δ(G).

A vertex w in a connected graph G strongly resolves two distinct vertices u and v V (G) if is any shortest u-w path or v-w path. set W of strong resolving every are resolved by some W. S subset hop dominating for ∈ \ there exists such that dG(u, v) = 2. The smallest cardinality called the domination number G. This paper presents characterization sets join, corona lexicographic product graphs. F...

‎a total dominating set of a graph $g$ is a set $d$ of vertices of $g$ such that every vertex of $g$ has a neighbor in $d$‎. ‎the total domination number of a graph $g$‎, ‎denoted by $gamma_t(g)$‎, ‎is~the minimum cardinality of a total dominating set of $g$‎. ‎chellali and haynes [total and paired-domination numbers of a tree, akce international ournal of graphs and combinatorics 1 (2004)‎, ‎6...

We solve several conjectures and open problems from a recent paper by Acharya [2]. Some of our results are relatives of the Nordhaus–Gaddum theorem, concerning the sum of domination parameters in hypergraphs and their complements. (A dominating set in H is a vertex set D ⊆ X such that, for every vertex x ∈ X\D there exists an edge E ∈ E with x ∈ E and E∩D 6= ∅.) As an example, it is shown that ...