05925112

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05925112 Dundar, Pinar Turaci, Tufan Dogan, Derya Weak and strong reinforcement number for a graph. Int. J. Math. Comb. 3, 91-97 (2010). 2010 The MADIS of Chinese Academy of Sciences, Beijing EN connectivity Smarandachely dominating $k$-set Smarandachely dominating $k$-number strong or weak reinforcement number Summary: Let $G= (V(G),E(G))$ be a graph. A set of vertices $S$ in a graph $G$ is called to be a Smarandachely dominating $k$-set, if each vertex of $G$ is dominated by at least $k$ vertices of $S$. Particularly, if $k=1$, such a set is called a dominating set of $G$. The Smarandachely domination $k$-number $\gamma_k(G)$ of $G$ is the minimum cardinality of a Smarandachely dominating $k$-set of $G$. $S$ is called weak domination set if $\deg(u)\le\deg(v)$ for every pair of $(u,v)\in V(G)- S$. The minimum cardinality of a weak domination set $S$ is called weak domination number and denoted by $\gamma_w(G)$. In this paper we introduce the weak reinforcement number which is the minimum number of added edges to reduce the weak dominating number. We give some boundary of this new parameter and trees. Furthermore, some boundary of strong reinforcement number has been given for a given graph $G$ and its complemented graph $\overline G$.