A double Roman dominating function on a graph G=(V,E) is f:V?{0,1,2,3} with the properties that if f(u)=0, then vertex u adjacent to at least one assigned 3 or two vertices 2, and f(u)=1, 2 3. The weight of f equals w(f)=?v?Vf(v). domination number ?dR(G) G minimum G. said be ?dR(G)=3?(G), where ?(G) We obtain sharp lower bound generalized Petersen graphs P(3k,k), we construct solutions providi...

The following fundamental result for the domination number γ(G) of a graph G was proved by Alon and Spencer, Arnautov, Lovász and Payan: γ(G) ≤ ln(δ + 1) + 1 δ + 1 n, where n is the order and δ is the minimum degree of vertices of G. A similar upper bound for the double domination number was found by Harant and Henning [On double domination in graphs. Discuss. Math. Graph Theory 25 (2005) 29–34...

Domination-type parameters are difficult to manage in Cartesian product graphs and there is usually no general relationship between the parameter both factors graph. This situation of domination number, Roman number or 2-domination among others. Contrary what happens with remains unknown cylinders, that is, a cycle path this paper, we will compute cylinders small cycles. We develop two algorith...

I n the first century of Roman domination silver jewelry in the Balkan region is very numerous, and local production of these decorations lasted until the middle of the 3rd century. In that production an important role played the autochthonous component. Gold jewelry from this region is of East-Mediterranean origin, and some shapes of ornaments and use of the techinques of filigree and granulat...

Let k ∈ Z +. A − distance Roman dominating function (kDRDF) on G = (V, E) is a f : V → {0, 1, 2} such that for every vertex v with f(v) 0, there u f(u) 2 d(u, v) ≤ k. The global (GkDRDF) if and only its complement G. weight of the value w(f) P x∈V f(x). minimum graph called domination number denoted as γ gR(G). gR(G) Note that, 1 usual γgR(G), is, γgR(G). authors initiated this study. In paper,...

Let G = ( V, E ) be a simple graph with vertex setxs V and edge set . A mixed Roman dominating function of is f : ∪ → {0, 1, 2} satisfying the condition that every element x ∈ for which f(x) 0 adjacent or incident to at least one y f(y) 2. The weight ω( ∑ domination number γ R minimum We first show problem computing * NP-complete bipartite graphs then we present upper lower bounds on number, so...