Let D = (V (D), A(D)) be a digraph. The competition graph of D, is the graph with vertex set V (D) and edge set {uv ∈ `V (D) 2 ́ : ∃w ∈ V (D),−→ uw,−→ vw ∈ A(D)}. The double competition graph of D, is the graph with vertex set V (D) and edge set {uv ∈ `V (D) 2 ́ : ∃w1, w2 ∈ V (D),−−→ uw1,−−→ vw1,−−→ w2u,−−→ w2v ∈ A(D)}. A poset of dimension at most two is a digraph whose vertices are some points ...

The aim of this paper is an extension of the theory of graph transformation systems in order to make them suitable for the speciication of reactive systems. For this purpose two main extensions of the algebraic theory of graph transformations are proposed. Firstly, graph transitions are introduced as a loose interpretation of graph productions, deened using a double pullback construction in con...

In a graph G, a vertex dominates itself and its neighbors. A subset S of V is called a dominating set in G if every vertex in V-S is adjacent to at least one vertex in S. The minimum cardinality taken over all, the minimal double dominating set which is called Fuzzy Double Domination Number and which is denoted as ) (G fdd  . A set V S  is called a Triple dominating set of a graph G if every ...

The main aim of this paper is an extension of the theory of algebraic graph transformation systems by a loose semantics. For this purpose, graph transitions are introduced as a loose interpretation of graph productions. They are deened using a double pullback construction in contrast to classical graph derivations based on double-pushouts. Two characterisation results relate graph transitions t...

For a (molecular) graph, the hyper Zagreb index is defined as HM(G) = ∑ uv∈E(G) (dG(u) + dG(v)) 2 and the hyper Zagreb coindex is defined asHM(G) = ∑ uv/ ∈E(G) (dG(u)+dG(v)) 2. In this paper, the hyper Zagreb indices and its coindices of edge corona product graph, double graph and Mycielskian graph are obtained.

The quadratic embedding constant (QE constant) of a graph is new characteristic value defined through the distance matrix. We derive formulae for QE constants join two regular graphs, double graphs and certain lexicographic product graphs. Examples include complete bipartite wheel friendship completely split graph, some associated to strongly

The buried hetero-structure (BH) InGaAsP-InP waveguide is used for asystem of double microring resonators (DMR). The light transmission and location ofresonant peaks are determined for six different sets of ring radii with different ordermode numbers. The effect of changing middle coupling coefficient on the box likeresponse is studied. It is found that the surge of coupling coefficient to the ...

Received (received date) Revised (revised date) Communicated by Editor's name ABSTRACT The network properties of double and triple xed step graphs are considered. We determine that the broadcast times of double and triple xed step graphs of diameter D are equal to D + 2 and D + 3, respectively. Some results on the embeddings of grids into these graphs with dilation 1 and 2 are given. For a trip...

A family G of isomorphic copies of a given graph G is said to be a suborthogonal double cover (SODC) of the complete graph K n by G, if every edge of K n belongs to exactly two members of G and any two diierent elements from G share at most one edge. We introduce the notion of an SODC as a generalization of the well-known concept of orthogonal double covers. Our objective is to investigate the ...

Abstract: A graph G with p vertices is said to be strongly multiplicative if the vertices of G can be labeled with p consecutive positive integers 1, 2, ..., p such that label induced on the edges by the product of labels of end vertices are all distinct. In this paper we investigate strongly multiplicative labeling of some snake related graphs. We prove that alternate triangular snake and alte...