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In this paper we introduce the concept of skew-quotient of Randić and sumconnectivity energy of directed graphs. We then obtain upper and lower bounds for skew-quotient of Randić and sum-connectivity energy of digraphs. Then, we compute the skewquotient of Randić and sum-connectivity energy of some graphs such as star digraph, complete bipartite digraph, the Sm ... P2 digraph and a crown digraph. [ABSTRACT FROM AUTHOR]

In recent time graphical analytics of uncertainty and indeterminacy has become major concern for data analytics researchers. In this direction, the mathematical algebra of neutrosophic graph is extended to interval-valued neutrosophic graph. However, building the interval-valued neutrosophic graphs, its spectrum and energy computation is addressed as another issues by research community of neutrosophic environment. To resolve this issue the current paper proposed some related mathematical notations to compute the spectrum and energy of interval-valued neutrosophic graph using the MATAB. [ABSTRACT FROM AUTHOR]

Representing a set of vertices in a graph means of a matrix was introduced by E. Sampath Kumar. Let G(V,E) be a graph and S ⊆ V be a set of vertices. We can represent the set S by means of a matrix as follows, in the adjacency matrix A(G) of G replace the aii element by 1 if and only if, vi ∈ S. In this paper we study the special case of set S being dominating set and corresponding domination energy of some class of graphs. [ABSTRACT FROM AUTHOR]

Representing a subset of vertices in a graph by means of a matrix was introduced by E. Sampath Kumar. Let G(V, E) be a graph and S ⊆ V be a set of vertices. We can represent the set S by means of a matrix as follows, in the adjacency matrix A(G) of G replace the aii element by 1 if and only if, vi ∊ S. In this paper we study the set S being dominating set and corresponding domination energy of some class of graphs. [ABSTRACT FROM AUTHOR]

Graph labeling where vertices and edges are assigned values subject to certain conditions have been motivated by various applied mathematical fields. Most of the problems in graph labeling are discussed on undirected graphs. Bloom G.S. and Hsu D.F. defined the labeling on directed graphs. In this paper, we discuss the adjacency matrices of graceful digraphs such as unidirectional paths, alternating paths, many orientations of directed star and a class of directed bistar. We also discuss the adjacency matrices of unidirectional paths and alternating paths if they are odd digraceful. [ABSTRACT FROM AUTHOR]

Given a graph G with n vertices and m edges, the term energy of graph E(G) was introduced by Gutman in chemistry, due to its relevance to the total π ― electron energy of carbon compounds. In 1971 McClelland obtained both lower and upper bounds for π 8213; electron energy. An improved upper bound was obtained by Koolen-Moulton in 2001. The lower and upper bounds for E(G) obtained in this paper are better than McClelland and Koolen-Moulton bounds. Also we obtained an upper bound for graph energy in terms of n as E(G) ≤ n/2[ 1 + √ n-2/2]. [ABSTRACT FROM AUTHOR]

Let G be a graph with vertex set V(G) = {v1,v2,..., vn}. Let A(G) be the adjacency matrix of a graph G. The rows of A(G) corresponding to a vertex v of G, denoted by s(v) is the string. The Hamming index of a graph G is the sum of the Hamming distances between all pairs of vertices of G. In this paper we obtain Hamming index generated by adjacency matrix of some thorn graphs. [ABSTRACT FROM AUTHOR]

Representation of a set of vertices in a graph by means of a matrix was intro- duced by Sampath Kumar. Let G(V,E) be a graph and S ⊆ V be a set of vertices, we can represent the set S by means of a matrix as follows, in the adjacency matrix A(G) of G replace the aii element by 1 if and only if vi ϵ S. In this paper we define set energy and find its properties and also study the special case of set S being a dominating set and corresponding domination energy of some special class of graphs. [ABSTRACT FROM AUTHOR]

RC-graphs are special type of graphs. This paper deals with the Eigen values of adjacency matrices and other related matrices of RC-graphs. Many interesting results on eigen values apart from eigen values of general graphs are obtained for RC-graphs. Several directions are initiated towards possible future study. [ABSTRACT FROM AUTHOR]