it is very important for managers, investors and financial policy-makers to detect and analyze factors affecting financial markets to obtain optimal decision and reduce risks. the importance of market analysis and attempt to improve its behavior understanding, has led analysts to use the experiences of other professionals in the fields such as social sciences and mathematics to examine the inte...

Throughout this paper, R will denote a commutative ring with identity and M is a unitary R- module and Z will denote the ring of integers. We introduce the graph Ω(M) of module M with the set of vertices contain all nontrivial non-essential submodules of M. We investigate the interplay between graph-theoretic properties of Ω(M) and algebraic properties of M. Also, we assign the values of natura...

In this paper, we study matching integral graphs of small order. A graph is called matching integral if the zeros of its matching polynomial are all integers. Matching integral graphs were first studied by Akbari, Khalashi, etc. They characterized all traceable graphs which are matching integral. They studied matching integral regular graphs. Furthermore, it has been shown that there is no matc...

Graph grammars have been studied by several authors. The motivations of these works have arisen from completely different areas of computer science, such as picture processing (Pfaltz and Rosenfeld, 1969; Montanari, 1970; Rosenfeld and Milgram, 1972; Pavlidis, 1972; Abe et al., 1973; Furtado and Mylopoulos, 1975; Fu and Brayer, 1975) or formal semantics of programming languages (Pratt, 1971). I...

graph theory based methods are powerful means for representing structural systems so that their geometry and topology can be understood clearly. the combination of graph theory based methods and some metaheuristics can offer effective solutions for complex engineering optimization problems. this paper presents a charged system search (css) algorithm for the free shape optimizations of thin-wall...