نتایج جستجو برای: chemical graph theory

تعداد نتایج: 1277645  

2003
Sandi Klavžar Petra Žigert

Fibonacci cubes were introduced in 1993 and intensively studied afterwards. This paper adds the following theorem to these studies: Fibonacci cubes are precisely the resonance graphs of fibonaccenes. Here fibonaccenes are graphs that appear in chemical graph theory and resonance graphs reflect the structure of their perfect matchings. Some consequences of the main result are also listed.

Journal: :Electr. Notes Theor. Comput. Sci. 2005
Francesc Rosselló Gabriel Valiente

Chemical reactions are described by edge relabeling graph transformation rules, in which a substrate chemical graph is transformed into a product chemical graph by breaking existing bonds and creating new bonds between atoms. These edge relabeling graph transformation rules are themselves chemical graphs, where the order of a bond before the chemical reaction is distinguished from the order of ...

The notion of strong arcs in a fuzzy graph was introduced byBhutani and Rosenfeld in [1] and fuzzy end nodes in the subsequent paper[2] using the concept of strong arcs. In Mordeson and Yao [7], the notion of“degrees” for concepts fuzzified from graph theory were defined and studied.In this note, we discuss degrees for fuzzy end nodes and study further someproperties of fuzzy end nodes and fuzz...

Journal: :Appl. Math. Lett. 2002
Gordon G. Cash

The Hosoya polynomial of a graph, H(G, z), has the property that its first derivative, evaluated at z = 1, equals the Wiener index, i.e., W(G) = H’(G, 1). In this paper, an equation is presented that gives the hyper-Wiener index, WW(G), in terms of the first and second derivatives of H(G,z). Also defined here is a hyper-Hosoya polynomial, HH(G,r), which has the property WW(G) = HH’(G, l), analo...

2013
Tatsuya Akutsu Hiroshi Nagamochi

Chemical compounds are usually represented as graph structured data in computers. In this review article, we overview several graph classes relevant to chemical compounds and the computational complexities of several fundamental problems for these graph classes. In particular, we consider the following problems: determining whether two chemical graphs are identical, determining whether one inpu...

Journal: :journal of physical & theoretical chemistry 2007
a. taherpour f. shafiee

topological indices are the numerical value associated with chemical constitution purporting for correlation ofchemical structure with various physical properties, chemical reactivity or biological activity. graph theory is adelightful playground for the exploration of proof techniques in discrete mathematics and its results haveapplications in many areas of sciences. one of the useful indices ...

Journal: :international journal of environmental research 2015
a. p toropova a. a. toropov j. b. veselinović a. m. veselinović e, benfenati

the dispersibility of graphene is modeled as a mathematical function of the molecular structure of solvent represented by simplified molecular input-line entry systems (smiles) together with the graph of atomic orbitals (gao). the gao is molecular graph where atomic orbitals e.g. 1s1, 2p4, 3d7 etc., are vertexes of the graph instead of the chemical elements used as the graph vertexes in the tra...

In this paper, a self-healing approach for smart distribution network is presented based on Graph theory and cut sets. In the proposed Graph theory based approach, the upstream grid and all the existing microgrids are modeled as a common node after fault occurrence. Thereafter, the maneuvering lines which are in the cut sets are selected as the recovery path for alternatives networks by making ...

Journal: :Discrete Applied Mathematics 2015
David Amos Yair Caro Randy Davila Ryan Pepper

Given a simple undirected graph G and a positive integer k, the k-forcing number of G, denoted Fk(G), is the minimum number of vertices that need to be initially colored so that all vertices eventually become colored during the discrete dynamical process described by the following rule. Starting from an initial set of colored vertices and stopping when all vertices are colored: if a colored ver...

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