The center (periphery) of a graph is the set of vertices with minimum (maximum) eccentricity. In this paper, the structure of centers and peripheries of some classes of composite graphs are determined. The relations between eccentricity, radius and diameter of such composite graphs are also investigated. As an application we determine the center and periphery of some chemical graphs such as nan...

sepahan is a new bread wheat cultivar derived from progenies of a cross made between azadi cultivar and some high yielding and resistant to rust advanced lines. all selections were made in kelardasht and iranshahr stations and early evaluations in karaj. it was also studied in regional uniform yield trials in moderate stations including kaboutar abad. results revealed that this line is more tol...

The crystal structure of the title Schiff base complex is obtained by single-crystal X-ray diffraction data.The solid state structure determination reveals that the coordination geometry around the copper(II) center istetrahedrally distorted square-planar. The crystal packing shows one dimensional infinite chains which arisesfrom the intermolecular interaction and stabilize the crystal packing.

this paper investigates the dynamics and stability properties of a discrete-time lotka-volterra type system. we first analyze stability of the fixed points and the existence of local bifurcations. our analysis shows the presence of rich variety of local bifurcations, namely, stable fixed points; in which population numbers remain constant, periodic cycles; in which population numbers oscillate amo...

in this paper, a novel approach for ranking fuzzy numbers based on the angle measure is introduced. several left and right spreads at each chosen levels of fuzzy numbers is used to determine center of mass points(cmps) and then, the angels between the cmps and the horizontal axis is calculated. the total angle is determined by averaging the computed angles and finally, the novel method is compa...

In this paper we propose a new method for ranking Z- numbers and generalizations. This method is based on the internal structure of the artificial neural network, which suggests that the structure of this network consists of inputs weights and the transfer function linear, nonlinear and sometimes linear and nonlinear. It is shown that the proposed method while possessing the ranking properties ...