if we consider some special conditions, we can assume fundamental group of a topological space as a new topological space. in this paper, we will present a number of theorems in topological fundamental group related to semilocally simply connected property for a topological space.

a novel discrete singular convolution (dsc)  formulation  is  presented for the seepage analysis in irregular geometric porous media. the dsc is a new promising numerical approach which has been recently applied to solve several engineering problems. for a medium with regular geometry, realizing of the dsc for the seepage analysis is straight forward. but dsc implementation for a medium with ir...

nonlinear knapsack problems (nkp) are the alternative formulation for the multiple-choice knapsack problems. a powerful approach for solving nkp is dynamic programming which may obtain the global op-timal solution even in the case of discrete solution space for these problems. despite the power of this solu-tion approach, it computationally performs very slowly when the solution space of the pr...

in this paper we study shadowing property for sequences of mappings on compact metric spaces, i.e. nonautonomous discrete dynamical systems. we investigate the relation of  weak contractions with shadowing and h-shadowing property.

different discrete models of population dynamics of certain insects have been investigated under various feasible conditions within the framework of nonlinear dynamics. evolutionary phenomena are discussed through bifurcation analysis leading to chaos. some tools of nonlinear dynamics, such as lyapunov characteristic exponents (lce), lyapunov numbers, correlation dimension, etc. are calculated ...

In studying through simulation, choosing an appropriate tool/language would be a difficult task because many of them are available. On the other hand, few research works focus on evaluation of simulation tools/languages and their comparison. This paper makes a couple of evaluations and ranks more than fifty simulation tools that are currently available. The first evaluation and ranking is in th...

introduction in recent years methods based on radio frequency waves have been used for detecting breast cancer. using theses waves leads to better results in early detection of breast cancer comparing with conventional mammography which has been used during several years. materials and methods in this paper, a new method is introduced for detection of backscattered signals which are received by...