Abstract: Publication date: May 2019 Source:Universal Journal of Computational Mathematics Volume 7 Number 1 Araceli Giménez Lorente It presents a mathematical modeling of a biological system, this is a particular case of two fractal sets, an attractor repeller pair, according to the definition given by the Morse-Smalle theory; these are complementary fractal sets, since the complementary of the fractal repeller set is the attractor set, as we can see in the demonstration. The existence of this model in Nature is found in the flight of starlings. This dynamic system works like a beat of a heart, where the movement of the systole is equivalent to the contraction (attractor set) of the flight trajectory of birds and the diastole movement to its expansion (repeller set).The modeling is presented with differential equations written in Matlab code, and several images of the fractal sets associated with the flight pattern of the starlings are generated, so that we can see this model more clearly. We will begin with a definition and its subsequent mathematical demonstration to study this complex system of complementary fractals. PubDate: May 2019

Abstract: Publication date: May 2019 Source:Universal Journal of Computational Mathematics Volume 7 Number 1 V. K. Shchigolev In this paper, some new approximations to the cumulative distribution function of the standard normal distribution via the He's homotopy perturbation method are proposed. There are several methods which provide an approximation of the integral in the formula for the cumulative distribution function by different numerical methods. For the same purpose, we first establish a differential equation of the second order that the cumulative distribution function satisfied subjected with the certain initial conditions. Then we apply the Homotopy Perturbation Method to solve the Cauchy problem for the governing equation. As well known, the result of solving an equation by this method and the convergence rate greatly depend on the choice of homotopy applied. Therefore, we consider two cases in this work. In one case, we construct the homotopy from the idea of simplicity. In the next case, we just follow the procedure of the general approach proposed early. As a result, we obtain several approximations which can be are easily calculated and are better than some other approximations. Numerical comparison shows that our approximations are very accurate. PubDate: May 2019

Abstract: Publication date: May 2019 Source:Universal Journal of Computational Mathematics Volume 7 Number 1 Maryam Mazdarani Ali Asghar Khakpoor and Bahare Agahi Keshe In the future molecular electronic is substitute the silicon electronic by the organic molecules. Due to p orbital's, upper and lower electron clouds, and resonance phenomenon, the aromatic hydrocarbon from the root of benzene can provide suitable environments for electron transition. A useful approach for this purpose is an appropriate pattern to predict electronic properties by topological indices method (TIM). Therefore, it is first tried to produce a relationship between the topological indices based on the number of rings; then F index values are measured for Circumacenes family. The gap energy changes in the family of C8(n+2)/3H(2n+22)/3 was calculated using Gaussian 09 Software by Hartree–Fock method. The relationships described the gap energy changes in the Circumacenes family achieved by F index. Finally, some heavier members of Circumacenes family are exposed to TIM to predict of Gap energy. PubDate: May 2019