Artigo de Pesquisa

Hendi FA, Shammakh W and Al-badrani H

This paper is devoted with two analytical methods; Homotopy perturbation method (HPM) and Adomian decomposition method(ADM). We display an efficient application of the ADM and HPM methods to the nonlinear fractional quadratic integral equations of Erdelyi-kober type. The existence and uniqueness of the solution and convergence will be discussed. In particular, the well-known Chandrasekhar integral equation also belong to this class, recent will be discussed. Finally, two numerical examples demonstrate the efficiency of the method.

Artigo de Pesquisa

Lubis MZ, Pujiyati S, Hestirianoto T and Wulandari PD

In wavelet method have a wavelet transform is a signal processing technique was developed as a method to obtain simultaneous, have high resolution frequency and time. Mother wavelet have one method with namely haar wavelet, haar wavelet had become an effective tool for solving many problems arising in many branches of sciences. Haar wavelet functions have been used since year at 1910. It was introduced by the Hungarian mathematician Alfred Haar. This article discuss about signal processing with haar wavelet (continuous wavelet transform) using whistle sound and position of dolphins. Results of modulus of Ca, b Coefficients-Coloration init mode + scale, demonstrating the maximum yield that is in the frequency of 4.1 kHz-5.9 kHz with the brightest colors, and need for the process of de-noising 1D to a level that is more, such as level 10. In this article indicates a change in position dolphins to signal that it generates, and proved this by using the haar wavelet analysis on a dependent threshold level. haar wavelet analysis on a dependent threshold level. Retained energy is 65, 87%-zeros 87, 01% in original and compressed signal with haar wavelet using dolphins whistle sound, Equations or methods used in this article is very effective to remove noise from whistle sound of dolphins.

Artigo de opinião

Hayashi N, Li C and Naumkin PI

We consider the long time asymptotics for dissipative nonlinear Schrödinger equations of order 1

Artigo de opinião

Gomes O

Scientific knowledge covers all aspects of life. Economics, in particular, addresses the choices, the behavior and the interactions of human beings in a wide range of circumstances, and even the most unsuspected themes can be subject to the scrutiny of this science. In this brief note we discuss what Economics is all about, resorting to a small set of contributions published in the recent past in a top Economics journal, namely the Journal of Economic Perspectives.

Artigo de Pesquisa

Zeen El-Deen MR

The aim of this paper is to discuss the folding of Cayley graphs of finite group.We prove that, for any finite group G,|G|=n and H is a subgroup of G. Then Cayley graph Γ=Cay(G,S) of G with respect to S=H\{1G} can be folded into a complete graph K, where r=|H|. Hence every Cayley graph Γ=Cay(G,S) of valency n-1 can not be folded. Also every Cayley graph Γ=Cay(G,S) of valency one can be folded and Γ=Cay(G,S), where S is generating set, every elements in it is self inverse and | |= 1 | | 2 SG, can be folded to an edge. Theorems governing these types of foldings are achieved.

Artigo de Pesquisa

Olayiwola MO

In this paper, an algorithm is constructed based on Variational Iterational Method (VIM) to solve Convection Diffusion equation. The algorithm converges faster and proved elegant. Numerical examples are presented to show the efficiency of the method.

Artigo de Pesquisa

Shahooth, Ahmad RR, Din U-KS, Swidan W, Al-Husseini OK and Shahooth WK

The aim of this study is to present numerical method for solving the linear Volterra-Fredholm integro-differential equations of the second kind. This method is called the Bernestein polynomials method. This technique transforms the integro-differential equations to the system of algebraic equations. Some numerical results are presented to illustrate the efficiency and accuracy of this method.

Artigo de Pesquisa

Gil M

We consider a class of nonautonomous discrete-time systems governed by semilinear vector difference equations with slowly varying linear parts. Sharp exponential stability conditions are suggested. They are formulated in terms of the eigenvalues of the coefficients and constants characterizing the nonlinearities. Our approach is based on the recent norm estimates for solutions of matrix equations.

Artigo de Pesquisa

EL-Kholy E and El-Sharkawey E

In this paper we introduced a new folding over a polygon we called it balanced folding, then we proved that for a balanced folding of a simply connected surface M there is a subgroup of the group of all homeomorphisms of M that acts 1-transitively on the 2-cells of M. Also we explored the relationship between balanced folding and covering spaces. Finally we obtained a general relation of the Euler number of surfaces which may balance folded over a polygon and we also listed all the possibilities if M is a sphere balanced folded over a triangle and we gave the subgroup mentioned above in each case.