International Journal of Industrial Mathematics
Volume:7 Issue: 3, Summer 2015

Let $G$ be a group and $\pi(G)$ be the set of primes $p$ such that $G$ contains an element of order $p$. Let $nse(G)$ be the set of the number of elements of the same order in $G$. In this paper, we prove that the simple group $L_2(p^2)$ is uniquely determined by $nse(L_2(p^2))$, where $p\in\{11,13\}$‎.‎

In this paper, we have proposed a new iterative method for finding the solution of ordinary differential equations of the first order. In this method we have extended the idea of variational iteration method by changing the general Lagrange multiplier which is defined in the context of the variational iteration method.This causes the convergent rate of the method increased compared with the variational iteration method. To prevent consuming large amount of the CPU time and computer memory and to control requires significant amounts of computations, the Taylor expansion of the iterative functions in each iteration are applied. Finally to extend the convergence region of the truncated series, also the Pade approximants are used. Error analysis and convergence of the method are studied. Some examples are given to illustrate the performance and efficiency of the proposed method. For comparison, the results obtained by the our method and the variational iteration method are ‎presented.

In this paper, we propose a successive approximation method based on fuzzy wavelet like operator to approximate the solution of linear fuzzy Fredholm integral equations of the second kind with arbitrary kernels. We give the convergence conditions and an error estimate. Also, we investigate the numerical stability of the computed values with respect to small perturbations in the first iteration. Finally, to show the efficiency of the proposed method, we present some test problems, for which the exact solutions are ‎known.‎

Fuzzy control systems have had various applications in a wide range of science and engineering in recent years. Since an unstable control system is typically useless and potentially dangerous, stability is the most important requirement for any control system (including fuzzy control system). Conceptually, there are two types of stability for control systems: Lyapunov stability (a special case of which is exponential stability) and input-output stability. This paper develops fuzzy Lyapunov stability through investigating the concept of stability for finite-dimensional systems under uncertainty and provides some related theorems. Considering the capability of fuzzy differential systems for modeling uncertainty and processing vague or subjective information in mathematical models, exponential stability and Lyapunov stability of fuzzy differential systems are presented. Also, numerical examples are given to support the theoretical ‎results.

This paper uses the weighted L$_1-$norm to propose an algorithm for finding a well-dispersed subset of non-dominated solutions of multiple objective mixed integer linear programming problem. When all variables are integer it finds the whole set of efficient solutions. In each iteration of the proposed method only a mixed integer linear programming problem is solved and its optimal solutions generates the elements of the well-dispersed subset non-dominated solutions (WDSNDSs) of MOMILP. According to the distance of non-dominated solutions from the ideal point theelements of the WDSNDSs are ranked, hence it does not need the filtering procedures. Using suitable values for the parameter of the proposed model an appropriate WDSNDSs by less computational efforts can be generated. Two numerical examples present to illustrate the applicability of the proposed method and compare it with earlier ‎work.‎

The heat and mass transfer analysis for MHD Casson fluid boundary layer flow over a permeable stretching sheet through a porous medium is carried out. The effect of non-uniform heat generation/absorption and chemical reaction are considered in heat and mass transport equations correspondingly. The heat transfer analysis has been carried out for two different heating processes namely; the prescribed surface temperature (PST) and prescribed surface heat flux (PHF). After transforming the governing equations into a set of non-linear ordinary differential equations, the numerical solutions are generated by an efficient Runge-Kutta-Fehlberg fourth-fifth order method. The solutions are found to be dependent on physical parameters such as Casson fluid parameter, magnetic parameter, porous parameter, Prandtl and Schmidt number, heat source/sink parameter, suction/injection parameter and chemical reaction parameter. Typical results for the velocity, temperature and concentration profiles as well as the skin-friction coefficient, local Nusselt number and local Sherwood number are presented for different values of these pertinent parameters to reveal the tendency of the solutions. The obtained results are compared with earlier results with some limiting cases of the problem and found to be in good ‎agreement.‎

‎This paper deals with one problem that needs to be addressed in the emerging field known under the name computing with perceptions‎. ‎It is the problem of describing‎, ‎approximately‎, ‎a given fuzzy set in natural‎ ‎language‎. ‎This problem has lately been referred to as the problem of retranslation‎. ‎An approaches to ‎dealing with the retranslation problem is discussed in the paper‎, ‎that is based on a pre-defined set of ‎linguistic terms and the associated fuzzy sets‎. ‎The retranslation problem is discussed in ‎terms of two criteria validity and informativeness‎.

In this study, based on the optimal free derivative without memory methods proposed by Cordero et al. [A. Cordero, J.L. Hueso, E. Martinez, J.R. Torregrosa, Generating optimal derivative free iterative methods for nonlinear equations by using polynomial interpolation, Mathematical and Computer Modeling. 57 (2013) 1950-1956], we develop two new iterative with memory methods for solving a nonlinear equation. The first has two steps with three self-accelerating parameters, and the second has three steps with four self-accelerating parameters. These parameters are calculated using information from the current and previous iteration so that the presented methods may be regarded as the with memory methods. The self-accelerating parameters are computed applying Newton''s interpolatory polynomials. Moreover, they use three and four functional evaluations per iteration and corresponding R-orders of convergence are increased from 4 ad 8 to 7.53 and 15.51, respectively. It means that, without any new function calculations, we can improve convergence order by $93\%$ and $96\%$. We provide rigorous theories along with some numerical test problems to confirm theoretical results and high computational efficiency.

Although Elzaki transform is stronger than Sumudu and Laplace transforms to solve the ordinary differential equations withnon-constant coefficients, but this method does not lead to finding the answer of some differential equations. In this paper, a method is introduced to find that a differential equation by Elzaki transform can be ‎solved?‎