INTERNATIONAL JOURNAL OF MATHEMATICAL MODELLING & COMPUTATION
Year:2012 | Volume:2 | Issue:3|Papers Count:8

The combined effect of non-Newtonian rheology and irreversible boundary reaction on dispersion in a Herschel-Bulkley fluid through a conduit (pipe/channel) is studied by using generalized dispersion model. The study explains the development of dispersive transport following the injection of a tracer in terms of three effective transport coefficients namely exchange, convective and dispersion coefficients. It is found that the exchange coefficient does not depend on yield stress and power law index but the convective and dispersion coefficients depend on yield stress and power law index.

A simple mathematical model of steady state oxygen distribution subject to diffusive transport and non- linear uptake in a retinal cylinder has been developed. The approximate analytical solution to a reaction-diffusion equation are obtained by using series expansions. The computational results for the scaled variables are presented through graphs. The effect of the important parameters (1) diffusion coefficient (2) metabolic rate constant (3) retinal capillary concentration are examined and discussed.

In this paper a mathematical simulation of a simplified internal combustion engine is presented. To contribute engine kinematics and its geometry, simple relations are derived for constrained motions. The equation of motion for the piston forms a singular boundary value problem. The uniqueness of the solution was studied in the Banach space. For solving governing equations an iterative numerical algorithm was used and the numerical method has shown very fast convergency. With this simulation the thermodynamics of expansion process is coupled with piston dynamics. Simulating an engine working at constant torque and polytropic expansions has shown high frequency piston vibration under certain conditions.

In this paper, we investigate the problems of consensus-making among institution in stock exchange with multiple criteria for evaluating performance when the players (institutions) are supposed to be egoistic and the score for each criterion for a player is supposed to be a positive score. Each player sticks to his superiority regarding the criteria. This paper introduces the models for computing minimal cost ratio and the maximal benefit for institutions.

In this paper we propose a method to approximate a parametric 3D -function by bicubic B-spline functions.

In this paper, the ambiguity of finite state irreducible Markov chain trajectories is reminded and is obtained for two state Markov chain. I give an applicable example of this concept in President election.

The main aim of this paper intends to discuss the solution of fuzzy Sylvester matrix equation AX+XB=C where A= (aij)ÎRn´n, B= (bij) ÎRm´m are crisp M- matrices, C= (cij) ÎRn´m is fuzzy matrix and XÎRn´m is unknown, by applying a special algorithm based on a class of ABS algorithms called Huang algorithm. At first, we transform this system to an (mn)´(mn) fuzzy system of linear equations. Then, we convert this system to three (mn)´(mn) crisp linear systems of equations, and we solve them simultaneously by ABS algorithm.

In this work, we study the performance of the sinc-Collocation method for solving Bratu’s problem. For different choices of step size, we consider the maximum absolute errors in the solutions at sinc grid points and tabulated in tables. The comparison of the obtained results verified that this method converges to the exact solution rapidly and with O (exp (-cÖn)) accuracy where c is independent of n.