abstract. the main contribution of the current paper is to propose a new effective numerical method for solving the first-order linear matrix differential equations. properties of the legendre basis operational matrix of integration together with a collocation method are applied to reduce the problem to a coupled linear matrix equations. afterwards, an iterative algorithm is examined for solvin...

In the past 2 decades latent variable modeling has become a standard tool in the social sciences. In the same time period, traditional linear structural equation models have been extended to include non-linear interaction and quadratic effects (e.g., Klein and Moosbrugger, 2000), and multilevel modeling (Rabe-Hesketh et al., 2004). We present a general non-linear multilevel structural equation ...

In this paper we study one-dimensional Fisher-Kolmogorov equation with density dependent non-linear diffusion. We choose the diffusion as a function of cell density such that it is high in highly cell populated areas and it is small in the regions of fewer cells. The Fisher equation with non-linear diffusion is known as modified Fisher equation. We study the travelling wave solution of modified...

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) d...

Analytical solutions have been obtained for both conservative and non-conservative forms of one-dimensional transport and transport-dispersion equations applicable for pollution as a result of a non-conservative pollutant-disposal in an open channel with linear spatially varying transport velocity and nonlinear spatially varying dispersion coefficient on account of a steady unpolluted lateral i...

In this paper, we have proposed a study on controllability and optimal harvestingof a prey predator model and mathematical non linear formation of the equation equilibriumpoint of Routh harvest stability analysis. The problem of determining the optimal harvestpolicy is solved by invoking Pontryagin0s maximum principle dynamic optimization of theharvest policy is studied by taking the combined h...

an experiment was carried out to estimate growth parameters of broiler chickens received artichoke extract in their drinking water using gompertz non-linear model and to compare gompertz non-linear regression equation and artificial neural network modeling in terms of their ability to predict body weight of broiler chicks at day 42 of age. a total number of 250 one- day- old ross 308 broiler ch...

A master equation (n dimensional non–Abelian current conservation law with mutually commuting current components) is introduced for multi-dimensional non-linear field theories. It is shown that the master equation provides a systematic way to understand 2-d integrable non-linear equations as well as 4-d self-dual equations and, more importantly, their generalizations to higher dimensions.

This article describes a set of experiences in modeling dynamic systems using Genetic Programming and Gene Expression Programming. We have made experiments in linear systems, non-linear systems and times series. The experiments in linear systems include linear pendulum, coupled mass-spring, electrical circuits, etc. In non-linear systems we have modeled the Van der Pol Equation, non-linear pend...