Three-layer finite difference method for solving linear differential algebraic systems of partial differential equations

A boundary value problem is examined for a linear differential algebraic system of partial differential equations with a special structure of the associate matrix pencil. The use of an appropriate transformation makes it possible to split such a system into a system of ordinary differential equations, a hyperbolic system, and a linear algebraic system. A three-layer finite difference method is applied to solve the resulting problem numerically. A theorem on the stability and the convergence of this method is proved, and some numerical results are presented.     

An exponential matrix method for solving systems of linear differential equations

This paper presents an exponential matrix method for the solutions of systems of high‐order linear differential equations with variable coefficients. The problem is considered with the mixed conditions. On the basis of the method, the matrix forms of exponential functions and their derivatives are constructed, and then by substituting the collocation points into the matrix forms, the fundamental matrix equation is formed. This matrix equation corresponds to a system of linear algebraic equations. By solving this system, the unknown coefficients are determined and thus the approximate solutions are obtained. Also, an error estimation based on the residual functions is presented for the method. The approximate solutions are improved by using this error estimation. To demonstrate the efficiency of the method, some numerical examples are given and the comparisons are made with the results of other methods. Copyright © 2012 John Wiley & Sons, Ltd.     

An efficient predictor-corrector method for solving nonlinear equations

This paper proposes an efficient continuation method for solving nonlinear equations. The proposed method belongs to a class of predictor-corrector methods and uses modified Euler's predictors in order that larger step-sizes may be accepted. Some numerical results show that the method obtains a solution with less computational effort than the ordinary Euler's method, especially when the starting point is far from the solution.     

An Iterative method for solving fractional differential equations

In the present paper non-linear, time fractional advection partial differential equation has been solved using the new iterative method presented by Daftardar-Gejji and Jafari [1]. The results are compared with those obtained by Adomian decomposition and Homotopy perturbation methods. It is demonstrated that the new iterative method gives the best approximation among these. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

One-step recursive method for solving systems of differential equations

In this work an iteration one-step method to integrate systems of nonlinear ordinary differential equations with initial values is presented     

Application to differential transformation method for solving systems of differential equations

In this paper, we present an analytical solution for different systems of differential equations by using the differential transformation method. The convergence of this method has been discussed with some examples which are presented to show the ability of the method for linear and non-linear systems of differential equations. We begin by showing how the differential transformation method applies to a non-linear system of differential equations and give two examples to illustrate the sufficiency of the method for linear and non-linear stiff systems of differential equations. The results obtained are in good agreement with the exact solution and Runge–Kutta method. These results show that the technique introduced here is accurate and easy to apply.     

A semi-analytical numerical method for solving evolution and elliptic partial differential equations

A new method for analyzing initial–boundary value problems for linear and integrable nonlinear partial differential equations (PDEs) has been introduced by one of the authors.     

An optimization method for solving some differential algebraic equations

In this paper, the problem of differential algebraic equations has been solved via Chebyshev integral method combined with an optimization method. Two approaches are used based on the index of the problem: in the first, the proposed method is applied on the original problem and in the second, the index of the problem is decreased and the modified problem is solved. An optimization technique is proposed to solve the resulting algebraic equations. Numerical results are included to confirm the efficiency and accuracy of the method.     

One method for solving systems of nonlinear partial differential equations

A method for reducing systems of partial differential equations to corresponding systems of ordinary differential equations is proposed. A system of equations describing two-dimensional, cylindrical, and spherical flows of a polytropic gas; a system of dimensionless Stokes equations for the dynamics of a viscous incompressible fluid; a system of Maxwell’s equations for vacuum; and a system of gas dynamics equations in cylindrical coordinates are studied. It is shown how this approach can be used for solving certain problems (shockless compression, turbulence, etc.).     

A computer science approach for solving elliptic differential equations

A method that combines computer science and numerical analysis techniques for the solution of elliptic partial differential equations in domains consisting of the union of rectangles is presented. It is applied to Laplace's equation and to the Navier–Stokes equations in several domains. The method is very flexible and can be easily modified to solve other equations. © 1995 John Wiley & Sons, Inc.     

On some high accuracy difference schemes for solving elliptic equations

Summary Two well known high accuracy Alternating Direction Implicit difference schemes for solving Laplace's equation and the Biharmonic equation are considered. The set of iteration parameters of Douglas is used in both problems. More complete optimum values of the parameters involved are given.     

关于解线性系统的一个有效的贝叶斯迭代方法

This paper concerns with the statistical methods for solving general linear systems. After a brief review of Bayesian perspective for inverse problems,a new and efficient iterative method for general linear systems from a Bayesian perspective is proposed.The convergence of this iterative method is proved,and the corresponding error analysis is studied.Finally, numerical experiments are given to support the efficiency of this iterative method,and some conclusions are obtained.     

Effective method for solving singularly perturbed systems of nonlinear differential equations

A boundary-value problem for a class of singularly perturbed systems of nonlinear ordinary differential equations is considered. An analytic-numerical method for solving this problem is proposed. The method combines the operational Newton method with the method of continuation by a parameter and construction of the initial approximation in an explicit form. The method is applied to the particular system arising when simulating the interaction of physical fields in a semiconductor diode. The Frechét derivative and the Green function for the corresponding differential equation are found analytically in this case. Numerical simulations demonstrate a high efficiency and superexponential rate of convergence of the method proposed. __________ Translated from Sovremennaya Matematika. Fundamental’nye Napravleniya (Contemporary Mathematics. Fundamental Directions), Vol. 15, Differential and Functional Differential Equations. Part 1, 2006.     

Regularity results for differential forms solving degenerate elliptic systems

We present a partial Hölder regularity result for differential forms solving degenerate systems $$d^\ast A(\cdot,\omega) = 0 \quad {\rm and} \quad d \omega = 0$$ on bounded domains in the weak sense. Here certain continuity, monotonicity, growth and structure condition are imposed on the coefficients, including an asymptotic Uhlenbeck behavior close to the origin. Pursuing an approach of Duzaar and Mingione (J Math Anal Appl 352(1):301–335, 2009), we combine non-degenerate and degenerate harmonic-type approximation lemmas for the proof of the partial regularity result, giving several extensions and simplifications. In particular, we benefit from a direct proof of the approximation lemma (Diening et al. 2010) that simplifies and unifies the proof in the power growth case. Moreover, we give the dimension reduction for the set of singular points.     

An efficient method for solving nonlocal initial-boundary value problems for linear and nonlinear first-order hyperbolic partial differential equations

In this paper, we present a new approach to solve nonlocal initial-boundary value problems of linear and nonlinear hyperbolic partial differential equations of first-order subject to initial and nonlocal boundary conditions of integral type. We first transform the given nonlocal initial-boundary value problems into local initial-boundary value problems. Then we apply a modified Adomian decomposition method, which permits convenient resolution of these problems. Moreover, we prove this decomposition scheme applied to such nonlocal problems is convergent in a suitable Hilbert space, and then extend our discussion to include systems of first-order linear equations and other related nonlocal initial-boundary value problems.