Integral Equation Method for Modeling of Two-Dimensional Geoelectricity Problems

The article computes the electromagnetic field on the surface of a layered medium with a local nonhomogeneity. The problem is transformed from three- to two-dimensional and the singulari-ties are investigated using the integral equation method. The proposed algorithm efficiently sim-ulates two-dimensional H-polarization fields by solving a system of integral equations. The method is particularly effective for solving inverse problems. __________ Translated from Prikladnaya Matematika i Informatika, No. 18, pp. 5–16, 2004.     

Integral Equation Method in Electromagnetic-Sounding Inverse Problems

The use of the integral equation method in electromagnetic-sounding inverse problems is considered. Several approaches to the solution of these inverse problems are proposed.     

A Modification of the Projection Method for Integral Equation of the First Kind

A modification of the projection method is proposed for an integral equation of the first kind with a Fourier core on an interval. The proposed method replaces the eigenvectors corresponding to a multiple eigenvalue with odd Hermite functions — the eigenfunctions of the Fourier sine transform on the half-line.     

Asymptotic Error Expansion for the Nystrom Method of Nonlinear Volterra Integral Equation of the Second Kind

1.IntroductionConsiderthenonlinearVolterraintegraJequationofthesecondkindHere,u(x)isanunknownfunction,f(x)andK(x,t,u)aregivencontinuousfunctionsdefined,respectively,on[a,b1andD={(x,t,u):aSx5b,aSt5x)-oc相似文献   

首次积分法求Boussinesq 方程的精确尖波解

首次积分法是一种求解非线性偏微分方程精确解的有效方法,利用首次积 分法获得了Boussinesq方程的一个精确尖波解.     

二阶线性微分方程的可积性判据

文章研究二阶线性微分方程y″+p(x)y′+q(x)y=0可积性.通过寻找p(x),q(x)满足的关系式得到方程可积的充分条件.     

Boundary Integral Equation Method in the Steady State Oscillation Problems for Anisotropic Bodies

The three-dimensional steady state oscillation problems of the elasticity theory for homogeneous anisotropic bodies are studied. By means of the limiting absortion principle the fundamental matrices maximally decaying at infinity are constructed and the generalized Sommerfeld–Kupradze type radiation conditions are formulated. Special functional spaces are introduced in which the basic and mixed exterior boundary value problems of the steady state oscillation theory have unique solutions for arbitrary values of the oscillation parameter. Existence theorems are proved by reduction of the original boundary value problems to equivalent boundary integral (pseudodifferential) equations. © 1997 by B.G. Teubner Stuttgart-John Wiley & Sons, Ltd.     

球面上第二类Fredholm积分方程配置方法

球面上第二类 Fredholm积分方程经球坐标变换可化为矩形域 H0 上的问题求解 .用有限元法构造H0 上的插值函数 ,它必须满足在 H0 的左、右两边连续 ,然后用配置方程求方程的近似解     

二阶常系数线性微分方程的积分形式通解及首次积分

利用一阶线性微分方程的通解 ,导出了二阶常系数线性微分方程的积分形式通解 .研究了通解的结构 ,并给出了首次积分 .     

非定常Stokes方程的多级增强Petrov-Galerkin低阶有限元方法

本文对非定常的Stokes方程采用等阶P1/P1元逼近,增强速度有限元空间,应用Petrov-Galerkin途径,根据多级增强空间是否与时间t有关,对时间项采用向后差分,给出了两种全离散的稳定有限元格式.并且证明了这两种格式的稳定性与收敛性.     

L~1空间带弱奇异核的第二类Fredholm积分方程解法探究

针对带有弱奇异核的第二类Fredholm积分方程数值解法问题,介绍了两种方法.一种方法是直接用L~1空间中的离散化方法求其数值解;另一种方法是将弱奇异核通过迭代变为连续核,再用L~1空间中的离散化方法求其数值解,且通过对具体算例作图分析,从而得出直接用L~1空间中离散化方法更好.     

Stokes问题的区域分解法

本文主要讨论了Ｓｔｏｋｅｓ问题的非重迭型两仓区域性情形的区域分解算法，首先讨论了连续情形，然后将区域分解算法应用到Ｓｔｏｋｅｓ问题的非协调离散情形。     

On the Numerical Solution of Nonstationary Heat-Conduction Outer Problems Using the Integral Equation Method

In this article, we propose three different methods for a numerical solution of the first initial condition boundary-value problem for the heat-conduction equation. Each method is based on the method of limit integral equations.     

Integral Equation Formulation of Oseen Flow Problems

An integral equation approach to the problem of Oseen flow pastobstacles is presented and an approximate solution of the appropriateintegral equations is obtained for low Reynolds numbers. Bothobstacles in bounded and unbounded media are examined.     

The Integral Equation Method and the Neumann Problem for the Poisson Equation on NTA Domains

The Neumann problem for the Poisson equation is studied on a general open subset G of the Euclidean space. The right-hand side is a distribution F supported on the closure of G. It is shown that a solution is the Newton potential corresponding to a distribution B ∈ε (clG), where ε(clG) is the set of all distributions with finite energy supported on the closure of G. The solution is looked for in this form and the original problem reduces to the integral equation TB = F. If the equation TB = F is solvable, then the solution is constructed by the Neumann series. The necessary and sufficient conditions for the solvability of the equation TB = F is given for NTA domains with compact boundary. The research was supported by the Academy of Sciences of the Czech Republic, Institutional Research Plan No. AV0Z10190503.     

Nonlinear Integral Equation of Inverse Scattering Problems of Wave Equation and Iteration

In this paper, we reduce the 1-D, 2-D and 3-D inverse scattering problems of the wave equation into the nonlinear integral equation. The iteration for solving the above integral equations has been considered.     

A Numerical Method of the Ramm Integral Equation

A numerical method for solving the ill-posed Ramm integral equation is presented in this paper. It is found that the method is stable and more accurate. Particularly, when the given data is contaminated by noise, satisfactory results are obtained by using the algorithm of this paper.     

带复数核的第一类Fredholm积分方程的正则化方法及其应用

本文推广了Ｔｉｋｈｏｎｏｖ正则化方法，导出了带复数核的第一类Ｆｒｅｄｈｏｌｍ积分方程的正则解应满足的正则积分微分方程，并讨论了正则解的收敛性·作为这一方法的应用，数值求解了与二维摇板造波问题相应的一类逆问题，并给出了选择最佳正则参数的一个实用的方法     

Iterative Method for Solving Integral Equations of the First Kind

A new iterative method is proposed for solving integral equations of the first kind. The efficiency of the method is demonstrated using examples of typical integral kernels.