WAVELET METHOD FOR BOUNDARY INTEGRAL EQUATIONS

1.IntroductionTheapplicationofwaveletstosignalandimageprocessinghasbeensuccessful.Buttherearefewresultsaboutnumericalsolutionforthepartialdifferentialequations.Wethinkthatitisenoughonlytousethecoefficiellts{h.}(asafilter)insignalandimageprocessing,butitisnotsufficientfornumericalcomputation[7][8][lo],whereweconsiderwaveletasaspecialfunctionseriesinsteadofafilter.Thenitbringssomeproblemssuchasthecomplicationoffunctionvaluecomputationandthedifficultytohandletheboundaryco.ditio.s[8][13]5etc.FOrt…     

一类积分方程的稳定性与吸引域

本文通过建立非线性积分不等式,讨论了一类具有时滞积分方程的渐近稳定性．获得了简捷而实用的充分准则,并给出了确定吸引域的方法．     

非线性弱奇性Volterra积分方程的谱配置法

基于已有文献的研究成果及前期工作,我们考察了非线性弱奇性Volterra积分方程（VIE）的谱配置法,并对该方法进行了收敛性分析.得到的结论是数值误差呈谱收敛.误差收敛阶与配置点个数及方程解的正则性相关.数值实验也证实了这一结论.本文的方法解决了已有文献中类似数值方法（Allaei（2016）,Sohrabi（2017））存在的问题.     

带变系数的第二类奇异积分方程的Galerkin解法

基于对未知函数用适当的正交多项式进行逼近，本文讨论了带变系数的第二类奇异积分方程的Galerkin解法，证明了逼近解的存在唯一性，给出了逼近解在带权L^2模和一致模下的误差估计．     

非线性第二类Volterra积分方程的Chebyshev谱配置法

我们在参考了相关文献的基础上,考察了一类非线性Volterra积分方程的Chebyshev谱配置法.方法中,我们将该类非线性方程转化为两个方程进行数值逼近.我们选择N阶Chebyshev Gauss-Lobatto点作为配置点,对积分项用N阶高斯数值积分公式逼近.收敛性分析结果表明数值误差的收敛阶为N^（1/2）-m,其中m是已知函数最高连续导数的阶数.我们也开展数值实验证实这一理论分析结果.     

FAST DENSE MATRIX METHOD FOR THE SOLUTION OF INTEGRAL EQUATIONS OF THE SECOND KIND

We present a fast algorithm based on polynomial interpolation to approximate matrices arising from the discretization of second-kind integral equations where the kernel function is either smooth, non-oscillatory and possessing only a finite number of singularities or a product of such function with a highly oscillatory coefficient function. Contrast to wavelet-like approximations, ourapproximation matrix is not sparse. However, the approximation can be construced in O(n) operations and requires O(n) storage, where n is the number of quadrature points used in the discretization. Moreover, the matrix-vector multiplication cost is of order O(nlogn). Thus our scheme is well suitable for conjugate gradient type methods. Our numerical results indicate that the algorithm is very accurate and stable for high degree polynomial interpolation.     

SOLUTION OF A CLASS INTEGRALEQUATIONS

1TwoTheoremsonmultipleintegrationTheorem1.1Supposethatf(t)isarbitrarycontinuousfunctiondefinedonRandh(fl,'')fi)isarbitrarycontinuousfunctiondefinedonm(1Sp0}ProofWeshallproveitbymathematicalinduction…     

二维Fredholm积分方程Nystrom方法的渐近展开及其外推

本文讨论了求解二维第二类Ｆｒｅｄｈｏｌｍ积分方程的Ｎｙｓｔｒｏｍ方法，得到了数值解的逐项渐近展开，从而可进行Ｒｉｃｈａｒｄｓｏｎ外推，提高数值解的精度。     

边界曲线积分方程的小波解法

The boundary measure method is applied to transfer the form of the integral equation in order to use the collocation method or Galerkin method. A simple way to computer the coefficients of the wavelet series is also introduced. The way presented in this paper can be used to solve PDE problem in the two dimension region with any form of boundary.     

第二类端点奇异Fredholm积分方程的分数阶退化核方法

本文针对第二类端点奇异Fredholm积分方程构造基于分数阶Taylor展开的退化核方法，设计了两种计算格式，一是在全区间上使用分数阶Taylor展开式近似核函数，二是在包含奇点的小区间上采用分数阶插值，在剩余区间上采用分段二次多项式插值逼近核函数.讨论了两种退化核方法收敛的条件，并给出了混合插值法的收敛阶估计.数值算例表明对于非光滑核函数分数阶退化核方法有着良好的计算效果，且混合二次插值法比全区间上的分数阶退化核方法有着更广泛的适用范围.     

IMPLICITY LINEAR COLLOCATION METHOD AND ITERATED IMPLICITY LINEAR COLLOCATION METHOD FOR THE NUMERICAL SOLUTION OF HAMMERSTEIN FREDHOLM INTEGRAL EQUATIONS ON 2D IRREGULAR DOMAINS

In this work, we adapt and compare implicity linear collocation method and iterated implicity linear collocation method for solving nonlinear two dimensional Fredholm integral equations of Hammerstein type using IMQ-RBFs on a non-rectangular domain. IMQs show to be the most promising RBFs for this kind of equations. The proposed methods are mesh-free and they are independent of the geometry of domain. Convergence analysis of the proposed methods together with some benchmark examples is provided which support their reliability and numerical stability.     

MULTIPLE POSITIVE SOLUTIONS TO A SYSTEM OF NONLINEAR HAMMERSTEIN TYPE INTEGRAL EQUATIONS

In this paper, we use cone theory and a new method of computation of fixed point index to study a system of nonlinear Hammerstein type integral equations, and the existence of multiple positive solutions to the system is discussed.     

一类非线性积分,微分方程的逼近解

在不主紧型条件和耗散型条件的情形下，得到了Ｂａｎａｃｈ空间中一类非线性积分，微分方程的逼近解。     

无限时滞的泛函积分方程与积分不等式

本文考虑形如ｘ（ｔ）＝ｗ（ｔ）＋∫＾ｔ０ｆ（ｔ，ｓ，ｘｓ）ｄｓ的具无限时滞的Ｖｏｌｔｅｒｒａ型积分方程。给出了这样一个方程存在唯一整体解的充分条件，并由此导出相应的积分不等式结果。     

LOCAL GAUSSIAN-COLLOCATION SCHEME TO APPROXIMATE THE SOLUTION OF NONLINEAR FRACTIONAL DIFFERENTIAL EQUATIONS USING VOLTERRA INTEGRAL EQUATIONS

This work describes an accurate and effective method for numerically solving a class of nonlinear fractional differential equations.To start the method,we equivalently convert these types of differential equations to nonlinear fractional Volterra integral equations of the second kind by integrating from both sides of them.Afterward,the solution of the mentioned Volterra integral equations can be estimated using the collocation method based on locally supported Gaussian functions.The local Gaussian-collocation scheme estimates the unknown function utilizing a small set of data instead of all points in the solution domain,so the proposed method uses much less computer memory and volume computing in comparison with global cases.We apply the composite non-uniform Gauss-Legendre quadrature formula to estimate singular-fractional integrals in the method.Because of the fact that the proposed scheme requires no cell structures on the domain,it is a meshless method.Furthermore,we obtain the error analysis of the proposed method and demon-strate that the convergence rate of the approach is arbitrarily high.Illustrative examples clearly show the reliability and efficiency of the new technique and confirm the theoretical error estimates.     

INTEGRAL BOUNDARY VALUE PROBLEM FOR FIRST ORDER IMPULSIVE INTEGRO-DIFFERENTIAL EQUATIONS

By developing a comparison result and using the monotone iterative technique, we obtain the existence of the minimal and the maximal solutions to an integral boundary value problem for first order impulsive integro-differential equations.     

Banach空间非线性混合单调Hammerstein型积分方程的迭代解

在Ｂａｎａｃｈ空间中，建立了“非线性混合单调型算子”不动点和最大最小耦合不动点的存在与迭代逼近定理，并应用到序Ｂａｎａｃｈ空间非线性混合单调Ｈａｍｍｅｒｓｔｅｉｎ型积分方程．     

求解一类具有Hibert核的奇异积分方程的小波方法

1　引　　言近年来,用小波方法数值求解积分方程越来越引起人们的注意.文献[1]提出的算法可将一类积分算子所对应的矩阵稀疏化,为小波方法快速求解积分方程开辟了一条新的道路这方面的研究不仅可以深入发展小波理论和应用算法,深入发展小波方法的功效,而且对边界元方法有重要的指导意义.然而研究稳健快速的数值方法,一直是这方面研究的难点问题.本文考虑带Hilbert核的奇异积分方程q(y)=12π∫2π0f(x)ctg12(x-y)dx,y∈[0,2π],(1.1)的小波数值解法;其中f(x)∈H2π,q(y)∈H2π是以2π为周期的Holder类函数;q(y)已知,f(x)待求解;(1.1)式右…     

非线性Volterra积分方程非平凡解的逼近方法及其应用

本文对一类具有卷积核的非线性Ｖｏｌｔｅｒｒａ型积分方程进行了讨论，给出了关于这类方程的非平凡解的存在性和解的逼近方法的一些结果。通过有关微分方程问题的实例，说明了所给结果的重要应用。     

SINGULAR INTEGRAL EQUATIONS WITH COSECANT KERNEL IN SOLUTIONS WITH SINGULARITIES OF ORDER ONE

In this article, periodic Riemann boundary value problem with period 2aπalong closed smooth contours is discussed, and then singular integral equation with kernel csc t-t0/a along closed smooth contours restricted in the strip 0< Rez相似文献