积分方程的核

This paper discusses the Noether theorem of complete singular integral equation which containsboth the convolution kernel and the Cauchy kernel, and comes up with the Noether theoremwhich is similar to the Fredholm integral equation, the convolution equation and the singularintegral equation.

本文讨论了既含卷积核又含Cauchy核的完全奇异积分方程的Noether定理，得到了与Fredholm积分方程、卷积型积分方程、奇异积分方程相类似的Noether定理。

This function satisfies the homogeneous boundary condition of Poisson's equation.

应用格林函数将边值问题化为积分方程，并通过建立一个规范化的边界方程来表示问题的边界，以克服积分方程核的奇异性。

The direct method of solution for non-normal type of singular integral equation with Hubert kernel is discussed. Their solution have form of integral and the condition of solution have form of the system of equations.

给出了具有Hilbert核非正则型奇异积分方程的直接解法，对核密度函数k在附加某些条件下，得出了方程积分形式的解和方程组形式的可解条件。

Based on a chosen normalized boundary equation, a new normalized boundary equation can be established such that the irregularity of the kernel of integral equations is overcame. Finally, natural frequency is obtained by the existence condition of nontrivial solution of the discrete algebraic equations derived from the integral equations.

边界方程有多种选择，在选定一种边界方程的基础上，可以通过建立一个新的边界方程来表示问题的边界，以克服积分核的奇异性；最后由积分方程的离散化方程组有非平凡解的条件，求得固有频率。

Green quasifunction method is applied to Poisson's equations. Fredholm integral equations of the second kind are obtained. Irregularity of the kernel of integral equations is overcome by choosing a suitable form of the normalized boundary equation.

应用准格林函数方法，可将Poison方程化为第二类Fredholm积分方程，通过边界方程的适当选择，积分方程核的奇异性被克服了。

The research achievement are acquired as follows: 1From mathematical models for inverse scattering in two dimensional homogenous media including Dirichlet, Neumann, Robin,all kinds of probable mixed boundaries and cracks, direct and inverse scattering are discussed, and ill-posed integral equation and indicator function method are formulated for the diverse of boundary identification. It is shown that the kernel of the integral equation characters the boundary of scatterer, which is determined by solving it by virtual of regularity method, meanwhile, some numerical tests are given.

本研究取得了如下研究成果： 1）在二维均匀介质逆散射各种边界识别的数学模型（包括Dirichlet，Neumann，Robin，各种可能的混合边界问题，裂纹问题）下，分别考虑了正散射问题和逆散射问题，推导了上述各种边界识别的不适定积分方程以及指示函数方法，由于积分方程的核充分表征了散射物的边界，由此说明只要利用正则化方法求解该积分方程，就可以确定散射物的边界，并给出了一些数值实验。

Firstly, Wavelet-Galerkin algorithm for solving the first kind of singular integral equation with the Hilbert kernel is proposed, we use the characteristic of periodic wavelet on L~2([0,1]) and Hilbert kernel to solve and make stiff matrix lower dimensions and become sparser through thresholding,thus the cost of computation is reduced. Because of the singularity of Hilbert kernel we use Tikhonov regularization method to solve the system of stiff equation. At last the convergence and numerical result of approximate solution are given. Secondly, an approach of regularization based on Fourier is presented for sideways heat equation; we give the theory proof and error estimate.

首先，提出了含Hilbert核的第一类奇异积分方程的小波伽辽金(Wavelet-Galerkin)数值算法，该算法中利用了L~2([0，1])上的周期小波和Hilbert核的特点进行处理，使得刚性矩阵维数降低并且通过阈值使得它更加稀疏，减少了计算量；由于Hilbert核的奇异性，通过Tikhonov正则化方法求解所得到的刚性方程组，给出了收敛性和数值结果；其次，对标准的一维逆热传导方程给出了一种基于Fourier正则化方法，给出了理论证明及其误差估计，解决了文献中算法与理论误差估计的不相匹配的现象，该正则化方法不仅保留了测量数据的部分高频成份，且与文献中的算法具有同样的计算量和误差估计。

By usingthe relation between the Bergman kernel and the Riemann mapping and Plemly for-mulae,the second boundary integral equation about the Bergman kernel is obtained,moreover,the integral kernel is a continuous,without any singularity,parametized Neu-mann kernel.We discuss the case of some symmetric property,and get correspondingresults.

主要利用Bergman核与Riemann映照之间的关系，推导出Bergman核满足带有参数化Neumann核的第二类边界积分方程，积分核是连续的没有任何奇性，并讨论了具有某种对称性质的情形。

The bending problem of simple-supported parallelogrammic plates on Winkler foundation is reduced to two simultaneous Fredholm integral equations of the second kind by applying Green quasifunction method. The Green quasifunction is set up by using the fundamental solution of Poisson equation and the normalized boundary equation.

应用准格林函数方法，即利用方程的基本解和规范化的边界方程构造一个准格林函数，将Winkler地基上简支平行四边形薄板的弯曲问题化为两个耦合的第二类Fredholm积分方程，此积分方程的核表示式在区域的边界上具有奇异性。

With degenerate approximations to the oneway LippmannSchwinger integral equation, we study a category of wideangle degenerate migrators that permit the implementation of seismic migration using fast Fourier transforms alone.

通过对LippmannSchwinger单程波动积分方程的退化核逼近，本文研究了一类宽角退化算子的偏移成像。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。