Asymptotic Speed of Wave Propagation for A Discrete Reaction-Diffusion Equation

We deal with asymptotic speed of wave propagation for a discrete reactlon-diffusion equation. We find the minimal wave speed c★ from the characteristic equation and show that c★ is just the asymptotic speed of wave propagation. The isotropic property and the existence of solution of the initial value problem for the given equation are also discussed.     

二阶微分方程反周期边值问题解的存在性

在这篇文章中,我们考虑了一类非线性二阶常微分方程反周期边值问题．利用上下解方法结合单调迭代技巧,我们得到了解的存在性结果．     

求n阶实方阵A的全部模最大的特征值及其相应特征向量的幂法

本文给出并论证了 ,当 n阶实方阵 A具有 i ( 1≤ i≤ n)个 (即任意多个 )模最大的特征值时 ,用幂法求出这些模最大的特征值及其相应特征向量的方法 .该方法是对幂法理论的进一步完善     

Variational iteration method for elastodynamic Green’s functions

In this study, a new application of the variational iteration method is presented. We use this method to obtain approximations to 3D Green’s function for the dynamic system of anisotropic elasticity. The numerical results obtained from convolution of Green’s function and data of the Cauchy problem are compared with the exact solution for cubic media.     

逃逸时间法生成M集中控制变量B的确定

逃逸时间算法是生成Mandelbrot集(简称M集)最常用的算法,本文针对非线性复映射f(z)=zm c为迭代函数的情形进行讨论.首先,根据逃逸时间算法的基本原理给出相应的算法步骤;然后,对迭代函数f(z)=zm c进行了详细研究,从而合理地确定了算法中需要控制的变量B(参数值c0的取值范围)的取值,这样就大大地减少了迭代次数,从而提高了算法的运算效率.     

有限个严格压缩映像隐迭代格式的逼近

假设E为一致凸的Banach空间,对偶空间E*有Kadec-Klee性质,K为E的非空闭凸子集{Ti:i=1,2,…,N}:K→K为Browder-Petryshyn意义下的严格伪压缩映像且F=∩Ni=1F(Ti)≠0.{αn}n∞=1满足0相似文献   

Banach空间中几乎渐近非扩张型映象具混合误差的迭代程序

研究了Banach空间中几乎渐近非扩张型映象不动点的迭代逼近问题,所得结果发展和改进了张石生教授,曾六川教授等人的一些最新成果.     

Double Sobolev gradient preconditioning for nonlinear elliptic problems

A mixed variable formulation of a second‐order nonlinear diffusion problem leads to a finite element matrix in a product form. This form enables the efficient updating of the nonlinearity in a Picard type iteration method, in which the preconditioner involves twice a discrete Laplacian. The article gives a conditioning analysis of this method, based on analytic investigations in the corresponding Sobolev function space that reveal the behaviour of this preconditioning. The further generalization of the preconditioner can produce arbitrarily low condition numbers by proper subdivisions of Ω, while still no differentiability of the nonlinear diffusion coefficient is required. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007     

Radiation transfer in a three-dimensionally inhomogeneous stochastic medium

Within the framework of a small-angle iteration method the propagation of radiation in a three-dimensionally inhomogenous stochastic scattering medium is considered. The results of the analysis show a significant dependence of the average light field on the statistical structure of scattering parameters of the medium. Deceased. Institute of Applied Optics, National Academy of Sciences of Belarus, 11, Belynitskii-Birulya Str., Mogilev, 212793. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 66, No. 2, pp. 234–240, March–April, 1999.