一个新的数值积分公式

本文主要构造了一个数值积分公式,进一步研究了数值积分公式中的中间点的渐进性,基于中间点的渐进性质,得到了该数值积分公式的校正公式,最后给出数值试验,数值试验表明该公式的精度非常高。     

一类求解常微分方程的有限差分法

基于数值积分公式中间点的渐近性质,获得了一类求解常微分方程初值问题有限差分方法,研究了新方法的相容性和稳定性.数值算例显示了新方法的有效性.     

积分第一中值定理中间点的一般渐近性质与求积公式

证明关于积分第一中值定理的中间点ξ的渐近性质的一般结果.而且,由此自然地推导出单节点数值积分公式.此求积公式具有高精度,还适于瑕积分的数值计算.     

辛普生公式中间点的渐近性(英文)

辛普生公式是数值积分中的著名公式.利用泰勒公式,讨论了当区间的两个端点都趋于其内一定点时辛普生公式中间点的渐近性,得到了具有一般性的结果.     

数值积分校正公式

通过两个例子说明一旦具有数值积分公式的余项表达式,只需利用代数精度概念即可确定余项里的中间点的具体数值,从而获得更高代数精度的数值积分校正公式.本文的方法可用于各类数值积分公式.     

校正梯形公式的推广

对数值积分中的校正梯形公式作出推广并讨论了中间值的渐近性.     

中矩形公式与梯形公式的注记

将数值积分中的中矩形公式与梯形公式推广到两个函数的情形,并讨论了中间值的渐近性质.     

辛普生公式的推广(英文)

推广了数值积分中著名的辛普生公式,讨论了中值点的渐近性.     

广义台劳公式“中间点”的渐近性

文［１］论证了一元台劳公式“中间点”的渐近性质。本文对广义合劳公式和多元台劳公式“中间点”的渐近性进行了讨论，并得出一些令人满意的结果。     

关于复函数的中值公式及“中间点”的渐近性

讨论几个复函数徽分中值公式的“中间点”渐近性，所得渐近估计式推广了有关文献中相应的结论，然后，建立复函数的积分中值公式及“中间点”的渐近性质，得到与实积分相类似的结果．     

关于一些数值求积公式的渐近性

该文给出了一些数值求积公式的渐近性质,这些公式包括求积分的矩形法则、梯形法则和抛物线法则,包含于余项中的中介点的位置当积分区间的长度趋于零时被确定,对应于该法则的校正公式被得到,它们具有较高的代数精度,我们也进行了一些数值试验,得到较满意的数值结果。     

Relative Asymptotic Efficiency of the Maximum Pseudolikelihood Estimate for Gauss–Markov Random Fields

A general version of the maximum pseudolikelihood estimate of parameters within the class of Gauss–Markov random fields is stated in a rigorous way. Its asymptotic properties, namely the consistency, the asymptotic normality, and the relative asymptotic efficiency are studied. Explicit formulas for the asymptotic covariance matrix are given, and a decrease of efficiency is proved. A numerical example is added to show that the efficiency can be improved by enlarging the range of the conditional distribution used in the estimator. This revised version was published online in June 2006 with corrections to the Cover Date.     

Calculation of effective moduli of composite materials

Effective properties of composite and porous materials are determined by using an approach based on two-scale asymptotic expansions. Explicit approximate formulas are derived for the effective moduli of composite and porous materials of elongated structures. A numerical method is proposed for finding solutions to cell problems, which are used to determine “exact” effective moduli. Examples are computed for a two-dimensional porous medium with variously shaped pores and various degrees of “elongation.” The effective moduli produced by the explicit approximate formulas prove to be similar to those found by numerically solving cell problems.     

Explicit Representations for Local Lagrangian Numerical Differentiation

It is shown that in Lagrangian numerical differentiation formulas, the coefficients are explicitly expressed by means of cycle indicator polynomials of symmetric group. Moreover, asymptotic expansions of the remainders are also explicitly represented as a fixed number of interpolation nodes approaching infinitely to the point at which the derivative is evaluated. This implies that complete explicit formulas for local Lagrangian numerical differentiation can be obtained.     

Asymptotic formulas for parabolic cylindrical functions and Hermite polynomials for large argument values

Expansions in the elgenfunctions of the Sturm-Liouville problem and perturbation expansions are applied to obtain asymptotic formulas for parabolic cylindrical functions and Hermite polynomials for large n. The formulas are compared with previously published formulas and, in particular, a numerical comparison is made for one Hermite polynomial.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 63, pp. 19–24, 1987.     

Asymptotic summation of power series

Summary. We give an asymptotic expansion in powers of of the remainder , when the sequence has a similar expansion. Contrary to previous results, explicit formulas for the computation of the coefficients are presented. In the case of numerical series (), rigorous error estimates for the asymptotic approximations are also provided. We apply our results to the evaluation of , which generalizes various summation problems appeared in the recent literature on convergence acceleration of numerical and power series. Received April 22, 1997     

On numerical realization of the function of the hereditary operator : PMM vol. 42, no. 6, 1978, pp. 1115–1122

The problem of numerical realization of a function of the hereditary operator acting on some function of time is considered. Laplace transformations are used for the operators with kernels of the Rabotnov and Rzhanitsyn type to obtain formulas which reduce the problem in question to that of computing a quadrature. When the variable assumes large values, the formulas become asymptotic equations with an estimable error of approximation.