三种不同意义下的最佳求积公式之间的关系

详细讨论了函数类KWr[a,b]上Sard和N iko lsk ii意义下以及基于给定信息的最佳求积公式三者之间的关系,并且提供了一种由基于给定信息的最佳求积公式得到其它两种求积公式的方法.     

关于求积公式序列收敛性的注记

利用Romberg递推求积算法,证明当子区间数目趋于无穷大时,复化求积公式序列一致收敛于积分真值,证明过程与插值型求积公式序列如Gauss型求积公式序列一致收敛不同.     

Sobolev类带权函数的基于给定信息的最佳求积公式

给出了r阶Sobo lev类KWr[a,b]带权函数的基于给定信息的最佳求积公式和它的误差估计式.这里的给定信息是指:已知函数在给定区间若干点上的函数值和直到r-1阶导数值.对r≤2,得到了最佳求积公式和误差估计式的显式结果.另外还给出了类KW2[a,b]中在节点的导数值为零的函数所组成的子类的相应的最佳求积公式.     

数值积分的双侧逼近及应用

通过分析基本数值求积公式的双侧逼近现象,利用加权平均的方法构造出了比原来求积公式至少高二次代数精度新的混合型求积公式,使得积分近似值精度得到大幅度提高,并给出应用它们求数值积分的具体实例.     

Cotes数值求积公式的校正

本文研究了Cotes数值求积公式代数精度的问题,给出了Cotes求积公式余项"中间点"的渐进性定理.利用该定理得到了改进的Cotes求积公式,并证明了改进后的Cotes求积公式比原来的公式具有较高的代数精度.     

一类高维沙德意义下的最佳求积公式

Schoenberg,I.J.证明了由一元自然样条插值得到的求积公式和沙德意义下最佳求积公式是一致的。后者是指在具有同样代数精度的求积公式中其余项的皮亚诺核最小者。从而样条插值型求积公式是定积分在一定意义下的最佳逼近。李岳生教授提出了一类多元     

Fibonacci求积公式对具有有界混合差分的光滑函数类的误差估计

考虑对具有有界混合差分的二元光滑函数类Ｂ＾γ，ｐ，θ的求积公式，本文证明了Ｆｉｂｏｎａｃｃｉ求积公式是渐近最优的，并求出了春误差的渐近最优价。     

一类Gauss-Jacobi数值求积公式的极限性质

讨论了形如∫aa+h(x-a)βf(x)dx的Gauss-Jacobi求积公式,当积分区间长度趋向于零时,确定了求积公式的余项中介点η的渐近性,并给出了校正公式,比原公式提高了两次代数精度.此外,本文的结论包含了文[3]的结果.     

有理插值型求积公式的存在性与收敛性

构造两种奇点预先给定的有理插值型求积公式(RIQFs),在一定条件下证明其存在唯一性和收敛性,结果推广了普通的插值型求积公式和Gauss型求积公式.     

一类求积公式的构造方法

本文利用 Euler-Maclaurin求和公式构造了一类求积公式 ,称为修正复合梯形公式 .它和复合梯形公式的求积节点及计算量是一样的 ,但收敛阶有很大的提高 ,特别适合于计算带有各种类型小波的数值积分 .     

基于切比雪夫节点的一类带显式系数的广义高斯求积公式(英文)

The goal here is to give a simple approach to a quadrature formula based on the divided diffierences of the integrand at the zeros of the nth Chebyshev polynomial of the first kind,and those of the（n-1）st Chebyshev polynomial of the second kind.Explicit expressions for the corresponding coefficients of the quadrature rule are also found after expansions of the divided diffierences,which was proposed in[14].     

A Chebyshev Quadrature Rule for One Sided Finite Part Integrals

This paper is concerned with a Chebyshev quadrature rule for approximating one sided finite part integrals with smooth density functions. Our quadrature rule is based on the Chebyshev interpolation polynomial with the zeros of the Chebyshev polynomial T_N+1(τ)−T_N−1(t). We analyze the stability and the convergence for the quadrature rule with a differentiable function. Also we show that the quadrature rule has an exponential convergence when the density function is analytic.     

On a quadrature formula of Micchelli and Rivlin

Micchelli and Rivlin (1972) obtained a quadrature formula of highest algebraic degree of precision for the Fourier-Chebyshev coefficients A_n(f), which is based on the divided differences of f′ at the zeros of the Chebyshev polynomial T_n(x). We give here a simple approach to questions of this type, which applies to the coefficients in arbitrary orthogonal expansion of f. As an auxiliary result we obtain a new interpolation formula and a new representation of the Turán quadrature formula.     

Novel weak form quadrature element method with expanded Chebyshev nodes

Based on the principle of minimum potential energy and the differential quadrature rule, novel weak form quadrature element method is proposed. Different from the existing ones, expanded Chebyshev grid points are used as the element nodes. A simple but general way is proposed to compute the strains at the integration points explicitly by using the differential quadrature rule. For illustration and verification, quadrature bar and beam elements are established. Several examples are given. Numerical results indicate that the proposed quadrature element method allows a longer time step as compared to elements with other nodes and is an accurate and efficient method for structural analysis.     

Quadrature rules based on partial fraction expansions

Quadrature rules are typically derived by requiring that all polynomials of a certain degree be integrated exactly. The nonstandard issue discussed here is the requirement that, in addition to the polynomials, the rule also integrates a set of prescribed rational functions exactly. Recurrence formulas for computing such quadrature rules are derived. In addition, Fejér's first rule, which is based on polynomial interpolation at Chebyshev nodes, is extended to integrate also rational functions with pre-assigned poles exactly. Numerical results, showing a favorable comparison with similar rules that have been proposed in the literature, are presented. An error analysis of a representative test problem is given. This revised version was published online in June 2006 with corrections to the Cover Date.     

ASYMPTOTIC REPRESENTATION FOR REMAINDER OF QUASI-HERMITE-FEJER INTERPOLATION POLYNOMIAL

Let Q_(2n+1)(f,x)be the quasi-Hermite-Fejer interpolation polynomial of functionf(x)∈C_[-1,1]based on the zeros of the Chebyshev polynomial of the second kind U_n(x)=sin((n+l)arccosx)/sin(arc cosx). In this paper, the uniform asymptotic representation for thequantity| Q_(2n+l)(f, x) -f(x) |is given. A similar result for the Hermite-Fejer interpolationpolynomial based on the zeros of the Chebyshev polynomial of the first kind is alsoestablished.     

一个广义Markov不等式（英）

This paper gives a generalized Markov inequality dx for every polynomial P of degree at most n provided that f′ is con tinuous and strictly increasing on [0,∞ ), where ‖?‖ denotes the uniform and T_n,stands for the n-th Chebyshev polynomial of the first kind.     

Suboptimal Kronrod extension formulae for numerical quadrature

Summary We consider cases where the Stieltjes polynomial associated with a Gaussian quadrature formula has complex zeros. In such cases a Kronrod extension of the Gaussian rule does not exist. A method is described for modifying the Stieltjes polynomial so that the resulting polynomial has no complex zeros. The modification is performed in such a way that the Kronrod-type extension rule resulting from the addition of then+1 zeros of the modified Stieltjes polynomial to the original knots of the Gaussian rule has only slightly lower degree of precision than normally achieved when the Kronrod extension rule exists. As examples of the use of the method, we present some new formulae extending the classical Gauss-Hermite quadrature rules. We comment on the limited success of the method in extending Gauss-Laguerre rules and show that several modified extensions of the Gauss Gegenbauer formulae exist in cases where the standard Kronrod extension does not.     

拟Grünwald插值算子在Wiener空间下平均误差的估计

We obtain an upper bound for the average error of the quasi-Grunwald interpo-lation based on the zeros of Chebyshev polynomial of the second kind in the Wiener space.     

关于Gauss-Turán求积公式的注记

1.引言 设w(x)是区间[-1,1]上的权函数,N是自然数集,X1,…,Xn(n∈N)是对应于权函数w(x)的n次正交多项式的零点,则具有最高代数精度2n-1,其中Πn表示所有次数≤n的多项式空间. 1950年,Turan[1]将上述经典的Gauss求积公式予以推广,证明了,若