关于 U-统计量自助逼近的一点注记

设 X_1,X_2,…,X_n 是来自分布 F 的独立同分布子样,T(X_1,…,X_n;;F)是依赖 X_1,X_2,…,X_n 且与 F 有关的随机变量.又设 F_n 为基于 X_1,X_1,…,X_n 的观察值 x_1,x_2,…x_n 的经验分布函数,而 Y_1,Y_2,…,Y_n 为来自 F_n 的独立同分布子样.所谓自助(bootstrap)法,即是以 T(Y_1,…,Y_n;F_n)在 F_n 下的分布去估计 T(X_1,…,X_n;F)在 F 下的分布.Bickol 与Freedman 在[1]中讨论了 U-统计量自助逼近的可能性.设 h(x,y)为关于变元对称的 Borel     

关于Von Mises统计量Berry-Esseen定理的一点注记

Let V_n be a von Mises Statistice with kernel φ(x₁,x₂,… ,x_m).     

关于假设检验的一点注记

在假设检验的过程中,对一个参数的检验法一般来说是不唯一的.对于正态总体,当均值已知,而就方差进行检验时,若能选用自由度为n的χ2统计量,则其为无偏检验,而且为一定标准下的最佳检验.     

常见连续型统计分布的一点注记

正态分布是概率论与数理统计中最重要的一个分布,本文讨论了常见的连续型统计分布与标准正态分布间的关系,结果表明:几乎所有的常见连续型统计分布都是标准正态分布的函数.     

关于高斯的一点注记

评价科学上的历史人物,学术界往往见仁见智,各有所执,这是常有的事。前些时读了陈庆益教授的“论高斯”一文(载本刊1984年第4期,145—147页),觉其所作论评不同凡响。诚然,正如该文所述,其观点与西方M.Kline是一致的,即认为Gauss主要是一位面向过去,更甚于面向未来的历史过渡性人物。Gauss的突出贡献是在数沦方面,而数论并不是19世纪的数学主流。当时的主流应是分析数学(变量数学)。无疑,对分析学主流的提法是符合历史事实的。但是本文乐于指出,该文忍略了Gauss在分析学领域的一     

关于偏微分不等式的一点注记

本文证明了如果多复变数的全纯函数满足一些偏微分不等式,则可导出函数本身的一些性质,如有界性,实部大于零等。第一部分讨论C~n中的平衡域的情形,这时偏微分不等式为一阶的。第二部分讨论C~n中的多圆柱的情形,这时偏微分不等式是二阶的。     

关于矩阵不等式的一点注记

本对[1],[2]中的不等式作了推广,改进了Ostrowsk-Taussky不等式,得到一个统一的不等式。     

关于正定矩阵的一点注记

一、引言与主要结果正定矩阵是代数学中的一个重要概念。近年来随着计算数学、统计学、经济学等学科的发展,它的重要性日益显出。1980年,Bellman.R.首先建立两个正定矩阵的类似于Cauchy-Schwarz不等式:     

关于推广的 U 统计量的若干极限性质

设{X_(ij),i≥1),j=1,2,…,c,是相互独立的 c 个随机序列,而每个序列,都是由 iid 随机变量组成的.又设Φ(x_(ij)=1,2,…,m_j,j=1,2,…,c)是 R~m 上的可测函数.固定其余变量,Φ是x_(1j),…,x_(m_jj)的对称函数,j=1,2,…,c.其中 m=m_1+…+m_c.P.K.Sen 引进了下面推广的 U 统计量.     

A Note on the Use of V and U Statistics in Nonparametric Models of Regression

We establish the asymptotic equivalence of V and U statistics when the statistic’s kernel depends on n. Combined with a lemma of B. Lee this result provides conditions under which U statistics projections and V statistics are asymptotically equivalent. The use of this equivalence in nonparametric regression models is illustrated with several examples; the estimation of conditional variances, skewness, kurtosis and the construction of a nonparametric R-squared measure.     

A Note on Extremes of Concomitants of Order Statistics

Let be a sequence of identically distributed variables. We study the asymptotic distribution of , where Y _[r:n] denotes the concomitant of the rth order statistic X _r:n , corresponding to , and is held fixed while . Conditions are given for the and to have the same asymptotic behavior as that we would apply if were i.i.d. The result is illustrated with a simple linear regression model , where is a stationary sequence with extremal index .     

A Note on Maximum Variance of Order Statistics from Symmetric Populations

The maximum variance of order statistics from a symmetrical parent population is obtained in terms of the population variance. The proof is based on a suitable representation for the variance of order statistics in terms of the parent distribution function.     

概率统计中一个定理的证明

设总体中个体总数为N,样本容量为n(nN),且总体有有限均值μ,方差σ2,当抽样是无放回时,证明了σ()=(N-n/N-i)~(1/2)σ/(n)~(1/2),其中σ()为的标准差.     

A Note on t-SFT-rings

We define a nonzero ideal A of an integral domain R to be a t-SFT-ideal if there exist a finitely generated ideal B ? A and a positive integer k such that a ^k  ? B _v for each a ? A _t , and a domain R to be a t-SFT-ring if each nonzero ideal of R is a t-SFT-ideal. This article presents a number of basic properties and stability results for t-SFT-rings. We show that an integral domain R is a Krull domain if and only if R is a completely integrally closed t-SFT-ring; for an integrally closed domain R, R is a t-SFT-ring if and only if R[X] is a t-SFT-ring; if R is a t-SFT-domain, then t ? dim R[[X]] ≥ t ? dim R. We also give an example of a t-SFT Prüfer v-multiplication domain R such that t ? dim R[[X]] > t ? dim R.     

A Note on Reflexivity

We prove some new results on Hadwin's general version of reflexivity that reduce the study of E-reflexivity (or E-hyperreflexivity) of a linear subspace to a smaller linear subspace. By applying our abstract results, we present a simple proof of D. Hadwin's theorem, which states that every C^∗-algebra is approximately hyperreflexive. We also prove that the image of any C^∗-algebra under any bounded unital homomorphism into the operators on a Banach space is approximately reflexive. We introduce a new version of reflexivity, called approximate algebraic reflexivity, and study its properties.     

A Note on NUCOMP

This note is a detailed explanation of Shanks-Atkin NUCOMP--composition and reduction carried out ``simultaneously'--for all quadratic fields, that is, including real quadratic fields. That explanation incidentally deals with various ``exercises' left for confirmation by the reader in standard texts. Extensive testing in both the numerical and function field cases by Michael J Jacobson, Jr, reported elsewhere, confirms that NUCOMP as here described is in fact efficient for composition both of indefinite and of definite forms once the parameters are large enough to compensate for NUCOMP's extra overhead. In the numerical indefinite case that efficiency is a near doubling in speed already exhibited for discriminants as small as .