纵向数据下药物剂量水平的统计分析

考虑在纵向数据情况下不会导致风险显著增加的最高剂量的估计问题.基于A IC(A kaike In form ation C riterion)的思想提出了一个新的估计方法,证明了该估计的强相合性,并通过模拟的结果说明了其对于中小样本的优良性.     

一个渐近的分布概率式

本文给出了一个渐近分布概率式的推广形式，并运用概率论知识给出它的一个证明     

一个渐近的分布概率式

本给出了一个渐近分布概率式的推广形式，并运用概率论知识给出它的一个证明。     

重截断和的渐近分布

设{X_n,n≥1}是i.i.d.随机变量序列,X_n,1≤…≤X_(n,n)是X_1,…,X_n的次序统计量。又设k_(n,1,) k_(n,2)是满足条件1≤k_(n,1)相似文献   

多个离散分布的信息差度量的渐近分布

本文中对于多信息源的信息差异性度量B,我们研究了B(u1,u2,…,us)的渐近分布,其中u1,u2,…us是某个概率分布的样本估计．在某些较弱的条件下,我们证明了nB(u1,u2,…,us)的极限分布是自由度为1的X2分布的加权和,其中n是样本容量,u1,u2,…,us不必相互独立．     

多维平稳序列相关阵估计量的渐近分布

若X_t是线性平稳序列、可表示为X_t=sum from j=-∞ to +∞(b_(t-j)ζ_j的形式、其中{ζ_j}j=0,±1,……是独立同分布的随机序列:Eζ_j=0,Eζ_j~2=σ~2>0。对于这种平稳随机序列,T.W.Anderson讨论了其相关系数估计量的渐近分布问题。本文将要讨论{ζ_j}是M维实四阶鞅差序列时,多维线性平稳序列(1)的相关系数组成的协方差阵的估计量的渐近分布问题。为此目的,我们研究了鞅差序列二次型的渐近分布,改进了作者在[2]中所得到的结果。並求出了此种协方差阵估计的渐近分布。     

Weibull分布族中参数的渐近有效估计

本文构造了Ｗｅｉｂｕｌｌ分布族（ｍｘ＾ｍ－１／θｅ＾－ｘｍ／θ，ｘ＞０，ｍ＞０，θ＞０）中形状参数，刻度参数θ的渐近中位无偏限制下的渐近有效估计ｍｎ，θｎ，同时不证明了Ｃ１θｎ＋Ｃ２Ｍｎ为Ｃ１θ＋Ｃ２ｍ的渐近有效估计（其中Ｃ１，Ｃ２为任意给定的常数。）     

回归函数改良核估计的渐近分布

设(X1,Y1),…,(Xn,Yn)是来自二元总体(X,Y)的样本,若EY＜∞,则回归函数m(x)＝E(Y｜X＝x)存在。在本文中,考虑m(x)的改良核估计     

部分线性模型回归系数估计的渐近分布

考虑部分线性模型Ｙ＝Ｘ‘β＋ｇ（Ｔ）＋ｅ，ｘ∈Ｄ，ｔ∈「０，１」，β为未知的参数向量，ｇ为未知函数，Ｃｈｅｎ给出此模型的一种估计如下，先用分段多项式逼近ｇ，然后用最小二乘法估计β，「１」得到估计量β的渐近正态性。因其渐近分布中含有未知参数，不能直接用于检验问题。     

均匀分布位置参数的估计量的渐近分布及应用

对区间长度为定值均匀分布位置参数的点估计量进行了研究,得到位置参数点估计量的渐近分布.讨论了渐近分布的相关性质.给出了位置参数的区间估计及其假设检验方法.     

基于保序回归估计的最大耐受剂量确定方法

I期临床试验研究的主要目标之一是评估药物在不同剂量水平下的毒性, 并且建议一个对病人既安全又有效的剂量, 即最大耐受剂量(MTD). 本文针对拓展的up-and-down设计, 进一步给出其基于保序回归估计的最大耐受剂量确定方法. 经大量模拟, 结果表明: 基于保序回归估计的最大耐受剂量确定方法对推荐MTD的准确性和精确度, 以及保护病人, 防止病人暴露在较高毒性剂量水平下方面实现了有意义的改善.     

The No Response Test for the reconstruction of polyhedral objects in electromagnetics

We develop a No Response Test for the reconstruction of a polyhedral obstacle from two or few time-harmonic electromagnetic incident waves in electromagnetics. The basic idea of the test is to probe some region in space with waves which are small on some test domain and, thus, do not generate a response when the scatterer is inside of this test domain. We will prove that the No Response Test checks analytic continuability of a time-harmonic field from the far field pattern into the domain for a non-vibrating test domain B.We show that two incident waves, defined by one incident direction and two appropriately chosen directions of polarization, are enough to recover the convex hull of polyhedrals. Based on this uniqueness result, we build up the No Response Test and we prove convergence in the sense that it fully reconstructs a convex polyhedral scatterer D or the convex hull of an arbitrary polyhedral scatterer.Further, we will describe the algorithmic realization of the No Response Test and show the feasibility of the method by reconstruction of convex polyhedral objects in three dimensions. This is the first formulation of the No Response Test for electromagnetics.     

Testing for increasing convex order in several populations

Increasing convex order is one of important stochastic orderings. It is very often used in queueing theory, reliability, operations research and economics. This paper is devoted to studying the likelihood ratio test for increasing convex order in several populations against an unrestricted alternative. We derive the null asympotic distribution of the likelihood ratio test statistic, which is precisely the chi-bar-squared distribution. The methodology for computing critical values for the test is also discussed. The test is applied to an example involving data for survival time for carcinoma of the oropharynx.     

Logistic回归模型选择的渐近概率

在许多情况下，我们需要对logistic回归模型中的重要变量进行选择，在本文中，我们对从信息论准则AIC选择出的模型给出了渐近分布和渐近概率。     

The Sample Covariance Is Not Efficient for Elliptical Distributions

It is well known that the sample covariance is not an efficient estimator of the covariance of a bivariate normal vector. We extend this result to elliptical distributions and we propose a simple explicit estimator, which is efficient in the normal case and which outperforms the sample covariance in general. Necessary and sufficient conditions are established under which this estimator is in general efficient for an elliptical distribution.     

Incorporating historical information in testing for a trend in Poisson means

An exact conditional test is developed for testing a trend in Poisson means when the historical control information is incorporated into the concurrent control data. An asymptotic conditional test is also developed as an alternative to the Tarone test. Asymptotic gains by the incorporation of the historical information is evaluated.     

Modified likelihood ratio test for homogeneity in normal mixtures with two samples

This paper investigates the modified likelihood ratio test（LRT） for homogeneity in normal mixtures of two samples with mixing proportions unknown. It is proved that the limit distribution of the modified likelihood ratio test is X^2（1）.     

THE ASYMPTOTIC DISTRIBUTIONS OF EMPIRICAL LIKELIHOOD RATIO STATISTICS IN THE PRESENCE OF MEASUREMENT ERROR

Suppose that several different imperfect instruments and one perfect instrument are independently used to measure some characteristics of a population. Thus, measurements of two or more sets of samples with varying accuracies are obtained. Statistical inference should be based on the pooled samples. In this article, the authors also assumes that all the imperfect instruments are unbiased. They consider the problem of combining this information to make statistical tests for parameters more relevant. They define the empirical likelihood ratio functions and obtain their asymptotic distributions in the presence of measurement error.     

方差未知时两样本正态混合模型齐-性的修正似然比检验

本文讨论了方差未知时检验两样本正态混合模型齐一性的修正似然比统计量的极限性质,证明了原假设下修正似然比统计量的渐近分布为自由度为1的卡方分布.