ON BAHADUR－TYPE ASYMPTOTIC EFFICIENCY OF POINT ESTIMATORS UNDER IRREGULAR TRUNCATED DISTRIBUTION FAM

ＯＮＢＡＨＡＤＵＲ－ＴＹＰＥＡＳＹＭＰＴＯＴＩＣＥＦＦＩＣＩＥＮＣＹＯＦＰＯＩＮＴＥＳＴＩＭＡＴＯＲＳＵＮＤＥＲＩＲＲＥＧＵＬＡＲＴＲＵＮＣＡＴＥＤＤＩＳＴＲＩＢＵＴＩＯＮＦＡＭＩＬＹ￥ＣｈｅｎＧｕｉｊｉｎｇ（陈桂景）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔ...     

Estimating parameters in one-way analysis of covariance model with short-tailed symmetric error distributions

We consider one-way analysis of covariance (ANCOVA) model with a single covariate when the distribution of error terms are short-tailed symmetric. The maximum likelihood (ML) estimators of the parameters are intractable. We, therefore, employ a simple method known as modified maximum likelihood (MML) to derive the estimators of the model parameters. The method is based on linearization of the intractable terms in likelihood equations. Incorporating these linearizations in the maximum likelihood, we get the modified likelihood equations. Then the MML estimators which are the solutions of these modified equations are obtained. Computer simulations were performed to investigate the efficiencies of the proposed estimators. The simulation results show that the proposed estimators are remarkably efficient compared with the conventional least squares (LS) estimators.     

在单参数双边截断型分布族中参数估计的一种新的渐近效率

为了克服在单参数双边截断型分布族中不能消除参数估计中在Ｂａｈａｒｄｕｒ意义下的超有效病态现象,本文提出了一种新的渐近效率．根据这种效率的定义,对一般 的参数函数,构造了适用的渐近中位无偏的渐近有效估计量．作为全文的理论基础,我们发现了渐近中位无偏估计的最优收敛速度．     

左截断右删失数据分位差估计及其渐近性质

我们研究了左截断右删失数据分位差,基于左截断右删失数据乘积限构造了分位差的经验估计,同时克服经验估计的非光滑性,提出了分位数差的核光滑估计.利用经验过程理论推导出这两个估计的渐近偏差和渐近方差,并且在左截断右删失数据下研究了这两个分位差的大样本性质,获得分位差估计的相合性和渐近正态性.同时给出计算模拟以验证光滑分位差估计的表现,在均方损失的意义下模拟结果表明光滑估计比经验估计具有更好的性质.     

MOMENT ESTIMATION FOR MULTIVARIATE EXTREME VALUE DISTRIBUTION

Moment estimation for multivariate extreme value distribution is described in this paper. Asymptotic covariance matrix of the estimators is given. The relative efficiencies of moment estimators as compared with the maximum likelihood and the stepwise estimators are computed. We show that when there is strong dependence between the variates, the generalized variance of moment estimators is much lower than the stepwise estimators. It becomes more obvious when the dimension increases.     

More Higher-Order Efficiency: Concentration Probability

Based on concentration probability of estimators about a true parameter, third-order asymptotic efficiency of the first-order bias-adjusted MLE within the class of first-order bias-adjusted estimators has been well established in a variety of probability models. In this paper we consider the class of second-order bias-adjusted Fisher consistent estimators of a structural parameter vector on the basis of an i.i.d. sample drawn from a curved exponential-type distribution, and study the asymptotic concentration probability, about a true parameter vector, of these estimators up to the fifth-order. In particular, (i) we show that third-order efficient estimators are always fourth-order efficient; (ii) a necessary and sufficient condition for fifth-order efficiency is provided; and finally (iii) the MLE is shown to be fifth-order efficient.     

截断参数分布族参数的可容许估计

在平方损失下Karlin[1]讨论了截断参数分布族参数的可容许估计问题．本文讨论了当待估参数为单调函数和多项式函数时的可容许估计问题.文[1]讨论的待估参数，形式上较特殊，有关结果可视为本文结论的一个特例．     

非正则双边截断分布族点估计的中偏差

本文研究了某一类非正则双边截断分布族的参数估计,利用( X(1),X(n))的联合分布函数及应用Taylor渐近展开的方法,得到了它的未知参数(θ1,θ2)满足中偏差原理,且求出了其精确的速率函数表达式,它的表达式不同于一般的速率函数.     

具有缺失数据的Eichhorn模型

为了解决在Eichhorn乘法扰动模型中存在的项目无回答问题,对敏感变量总体均值在辅助变量总体均值已知与未知条件下提出了比率插补方法.理论比较和数值模拟得出的结果表明提出的插补方法比传统的方法效率更高.     

Sampling for estimating weighted totals and averages

Summary Although sample surveys are widely used to estimate weighted totals and averages, yet a systematic discussion of the subject is not available in the literature. In this paper efficiencies of estimators under various plans have been obtained and compared when sample surveys are carried out to estimate weighted totals and averages.