正态分布尺度参数基于残缺观测数据的置信区间

对于残缺的样本观测数据，讨论了正态分布总体尺度参数的区间估计问题。给出了适用于残缺观测数据的构造置信区间的一种方法，即只需知道样本的任意两个关于样本中心对称顺序统计量的值，就可求出总体多数的置信区间。讨论了相应的分布密度函数，给出了大样本近似分布。     

Behrens-Fisher问题的正态逼近

 本文提出用基于得分检验的正态逼近方法来解决Behrens-Fisher问题，即比较方差比未知时两正态总体的均值。模拟结果显示：在所有的研究情况下，我们的方法都能很好地控制第一类错误，检验功效也不差；而最常用的Welch近似t检验在样本量不等时大多数情况都不能控制第一类错误。     

Convergence of the moment generating function of standardized quantiles

A sequence of independent, identically distributed random variables is considered. Given a simple local condition on the distribution of these random variables, we give necessary and sufficient conditions on the tails of the distribution for the moment generating function of a standardized quantile of the first n observations to converge to the moment generating function of an appropriate normal distribution as n →infinity;. This result is actually a special case of a more general result which can also be used to show convergence in distribution and convergence of moments of standardized quantiles.     

Almost unbiased ratio and product estimators based on interpenetrating subsamples

This paper proposes two classes of almost unbiased ratio and product estimators, in the case of interpenetrating subsample designs, which include the estimators considered by earlier authors. Several other almost unbiased ratio and product estimatbrs are given whlch are particular members of the proposed classes of estimators. Optimum estimators are also identified in these classes.     

Higher order local unbiasedness with computer algebra

Unbiased estimation methods that are in some way local on the parameter space have been initiated by Barankin (1948) and Fraser (1964). The later methods involving local unbiasedness are extended to higher (derivative or difference) order at a parameter value (θ) and provide a basis for a computer algebra implementation concerning the improvement of unbiased estimates.     

Adjusting the degrees of freedom for the jackknife

The rule of thumb given by Mosteller and Tukey for obtaining the degrees of freedom which are appropriate for the approximate t-statistic associated with the jackknife is discussed.Examples of possible misapplication of this rule are given.     

New representations of the noncentral chi-square density and cumulative

Representations of noncentral chi-square cumulative distribution function and probability density function are reviewed and new repre¬sentations are given. One representation of the cdf in terms of an integral is easily computed on any machine which has an accurate algorithm for computing the normal cdf.     

弗吉尼亚·伍尔夫小说文本经典性的生成机制重释评骘

在英国现代小说理论的发展史上，弗吉尼亚·伍尔夫的“文本经典性”观念一直是国内外文评界常说常新的议题。这一涉及小说结构原则的核心创作理念侧重于将语言实验的认识论视角伸向由无数印象片断构成的重要瞬间的幽暗意识深处，认为人类最真实的生存状态才应是小说文本理应捕捉的“重要时刻”。她的文本生成观体现了小说艺术的持久力和生命意识的情感化，这种开放的唯美主义思维模式引领了当今西方文论建设的新方向，同时也给物欲横流的迷茫的现代人类带来了更多的生命启示和生活希冀。     

Empirical likelihood ratio-based goodness-of-fit test for the logistic distribution

The logistic distribution has been used to model growth curves in survival analysis and biological studies. In this article, we propose a goodness-of-fit test for the logistic distribution based on the empirical likelihood ratio. The test is constructed based on the methodology introduced by Vexler and Gurevich [17 A. Vexler and G. Gurevich, Empirical likelihood ratios applied to goodness-of-fit tests based on sample entropy, Comput. Stat. Data Anal. 54 (2010), pp. 531–545. doi: 10.1016/j.csda.2009.09.025[Crossref], [Web of Science ®] , [Google Scholar]]. In order to compute the test statistic, parameters of the distribution are estimated by the method of maximum likelihood. Power comparisons of the proposed test with some known competing tests are carried out via simulations. Finally, an illustrative example is presented and analyzed.     

汉语物象词语初探

物象词语是汉语词汇系统中具有鲜明形象色彩义的类聚之一。文章从命名取象特点、参照物、生成动因与生成机制等方面,对物象词语的一系列特征进行了探析;此外,还就物象词语在对外汉语词汇教学中的必要性也发表了看法。