How far from identifiability? A systematic overview of the statistical matching problem in a non parametric framework

Statistical matching consists in estimating the joint characteristics of two variables observed in two distinct and independent sample surveys, respectively. In a parametric setup, ranges of estimates for non identifiable parameters are the only estimable items, unless restrictive assumptions on the probabilistic relationship between the non jointly observed variables are imposed. These ranges correspond to the uncertainty due to the absence of joint observations on the pair of variables of interest. The aim of this paper is to analyze the uncertainty in statistical matching in a non parametric setting. A measure of uncertainty is introduced, and its properties studied: this measure studies the “intrinsic” association between the pair of variables, which is constant and equal to 1/6 whatever the form of the marginal distribution functions of the two variables when knowledge on the pair of variables is the only one available in the two samples. This measure becomes useful in the context of the reduction of uncertainty due to further knowledge than data themselves, as in the case of structural zeros. In this case the proposed measure detects how the introduction of further knowledge shrinks the intrinsic uncertainty from 1/6 to smaller values, zero being the case of no uncertainty. Sampling properties of the uncertainty measure and of the bounds of the uncertainty intervals are also proved.     

以“中国梦”为主题开展大学班级文化建设

对"中国梦"进行理论阐释及宣传教育,不仅是中国意识形态建设的需要,更是社会主义文化繁荣和发展的需要。对此,以"中国梦"为主题开展大学班级文化建设,既是对大学生进行思想政治教育的重要内容,也是培育大学生思想文化素养的必然要求。在厘清以中国梦为主题开展大学班级文化建设内涵及功能的前提下,深入分析当前以中国梦为主题,开展大学班级文化建设面临的困境及问题,提出针对"中国梦"主题教育的现实要求。     

On some generalized ageing orderings

Some partial orderings that compare probability distributions with the exponential distribution are found to be very useful to understand the phenomenon of ageing. Here, we introduce some new generalized partial orderings which describe the same kind of phenomenon of some generalized ageing classes. We give some equivalent conditions for each of the orderings. Inter-relations among the generalized orderings have also been discussed.     

章回小说景物描写及其转变

早期章回体小说中景物描写很少与说唱文学和史传文学有关。由于说唱文学注重其商业性，以及观众的大众化、审美趣味的世俗化使得景物描写不可能大段的出现；而史传文学对言行的关注以及尽量客观化的叙事方式也限制了景物描写。章回体小说题材内容经历了从国家、家庭到个人发展过程，同时也经历了从集体编著到个人独创的过程，这也影响了小说的景物中描写，使得景物描写呈现由少渐多的趋势。     

Characterizing the Noncancer Toxicity of Mixtures Using Concepts from the TTC and Quantitative Models of Uncertainty in Mixture Toxicity

This article explores the use of an approach for setting default values for the noncancer toxicity, developed as part of the Threshold of Toxicological Concern (TTC), for the evaluation of the chronic noncarcinogenic effects of certain chemical mixtures. Individuals are exposed to many mixtures where there are little or no toxicological data on some or all of the mixture components. The approach developed in the TTC can provide a basis for conservative estimates of the toxicity of the mixture components when compound-specific data are not available. The application of this approach to multiple chemicals in a mixture, however, has implications for the statistical assumptions made in developing component-based estimates of mixtures. Specifically, conservative assumptions that are appropriate for one compound may become overly conservative when applied to all components of a mixture. This overestimation can be investigated by modeling the uncertainty in toxicity standards. In this article the approach is applied to both hypothetical and actual examples of chemical mixtures and the potential for overestimation is investigated. The results indicate that the use of the approach leads to conservative estimates of mixture toxicity and therefore its use is most appropriate for screening assessments of mixtures.     

汉英语言动静思维溯源

汉英语言大相径庭,二语间的对比研究屡见不鲜,视阈颇为复杂。笔者以二语间的动静思维研究为目的,通过对汉英语言＂主流词＂的动静表征溯源,得出了中西哲学渊源动静各异的正解。     

Sensitivity analysis in statistical decision theory: A decision analytic view

Sensitivity analysis provides a way to mitigate traditional criticisms of Bayesian statistical decision theory, concerning dependence on subjective inputs. We suggest a general framework for sensitivity analysis allowing for perturbations in both the utility function and the prior distribution. Perturbations are constrained to classes modelling imprecision in judgements The framework discards first definitely bad alternatives; then, identifies alternatives that may share optimality with a current one; and, finally, detects least changes in the inputs leading to changes in ranking. The associated computational problems and their implementation are discussed.     

中美高校学生实习的比较研究

实习作为普通高校人才培养的一个重要环节，是学习与就业的重要纽带。文章通过对中美两国高校学生实习情况的概述和比较，分析了美国高校学生实习的有利条件，并结合中国国情，系统地阐述了目前中国高校学生实习活动中存在的问题，有针对性地提出了一系列可行性建议。     

清代各阶层对孀居妇女采取的救济措施浅谈

从明太祖朱元璋开始,朝廷正式提倡女性为死去的丈夫守节,并对妇女从一而终行为进行表彰,从而建立了特有的专门针对女性的旌表制度。清统治者夺取政权后,继承了旌表制度。为了更好地维护旌表制度,有清一代从朝廷到地方,到家族,甚至个人都采取了一些救济措施,以资助孀居妇女养活自己、抚养孩子、赡养老人,从而最终实现妇女对贞节的坚守,达到朝廷提倡的对从一而终道德目标的追求。这也是有清一代节妇数量庞大的一个重要原因。     

单弦牌子曲与长阳南曲渊源关系探讨

索源于中国音乐历史长河之中，比较历代各种音乐类型的结构及表现形式，长阳南曲以复制的方式传承了单弦牌子曲的表现形式及主要伴奏乐器，在传承中完全承袭了单弦牌子曲的“曲牌联套体”的音乐结构。长阳南曲鲜活地再现了单弦牌子曲。单弦牌子曲是长阳南曲的源头。