Pseudo MLE for semiparametric transformation model with doubly truncated data

In this article, we consider the efficient estimation of the semiparametric transformation model with doubly truncated data. We propose a two-step approach for obtaining the pseudo maximum likelihood estimators (PMLE) of regression parameters. In the first step, the truncation time distribution is estimated by the nonparametric maximum likelihood estimator (Shen, 2010a) when the distribution function $K$ of the truncation time is unspecified or by the conditional maximum likelihood estimator (Bilker and Wang, 1996) when $K$ is parameterized. In the second step, using the pseudo complete-data likelihood function with the estimated distribution of truncation time, we propose expectation–maximization algorithms for obtaining the PMLE. We establish the consistency of the PMLE. The simulation study indicates that the PMLE performs well in finite samples. The proposed method is illustrated using an AIDS data set.     

湘语“V+X+N（L）”的结构形式及来源

湖南境内湘语“V+X+N（L）”的结构形式共有四种：“V+在+N（L）”、“V+到+N（L）”，“V+体貌助词+N（L）”和“V+体貌助词+在+N（L）”。“V+体貌助词+在+N（L）”的来源于六朝时期就已常见的“（S-P）在NL”结构。     

绵阳市郊区几种蔬菜的施肥现状及平衡施肥方案

调查分析了绵阳市郊区 (石马、龙门、塘汛 )蕃茄、黄瓜、菜豆 3种蔬菜的平衡施肥状况。结果发现其施肥养分比 (N∶P2 O5∶K2 O)分别为 1∶0 .6 2∶0 .6 0、1∶0 .53∶0 .57、1∶0 .52∶0 .6 0 ,与其吸肥特性相比 ,施氮相对较多 ,施钾明显偏低 ,氮钾比失调。因此 ,推荐施肥方案要求控制氮肥 ,保证磷肥 ,增加钾肥用量 ,使施肥的N∶P2 O5∶K2 O分别应达到 1∶0 .6 2∶1.10 (蕃茄 ) ,1∶0 .55∶1.2 0 (黄瓜 ) ,1∶0 .50∶1.15(菜豆 )。     

秉承行业协会理念 构建中国农民合作组织体系

随着我国市场经济体制的不断完善,如何在新形势下提高农民组织化程度日益成为人们关注的热点问题。中国需要一个能够在农民与市场、政府、社会之间发挥有效作用的中介组织。从发达国家的成功经验看,这个中介组织就是农业行业协会。但是在中国,人们对行业协会的理解却存在误区。鉴于此,我们从论述行业协会的定义、属性、职能出发,继而探讨农业领域行业协会的独特性,最终提出秉承行业协会理念、构建中国农民合作组织体系的必要性与可行性建议。     

“女汉子”说略

“女汉子”一词的形成是语义、语法、语用综合作用的结果。语义上，“汉子”在近现代常见语例中常指性格坚毅、豪爽、大气的男性，语义凸显的是性格特征，性格特征义素强化和性别特征义素弱化为“女汉子”的产生提供了基础。语法上，偏正式合成词“女X”的存在为“女汉子”的产生提供了可能，而“X汉子”结构直接为“女汉子”提供了可以类推的格式参照，“女汉子”正是在词形类推的机制下组合而成的偏正格式。语用上，因其词形上直接的性别冲突，具有新异的修辞效果，内容上概括了爽直独立的一类女性，故广受关注，使用频率颇高。     

An L-statistic approach to a test of exponentiality against IFR alternatives

In this note we consider the problem of testing exponentiality against IFR alternatives. A measure of deviation from exponentiality is developed and a test statistic constructed on the basis of this measure. It is shown that the test statistic is an L-statistic. The asymptotic as well as the exact distribution of the test statistic is obtained and the test is shown to be consistent.     

正庚醛合成壬烯酸的研究

本文由正庚醛合成壬烯酸 ,确定了适于工业生产的催化剂及其用量和反应时间 ,解决了产品的后处理问题 ,获得了较满意的产率     

哈特曼基于价值的意志自由何以可能

N.哈特曼价值接受理论的根本前提是人先天携带着"模糊的"价值意识,这在一定程度上消解了价值绝对主义与价值相对主义之间的张力,同时显明整个价值柏拉图主义的二难困境。其价值决定与因果决定、目的性关系的结构理论为弥合本体论与价值论、是与应当之间的鸿沟提供了一条深刻而又独具理论魅力的范式。然而,人不能违背因果决定,却能违背价值决定,具有违背价值秩序的自由,无疑又是对其已建立的道德之价值基础的否定,暴露出其价值伦理学的内在困境。     

Archival data in program evaluation and policy analysis

Evaluators have typically avoided using existing data sets, choosing instead to collect their own information to maintain control over both the content and quality of the data. As demands on action researchers increase without provision for additional resources, primary data collection may become a luxury and the use of archival data may increase. Though archival data has practical and methodological advantages, there are limitations associated with the utilization of such information. The general problems with secondary data sources include the accuracy, acceptability and accessibility of the information. Following a discussion of these general problems, an example from the Civilian Health and Medical Program of the Uniformed Services (CHAMPUS) reimbursement data set is presented to illustrate specific difficulties with using archival data for evaluation research. Strategies are then presented for minimizing these difficulties, including determining the feasibility of utilization of such data sources, methods for assessing their accuracy and factors to consider in the data acquisition process.