Efficient Estimation of a Distribution Function under Quadrant Dependence

LetX₁,X₂, ..., be real-valued random variables forming a strictly stationary sequence, and satisfying the basic requirement of being either pairwise positively quadrant dependent or pairwise negatively quadrant dependent. LetF^ be the marginal distribution function of theX_ips, which is estimated by the empirical distribution functionF_n and also by a smooth kernel-type estimateF_n, by means of the segmentX₁, ...,X_n. These estimates are compared on the basis of their mean squared errors (MSE). The main results of this paper are the following. Under certain regularity conditions, the optimal bandwidth (in the MSE sense) is determined, and is found to be the same as that in the independent identically distributed case. It is also shown thatn MSE(F_n(t)) andnMSE (F^_n(t)) tend to the same constant, asn→∞ so that one can not discriminate be tween the two estimates on the basis of the MSE. Next, ifi(n) = min {k∈{1, 2, ...}; MSE (F_k(t)) ≤ MSE (F_n(t))}, then it is proved thati(n)/n tends to 1, asn→∞. Thus, once again, one can not choose one estimate over the other in terms of their asymptotic relative efficiency. If, however, the squared bias ofF^_n(t) tends to 0 sufficiently fast, or equivalently, the bandwidthh_n satisfies the requirement thatnh³_n→ 0, asn→∞, it is shown that, for a suitable choice of the kernel, (i(n) ?n)/(nh_n) tends to a positive number, asn→∞ It follows that the deficiency ofF_n(t) with respect toF^_n(t),i(n) ?n, is substantial, and, actually, tends to ∞, asn→∞. In terms of deficiency, the smooth estimateF^_n(t) is preferable to the empirical distribution functionF_n(t)     

体词谓语句的生成条件

体词谓语句是以体词作谓语,能够自由生存的句子,它是现代汉语中一种独立的句型而非动词句的省略。体词具备陈述功能,是其作谓语的语法条件,体谓句的陈述关系,主要是由两个单独体词间的并列、偏正关系,因修饰语的参与转化而来的。从语义角度说,体谓句中主谓两部分的逻辑关系、语义制约,以类的形式出现,是句子赖以存在的基础。     

“（是）……的”类句式已然义的层次性分析——以“S（是）AV（O）的”句式为例

以学界广为关注的“S（是）AV（（））的”句式为例，重点分析“（是）……的”类句式在语境、词汇和句法三个层面所显示的不同已然义特征，并以此为基础对国内外关于已然义“（是）……的”类句式的相关研究进行简要的评价。     

Smooth tail-index estimation

The two parametric distribution functions appearing in the extreme-value theory – the generalized extreme-value distribution and the generalized Pareto distribution – have log-concave densities if the extreme-value index γ∈[?1, 0]. Replacing the order statistics in tail-index estimators by their corresponding quantiles from the distribution function that is based on the estimated log-concave density ? f _n leads to novel smooth quantile and tail-index estimators. These new estimators aim at estimating the tail index especially in small samples. Acting as a smoother of the empirical distribution function, the log-concave distribution function estimator reduces estimation variability to a much greater extent than it introduces bias. As a consequence, Monte Carlo simulations demonstrate that the smoothed version of the estimators are well superior to their non-smoothed counterparts, in terms of mean-squared error.     

Bounded risk estimation of a linear combination of location parameters in negative exponential distributions via three-stage sampling

The paper deals with the problem of bounded risk point estimation for a linear combination of location parameters of two negative exponential distributions. Isogai and Futschik considered the situation when the location and scale parameters are all unknown. They proposed purely sequential procedures and gave second order expansions of the average sample sizes and risks. In this paper we propose three-stage procedures and derive second order expansions of the average sample sizes and risks. Further, we compare the results with those from previous work.     

Teenage childbearing: young sole mothers challenge the stereotypes

Teenage sole mothers in receipt of welfare benefits are seriously affected by systematic and radical restructuring of Aotearoa/New Zealand’s state welfare system since 2008. With few exceptions, the changes oblige beneficiaries to prioritise obtaining paid work. To address questions of how welfare changes and socio-cultural context in Aotearoa New Zealand are experienced by teenage mothers we conducted a narrative study of 10 young women’s stories of sole mothering as beneficiaries. Purposeful sampling was used to recruit young mothers who were attending, or had recently attended a specialist school for teen parents. Thematic analysis of interview narratives represented experiences of financial and social deprivation, negative stereotyping, stigma and resistance. In contrast to the government’s explicit goal of getting welfare recipients into paid employment, the teenage mothers in our study placed full-time mothering as their principal duty. They also acknowledged the material and social advantages of entering paid employment, and were committed to working but only when their child was ‘settled and ready’ – a decision they understood to be their responsibility.     

《祖堂集》中“且置”式问句的历史形成及其动因

《祖堂集》中的"且置"式问句是一种含有处置义的句式,把不易或不必处理的问题转换为当下相关的问题提出,具有两种语用功能:一是起到化难为易作用;一是起到换位思考作用。该句式萌芽于南北朝时期的佛经文献,成熟于五代,禅宗口语问答的语用环境是"且置"式形成的主要动因,线性增量原则是其主要机制。     

指类句的修辞性嬗变

指类句可加以改造而获得特定修辞效果,"全都……,只有……"这一句式就是一例。此类修辞效果是通过"全都……"增强语句的语义信息到极致获得反衬,继而通过"只有……"突显例外现象实现的。指类句是对一类事物属性的隐性全称量化,同时又容忍例外现象。对指类句的元语用分析表明,在元语用层次,理解指类句的认知机制、指类句理解的心理逻辑和语言使用的会话修辞逻辑使得这种改造成为可能。     

70年代国外习得顺序研究综述(二)

本文回顾了70年代句子习得顺序的相关研究,主要涉及否定句、疑问句的习得顺序的相关研究,也提及70年代提出的关于关系从句的习得顺序的三大研究假设,最后指出70年代习得顺序研究的意义和不足之处以及之后该领域的主要研究动态。     

“烘云托月”与“说不可说”冯友兰新理学“负方法”的关学阐释

在冯友兰新理学关于方法论的论述中，其用“负方法”对形而上学的“讲述”对美学有着深刻的启示意义，甚至可以说它本身就涵蕴着丰富的关学意味。道家的方法、禅宗的方法和诗的言说，是“负方法”的三种典型言说方式，这三种言说形式具有美学阐释的可能性，表现在直觉性、神秘性、超越性和浑整性4个方面。