A direct procedure for monitoring the coefficient of variation using a variable sample size scheme

A variable sample size (VSS) scheme directly monitoring the coefficient of variation (CV), instead of monitoring the transformed statistics, is proposed. Optimal chart parameters are computed based on two criteria: (i) minimizing the out-of-control ARL (ARL₁) and (ii) minimizing the out-of-control ASS (ASS₁). Then the performances are compared between these two criteria. The advantages of the proposed chart over the VSS chart based on the transformed statistics in the existing literature are: the former (i) provides an easier alternative as no transformation is involved and (ii) requires less number of observations to detect a shift when ASS₁ is minimized.     

我国证券集团诉讼制度的构建

证券侵权行为的损害后果具有“小额多数”的特征,我国现行的单独诉讼、共同诉讼由于其自身的局限性而无法适应此类群体纠纷中保护分散性利益、制裁群体性侵害、为公众提供有效救济途径的需要,因此有必要建立专门的证券集团诉讼制度。借鉴美国证券集团诉讼制度的经验,改变人数不确定的代表人诉讼机制,是现阶段的可行之选。     

可持续生计分析框架下不同子女数量农户家庭生计策略的分析

利用可持续生计分析框架,以湖北4个县市为例,分析了不同子女数量农户的家庭生计策略。研究发现由于子女数量不同,相比子女较多的农户家庭,子女较少的农户家庭生计策略呈现出农业集约化程度较高、生计多样化程度较高以及子女外出务工人数较少的特点,这是子女较少农户为兼顾降低家庭脆弱性和提高家庭收入所做出的适合自身的生计策略。本文还发现,随着父母年龄的变老,子女较少的农户存在潜在的生计隐患。据此,本文提出了提高农户生计资本、以及政府帮助降低农户家庭脆弱性的政策建议。     

封闭人群生存人数整体预测--以Lee-Carter模型为例

由不同组别人群组成封闭人群整体生存人数的预测是相关经济、社会问题研究的基础。现有文献在研究相关问题时,使用的方法为：首先根据动态死亡率模型对其中具有相同特征不同部分的生存人数进行预测,之后通过加总得到整体人数的预测（简称现有方法）。由于现有方法忽略了不同特征人群死亡率变动间相关性的影响,会低估生存人数的波动性。本文使用Lee?Carter模型,在将封闭人群按性别分组的基础上,给出了构建生存人数整体预测模型的过程和实例。并通过理论分析和数值模拟两个视角对现有方法和新方法做了比较。比较结果指出：在死亡率波动具有广泛相关性的现实世界中,只有在均值预测时,现有方法才可以达到预期效果,因此笔者建议在对整体人数（特别是涉及方差和分布函数）预测时,使用本文介绍的整体生存人数预测模型。     

x~n+1在有理数域上的因式分解

从特殊情况研究多项式f(x)=xn+1在有理数域上的因式分解.对于正整数,设H(n)是n的大于1的奇约数的个数.本文用初等数论和近世代数的知识证明了:多项式xn+1在有理数域上可分解为H(n)+1个不可约因式的乘积,即D(f)=H(n)+1.     

简论李觏的土地思想

李觏是北宋中期重要的思想家,在李觏的整个思想体系中,经济思想占有很重要的地位。李觏非常重视土地问题,土地思想是李觏经济思想的核心。针对当时土地兼并日益激烈引起的社会危害,李觏也提出了关于土地问题的看法。他的土地思想经历了前后两个时期,前期主要从分配角度分析,主张平土均田。后期主要从生产角度批判土地兼并。李觏提出了＂平土均田＂、＂井田制＂、＂农业劳动力＂、＂尽地力、广垦辟＂、＂限田＂等抑制土地兼并,发展农业,保护农民利益的思想。     

Step-wise group screening with equal prior probabilities and no errors in observations

This paper introduces a screening procedure called step-wise group screening for isolating defective factors from a population consisting of defective (or important) and non-defective     

书号实名申领制探析——以湖北省为例

鉴于先前较为混乱的书号管理秩序及其给出版业带来的消级影响，书号实名中领制应运而生，它对于国家整合出版资源、加强宏观调控、规范市场秩序，出版社加快出版节奏、提高市场竞争都有一定的成效，但书号实名申领制在具体的运物过程中，也还存在一些弊端，因此，它还有待于进一步改进。     

Step-wise group screening designs with errors in observations

The performance of step-wise group screening In terms of the expected number of runs and the expected number of incorrect decisions, Is considered. A method for obtaining optimal step-wise designs Is presented, for the cases in which the direction of each defective factor is assumed to be known a-priori and the observations are subject to error.     

Ranking paired contestants

The ranking of paired contestants (players) after a series of contests is difficult when every player does not play every other player. In the 1975 JASA Mark Thompson presented a maximum likelihood solution based on the assumption that the probability of any one player defeating any other is a function only of the difference in their ranks. Here the linear approximation to that likelihood is shown to lead to a nonparametric measure of the efficacy of the ranking, called the net difference in ranks (NDR) , which is the sum of the differences in ranks of the paired players in the observed contests that agree with the ranking minus the sum of the differences in ranks in the observed contests that disagree with the ranking (upsets) . The subject is part of a large literature that has been consolidated by H.A. David in The Method of Paired Comparisons (1963, 1988). The method was introduced by the psychophysicist Fechner in 1860 and has been widely applied to sensory testing,