道路工程项目关键路径上活动相对重要程度的探讨

文章在项目网络结构的基础上,提出了一种排列项目活动相对重要程度的方法.在此基础上,对道路项目网络结构关键路径中的活动相对重要程度进行了研究.本文研究使项目管理人员能识别所有项目活动的相对重要程度,确定项目活动管理的优先秩序,从而为实现项目资源的合理配置和对进度进行有效控制提供了依据.     

The empirical distribution function as a tail estimator

It is shown that the empirical distribution function performs well in tail estimation. Consistency as well as the relative error are considered. The results hold true without any condition on the theoretical distribution function.     

基于模糊优选神经网络BP法的低温物流中心设计储藏能力预测

在选择影响低温物流中心设计储藏能力的合适因子基础之上，将模糊优选神经网络BP模型应用于第三方低温物流中心的设计储藏能力预测上，结果表明预测值具有较高的可信度。     

Estimating survivor function using optimally selected order statistics

This paper deals with the estimation of survivor function using optimally selected order statistics when the sample sizen is large. We use the estimates (μ*,σ*) based on the optimum set of order statistics for largen and fixedk (≤n) such that the estimate has optimum variance property. The asymptotic relative efficiency of such an estimator is compared with the one based on the complete sample. The general theory of the problem and specific details with respect to a two-parameter Normal, Logistic, Exponential and Pareto distributions is considered as an example.     

Risk preference and indirect utility in portfolio-choice problems

We consider a portfolio-choice problem with one risky and one safe asset, where the utility function exhibits decreasing absolute risk aversion (DARA). We show that the indirect utility function of the portfolio-choice problem need not exhibit DARA. However, if the (optimal) marginal propensity to invest is positive for both assets, which is true when the utility function exhibits nondecreasing relative risk aversion, then the DARA property is carried over from the direct to the indirect utility function.     

低分子量PEO均聚物薄膜的结晶研究

采用DSC测试了聚氧化乙烯（PEO）均聚物的结晶温度（TC）和熔融温度（Tm）,利用偏光显微镜（POM）研究了PEO的结晶温度、结晶时间以及PEO的相对分子质量等因素对PEO结晶形态的影响.结果表明：结晶温度对PEO均聚物结晶形态的影响比较显著,在较低温度下（室温下）,PEO形成普通球晶,并随结晶温度升高球晶尺寸逐渐增大,当结晶温度在室温以上时,PEO结晶形态比较完善,结晶尺寸比较大,而且PEO的结晶除黑十字消光外,还带有环形裂纹;结晶时间和PEO相对分子质量的改变只能够影响PEO晶体的尺寸,对PEO晶体的形态并没有太大的影响.     

More Relatively‐Poor People in a Less Absolutely‐Poor World

Relative deprivation, shame, and social exclusion can matter to the welfare of people everywhere. The paper argues that such social effects on welfare call for a reconsideration of how we assess global poverty. We argue for using a weakly‐relative measure as the upper‐bound complement to the lower‐bound provided by a standard absolute measure. New estimates of poverty are presented. The absolute line is $1.25 a day at 2005 prices, while the relative line rises with the mean, at a gradient of 1:2 above $1.25 a day, consistently with national poverty lines. We find that the incidence of both absolute and weakly‐relative poverty in the developing world has been falling since the 1990s, but more slowly for the relative measure. While the number of absolutely poor has fallen, the number of relatively poor has changed little since the 1990s, and is higher in 2008 than 1981.     

Creating an Opportunity Society

This paper comments on the work of Rector et al. (1999a, 1999b). The poverty lines implicit in their restrictive material deprivation approach are disputed and the claim that America has triumphed over poverty is rejected. Evidence is presented showing that poverty among the poorest Americans has significantly increased and is now near an all time high. The long economic expansion since the recession of 1990–1991 has left hardcore poverty essentially unchanged and relative deprivation among the poorest of the poor has increased     

中国产业结构升级 内生动力：需求还是供给

一国产业结构转型的内生动力包括需求和供给两个方面。本文构建了综合上述两类影响因素的产业结构转型模型。通过对模型的校准和模拟，本文发现需求方面的收入增长和供给方面的资本深化两个因素对我国结构转型的影响较大，而技术进步率差异的影响程度较小。因此，保持一定的投资速度，从而稳定增长，提高居民收入，深化资本劳动比是调整产业结构的重要力量。同时，为了在未来推动产业结构升级，需要进一步提高第一产业和第二产业的技术进步率。     

基于组织认知水平的知识质量研究

从知识效用的角度探讨知识质量问题,给出基于组织认知水平的知识相对质量定义。通过分析构建基于组织认知水平的知识质量转移模型和知识测定模型,提出知识相对质量的测定方法,为进一步研究高效知识管理提供方法支持。最后,选取模具设计知识作为知识范围,以模具概要设计为示例给出说明知识相对质量的测定步骤。