增算子不动点定理及其应用

本文建立了若干新的增算子不动点存在定理,作为应用,作者研究了在Banach空间中一类含间断项Volterra积分方程解的存在性,我们的结果改进和推广了诸多已知结果。     

Who Gets What From Government? Distributional Consequences of Child‐Care Assistance Policies

Given the fragmented structure of child‐care assistance in the United States, it has been difficult to obtain accurate estimates of which families are assisted, through which mechanisms, and at what level. Making use of survey data from New York City, we analyze the distribution of several forms of public child‐care assistance. Results suggest that about 40% of all families with young children receive some form of child‐care assistance. Considering all forms of assistance, the distribution of child‐care help is targeted in both expected and some unexpected ways. Implications of these results are discussed in the context of U.S. child‐care policies governing access and benefit levels.     

问题:科学创新的起点

从问题的角度出发 ,提出了问题是科学创新的起点 ,并进一步阐述了问题的来源和问题的意义。只要我们善于从问题出发 ,立足于问题 ,我们的科学创新就会有一番新天地。     

Defining the linear portion of a sigmoid‐shaped curve: bend points

Formulae are provided that define the ‘bend points’, the beginning and end of the essentially linear dose–response region, for the four‐parameter logistic model. The formulae are expressed in both response and dose units. The derivation of the formulae is shown in order to illustrate the general nature of the methodology. Examples are given that describe how the formulae may be used while planning and conducting bioassays. Copyright © 2003 John Wiley & Sons, Ltd.     

江苏省基础设施投资对社会其他部门投资影响效应研究

从理论上看,基础设施投资对社会其他部门投资的影响并不明确。前者对后者既有“挤入”效应又有“挤出”效应。总投资模型对1978—2003年江苏省基础设施投资与社会其他部门投资二者关系进行了实证分析。结果表明,基础设施投资每增加一单位可以挤入约0.634单位社会其他部门的投资。因此,在江苏省增加基础设施投资能够达到刺激投资、扩大社会总需求的目的。     

Making the Best of a Bad Job? Female Part‐Timers’ Orientations and Attitudes to Work

This article uses data from 50 qualitative interviews with female part‐time workers in low‐level jobs in Britain to illustrate their attitudes, orientations and aspirations towards paid work. The research reports two main findings. Firstly, even female part‐time workers at the bottom end of the occupational structure are not a homogeneous group of workers. Secondly, they are not all highly satisfied with their jobs. The article argues that many women (especially those in working‐class households) still do not have a genuine choice between ‘family work’ and ‘market work’. It concludes by presenting a theoretical model of orientations to work.     

On the preservation of copula structure under truncation

The author characterizes the copula associated with the bivariate survival model of Clayton (1978) as the only absolutely continuous copula that is preserved under bivariate truncation.     

民间文学的收集整理与人类学研究--以洪水神话和族群认同研究为例

本文以西南和中南少数民族民间故事中的洪水神话对人类学族群认同研究的作用为例,说明民间文学作品对人类学研究的作用.指出,由于民间文学收集整理方面的原因,致使它作为人类学研究资料具有不足之处.     

区域经济增长与环境质量演进关系模型研究——基于环境库兹涅茨曲线

从社会福利最大化角度出发,通过设定物品消费偏好指数,建立两物品模型,推导出了区域环境最佳投资水平;在此基础上,从理论上证明了环境库兹涅茨曲线存在的依据以及在环境质量最低点和环境质量发生根本性好转的转折点的社会总投资水平。最后,得出环境质量演化过程曲线取决于社会经济发展状况,它与非环境物品生产函数和排污生产函数的技术参数、居民收入水平以及对环境物品和非环境物品的消费偏好以及国民收入分配政策等有关,而非仅仅与经济增长状况有关。     

A relation for the covariances of order statistics from n independent and non-identically distributed random variables

We derive a simple relation satisfied by the covariances of order statistics in the i.i.d. case and then generalize it to the case when the variables are independent and non-identically distributed. This relation could be employed successfully either to check the calculations or to reduce the amount of direct computations involved in evaluating the covariances of order statistics from an outlier model.