Analysis of local influence in geostatistics using Student's t-distribution

This article aims to estimate parameters of spatial variability with Student's t-distribution by the EM algorithm and present the study of local influence by means of two methods known as likelihood displacement and Q-displacement of likelihood, both using Student's t-distribution with fixed degrees of freedom (ν). The results showed that both methods are effective in the identification of influential points.     

Measuring Gross Flows in the Labor Force: An Overview of a Special Conference

The measurement of flows in the American labor market has challenged researchers for years. Several problems, including response variability, rotation group bias, and matching errors, hinder accurate measurement of the flows. The Bureau of the Census and the Bureau of Labor Statistics jointly sponsored a conference to examine these problems, present current research on solutions to the problems, and submit recommendations for improving the data. Recommendations include procedural changes in the Current Population Survey as well as new estimation techniques.     

关于加强高校入党积极分子培养的探讨

培养大学生入党积极分子,是高校党组织的一项重要工作。要解放思想,加强理论教育、成立各种理论研讨小组,加强党校的网络化教育。要在活动中加强对入党积极分子的教养和考察,同时加强学生党员与入党积极分子的交流,加强日常管理和规范考察程序,做好早选苗、早培养、严格把关、定向培养、相结合的工作。只有通过各种途径做好对入党积极分子的培养,才能为高校党组织发展提供后备力量。     

关于中国零售业会员制的思考

近年来,中国市场上许多零售业的会员店先后出现了"水土不服"的现象,对这一现象进行了调查和分析,提出了建立适合中国市场的零售业会员制模式应注意的问题.     

基于投影的直觉模糊数多属性决策方法

针对指标取值以直觉模糊数形式给出的多属性决策问题,提出了一种基于投影的直觉模糊决策方法.该方法依据一般投影分析方法的基本思路,给出了解决属性取值为直觉模糊数的多属性决策问题的计算步骤,其核心是通过构建并求解每个方案在虚拟正、负理想方案上的投影,进而计算出每个方案对虚拟正、负理想方案的相对隶属度,即可得到所有方案的排序结果.最后给出的数值算例表明,该方法简单、有效和易于计算.     

“三权分置”下集体土地所有权的立法表达

植根于“两权分离”的集体土地所有权法律制度已经难以满足“三权分置”下的农地改革实践,集体土地所有权基本构造体系的缺陷集中体现在:权利属性与权利主体的模糊性;行使主体与行使机制的不健全;权能体系和保障机制欠缺。未来立法应该在坚持农村土地集体所有的基础上,对集体土地所有权基本构造体系与农民集体成员权综合治理体系进行科学的立法表达。完善集体土地所有权基本构造体系需要：明确特定社区范围内的成员集体是集体土地所有权的权利主体;明晰农村集体经济组织是集体土地所有权的代表行使主体;丰富集体土地所有权的权能体系。农民集体成员权是克服集体土地所有权制度缺陷的重要设计,建构其综合治理体系应该在理论上厘清农村集体土地所有权与农民集体成员权之间的关系,设计出科学可行的集体成员身份认定标准,丰富农民集体成员权利体系,健全农民集体成员权利行使规则与救济规则。     

模糊集合隶属函数确定中的哲学思考

模糊集合是模糊数学的基础 ;隶属函数是刻画模糊集合的数学表达式。隶属函数的确定 ,允许有一定的人为技巧 ,但并不能由此而否定模糊逻辑和模糊推理。以确定模糊集合的隶属函数的最常用的统计方法为例 ,对隶属函数确定过程中的哲学分析表明 :模糊集合中确定的隶属函数并不是主观随意的产物 ,而仍然具有一定的历史客观性 ,体现了主客观的辩证统一     

具有不确定信息的风险型多目标决策理论及应用

具有不确定信息的多目标决策问题是一类常见的决策问题。给出该决策问题指标的分类方法和指标值的规格化公式,建立方案的距优距劣综合加权距离为最小的目标函数,从而得到一类求解这一问题的数学模型,并给出了一种目标权重的确定方法,很适用于实际问题,为解决不确定性系统的多目标决策问题提供了一种思路和方法。最后将其应用到水资源系统风险决策的一个实例中,表明了方法的可行性。     

Integrating Uncertainty and Interindividual Variability in Environmental Risk Assessment

An integrated, quantitative approach to incorporating both uncertainty and interindividual variability into risk prediction models is described. Individual risk R is treated as a variable distributed in both an uncertainty dimension and a variability dimension, whereas population risk I (the number of additional cases caused by R) is purely uncertain. I is shown to follow a compound Poisson-binomial distribution, which in low-level risk contexts can often be approximated well by a corresponding compound Poisson distribution. The proposed analytic framework is illustrated with an application to cancer risk assessment for a California population exposed to 1,2-dibromo-3-chloropropane from ground water.     

Human Variability in Susceptibility to Toxic Chemicals— A Preliminary Analysis of Pharmacokinetic Data from Normal Volunteers

The tenfold "uncertainty" factor traditionally used to guard against human interindividual differences in susceptibility to toxicity is not based on human observations. To begin to build a basis for quantifying an important component of overall variability in susceptibility to toxicity, a data base has been constructed of individual measurements of key pharmacokinetic parameters for specific substances (mostly drugs) in groups of at least five healthy adults. 72 of the 101 data sets studied were positively skewed, indicating that the distributions are generally closer to expectations for log-normal distributions than for normal distributions. Measurements of interindividual variability in elimination half-lives, maximal blood concentrations, and AUC (area under the curve of blood concentration by time) have median values of log10 geometric standard deviations in the range of 0.11-0.145. For the median chemical, therefore, a tenfold difference in these pharmacokinetic parameters would correspond to 7-9 standard deviations in populations of normal healthy adults. For one relatively lipophilic chemical, however, interindividual variability in maximal blood concentration and AUC was 0.4--implying that a tenfold difference would correspond to only about 2.5 standard deviations for those parameters in the human population. The parameters studied to date are only components of overall susceptibility to toxic agents, and do not include contributions from variability in exposure- and response-determining parameters. The current study also implicitly excludes most human interindividual variability from age and illness. When these other sources of variability are included in an overall analysis of variability in susceptibility, it is likely that a tenfold difference will correspond to fewer standard deviations in the overall population, and correspondingly greater numbers of people at risk of toxicity.