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41.
A test of congruence among distance matrices is described. It tests the hypothesis that several matrices, containing different types of variables about the same objects, are congruent with one another, so they can be used jointly in statistical analysis. Raw data tables are turned into similarity or distance matrices prior to testing; they can then be compared to data that naturally come in the form of distance matrices. The proposed test can be seen as a generalization of the Mantel test of matrix correspondence to any number of distance matrices. This paper shows that the new test has the correct rate of Type I error and good power. Power increases as the number of objects and the number of congruent data matrices increase; power is higher when the total number of matrices in the study is smaller. To illustrate the method, the proposed test is used to test the hypothesis that matrices representing different types of organoleptic variables (colour, nose, body, palate and finish) in single‐malt Scotch whiskies are congruent.  相似文献   
42.
Hahn [Hahn, J. (1998). On the role of the propensity score in efficient semiparametric estimation of average treatment effects. Econometrica 66:315-331] derived the semiparametric efficiency bounds for estimating the average treatment effect (ATE) and the average treatment effect on the treated (ATET). The variance of ATET depends on whether the propensity score is known or unknown. Hahn attributes this to “dimension reduction.” In this paper, an alternative explanation is given: Knowledge of the propensity score improves upon the estimation of the distribution of the confounding variables.  相似文献   
43.
绿色供应链管理动力/压力影响模型实证研究   总被引:3,自引:0,他引:3  
文章借鉴国外文献及国内环保专家的意见设计问卷进行调研,通过因子分析识别出中国制造企业绿色供应链管理的压力/动力和实践的主要因子.对因子进行相关分析和回归分析,根据数据结合国内外相关情况探讨动力/压力是如何影响绿色供应链管理实践,提出中国制造企业绿色供应链管理的动力/压力影响模型.  相似文献   
44.
文章简要阐述了反馈信息,论述了作文工作研究的意义及在作文写作中有效的信息反馈形式,提出了增强写作能力的可行措施。  相似文献   
45.
根据现有文献研究成果,结合实际调研分析,将供应链风险因素整理归纳为系统风险、供应风险、物流风险、信息风险、财务风险、管理风险、需求风险和环境风险。每种风险因素并非独立存在,而是相互影响、互为根源。其非线性叠加结果将会放大供应链整体风险水平。因此,必须认识到其存在的风险,只有在明确各种风险产生根源的基础上,才能恰当地制定、选择和采取有效措施,规避风险,确保供应链整体绩效稳步提高。  相似文献   
46.
Summary.  As a part of the EUREDIT project new methods to detect multivariate outliers in incomplete survey data have been developed. These methods are the first to work with sampling weights and to be able to cope with missing values. Two of these methods are presented here. The epidemic algorithm simulates the propagation of a disease through a population and uses extreme infection times to find outlying observations. Transformed rank correlations are robust estimates of the centre and the scatter of the data. They use a geometric transformation that is based on the rank correlation matrix. The estimates are used to define a Mahalanobis distance that reveals outliers. The two methods are applied to a small data set and to one of the evaluation data sets of the EUREDIT project.  相似文献   
47.
诉讼对抗是诉讼的结构性因素,诉讼当事人的双方被置于相互对立、相互抗争的地位上并展开攻击和防御活动,以发现案件真实。对抗的弊端是:过度对抗引起诉讼拖延,对抗加大了诉讼成本,对抗发现真实功能的发挥越来越有限。近年来,诉讼合作迅速兴起,有利于兼顾当事人各方的利益,提高诉讼效率,节约诉讼成本,促进和谐社会的形成。坚持诉讼对抗与诉讼合作并重,是我国司法改革的方向。  相似文献   
48.
文章运用DEA方法,评价了北京、东京、上海以及横滨等城市2003年-2005年间供水系统的静态效率,发现日本三个城市供水系统的效率要高于中国三个城市的效率,造成这种状况的原因主要在于中国的水价体系还不够完善,供水企业收益不能完全回收其成本。  相似文献   
49.
This article applies a series of concepts from Niklas Luhmann's systems theory in an analysis of modern welfare organisations. The point of departure is that social help in late modern welfare states has become 'polycentric' in that 'help' is today being defined by various different agents: public, voluntary and private care providers. Empirically, this article investigates re-housing work with homeless people, a kind of social work which involves several different welfare organisations. The case study shows how these organisations define themselves by making internal constructions of their surroundings, and how their self-enclosed nature creates a certain 'insensitivity' towards one another. How to coordinate and translate within this 'polyphony' of incomparable observations and values represents a major managerial challenge for present-day social workers.  相似文献   
50.
We consider samples drawn without replacement from finite populations. We establish optimal lower non-negative and upper non-positive bounds on the expectations of linear combinations of order statistics centered about the population mean in units generated by the population central absolute moments of various orders. We also specify the general results for important examples of sample extremes, Gini mean differences and sample range. The paper completes the results of Papadatos and Rychlik [2004. Bounds on expectations of L-statistics from without replacement samples. J. Statist. Plann. Inference 124, 317–336], where sharp negative lower and positive upper bounds on the expectations of the combinations were presented for the without-replacement samples.  相似文献   
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