Dealing with heterogeneity in ordinal responses

Quality & Quantity - In sample surveys where people are asked to express their personal opinions it is conceivable to register a high level of indecision among respondents and this circumstance...     

Structural equation modeling with ordinal variables: a large sample case study

In the behavioral sciences, response variables are often non-continuous, ordinal variables. Conventional structural equation models (SEMs) have been generalized to accommodate ordinal responses. In this study, three different estimation methods on real data were performed with ordinal variables. Empirical results obtained from the different estimation methods on given real large sample educational data were investigated and compared to recent simulation results. As a result, even very large sample is available, model estimations and fits for ordinal data are affected from inconvenient estimation methods thus it is concluded that asymptotically distribution free estimation method specialized for ordinal variables is more convenient way to model ordinal variables.     

Polychoric versus Pearson correlations in exploratory and confirmatory factor analysis of ordinal variables

Given that the use of Likert scales is increasingly common in the field of social research it is necessary to determine which methodology is the most suitable for analysing the data obtained; although, given the categorization of these scales, the results should be treated as ordinal data it is often the case that they are analysed using techniques designed for cardinal measures. One of the most widely used techniques for studying the construct validity of data is factor analysis, whether exploratory or confirmatory, and this method uses correlation matrices (generally Pearson) to obtain factor solutions. In this context, and by means of simulation studies, we aim to illustrate the advantages of using polychoric rather than Pearson correlations, taking into account that the latter require quantitative variables measured in intervals, and that the relationship between these variables has to be monotonic. The results show that the solutions obtained using polychoric correlations provide a more accurate reproduction of the measurement model used to generate the data.     

Classification and benchmark of City Logistics measures: an empirical analysis

Urban freight distribution accounts for a significant share of pollution and congestion in urban areas. To reduce these negative impacts, municipalities have implemented several City Logistics (CL) measures. This paper presents the empirical analysis of a dataset of 70 European cities that have been piloting or rolling out a CL measure, to provide an updated indication of the status of CL initiatives and analyse the diffusion of CL internationally. The research objective is also to help understand the contextual factors might explain their introduction. To this end, a set of City Logistics Indices (CLI) is used as indicators of the breadth and number of CL measures implemented in a city. A statistical correlation of these CLIs with respect to a set of independent variables, namely the contextual factors, is also performed. Results reveal that the level of pollution, the diffusion of e-commerce and GDP are important drivers of CL deployment.     

分层次培训是集快乐、高效和有趣的培训模式

分层次培训是一种适合职业教育的有效培训模式,莱阳市职业中等专业学校在汽车运用与维修专业中采用分层次培训,倡导快乐、高效、有趣学习,通过不同能力学生的培训包的设计和直观培训、场景培训、仿真培训、步进培训等培训方法的运用,使低年级的学生体验到学习的乐趣,激发继续学下去的欲望。通过校企互动,密切合作,引入真实生产项目,将培训过程和生产过程融合在一起,让高年级的学生体会到学有所得、学有所成、学有所长的终极目标,提升了责任感与能力。     

Cardinal versus ordinal criteria in choice under risk with disconnected utility ranges

This paper provides a formal justification for the existence of subjective random components intrinsic to the outcome evaluation process of decision makers and explicitly assumed in the stochastic choice literature. We introduce the concepts of admissible error function and generalized certainty equivalent, which allow us to analyze two different criteria, a cardinal and an ordinal one, when defining suitable approximations to expected utility values. Contrary to the standard literature requirements for irrational preferences, adjustment errors arise in a natural way within our setting, their existence following directly from the disconnectedness of the range of the utility functions. Conditions for the existence of minimal errors are also studied. Our results imply that neither the cardinal nor the ordinal criterion do necessarily provide the same evaluation for two or more different prospects with the same expected utility value. As a consequence, a rational decision maker may define two different generalized certainty equivalents when presented with the same prospect in two different occasions.     

Hierarchical integration in production planning: Theory and practice

This paper discusses the issue of integrating various decision levels in hierarchical production planning systems. First the theory is briefly reviewed and then two case studies are presented. It is argued that it is not sufficient to have a good decision model at every level of the decision hierarchy. The different models should be carefully integrated. The potential problems resulting from a lack of integration are discussed. These problems are then illustrated in two case studies in order to be able to focus on actual managerial issues. It is shown how different decision levels supported by decision models were integrated in these two applications. Two important features are the crucial role of crossfunctional managerial committees in the integration process and the introduction of slack to avoid disaggregation problems.We do not claim to be exhaustive in presenting the problems related to integration nor do we claim that the solutions to the cases are the best possible ones. We do, however, hope that this paper motivates production managers to take a serious look at their hierarchical planning procedures.     

Political Profit: Taxing and Spending in the Hierarchical State

A bstract . The actions of government fall into two types: taxes (the taking of property ) and expenditures (the awarding of gifts ). Politicians profit as long as the value of resources raised from taxation exceeds the cost of expenditures. From their point of view, fiscal efficiency consists in maximizing the support obtained by spending and minimizing the opposition generated by taxing. This is accomplished by spending on well-organized groups and taxing the uninformed public. This results in the "iron law of political redistribution" in which income and wealth are transferred from the latter to the former. In a hierarchical State , it is usually profitable for those at the top to centralize control over taxing and spending, if for no other reason than to make it difficult for politicians at lower levels to compete against them. This gives rise to the "law of hierarchical centralization "—in a hierarchical State, power becomes centralized over time. The greater the power of government, the faster this process takes place. In order to avoid this problem, one could design constitutions which are non-hierarchical in nature, in which each unit of government is completely autonomous from the others, as firms are in a free market.     

Classification in automobile insurance using a DEA and discriminant analysis hybrid

In this article, we adopt an efficiency approach to the two-group linear programming method of discriminant analysis (DA), using principles taken from data envelopment analysis (DEA), to predict group membership in an insurance underwriting scheme. Using an empirical insurance data base we illustrate the effectiveness of our model as a decision-making tool to distinguish among automobile insurance applicants by contrasting our hybrid model with both statistical and LP methods of discriminant analysis. We find for this insurance application that our hybrid model significantly outperforms the more traditional methods in separation and misclassification outcomes.     

Classification performance of mathematical programming techniques in discriminant analysis: Results for small and medium sample sizes

The performance on small and medium-size samples of several techniques to solve the classification problem in discriminant analysis is investigated. The techniques considered are two widely used parametric statistical techniques (Fisher's linear discriminant function and Smith's quadratic function), and a class of recently proposed nonparametric estimation techniques based on mathematical programming (linear and mixed-integer programming). A simulation study is performed, analyzing the relative performance of the above techniques in the two-group case, for various small sample sizes, moderate group overlap and across six different data conditions. Training samples as well as validation samples are used to assess the classificatory performance of the techniques. The degree of group overlap and sample sizes selected for analysis in this paper are of interest in practice because they closely reflect conditions of many real data sets. The results of the experiment show that Smith's nonlinear quadratic function tends to be superior on the training samples and validation samples when the variances–covariances across groups are heterogeneous, while the mixed-integer technique performs best on the training samples when the variances–covariances are equal, and on validation samples with equal variances and discrete uniform independent variables. The mixed-integer technique and the quadratic discriminant function are also found to be more sensitive than the other techniques to the sample size, giving disproportionally inaccurate results on small samples.     

浙江高等教育层次结构与科类结构的优化研究

本文分析浙江高等教育层次结构和科类结构的现状及存在的问题,由此提出优化层次结构和科类结构的对策:构建梯度合理、职责明晰的层次结构,打造调整与需求适应、改造与发展并举的科类结构。     

浙江高等教育层次结构与科类结构的优化研究

本文分析浙江高等教育层次结构和科类结构的现状及存在的问题,由此提出优化层次结构和科类结构的对策：构建梯度合理、职责明晰的层次结构,打造调整与需求适应、改造与发展并举的科类结构。     

Classification transitions under expansion of inputs and outputs in data envelopment analysis

An exchange between Thomas R. Nunamaker and T. Ahn, A. Charnes and W. W. Cooper which revolves around possible behavior of the DEA efficiency measure. In particular, Ahn, Charnes and Cooper provide a counterexample to Nunamaker's assertion that adding inputs to a DMU (Decision Making Unit) which had previously attained an efficiency of 0* = 1 with fewer inputs would never alter this value, no matter how inefficient the use of the additional inputs. Here we want to add additional insight by showing the condition under which Nunamaker's proposition is true. Using the notation and concepts from Charnes, Cooper and Thrall, we shall see that this proposition is true if and only if the previously attained 0* = 1 is uniquely optimal.     

基于土木结构递阶分散控制的稳定性研究

采用递阶分散控制的方法对土木结构进行振动控制,同时结构满足稳定性要求。控制作用分为局部和全局控制两级,局部控制器对子结构的振动控制,用李雅普诺夫方法来获得子结构稳定,而全局控制器来减小子结构之间相互作用而保证结构全局稳定性。对悬臂梁结构进行了控制稳定性仿真分析,将振动仿真结果与集中控制的结果进行对比分析。结果表明,基于递阶分散的控制方法保证大型土木结构的稳定性。     

Classification and Discrimination Problems with Applications, Part IIa

Abstract  In Part I exact results for univariate (" p = 1") two-group ("k = 2") classification problems were derived assuming normality and equality of the variances. In Part IIa asymptotic results for multivariate (" p > I") two-group classification and discrimination problems are based on the corresponding assumptions of multivariate normality and equality of the covariance matrices. The results (4.6.5), (4.6.6) and (4.6.7) are believed to be new.
The asymptotic results in Section 4.6, together with results presented elsewhere in the literature, constitute the basis of various detailed proposals to deal with problems from actual statistical practice. Most of these proposals are modifications or specifications of existing ones. We shall pay some attention to (I) testing whether differences exist. But we are mainly interested in: (II) constructing a discriminant function, (III) assigning the individual under classification, and in (IV) constructing a confidence interval for "the" posterior probability that the individual under classification belongs to Population 2.
An important part in our theory is played by various techniques for selecting variables in discriminant analysis. The need for such techniques follows from Section 4.10. The consequences of building-in a selection technique are discussed in Section 4.12. One of our proposals motivates the theory presented in Chapter 3 and is mentioned here for that reason: employ a large part of the data, say 70%, in order to construct a discriminant function (via a selection of variables); by applying this function to the rest of the data, the exact univariate theory of Part I becomes of application. Part IIb will contain a chapter on applications.     

小区业主的建筑物区分所有权客体界分——一个经济学的解释

居民小区业主的建筑物区分所有权客体问题不是个法学问题而是个经济学问题。从经济学角度来看,确定业主的建筑物区分所有权客体应该立足于物品功能的发挥和购房者需求的满足。以此为原则,如果一个物品属于建筑物区分所有权客体,必须同时具备三个条件:第一,与商品房核心部分在功能上应该互补;第二,独立销售时对购房者来说其属于垄断性物品且不属于自然垄断;第三,属于俱乐部物品或私人物品。     

“互联网+电子商务”背景下高职跨境电商人才分层分类培养模式研究——基于宁波城市职业技术学院的教学实践

互联网+电子商务背景下,跨境电商的急速发展,对于人才的需求缺口也日益显著。从事跨境电商业务不仅要熟悉跨境电商平台的操作技能、传统外贸的交易流程,更需要外语基础与交流能力。高职院校以培养应用型人才为目标,跨境电商的发展给人才培养提供了契机。