An analysis of two probabilistic model induction techniques

Two probabilistic model induction techniques, cart and constructor, are compared, via a series of experiments, in terms of their ability to induce models that are both interpretable and predictive. The experiments show that, although both algorithms are able to deliver classifiers with predictive performance close to that of the optimal Bayes rule,constructor is able to generate a probabilistic model that is more easily interpretable than the cart model. On the other hand, cart is a more mature algorithm and is capable of handling many more situations (e.g., real-valued training sets) thanconstructor. A variety of characteristics of both algorithms are compared, and suggestions for future research are made.     

A Comment on Ali Tas˛ıran's `Wage and income effects on the timing and spacing of births in Sweden and in the United States'

This note reviews and evaluates Taşıran's (1995) claim that estimated female wage effects on Swedish fertility dynamics reported by Heckman and Walker (1990) are not robust to the use of microwage data. The results reported here indicate that once individual wage measures have been purged of measurement error, estimated female wage effects are not sensitive to the introduction of microwages. The results reported by Heckman and Walker (1990) persist even with the use of microwage data. Received: 8 March 1996/Accepted: 4 December 2001 I thank Tom MaCurdy, Eric French and two anonymous referees for useful comments. This research was supported by NICHD grants HD-19226 and HD-28685. The usual disclaimer applies. Responsible editor: Klaus F. Zimmermann.     

Integer programming formulations of statistical classification problems

A series of approaches is presented to formulate statistical classification problems using integer programming. The formulations attempt to maximize the number of observations that can be properly classified and utilize single function, multiple function and hierarchical multiple function approaches to the problems. The formulations are tested using standard software on a sample problem and new approaches are compared to those of other authors. As the solution of such problems gives rise to various awkward features in an integer programming framework, it is demonstrated that new approaches to formulation will not be completely successful in avoiding the difficulties of existing methods, but demonstrate certain gains.     

Feature Selection for Consistent Biclustering via Fractional 0–1 Programming

Biclustering consists in simultaneous partitioning of the set of samples and the set of their attributes (features) into subsets (classes). Samples and features classified together are supposed to have a high relevance to each other which can be observed by intensity of their expressions. We define the notion of consistency for biclustering using interrelation between centroids of sample and feature classes. We prove that consistent biclustering implies separability of the classes by convex cones. While previous works on biclustering concentrated on unsupervised learning and did not consider employing a training set, whose classification is given, we propose a model for supervised biclustering, whose consistency is achieved by feature selection. The developed model involves solution of a fractional 0–1 programming problem. Preliminary computational results on microarray data mining problems are reported.This research work was partially supported by NSF, NIH and AirForce grants.     

Analysis of overdispersed paired count data

This article is about the statistical analysis of overdispersed paired count data for comparing two treatments. The data consist of the number of events obtained in a stratum during the fixed observation period. Three types of model are discussed: the Poisson, a mixed, and a semiparametric model. Overdispersion is represented in the last two models but not in the Poisson model. Of particular interests are to examine whether there is any loss of efficiency in using the estimate of the treatment effect obtained under other two models if the mixed model is true, and also whether overdispersion leads to a larger variance of the estimate than that expected from the Poisson model. It is shown that all three models provide the same estimate of the treatment effect (i.e., there is no loss of efficiency) and that the variance of the estimate of the treatment effect obtained under the Poisson model is the same as that based on the mixed model. However, the semiparametric model provides the variance of the estimate larger than those obtained under the other two models.     

ABC Classification: Service Levels and Inventory Costs

ABC inventory classifications are widely used in practice, with demand value and demand volume as the most common ranking criteria. The standard approach in ABC applications is to set the same service level for all stock keeping units (SKUs) in a class. In this paper, we show (for three large real life datasets) that the application of both demand value and demand volume as ABC ranking criteria, with fixed service levels per class, leads to solutions that are far from cost optimal. An alternative criterion proposed by Zhang et al. performs much better, but is still considerably outperformed by a new criterion proposed in this paper. The new criterion is also more general in that it can take criticality of SKUs into account. Managerial insights are obtained into what class should have the highest/lowest service level, a topic that has been disputed in the literature.     

公务员三维分类分级模型与考核指标设计研究

在对我国公务员分类分级考核现状分析的基础上,以考核为导向,按照职能、专业、管理层次等3个维度建立公务员分类分级的三维模型,并在此基础上设计公务员年度考核指标体系。     

类型学视野下高校创新创业教育的分层分级分类模式探析

与欧美发达国家相比,我国高校创新创业教育起步晚、积累少、模式雷同,大学生创新创业能力远未达到国家人才战略的要求。以重庆邮电大学为例,基于类型学的研究视角和学理基础,着眼于培养具有创业精神、创新能力的高素质拔尖人才,按照高校创新创业教育目标层次、服务对象、实施载体,构建了高校创新创业教育分层分级分类的全新模式。反思重庆邮电大学的实践探索,认为我国高校创新创业教育今后理应在准确定位高校创新创业教育、系统建立高校创新创业教育课程体系、大力拓展高校创新创业教育实践平台、科学构建高校创新创业教育管理机制等方面下功夫。     

转喻视角下英语间接回指的分类研究

回指是一个语言表达式在同一篇章中被用来指代另一个语言表达式所表达的意义或事物的语言现象.回指可以分为直接回指和间接回指.从认知语言学中的概念转喻视角,以间接回指中整体与部分之间的映射以及间接回指中部分与部分之间的映射为依据,间接回指可分为辐射类、预设类、上下义类三大类和邻近类、因果类、前后景类三大类.