Any complete preference structure without circuit admits an interval representation

This article proves that all complete preference structures where the strict preference relation (P) has no circuit admit a representation by intervals of the real line; the rule for deciding whether an interval is indifferent or preferred to another is less straightforward than for interval orders: strict preference is indeed compatible with a certain degree of overlapping of intervals, the allowed degree being specified by means of a so-called tolerance function.     

De minimis and equity in risk

Indices and orderings are developed for evaluating alternative strategies in the management of risk. They reflect the goals of reducing individual and collective risks, of increasing equity, and of assigning priority to the reduction and to the equity of high risks. Individual risk is defined as the (random or non-random) level of exposure to a danger. In particular the role of a lower negligibility level is investigated. A class of indices is proposed which involves two parameters, a negligibility level and a parameter of inequality aversion, and several interpretations of the indices are discussed. We provide a set of eight axioms which are necessary and sufficient for this class of indices, and we present an approach to deal with partial information on the parameters.     

A fast splitting procedure for classification trees

This paper provides a faster method to find the best split at each node when using the CART methodology. The predictability index is proposed as a splitting rule for growing the same classification tree as CART does when using the Gini index of heterogeneity as an impurity measure. A theorem is introduced to show a new property of the index : the for a given predictor has a value not lower than the for any split generated by the predictor. This property is used to make a substantial saving in the time required to generate a classification tree. Three simulation studies are presented in order to show the computational gain in terms of both the number of splits analysed at each node and the CPU time. The proposed splitting algorithm can prove computational efficiency in real data sets as shown in an example.     

品牌资产及其测量中的概念解析

品牌资产(品牌权益)是近年来营销领域中研究的热点问题,然而对于其基本概念的曲解却阻碍了对这个重要问题的进一步研究。本文针对品牌资产涉及的几个概念(品牌资产、品牌权益、品牌价值)及其相互关系加以解释,并将主要的品牌资产的测量方法进行分类,目的是澄清人们对于品牌资产基本概念的模糊认识,为进一步深入研究指明方向。     

Early experiences of mentoring: Design and use of multimedia materials for teaching OR/MS

The MENTOR project, based at the University of Strathclyde, is producing multimedia computer based learning materials with the aim of improving both the effectiveness and the efficiency of teaching Operational Research/Management Science in higher education. The process of development has been carefully designed to encourage ownership of and commitment to the materials amongst lecturing staff in Universities, with the aim of ensuring widespread use. The paper outlines this process of development and design of materials. Experiences in introducing students to the use of these materials as an integrated part of a Management Science class are reported. Feedback from students has been very positive but also indicates the need for ongoing support and direction.     

Determination of recovery effort for a probabilistic recovery system under various inventory control policies

In this study we investigate the desired level of recovery under various inventory control policies when the success of recovery is probabilistic. All the used and returned items go into a recovery process that is modelled as a single stage operation. The recovery effort is represented by the expected time spent for it. The effect of increasing recovery effort on the success probability together with unit cost of the operation is included by assuming general forms of dependencies. Alternative to recovered items, demand is satisfied by brand-new items. Four inventory control policies that differ in timing of and information used in purchasing decision are proposed. The objective is to find the recovery level together with inventory control parameter that minimize the long-run average total cost. A numerical study covering a wide range of system parameters is carried out. Finally computational results are presented with their managerial implications.     

一种基于闭排队网络的集装箱码头设备配置优化模型

将集装箱码头龙门吊装卸工艺抽象为闭排队网络模型,采用估算均值法计算了顾客到达和服务时间分布为一般情况的闭排队网络系统性能指标.仿真结果表明,闭排队网络模型计算结果可以为集装箱码头设备配置提供一定的决策支持.     

泡沫增强聚合物体系配方研究

在分析了聚合物驱提高采收率技术在实际应用中的局限性基础上,提出了采用就地起泡形成泡沫的泡沫增强聚合物体系以减小聚合物沿大通道窜流的问题。为了有效确定该体系的配方,实验中采用了均匀设计实验方法安排实验,并运用DPS数据处理软件对实验数据进行了二次多项式逐步回归处理,找出了影响该体系性能的主要因素。     

高宽课程一日常规本土化的“症状”分析

高宽课程一日常规是幼儿一天活动的顺序,因其支持幼儿的主动性发展顺应了各国教育改革的潮流而备受推崇。但其本土化在教育实践中出现了教师没能领悟到高宽课程理念的精髓、在实践中过于注重形式、本土化探索的积极性不高等方面的“症状”。本文从文化、园长、教师和家长四个方面对上述“症状”进行了“病源”分析。最后提出在移植高宽课程一日常规时应充分考虑到文化差异、强化对高宽课程的深入研究、加强师资培训,搭建师资培训平台、重视园长培训,提供宽松的教育环境、加强家园合作,获得家长支持等五条建议,以求“对症治疗”,使高宽课程一日常规为中国学前教育事业发展提供有益的借鉴。     

地震灾后重建绩效测量——以汶川、玉树、芦山地震为例

灾后重建是保障地震灾区群众重归正常生产生活的重要工作,那么如何测量灾后重建绩效,哪些因素会影响灾后重建绩效?文章回顾了灾后重建绩效相关研究文献,在此基础上认为效果和效率是灾后重建绩效的两大方面,以"消除灾害影响并恢复到灾前水平所用的时间"作为衡量灾后重建绩效的标准,能够反映灾后重建的效果和效率,具有可行性。以此为基础建立了灾后重建绩效的分析框架和测量方法,并选择汶川地震、玉树地震和芦山地震作为案例,对三次地震灾区的重建绩效进行了对比分析并简要分析了绩效差异原因。结果表明,三次地震灾后重建基本如期完成了灾后重建目标任务,但因存在灾害程度不同、对口支援质量不同等原因,三次地震灾后重建绩效存在一定差异。