基于聚类分析电信运营企业仓库布局优化研究

以某电信运营企业为例,在现场调研的基础上,分析了企业仓库布局的主要问题,应用聚类分析方法,提出了仓库布局优化方案,并进行了方案的综合评价.     

Robustness issues in multilevel regression analysis

A multilevel problem concerns a population with a hierarchical structure. A sample from such a population can be described as a multistage sample. First, a sample of higher level units is drawn (e.g. schools or organizations), and next a sample of the sub‐units from the available units (e.g. pupils in schools or employees in organizations). In such samples, the individual observations are in general not completely independent. Multilevel analysis software accounts for this dependence and in recent years these programs have been widely accepted. Two problems that occur in the practice of multilevel modeling will be discussed. The first problem is the choice of the sample sizes at the different levels. What are sufficient sample sizes for accurate estimation? The second problem is the normality assumption of the level‐2 error distribution. When one wants to conduct tests of significance, the errors need to be normally distributed. What happens when this is not the case? In this paper, simulation studies are used to answer both questions. With respect to the first question, the results show that a small sample size at level two (meaning a sample of 50 or less) leads to biased estimates of the second‐level standard errors. The answer to the second question is that only the standard errors for the random effects at the second level are highly inaccurate if the distributional assumptions concerning the level‐2 errors are not fulfilled. Robust standard errors turn out to be more reliable than the asymptotic standard errors based on maximum likelihood.     

灰色聚类综合评价方法在住宅建筑方案选优中的应用

阐述了基于灰色聚类原理开发出的一种综合评价方法，其应用于住宅建筑方案选优，既可选出相对最优方案，又可直观地评出其属于何种等级的灰类。     

Why I am a Psychology Major: An Empirical Analysis of Student Motivations

The underlying “architecture of the decision to pursue a degree in psychology was quantified using the Method of Sorting technique to identifying the critical issues necessary to make this choice. Multidimentsional scaling procedures were employed to construct a three-dimensional map representing the relationships between reasons for selecting psychology as a major. Freshman and senior psychology majors (N = 165) from a regional university and a large research-based institution rated the relative importance of items in their decision-making process. Hierarchical clustering procedures revealed seven different groups of students. Although significant differences associated with class standing were not found, institutional affiliation did influence cluster composition. Reflecting local emphases, students at the regional institution had a greater interest in Counseling Psychology, whereas those at the research-based school focused on Clinical Psychology. This semantic map and the associated item clusters arising from psychology student data provides an empirical basis for, amongst other things, course selection, faculty-initiated program design or revision, strategic niche marketing, and student retention.     

基于模糊综合评判的物流运输企业客户群体价值评估

论述了物流运输企业实施客户群体价值评估的意义,给出了基于模糊综合评判的对现代物流运输企业客户进行价值评价的基本思路。     

基于自组织创新网络的集群式供应链体系研究

基于自组织创新网络理论来分析集群式供应链系统的成因及其架构,介绍了“武汉.中国光谷”的集群式供应链系统,并结合该案例总结集群式供应链进行自组织创新的五个过程。     

保税区发展商贸物流中心的瓶颈分析

提出了争取扩大保税区政策优势，继续保持区位优势的基础上，迅速加强以大中华区商贸物流中心为实体产业核心的产业集聚发展的思路。     

我国居民消费结构的趋势分析

采用“双对数模型”对我国城乡居民的消费结构进行了趋势分析,通过“聚类分析”对我国各省市居民消费结构之间的异同进行考察并作比较研究,总结出了我国居民消费呈现富裕型、娱乐教育文化服务类消费攀升的趋势特点。     

国债挤出效应的实证分析

发行国债投资于基础设施是带动经济增长的重要手段，但随着国债发行规模的不断扩大，国债对民间投资是否存在挤出作用成为了理论界关注的焦点。文章通过对投资主体投资份额、总量的相关分析以及国债投资方向的聚类分析，认为现阶段由于国债投资方向与宏观经济环境的原因，国债发行对民间投资挤出作用较小，带动作用较大。     

论旅游产业集群的系统架构

在旅游产业集群研究过程中，首先需要解决的问题是搭建旅游产业集群的系统架构。一般来说，旅游产业集群包括3个层次：宏观旅游产业集群、中观旅游产业集群和微观旅游产业集群。无论哪个层面的旅游产业集群都以旅游资源为经营核心，以旅游企业为经营依托。旅游产业集群有4种网络结构：区域关系网络、产业关系网络、市场关系网络和社会关系网络。此外，旅游产业集群还包括协作型和竞争型2种市场结构。正是层次结构、网络结构和市场结构，才形成了旅游产业集群的系统架构。