Maximum expected entropy transformed Latin hypercube designs

Existing projection designs (e.g. maximum projection designs) attempt to achieve good space-filling properties in all projections. However, when using a Gaussian process (GP), model-based design criteria such as the entropy criterion is more appropriate. We employ the entropy criterion averaged over a set of projections, called expected entropy criterion (EEC), to generate projection designs. We show that maximum EEC designs are invariant to monotonic transformations of the response, i.e. they are optimal for a wide class of stochastic process models. We also demonstrate that transformation of each column of a Latin hypercube design (LHD) based on a monotonic function can substantially improve the EEC. Two types of input transformations are considered: a quantile function of a symmetric Beta distribution chosen to optimize the EEC, and a nonparametric transformation corresponding to the quantile function of a symmetric density chosen to optimize the EEC. Numerical studies show that the proposed transformations of the LHD are efficient and effective for building robust maximum EEC designs. These designs give projections with markedly higher entropies and lower maximum prediction variances (MPV''s) at the cost of small increases in average prediction variances (APV''s) compared to state-of-the-art space-filling designs over wide ranges of covariance parameter values.     

青年干部事业成功因素探析

青年干部无论做什么工作,其成功的期望值都很高.然而,事业的成功不是唾手可得的,还必须掌握事业成功的一些关键因素,这就是自信、创新、意志、人格精神和时间管理.     

浅淡图书馆如何加强网络环境下的服务理念

在网络环境下应不断加强读者教育机制,不断改进图书馆的管理,以体现“以人为本”的管理和服务理念,促进图书馆的读者服务进一步完善。     

基于Malmquist指数的中国移动动态效率研究

运用DEA-Malmquist指数的方法,分析了2006～2008年中国移动动态效率。研究结果表明,中国移动技术效率明显提升,而技术进步率低,这与中国移动长期依靠高投入换取高增长密切相关。同时对中国移动东、中、西部地区的全要素生产率指数以及构成因素进行对比分析,发现各区域变化率指数逐渐拉开,区域差异将逐渐缩小。     

基于稀疏主成分的能源利用效率综合评价及影响因素分析

基于能源消耗水平、能源高效利用水平、污染排放水平和污染治理水平四大准则层构建了评价能源利用效率的指标体系,使用数据包络分析、稀疏主成分方法和熵值法得到了我国各省市自治区2008-2018年的能源利用效率综合评价结果。在此基础上通过构建省际动态面板模型研究了能源利用效率的影响因素,回归结果显示：经济开放性、人均GDP、第三产业占比对能源利用效率有显著的正影响,能源消费结构、政府环境规制对能源利用效率有显著的负影响。最后就如何提高能源利用效率提出了相应的政策建议。     

空间聚集条件下城市TFP增长的影响因素研究

利用中国264个地级及地级以上城市的空间面板数据和空间杜宾模型,研究在空间聚集条件下,全要素生产率(TFP)增长与城市规模及人力资本、基础设施等相关影响因素的关系,得出以下主要结论：在考虑空间权重后,全要素生产率增长指数与城市规模由倒“U”型曲线变为“U”型曲线,全要素生产率增长指数与城市规模对数的间接效应成“U”型曲线,直接效应和总效应成倒“U”型曲线;人力资本、基础设施指数、第三产业占总的就业比重、财政收入、科学支出的直接效应为负,间接效应和总效应为正;人口密度、房价收入比指标的直接效应为正,间接效应和总效应为负;教育支出、城市化水平、万人图书馆藏量、工资收入、劳动生产率、劳动力的直接效应、间接效应和总效应都为负。〖BP(〗〖BP)〗并提出相应的政策建议。     

Mixtures of general location model with factor analyzer covariance structure for clustering mixed type data

Cluster analysis is one of the most widely used method in statistical analyses, in which homogeneous subgroups are identified in a heterogeneous population. Due to the existence of the continuous and discrete mixed data in many applications, so far, some ordinary clustering methods such as, hierarchical methods, k-means and model-based methods have been extended for analysis of mixed data. However, in the available model-based clustering methods, by increasing the number of continuous variables, the number of parameters increases and identifying as well as fitting an appropriate model may be difficult. In this paper, to reduce the number of the parameters, for the model-based clustering mixed data of continuous (normal) and nominal data, a set of parsimonious models is introduced. Models in this set are extended, using the general location model approach, for modeling distribution of mixed variables and applying factor analyzer structure for covariance matrices. The ECM algorithm is used for estimating the parameters of these models. In order to show the performance of the proposed models for clustering, results from some simulation studies and analyzing two real data sets are presented.     

基于聚类分析的中国农村养老区域划分研究

本文利用国家统计局及人力资源和社会保障部编制的年鉴资料．从中选取了18个与农村养老区域划分相关的统计指标,采用因子分析和聚类分析方法对我国31个省（自治区、直辖市）的农村进行了养老区域类型的划分,并提出相关的对策建议．以期为我国新型农村社会养老保险政策的实施及各区域农村养老保障模式的选择提供依据和参考。     

俄罗斯低生育率的成因及“母亲资本法”的成效评价

近年来俄罗斯人口数量的急剧减少与人口低生育率有直接联系,经济因素、社会生育观、宗教以及价值观差异、个人家庭状况都影响出生率动态,"母亲资本法"的出台对人口出生率的促进作用是毋庸置疑的,但这些社会家庭政策同时也存在迄待完善的地方。     

福建省承接台湾产业转移问题研究——基于产业梯度视角

采用产业梯度转移理论分析福建省承接台湾产业转移问题。根据该理论,当经济与技术发展存在区域梯度差并且产业技术形成从高梯度向低梯度地区扩散的趋势时才发生产业转移。福建省由于经济快速发展,与台湾的产业发展存在梯度差,生产要素具有比较优势,这使得福建省承接台湾产业转移具有优势。文中根据推拉力模型讨论了福建省承接台湾产业转移中的影响因素,提出了福建省需要加强基础设施建设,提高引资的技术含量,着重引入符合产业发展规划的龙头企业,优化投资软环境,加强海西品牌建设等政策建议。