Studying Complexity of Model-based Clustering

Cluster analysis is a popular statistics and computer science technique commonly used in various areas of research. In this article, we investigate factors that can influence clustering performance in the model-based clustering framework. The four factors considered are the level of overlap, number of clusters, number of dimensions, and sample size. Through a comprehensive simulation study, we investigate model-based clustering in different settings. As a measure of clustering performance, we employ three popular classification indices capable of reflecting the degree of agreement in two partitioning vectors, thus making the comparison between the true and estimated classification vectors possible. In addition to studying clustering complexity, the performance of the three classification measures is evaluated.     

Conditional VAR and Expected Shortfall: A New Functional Approach

We estimate two well-known risk measures, the value-at-risk (VAR) and the expected shortfall, conditionally to a functional variable (i.e., a random variable valued in some semi(pseudo)-metric space). We use nonparametric kernel estimation for constructing estimators of these quantities, under general dependence conditions. Theoretical properties are stated whereas practical aspects are illustrated on simulated data: nonlinear functional and GARCH(1,1) models. Some ideas on bandwidth selection using bootstrap are introduced. Finally, an empirical example is given through data of the S&P 500 time series.     

如何对区域活动中的幼儿进行评价

幼儿园区域活动是幼儿获取知识技能、体验生活的一种幼儿教育形式,它通过为幼儿提供熟悉的活动环境和材料,促进幼儿主动参与活动、自主选择、合作交流和勇于探索,达到个人素质逐步提高的目的。区域活动中孩子以小组或个人的形式自由观察、探索、操作、摆弄,以获得自身的快乐和小成就为目的。区域活动中幼儿的行为,能表现出幼儿在活动中的情绪、操作技能、认知基础、社会性发展等多方面的状态。幼儿的活动离不开教师的有效观察和适时介入,只有教师能正确看待幼儿的活动行为,客观评价幼儿活动状态,才能真正支持幼儿发展。     

Functional Partial Linear Single‐index Model

This paper deals with the problem of predicting the real‐valued response variable using explanatory variables containing both multivariate random variable and random curve. The proposed functional partial linear single‐index model treats the multivariate random variable as linear part and the random curve as functional single‐index part, respectively. To estimate the non‐parametric link function, the functional single‐index and the parameters in the linear part, a two‐stage estimation procedure is proposed. Compared with existing semi‐parametric methods, the proposed approach requires no initial estimation and iteration. Asymptotical properties are established for both the parameters in the linear part and the functional single‐index. The convergence rate for the non‐parametric link function is also given. In addition, asymptotical normality of the error variance is obtained that facilitates the construction of confidence region and hypothesis testing for the unknown parameter. Numerical experiments including simulation studies and a real‐data analysis are conducted to evaluate the empirical performance of the proposed method.     

能效标识对节能产品选择的引导效用分析——基于京东家电线上销售的实证检验

搜集冰箱、洗衣机、空调三种大家电的线上销售数据,通过描述性分析、组间差异比较、多元回归分析等方式分析能效标识的市场引导效果。结果显示消费者对不同等级家电产品的选择量存在差异,但不同能效等级间消费者满意度并无明显差异,能效等级并非是影响消费者选择和满意度的显著因素。     

煤炭大数据指数编制及经验模态分解模型研究

基于开放性数据源、连续观测昨多变量数据编制的大数据指数,与传统的统计调查指数存在的差异不仅在于数据本身的无限扩张,而且在于编制方法以及分解研究的规则、模型方面的差异。在大数据背景下,率先尝试性地提出大数据指数的定义和数据假设,将"互联网大数据指数"引入煤炭交易价格指数综合编制太原煤炭交易大数据指数,从而反映煤炭价格的变动趋势;导入经验模态分解模型,对所编制的煤炭大数据指数进行分解研究,尝试比较与传统的统计调查指数的差异。研究表明:新编制的煤炭价格大数据指数要比太原煤炭交易价格指数更为敏感和迅速,能更好地反映煤炭价格的变动趋势。随着"互联网+"和大数据战略的逐渐普及,基于互联网大数据编制的综合指数会影响到更多领域,将成为经济管理和社会发展各个领域的晴雨表和指示器;与传统统计调查指数逐步融合、互补或者升级,成为宏观经济大数据指数的重要组成部分。     

中印贸易的竞争性与互补性研究

近年来中印双边贸易发展迅速.本文在描述中印双边贸易发展现状的基础上,通过贸易强度指数、产业内贸易指数、贸易特化系数、出口相似度指数、显性比较优势指数五个指标研究了中印贸易竞争性和互补性,揭示中印两国的比较优势并总结中印贸易的特征.结果显示,中印贸易结构有一定的竞争性,但也有很大的互补性.     

马克思主义的价值评判标准为什么是正确的

马克思主义的价值评判标准是马克思主义理论的重要组成部分,它来源于无产阶级革命斗争的实践,突破了现代伦理学的意识内在性的困境,代表广大人民群众的需求和利益,具有鲜明的人民性。马克思主义的价值评判标准批判地继承了西方价值理论,对金钱本位的价值观进行了批判,体现了科学性与价值性的统一,并且处于不断的创新与发展之中。     

学位与研究生教育自我评估指标体系的研究

本文针对国内学位与研究生教育领域发展中存在着国内高校学科自我评估体系尚不健全等问题,对学位与研究生教育学科自我评估系统进行了研究,并结合工科院校的特点和实际情况,研究工科院校学科建设管理及自我评估工作,在理论研究、现状调研和专家走访的基础上,依托原有评估指标体系提出自我评估指标体系意见。