Small area estimation of the mean using non-parametric M-quantile regression: a comparison when a linear mixed model does not hold

The demand for reliable statistics in subpopulations, when only reduced sample sizes are available, has promoted the development of small area estimation methods. In particular, an approach that is now widely used is based on the seminal work by Battese et al. [An error-components model for prediction of county crop areas using survey and satellite data, J. Am. Statist. Assoc. 83 (1988), pp. 28–36] that uses linear mixed models (MM). We investigate alternatives when a linear MM does not hold because, on one side, linearity may not be assumed and/or, on the other, normality of the random effects may not be assumed. In particular, Opsomer et al. [Nonparametric small area estimation using penalized spline regression, J. R. Statist. Soc. Ser. B 70 (2008), pp. 265–283] propose an estimator that extends the linear MM approach to the case in which a linear relationship may not be assumed using penalized splines regression. From a very different perspective, Chambers and Tzavidis [M-quantile models for small area estimation, Biometrika 93 (2006), pp. 255–268] have recently proposed an approach for small-area estimation that is based on M-quantile (MQ) regression. This allows for models robust to outliers and to distributional assumptions on the errors and the area effects. However, when the functional form of the relationship between the qth MQ and the covariates is not linear, it can lead to biased estimates of the small area parameters. Pratesi et al. [Semiparametric M-quantile regression for estimating the proportion of acidic lakes in 8-digit HUCs of the Northeastern US, Environmetrics 19(7) (2008), pp. 687–701] apply an extended version of this approach for the estimation of the small area distribution function using a non-parametric specification of the conditional MQ of the response variable given the covariates [M. Pratesi, M.G. Ranalli, and N. Salvati, Nonparametric m-quantile regression using penalized splines, J. Nonparametric Stat. 21 (2009), pp. 287–304]. We will derive the small area estimator of the mean under this model, together with its mean-squared error estimator and compare its performance to the other estimators via simulations on both real and simulated data.     

Within groups analysis of covariance: multiple comparisons at specified design points using a robust measure location when there is curvature

Consider the situation where measurements are taken at two different times and let M_j(x) be some conditional robust measure of location associated with the random variable Y at time j, given that some covariate X=x. The goal is to test H₀: M₁(x)=M₂(x) for each x∈ x₁,?…?, x_K such that the probability of one or more Type I errors is less than α, where x₁,?…?, x_K are K specified values of the covariate. The paper reports simulation results comparing two methods aimed at accomplishing this goal without specifying some parametric form for the regression line. The first method is based on a simple modification of the method in Wilcox [Introduction to robust estimation and hypothesis testing. 3rd ed. San Diego, CA: Academic Press; 2012, Section 11.11.1]. The main result here is that the second method, which has never been studied, can have higher power, sometimes substantially so. Data from the Well Elderly 2 study, which motivated this paper, are used to illustrate that the alternative approach can make a practical difference. Here, the estimate of M_j(x) is based in part on either a 20% trimmed mean or the Harrell–Davis quantile estimator, but in principle the more successful method can be used with any robust location estimator.     

接力和独立方式对多群体方案创建影响的实验研究

实验主体为在校管理类大专生,组成100个3人群体,按接力和独立两种方式组建多群体,研究了不同的方式对某一企业物流实例创建改进方案的影响.发现组织方式对多群体创建的名义方案数量无显著影响,实际方案数量以及实际方案质量方面接力方式均优于独立方式,同时发现接力方式在实施过程中存在一些弊端.     

后勤产业可持续发展战略实证研究分析

通过高校后勤企业运行现状的实证调查分析,以定量分析结论为依据,阐述了高校后勤企业所面临的管理体制、运行机制、产权制度等方面的问题,并探究了解决的途径,提出高校后勤企业要走可持续发展之路的战略目标。     

结构动力学课程建设及教学实践研究

围绕国家和区域发展需求,结合学校发展定位和人才培养目标,对结构动力学课程进行教学改革与实践。鉴于专业课枯燥单调的特点,在授课过程中采用案例式、讨论式、激趣式等教学方法,活跃课堂氛围,提高学生学习兴趣;改变传统课程考核模式,注重全过程全新考核评价;深入挖掘课程中蕴含的思政教育资源并有机融入课堂,将中华传统优秀文化和辩证唯物主义思想渗透到课程学习,强化学生工程伦理教育,培养学生精益求精的大国工匠精神,激发学生科技报国的家国情怀和使命担当,全面提升研究生知识创新和实践创新能力,可为同类课程提供借鉴与参考。     

早期儒家和犹太—基督教传统中的智慧观：比较研究的思考

智慧是一切哲学与宗教传统的中心,本文是对早期儒家和犹太-基督教传统中的智慧观比较研究的一种思考,通过分析两种传统中智慧观的同中之异和异中之同来把握智慧的本质和价值,力图从比较的框架来审视智慧的哲学含义、伦理蕴涵和宗教层面,进而理解早期儒家和犹太—基督教传统中智慧观在文化、政治和哲学上的分歧之处。     

胡绳史料学思想初探

胡绳对以史料见长的史家一贯持批评态度,认为他们的工作只是停留在史学研究的初始阶段,但这并不表明他不重视史料在史学研究中的作用,而是提出以马克思主义来指导史料工作,在对史料进行考证的同时对其价值的高低做出评判,强调史料要为观点服务。     

翻译的关系论

关系是反映事物及其特性之间相互联系的哲学范畴。翻译学既是本体学科,也是关系学科。从关系在语言学研究的沿革和嬗变过程中,我们也可以把握关系在翻译学研究中若隐若现的脉络。翻译学研究中的三种范式清晰勾勒出翻译学研究中的关系衍变。从关系论的角度,翻译学研究要考察的是客体之间的关系、主体和客体之间的关系及主体之间的关系。关系在量上是一切翻译现象的总和,在质上孕育着一切翻译现象的萌芽、胚胎,发展与变化。翻译学作为一门独立的学科,关系将凸显出它在翻译学研究中的价值。     

俄汉语情态比较研究

情态是人类语言中一个重要的语法范畴。文章介绍俄汉语情态研究现状,对比两种语言在情态表达手段上的异同,以便为语言学习、交际以及教学提供有益的帮助。     

基本层次范畴视域下英语名词词汇学习研究

名词词汇是英语学习中的重点和难点,也是语言学理论研究的问题之一。基于认知语言学的“基本层次范畴理论”,就英语名词词汇的学习方法进行了探讨,以期对英语名词词汇的习得有一定的启示。