Robust estimation of the ratio of scale parameters for positive random variables

An estimator of the ratio of scale parameters of the distributions of two positive random variables is developed for the case where the only difference between the distributions is a difference in scale. Simulation studies demonstrate that the estimator performs much better, in terms of mean squared error, than the most popular one among those estimators currently available.     

A transformation for estimating the trinomial logit model with grouped data

For logit models where the outcome variables are the proportions of individuals falling into each of three categories, this paper develops a data transformation through which GLS estimates can be obtained by running OLS on the transformed data.     

Distorted Copulas: Constructions and Tail Dependence

Given a copula C, we examine under which conditions on an order isomorphism ψ of [0, 1] the distortion C _ψ: [0, 1]² → [0, 1], C _ψ(x, y) = ψ{C[ψ^?1(x), ψ^?1(y)]} is again a copula. In particular, when the copula C is totally positive of order 2, we give a sufficient condition on ψ that ensures that any distortion of C by means of ψ is again a copula. The presented results allow us to introduce in a more flexible way families of copulas exhibiting different behavior in the tails.     

Nearly Gaussian Distributions and Application

We consider the random variable X that is not Gaussian but for which X ^c , where c = (2k + 1)/(2j + 1) with k, j ? {0, 1,…}, is approximately Gaussian. A variable of this type is used to model the errors made by meteorologists when forecasting temperatures.     

On the behaviour of some transforms of the sample correlation coefficient in samples from the bivariate t and the bivariate X2distribution

The present paper studies the normality of five transformations suggested in the literature to normalize the sample correlation coefficient. The parent populations are the bivariate t and the bivariate X ²The results in the previous work of Subrahmaniam and Gajjar are exploited to assess their performance. The density estimation procedure of Tarter and Kronmal is used to provide empiric support to the asymptotic results     

论高校图书馆服务功能的转型

在新的历史形势下,高校图书馆为顺应学校教学和科研的需要,必须实现服务功能的转型。本文从人员服务意识和综合素质等方面进行了阐述。     

技术转化障碍与经济增长方式转变——大中型工业企业的经验证据

技术向物质生产力转化的障碍是长期以来经济增长方式难以转变的一个重要原因,但是鲜有相关的经验研究.本文在技术外溢背景下设计了检验技术转化障碍的研究框架,发现了国有企业的研发效率只有非国有企业的一半,但是国有企业和非国有企业都存在技术转化障碍,因此技术转化障碍问题并非国企特殊的难题,而是一个一般性的难题.另外,本文还发现国企研发并不存在所谓的技术外溢,相反非国有企业的研发活动却存在技术外溢.     

从阶级斗争到人民共和——我国政治学研究的逻辑转换析论

十一届三中全会以后,我国政治学科得以恢复重建。近三十年来,我国政治学的学术研究沿着从阶级斗争到人民共和的主轴,实现了内在逻辑的转换发展,其体现为:重心论域的转移发展;思想方法的调整转换;研究视角的切换转变;分析范式的嬗变更设;主导思维的归位置换;主题内容的演进变迁;研究视野的开拓扩展;研究方法的丰富发展;科学程度的增强提升;任务功能的变更发展。这一转换发展不仅显示着我国政治学学术发展的基本特点和未来趋势,而且映现着我国社会政治的历史转折,彰显着共和国政治的本质精神和内在精髓,提示着人民政治发展的实然战略和路径。     

南北宋社会变动与山水画风格之演变

南宋中后期山水画出现供游赏的景象和表现歌舞湖山、尽情享受的思想,不能完全指向南宋统治者偏安不思振作。这种情景在北宋后期业已出现,是北宋后期至南宋社会变动的反映,也是以权臣为代表的官僚大地主集团的生活写照。南宋中后期,这种生活更趋细腻和精致。山水画是所谓"君子"喜好,即专属士大夫所钟爱,园林别业又是士大夫们的生活场所。士大夫们不仅希望将"君子"喜好山水尽置于园景中,而且希望通过绘画将第一自然的原生状态的山水,转变为第二自然的审美状态的山水。由此山水画的意境与园林别业的意境被绾结在一起。兼工山水画的士大夫,他们笔下的山水画是其园林别业的"记忆"或"写意"。画院画工虽然一般多是没有文化的伎艺人,但能留其名的山水画家则多出自士大夫阶层,他们与官僚士大夫过从甚密,他们笔下的山水画,或是园林别业的"写实",或从园林别墅的四至景色得到灵感乃至创作出江山如此多娇的图画。南宋官僚士大夫的园林别业因人工迭山凿池而形成诸多特色,对山水画风格的演变亦有直接影响。     

试论1928年迁都对北京的影响

1928年国民政府迁都南京,改北京为北平[1]。失去"国都"光环的北平在呈现百业凋零态势的同时,城市发展亦发生了深刻的变化,城市自我意识和地方特色得以彰显。这一阶段是北京这一传统的政治中心古城向现代化城市转型的重要环节,对理解近代北京发展历程及今天的首都建设都不无裨益。