Bayes linear analysis for graphical models: The geometric approach to local computation and interpretive graphics

This paper concerns the geometric treatment of graphical models using Bayes linear methods. We introduce Bayes linear separation as a second order generalised conditional independence relation, and Bayes linear graphical models are constructed using this property. A system of interpretive and diagnostic shadings are given, which summarise the analysis over the associated moral graph. Principles of local computation are outlined for the graphical models, and an algorithm for implementing such computation over the junction tree is described. The approach is illustrated with two examples. The first concerns sales forecasting using a multivariate dynamic linear model. The second concerns inference for the error variance matrices of the model for sales, and illustrates the generality of our geometric approach by treating the matrices directly as random objects. The examples are implemented using a freely available set of object-oriented programming tools for Bayes linear local computation and graphical diagnostic display.     

论二元户籍制度在中国的生成

我国二元户籍制度的构建过程分为三个阶段,即制度初建阶段、法制建设阶段和制度完善阶段。大量研究成果表明,二元户籍制度在中国的生成是经济、社会、政治及意识形态等因素综合影响的结果,其中政府最高决策层在制度选择过程中起到了决定性作用,并深刻影响了近三十年来的户籍制度改革进程。     

外语教师队伍建设要重视造就学者型教师

外语教师队伍建设要从改变教师的传统教育理念,加强专业理论知识学习,提高教师的反思意识,研究教师的发展模式等方面入手,引导培养青年教师向学者型教师发展。     

Estimation of the parameters of symmetric stable ARMA and ARMA–GARCH models

In this article, we first propose the modified Hannan–Rissanen Method for estimating the parameters of autoregressive moving average (ARMA) process with symmetric stable noise and symmetric stable generalized autoregressive conditional heteroskedastic (GARCH) noise. Next, we propose the modified empirical characteristic function method for the estimation of GARCH parameters with symmetric stable noise. Further, we show the efficiency, accuracy and simplicity of our methods with Monte-Carlo simulation. Finally, we apply our proposed methods to model the financial data.     

公共管理模式嬗变的政治学分析

本文从政治学资源配置的角度概括了公共管理模式的本质与特征、分析公共管理模式嬗变的理论根源和实践背景,并结合当前正在发生的金融危机探讨公共管理模式的流变及方向,力图揭示当今公共管理在资源配置机制上的变化规律和最新特征。     

Extension of the Application of Conway‐Maxwell‐Poisson Models: Analyzing Traffic Crash Data Exhibiting Underdispersion

The objective of this article is to evaluate the performance of the COM‐Poisson GLM for analyzing crash data exhibiting underdispersion (when conditional on the mean). The COM‐Poisson distribution, originally developed in 1962, has recently been reintroduced by statisticians for analyzing count data subjected to either over‐ or underdispersion. Over the last year, the COM‐Poisson GLM has been evaluated in the context of crash data analysis and it has been shown that the model performs as well as the Poisson‐gamma model for crash data exhibiting overdispersion. To accomplish the objective of this study, several COM‐Poisson models were estimated using crash data collected at 162 railway‐highway crossings in South Korea between 1998 and 2002. This data set has been shown to exhibit underdispersion when models linking crash data to various explanatory variables are estimated. The modeling results were compared to those produced from the Poisson and gamma probability models documented in a previous published study. The results of this research show that the COM‐Poisson GLM can handle crash data when the modeling output shows signs of underdispersion. Finally, they also show that the model proposed in this study provides better statistical performance than the gamma probability and the traditional Poisson models, at least for this data set.     

“投票悖论”的分析及其矫正——理性选择理论的“投票现象”应用批判

投票机制是民主政治的制度性保障,但它却存在着一个悖论。这一悖论可被简单地表述为：在投票参与者意识到自己的选票对结果的影响是微不足道的时候,他们往往不会牺牲闲暇以及交通成本等方面的付出到投票站投出手中的选票。美国大选仅仅具有半数左右的参与率似乎也在事实上为以上＂洞见＂提供了心理学依据和社会学依据。在试图解决投票悖论这一问题的过程中,具体分析理性选择理论是如何从一个过分武断化了的前提出发,而走向一条循环论证的死胡同的;进而希望通过为投票动机添加新的变量的方式来缓解理性选择理论的这种弊病。     

利率下降对我国居民跨期消费选择的影响分析

利率下降对居民跨期消费选择影响存在收入效应和替代效应.由于这两种效应对居民当期消费的作用方向完全相反,因而总效应要取决于这两种效应的强弱.对于我国中低收入居民来说,利率下降对其跨期消费选择的收入效应特别明显,替代效应则趋于零,因而降患反而会减少其当期消费数量.对于我国中高收入居民来说,利率下降对其跨期消费选择的替代效应在很大程度上被收入效应所抵消了,因而降息拉动其当期消费也不明显.为了刺激居民消费,除了实施降息政策以外,还必须采取其他政策与之配合.     

政府工具选择与应用

本文首先对我国政府工具的内涵与分类进行了一个简单的陈述和一个简要的分析,在此基础上对政府工具选择的影响因素和应注意的问题进行了探讨,最后重点分析了我国政府工具应用中存在的问题及我国政府工具应用的改进建议。     

理论教学、传统实验与“有限元分析”有机结合的探索与研究

＂有限元分析＂是工程领域进行数值计算的极为重要的方法之一。为使学生掌握有限元方法的基本原理和编程技巧,更好地应用有限元分析这一强有力的数值计算工具,文章将理论分析、传统实验与计算机数值模拟有机结合,结合工程应用的具体实践,在有限元教学中不断渗透学科发展的前沿知识,从教学方式、内容选择、实验设计等几个方面作了一系列探索。