Generalized Laplacian approximations in Bayesian inference

This paper presents a new Laplacian approximation to the posterior density of η = g(θ). It has a simpler analytical form than that described by Leonard et al. (1989). The approximation derived by Leonard et al. requires a conditional information matrix R_η to be positive definite for every fixed η. However, in many cases, not all R_η are positive definite. In such cases, the computations of their approximations fail, since the approximation cannot be normalized. However, the new approximation may be modified so that the corresponding conditional information matrix can be made positive definite for every fixed η. In addition, a Bayesian procedure for contingency-table model checking is provided. An example of cross-classification between the educational level of a wife and fertility-planning status of couples is used for explanation. Various Laplacian approximations are computed and compared in this example and in an example of public school expenditures in the context of Bayesian analysis of the multiparameter Fisher-Behrens problem.     

机械装置转子支承系统临界转速估算K3法

根据机械振动和积木式传递矩阵法的原理,提出了用于估算单、双转子系统一阶临界转速的实用方法,从而得到的“K3表”可方便地使用于产品的方案设计阶段或现场排故,并可得到满意的工程精度。     

论古今声调的变化

本文就古今声调的变化进行了系统的论述,探索并归纳了古今声调的演变规律。     

试论高校体育乒乓球教学中学习动机的培养

学习动机是学生学习的基本动力因素之一。该文通过对教学目标设置、创设激起内驱力的情境和积极进行反馈等方面进行分析 ,论述了高校体育乒乓球教学中培养学生良好的学习动机 ,对提高教学质量将起到积极的推动作用。     

大同方言“舒声促化”与轻声音节的关系

文章对大同方言中存在的舒入两读字进行了分类,并对这些舒声字读为入声后其韵母的音色变化进行了分析。这些字的共同特点是音长变短,一部分入声字的喉塞音韵尾【】逐渐消失,与普通话的轻声音节一致,另一部分字还将继续保留喉塞音韵尾【】的特点。     

论我国企业编制"增值表"的现实必要性

增值表确能提供相当有用的财务信息 ,它丰富了企业对外报表的内容 ,借鉴国外有关社会责任会计的理论和方法 ,编制有中国特色的增值表 ,不仅必要 ,而且势在必行     

大学英语语调交际功能的课堂教学研究与实践

大学英语课堂教学不能只注意学生英语语音，更重要的是在语音的基础上掌握语调及其功能。从学生语言运用能力的角度来说语调的教学比纯语音教学应该更重要，因为同一个单词或句子用不同的语调在同等交际背景下传递出的含义就会不同，有时还会是相反的含义。以语调的交际功能为出发点，运用语用学的相关理论，设计并分析了基于语调交际功能的英语课堂教学模式的实践，探讨了这种模式的可行性和有效性，以引起大家对语调教学的重新思考。     

中国服务业显性比较优势测算——基于前向联系增加值出口

基于"前向联系增加值出口"方法,测算了1995-2011年中国服务业细分产业层面及按要素密集度特征分类层面的显性比较优势指数(RCA_F),并同基于"总出口"1的比较优势指数(RCA)进行了比较。研究发现,中国在全球价值链分工中,比较优势集中在资本密集型服务业领域,且实现了比较劣势向比较优势的转变;劳动、知识密集型服务业及健康教育公共服务均尚未取得比较优势,但是有迹象表明三个领域的比较劣势有改善的趋势。与基于前向联系增加值出口核算结果相比,基于总出口核算结果"高估"了劳动密集型产业的比较优势,其中对建筑业和零售贸易两个部门的估计偏差最大;同时,在资本、知识密集型两个领域存在不同程度的"低估"现象。     

A simple algorithm for calculating values for folded normal distribution

Folded normal distribution originates from the modulus of normal distribution. In the present article, we have formulated the cumulative distribution function (cdf) of a folded normal distribution in terms of standard normal cdf and the parameters of the mother normal distribution. Although cdf values of folded normal distribution were earlier tabulated in the literature, we have shown that those values are valid for very particular situations. We have also provided a simple approach to obtain values of the parameters of the mother normal distribution from those of the folded normal distribution. These results find ample application in practice, for example, in obtaining the so-called upper and lower α-points of folded normal distribution, which, in turn, is useful in testing of the hypothesis relating to folded normal distribution and in designing process capability control chart of some process capability indices. A thorough study has been made to compare the performance of the newly developed theory to the existing ones. Some simulated as well as real-life examples have been discussed to supplement the theory developed in this article. Codes (generated by R software) for the theory developed in this article are also presented for the ease of application.     

Testing for Serial Independence: Beyond the Portmanteau Approach

Portmanteau tests are typically used to test serial independence even if, by construction, they are generally powerful only in presence of pairwise dependence between lagged variables. In this article, we present a simple statistic defining a new serial independence test, which is able to detect more general forms of dependence. In particular, differently from the Portmanteau tests, the resulting test is powerful also under a dependent process characterized by pairwise independence. A diagram, based on p-values from the proposed test, is introduced to investigate serial dependence. Finally, the effectiveness of the proposal is evaluated in a simulation study and with an application on financial data. Both show that the new test, used in synergy with the existing ones, helps in the identification of the true data-generating process. Supplementary materials for this article are available online.