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.     

TESTING SPHERICITY UNDER A MIXTURE MODEL

The robustness of Mauchly's sphericity test criterion when sampling from a mixture of two multivariate normal distributions is studied. The distribution of the sphericity test criterion when the sample covariance matrix has a non-central Wishart density of rank one is derived in terms of Meijer's G-functions; its distribution under the mixture model is then deduced. The robustness is studied by computing actual significance levels of the test under the mixture model using the critical values under the usual normal model.     

南瓜营养液的生产技术

介绍了南瓜营养液的生产工艺和动物实验效果。     

Estimation of noncentrality parameters

We propose some estimators of noncentrality parameters which improve upon usual unbiased estimators under quadratic loss. The distributions we consider are the noncentral chi-square and the noncentral F. However, we give more general results for the family of elliptically contoured distributions and propose a robust dominating estimator.     

中小企业CRM系统的OLAP设计与实现

根据中小企业CRM发展需求,构建了OLAP分析模型,为企业提供决策支持.     

构建以人为本的英语教学模式

传统的英语教育模式忽视了学生的个性意识、个性特点和个性需要,违背了人本主义的教育教学理念。如何提高教学效率一直是外语教师主要探讨的问题。文章运用人本主义的教学理念,结合实际探讨了如何构建以人为本的新型教学模式以改进英语教学,提高教学效率。以人为本的新型教学模式包括:创立民主愉悦的课堂教学环境、构建个性化的学习空间、设计师生共同探索的教学活动、建立协作性的教学模式。     

大学计算机专业“基础原理”课的教学探讨

本文针对现代大学生学习计算机专业“基础原理”课程存在的种种客观问题,通过分析这些问题找出其中原因,并介绍对这些问题所采取的解决方案。教学实践表明,这些方案对学生学习“基础原理课”起到了较好的效果,提高了这类课程的教学质量。     

深圳证券交易所不同指数收益率的波动比较

股票价格指数的波动的大小通常代表了它的风险程度,研究股指的波动对风险管理、投资组合以及价格预测有着十分重要的意义。文章采用时间序列分析方法,对深圳证券交易所的三种价格指数建立GARCH模型,并对这三种指数的波动率进行比较。     

论大学英语水平统一测试的优越性

我国现行有两套考试系统用以测试大学英语水平:大学英语46、级考试(CET-4/6)用来衡量非英语专业学生的英语水平,而英语专业48、级(TEM-4/8)考试则用来测评英语专业学生的英语水平。依据Bachman和Palmer语言测试原则,为了保证语言测试的有效性,语言测试任务应该与语言应用任务相对应,这种对应是语言测试的出发点和目的。既然如此,对于非母语的中国大学生而言,就没有必要以英语专业或非英语专业的区分用不同的测试来区分他们的英语水平。从这一点出发,完全可以将现行测试非英语专业学生CET-4/6和测试英语专业学生的TEM-4/8合二为一。问卷调查分析也表明,实行全国大学英语统一测试比分成两套考试系统的英语测试更具优越性。     

高等院校英语强化课程的评估体系与评估模式的构建

文章选取培正商学院的一年英语强化教改项目作为研究个案,根据(背景—输入—过程—输出CIPP)评估理论,利用质性评价和量性评价相结合的手段,对强化项目的背景和过程进行了评价。并由此构建出了一个针对高职高专院校公共外语教学的、具有自我约束并持续改进的课程评估体系。