半极大条件环的探讨

主要讨论对左(右)理想满足半极大条件的环与对零因子满足极大条件的环的性质。     

Brief Research Report: Bayesian Versus REML Estimations With Noninformative Priors in Multilevel Single-Case Data

Abstract

Recently, researchers have used multilevel models for estimating intervention effects in single-case experiments that include replications across participants (e.g., multiple baseline designs) or for combining results across multiple single-case studies. Researchers estimating these multilevel models have primarily relied on restricted maximum likelihood (REML) techniques, but Bayesian approaches have also been suggested. The purpose of this Monte Carlo simulation study was to examine the impact of estimation method (REML versus Bayesian with noninformative priors) on the estimation of treatment effects (relative bias, root mean square error) and on the inferences about those effects (interval coverage) for autocorrelated multiple-baseline data. Simulated conditions varied with regard to the number of participants, series length, and distribution of the variance within and across participants. REML and Bayesian estimation led to estimates of the fixed effects that showed little to no bias but that differentially impacted the inferences about the fixed effects and the estimates of the variances. Implications for applied researchers and methodologists are discussed.     

铁水含硅量预报中的模糊控制方法

对铁水含硅量及对应的响应量进行分级,利用模糊控制理论将语言控制规则表示为模糊关系,经过计算得出精确化的模糊控制表,适用于中、小型钢厂,可节省一定的人力、物力.     

对高校新闻教育现状的思考

文章结合国际新闻传播发展的现状和国内新闻教育事业的实际，对我国传统新闻教育的教学内容、课程体系、教学模式等问题进行了分析和反思，并从宏观和微观两方面对新闻教育革新提出了一些建议。     

Application of the Bayes’ theory to the failure rate evaluation of electrical apparatus

The Weibull distribution has been widely used in reliability fields. A mixed Weibull distribution represents a popu- lation that consists of several Weibull subpopulations. In this paper, a new approach which combines the least-squares method with Bayes’ theorem, takes advantage of the parameter estimation for single Weibull distribution is developed to estimate the pa- rameters of each subpopulation. The estimates given by this paper also satisfy the maximum likelihood equation. The estimates of the failure rate of the mixed Weibull population are given. An actual test data is computed by using the proposed method. The Kolmogorov-Smirnov goodness-of-fit test turns out that the proposed method yields more accurate result.     

参数的广义矩法估计

对参数的矩法估计是一个基本方法,它首先要求随机变量的矩存在;但是对某些分布,它不存在矩,因此,对该分布参数的估计矩法将失效。本文提出广义矩概念,并给出了广义矩存在的条件,利用广义矩对参数作出估计,弥补了不存在短或矩的阶不够大时导致参数估计矩法失效的不足。     

基于行处理的SAGE算法在PET图像重建中的应用

运用基于行处理(RA)的"单块"投影子集法改进了空间交替广义期望最大(SAGE)算法的收敛性. 新的RA-SAGE算法以正交单投影序列的方式对投影数据进行处理, 以减少投影间的相关性, 达到加速收敛的效果. 此外, 在迭代搜索同时, 新算法结合了超松弛变量, 使其能快速接近全局最大似然解. 实验中, 运用RA-SAGE与SAGE对正电子发射断层(PET)进行了重建. 结果表明,RA-SAGE收敛性能比SAGE优越, 且重建图像质量较高.     

CM模式的项目管理研究

CM模式是20世纪80年代开始在国际上出现的一种新的项目管理模式。对CM模式和传统的管理模式进行了比较；研究了CM模式的特点，提出了工程项目中应用CM模式的关键问题和解决方法。     

从听课评估向教师自我反思模式的转化

以听课评估教师的传统作法已逐显其弊端，本文提出应以“自我反思实践”为指导，促使教师贯彻学生参与，活动方式和信息输出三项最大化原则，从而达到提高教学质量，完善教师评估体系的目的。     

Examining Normality in Incomplete Data Sets: A Note on a Multiple Testing Approach

A multiple testing procedure for examining the assumption of normality that is often made in analyses of incomplete data sets is outlined. The method is concerned with testing normality within each missingness pattern and arriving at an overall statement about normality using the available data. The approach is readily applied in empirical research with missing data using the popular software Mplus, Stata, and R. The procedure can be used to ascertain a main assumption underlying frequent applications of maximum likelihood in incomplete data modeling with continuous outcomes. The discussed approach is illustrated with numerical examples.