化学教学的“设疑—研讨”模式

提出了“设疑—研讨”教学模式 ,并运用于中学化学教学中 ,通过设疑、讨论、总结和评价四步教学法 ,培养了学生思维能力和创新能力     

DELPHI中图形的连续旋转与动画的实现

阐述了在DELPHI语言中利用Canvas的Pixels[]属性来实现图形连续旋转和利用CopyRect()函数实现动画的方法 .     

教育技术的范式及其历史演变

教育技术的 4个范式包括媒体范式、传播与系统范式、行为科学范式、认知科学范式。许多教育技术学者开始探索并发展新的范式。库恩的科学范式的理论 ,讨论了教育技术领域的范式变迁 ,指出这实际上是一个范式持续在演变的过程。     

知识经济与高等教育改革

知识经济与高等教育密不可分 ,没有现代化高等教育就不能产生知识经济。在知识经济时代 ,教育特别是高等教育将发挥以往时代从未有过的关键性作用。深化高教改革已成必然     

增长曲线模型非齐次线性估计的可容许性

讨论增长曲线模型Y =X1BX2 +ε中回归矩阵B的函数C1BC2 的估计L1YL2 +A ,在矩阵损失 (LT2 L1)Y +A - (ST2 XT2 S1X1)B (LT2 L1)Y +A - (ST2 XT2 S1X1)B T 下 ,我们得到了非齐次线性估计L1YL2 +A在非齐次线性估计类Г ={L1YL2 +A|L1:t×p ,L2 ;n×n ,A :t×s均为已知实阵 }中可容许的充要条件 :L1YL2在Г0 ={L1YL2 |L1:t×p ,L2 :n×s均为已知实阵 }中容许且当LT2 XT2 L1X1=ST2 XT2 S1X1时有A =0。     

谈班主任的工作方法

根据班主任工作实践 ,总结出以下工作方法 :以身作则 ,身教重于言教 ;以科学家的科学精神教育学生 ,激励学生进步 ;深入到学生中去 ,注重调查研究 ;做好分类教育管理 ;狠抓思想教育 ,重视日常管理。此外 ,从重视学习 ,提高整体素质 ;抓好班风建设 ,促优良学风形成 ;严爱相济 ,循循善诱等几个方面 ,介绍了工作体会     

Empirical likelihood confidence intervals for the mean of a population containing many zero values

If a population contains many zero values and the sample size is not very large, the traditional normal approximation‐based confidence intervals for the population mean may have poor coverage probabilities. This problem is substantially reduced by constructing parametric likelihood ratio intervals when an appropriate mixture model can be found. In the context of survey sampling, however, there is a general preference for making minimal assumptions about the population under study. The authors have therefore investigated the coverage properties of nonparametric empirical likelihood confidence intervals for the population mean. They show that under a variety of hypothetical populations, these intervals often outperformed parametric likelihood intervals by having more balanced coverage rates and larger lower bounds. The authors illustrate their methodology using data from the Canadian Labour Force Survey for the year 2000.     

Sample sizes for estimation in clinical research

A sample size justification should be given for all clinical investigations. However, sometimes the objective of a trial is to estimate an effect with a view to planning a later definitive study. This paper describes the calculations for designing studies where one wishes to adopt an estimation approach through using confidence intervals around the overall response. Calculations are given for data anticipated to take a Normal form. Copyright © 2004 John Wiley & Sons, Ltd.     

Bayesian analysis of mixture modelling using the multivariate t distribution

A finite mixture model using the multivariate t distribution has been shown as a robust extension of normal mixtures. In this paper, we present a Bayesian approach for inference about parameters of t-mixture models. The specifications of prior distributions are weakly informative to avoid causing nonintegrable posterior distributions. We present two efficient EM-type algorithms for computing the joint posterior mode with the observed data and an incomplete future vector as the sample. Markov chain Monte Carlo sampling schemes are also developed to obtain the target posterior distribution of parameters. The advantages of Bayesian approach over the maximum likelihood method are demonstrated via a set of real data.