教育媒体与技术在机械制图课程教学中的优化运用

为了获得良好的教学效果,提高教育教学质量,关键是如何实现教育媒体与技术在课程教学中的优化运用。文章在调查研究和理论分析的基础上,建立了基于教育媒体与技术的优化教学模型,重点介绍了教育媒体与技术在机械制图课程教学中优化运用的一些做法和经验。     

项目研究法在培养学生创新素质中的应用

如何密切理论教学与工程实践的联系是目前高等教育提高教学质量,提高学生实践能力需要思考的一个重要问题。以《工业通风与除尘》课程为例,采用项目研究法对这一问题进行了的讨论。通过设定具体条件,让学生在课堂学习过程中,将理论与实践紧密结合起来,并将课程的各部分内容有机结合起来,从而为应用创新型人才培养在课程教学上提供一些思路。     

Failure Probability Under Parameter Uncertainty

In many problems of risk analysis, failure is equivalent to the event of a random risk factor exceeding a given threshold. Failure probabilities can be controlled if a decisionmaker is able to set the threshold at an appropriate level. This abstract situation applies, for example, to environmental risks with infrastructure controls; to supply chain risks with inventory controls; and to insurance solvency risks with capital controls. However, uncertainty around the distribution of the risk factor implies that parameter error will be present and the measures taken to control failure probabilities may not be effective. We show that parameter uncertainty increases the probability (understood as expected frequency) of failures. For a large class of loss distributions, arising from increasing transformations of location‐scale families (including the log‐normal, Weibull, and Pareto distributions), the article shows that failure probabilities can be exactly calculated, as they are independent of the true (but unknown) parameters. Hence it is possible to obtain an explicit measure of the effect of parameter uncertainty on failure probability. Failure probability can be controlled in two different ways: (1) by reducing the nominal required failure probability, depending on the size of the available data set, and (2) by modifying of the distribution itself that is used to calculate the risk control. Approach (1) corresponds to a frequentist/regulatory view of probability, while approach (2) is consistent with a Bayesian/personalistic view. We furthermore show that the two approaches are consistent in achieving the required failure probability. Finally, we briefly discuss the effects of data pooling and its systemic risk implications.     

VARIANCE ESTIMATION IN NONPARAMETRIC MULTIPLE REGRESSION

ABSTRACT

We consider the variance estimation in a general nonparametric regression model with multiple covariates. We extend difference methods to the multivariate setting by introducing an algorithm that orders the design points in higher dimensions. We also consider an adaptive difference estimator which requires much less strict assumptions on the covariate design and can significantly reduce mean squared error for small sample sizes.     

中央苏区调查统计工作的内容和成效 ——中央苏区调查统计工作的光辉实践与有益启示（二）

 中央苏区制发了众多的统计报表全面反映战争和建设情况，采取多种调查统计方法确保数据真实可靠，并利用丰富的调查统计资料积极开展统计分析，及时发布统计资料，为革命战争和苏区经济建设服务。     

总体镜下的中国模式

随着＂华盛顿共识＂的式微,＂中国模式＂正日益兴起。当前,理论界热议中的＂中国模式＂尚处于一种能指的狂欢状态。从方法论上来看,分析还原论的方法堵塞了认知＂中国模式＂的道路,这种方法表征的是思维的初级阶段。打破目前僵局的唯一路径,就是要彻底变革思维方式,用马克思的方法——总体性的方法研究马克思主义中国化进程中的事物——＂中国模式＂,这种方法的基本运思理路是面向总体,维护总体与获得总体。惟此,＂中国模式＂方能走向澄明之境。     

素描教学的价值和意义

在素描教学中,由于对其体系的意义和价值缺乏基本认识,仍存在着单纯追求技法的倾向。素描教学方法说到底就是不断引导、启发学生进行观察实践和作画实践的过程,也是不断提高学生审美修养和悟性的过程。     

有限宽裂纹板受一对集中剪力时弹塑性解

针对运用断裂力学传统方法进行裂纹尖端的弹塑性应力场分析均为小范围塑性区的假定，不能准确反映塑性区应力情况的问题，利用裂纹线场分析方法，对理想弹塑性材料的有限宽平面板在裂纹面受到一对集中剪力作用时裂纹线附近的应力场及弹塑性边界进行了分析。不采用小范围塑性区的假设，直接通过将裂纹线附近弹塑性边界上弹性应力场与塑性应力场的匹配，获得了裂纹线附近弹塑性应力场的解析解以及弹塑性边界上单位法向量的表达式。用裂纹线分析方法可以准确地反映裂纹附近的弹塑性应力分布，该种方法的应用将成为断裂力学的一个重要发展方向，对石油天然气构造应力分析、材料力学分析具有参考价值。     

Nonparametric tests for scale shift at an unknown time point

A class of linear rank tests is suggested for testing a shift in scale at an unknown time point in a sequence of independent observations. The tests,based on inverse normal scores and on ordered exponential scores,are shown to be asymptotically as efficient as their distribution-oriented competitors. Critical values and powers for these two rank tests are also discussed.     

Estimation on Varying-Coefficient Partially Linear Model With Different Smoothing Variables

The authors give the estimation on the varying-coefficient partially linear regression model with different smoothing variables. The efficient estimators of the intercept function and the coefficient functions are obtained by a one-step back-fitting technique based on their initial estimators given by local linear technique and the averaged method. Furthermore, their asymptotic normalities are given. Some simulation studies are used to illustrate the performances of the estimation.