高职数控专业“机械制图”课程改革与实践——以黑龙江农业工程职业学院为例

"机械制图"是数控专业第一门综合性很强的专业基础课程,要改进以往教学方式、方法,重新组合教学内容;在教学中,强化学生充分利用课余时间,做到"课前预习""课后训练",培养终身学习意识;充分发挥学生的特长及个性,给学生搭建一个自我展示的平台,使学生在学习中逐步建立起专业学习兴趣与乐趣,着重培养学生良好的学习、工作习惯及专业学习方法,提高专业知识学习能力,从而提高学生的综合竞争能力。     

Confidence Intervals of Performance Measures for an M/G/1 Queueing System

In this article, we discuss constructing confidence intervals (CIs) of performance measures for an M/G/1 queueing system. Fiducial empirical distribution is applied to estimate the service time distribution. We construct fiducial empirical quantities (FEQs) for the performance measures. The relationship between generalized pivotal quantity and fiducial empirical quantity is illustrated. We also present numerical examples to show that the FEQs can yield new CIs dominate the bootstrap CIs in relative coverage (defined as the ratio of coverage probability to average length of CI) for performance measures of an M/G/1 queueing system in most of the cases.     

Inference Based on Order Statistics from the Generalized Pareto Distribution and Application

ABSTRACT

In this article, we derive exact explicit expressions for the single, double, triple, and quadruple moments of order statistics from the generalized Pareto distribution (GPD). Also, we obtain the best linear unbiased estimates of the location and scale parameters (BLUE's) of the GPD. We then use these results to determine the mean, variance, and coefficients of skewness and kurtosis of certain linear functions of order statistics. These are then utilized to develop approximate confidence intervals for the generalized Pareto parameters using Edgeworth approximation and compare them with those based on Monte Carlo simulations. To show the usefulness of our results, we also present a numerical example. Finally, we give an application to real data.     

Exact Inference for the pth-Quantile and the Reliability of the Two-Parameter Exponential Distribution with Singly Type II Censoring: A Standard Approach

Starting from a standard pivot, exact inference for the pth-quantile and for the reliability of the two-parameter exponential distribution in case of singly Type II censored samples is developed in this article. Fernandez (2007 Fernandez , A. J. ( 2007 ). On calculating generalized confidence intervals for the two-parameter exponential reliability function . Statistics 41 : 129 – 135 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) first obtained some of the results proposed in this article, but, differently from what are proposed here, and developed his theory starting from a generalized pivot. An illustrative example shows that, with the expressions proposed in this article, it is also possible to overcome some shortcomings raising from the formulas by Fernandez (2007 Fernandez , A. J. ( 2007 ). On calculating generalized confidence intervals for the two-parameter exponential reliability function . Statistics 41 : 129 – 135 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]). Finally, a new expression for the moments of the pivot is obtained.     

Improved bootstrap confidence intervals in certain toxicological experiments

The bootstrap, the jackknife, and classical methods are compared through their confidence intervals for the proportion of affected fetuses in a common type of animal experiment. Specifically, suppose that for the ith of M pregnant animals, there are x _i affected fetuses out of n _i total in the litter. The conditional distribution of x _i given n _i is sometimes modeled as binomial (n _i p _i ), where p _i is a realization from some unknown continuous density. The p _i are not observable and it is of interest in some toxicological experiments to find confidence intervals for E(p). Theory suggests that the proposed parametric bootstrap should produce higher order agreement between the nominal and actual coverage than that exhibited by the usual nonparametric bootstrap. Some simulation results provide additional evidence of this superiority of the modified parametric bootstrap over the jack-knife and classical approaches. The proposed resampling is flexible enough to handle a more general model allowing correlation between p _i and n _i .     

广东省废水排放量预测及宏观控制研究

文章对广东省废水排放现状进行了综合分析,结合历史资料和灰色预测方法对未来广东省的废水排放量进行了仿真预测,并提出了未来广东省加强废水排放治理的重要性和建议.     

统筹法在审核建筑工程量中的应用

计算建筑工程量,是审核建筑工种预算的重要环节,它直接影响审核工程预算的质量和速度,本文提出了在审核建筑工程预算中,应用统筹法计算工程量的方法。     

让课堂教学充满吸引力、活力与魅力

本文根据全国第二次普通高校本科教学工作会议关于大力加强教学工作,切实提高教学质量的精绅,论述了提高课堂教学质量的重要性,探讨了如何提高课堂教学质量,着重阐述了提高课堂教学质量的关键在于科学性、思想性与艺术性的有机结合,让课堂教学具有吸引力,充满活力,富有魅力,成为培育优秀学风和培养优秀人才的主要阵地。     

在基础有机化学实验中采用少量化制备仪进行合成的研究

目前国内高等师范和理工院校在有机合成实验中普遍采用标准磨口中（常）量有机合成制备仪。它体积大，耗用试剂较多，实验时间长，而且与当前的教学及教材不相适应。个别院校采用微量制备仪，虽可克服常量存在的缺点，但产量又太少，附属设备须全部更换，另外需购买大型检测设备；我们有鉴及此，设计了一整套少量化制备仪，从根本上解决了大和小的问题，又较适应教材，而又优于教材，节约了实验费用，缩短了实验时间，达到了教学目的。     

量化误差效应对数字图象处理的影响

从平均的角度，定量分析了量化误差效应对数字图象处理的影响，导出了平均量化误差和量化误差概率的计算公式，可指导具体的算法设计和定量分析量化误差．