利用计算机提高专业课程实践教学环节成绩评定的科学性

文章对如何利用计算机技术提高工科专业毕业设计成绩评定的科学性、公正性进行了探讨.     

High Stakes: Time Poverty,Testing, and the Children of the Working Poor

Sociological interest in the implementation of policy generally focuses on the ways a single stream of policy creates a set of measurable consequences either for parents or children. This article takes an ethnographic approach to the study of conflicting policy mandates that collide in the lives of families moving from welfare to work at the same time that schools are implementing high stakes tests and the end of social promotion. We show that these two policies make contradictory demands on parents, to the potential detriment of children. Ethnographic research reveals the ways in which multiple and incompatible forms of policy impact poor families, putting them in the unhappy position of choosing between economic stability or mobility and children's educational performance.     

Cost–benefit analysis of a PMTCT program in Mozambique

The costs and benefits of a HIV/AIDS PMTCT program in a Mozambican city were calculated. The provision and non-provision of infant feeding formula were considered, along with voluntary counselling and testing, and anti-retroviral treatment with Nevirapine. Costs were calculated in monetary units and benefits as deaths averted and disability-adjusted life years. The UNAIDS cost-effectiveness tool for evaluating ARV drug and substitute feeding interventions was used. The costs of the program were compared with the costs of treating HIV-infected children. With no infant feeding formula, there would be a total savings of US$5242 and a negative cost per DALY of US$1.53 without infant feeding formula. With formula, net annual costs would be US$141,268 and cost per DALY US$38.69. Citywide, each year 132 infant deaths would be averted by use of Nevirapine and eight averted by the breastmilk replacement program. All program options have reasonable cost-effectiveness ratios.     

Optimal Software Free Trial Strategy: Limited Version,Time‐locked,or Hybrid?

Limited version, time‐locked, and hybrid are three software free trial strategies employed by software firms to exploit increased installed base and/or reduction of consumers' uncertainty about software quality. We develop an analytical model to examine these three software free trial strategies. We find that the hybrid strategy weakly dominates the limited and time‐locked versions, and the intensity of the network effects is a key factor determining which strategy is optimal.     

A pivot function and its limiting distribution: applications in goodness of fit and testing hypothesis

ABSTRACT

In this paper, a pivot function which is in terms of the sample and the underlying population distribution is introduced. It is assumed that the population distribution is continuous and strictly increasing on its support. Then, the martingale central limit theorem is applied to prove that limiting distribution of the pivot function is the standard normal. Interestingly, this result provides a unified procedure that can be applied for the goodness of fit, and for the purpose of parametric and nonparametric inferences, for the populations having distribution functions that are continuous and strictly increasing on their supports. The method is fairly simple and can be easily applied.     

基于组态软件和可编程逻辑控制器的活毒废水处理自动监控系统

目的在满足活毒废水处理系统连续、安全、稳定的前提下,实现处理系统的自动监控。方法采用集工业控制计算机、通用监控系统（MCGS）组态软件、可编程逻辑控制器（PLC）于一体的自动监控技术。结果自动监控系统图形表现和数据处理能力及抗干扰能力强,实现了数据的集中管理、自动控制、故障检测等多方面功能。结论基于组态软件和PLC的活毒废水处理自动监控系统,具有可靠性高、维护简单等特点,为活毒废水处理系统运行的连续性、稳定性和安全性提供了保证。     

Optimal Allocation of Effort to Software Maintenance: A Queuing Theory Approach

We develop variations of the M|G|1 queue to model the process of software maintenance within organizations and use these models to compute the optimal allocation of resources to software maintenance. User requests are assumed to arrive following a Poisson process and a binomial distribution is used to model duplication of requests. We obtain expressions for expected queue lengths with an exponential server using an N‐policy for an integer N≥1. We also obtain the optimal batching size and mean service rate by minimizing the total cost consisting of the cost of the server, the cost of waiting, and the fixed cost of maintenance, if applicable.     

基于FNN的软件项目绩效评价模型研究

从分析软件项目绩效评价指标体系不完善、评价方法不规范和模型考虑因素过于单一入手,应用统计分析理论建立软件组织状态、软件项目自身特征的指标体系;以文献研究的方式,界定软件项目绩效的内涵;提出了一种新的网络拓扑结构设计方法,建立了基于模糊神经网络的软件项目绩效评价模型;引入改进粒子群学习算法,准确高效地解决了评价模型连接权系数的确定问题。实证研究表明,该模型能够有效地评价软件项目绩效和识别项目风险因素,对软件组织制定风险规避策略、改善项目绩效水平、提供了决策支持信息。     

胖尾分布及长记忆下的动态 EVT-VaR 测度研究

针对金融收益胖尾分布特征及条件波动率长记忆性特征,运用 FIGARCH 对条件波动率建模、极值理论( extreme value theory,EVT) 对标准收益序列的尾部建模,测度出金融市场动态极值风险,进而运用返回测试( back-testing) 技术,对模型在样本内的测度准确性与样本外的推广能力进行稳健性检验． 实证研究结果表明,无论是中国新兴市场,还是西方成熟发达市场,金融收益与标准收益均呈现出明显的有偏胖尾分布特征; 金融收益条件波动率均展现出长记忆性特征; EVT 与 FIGARCH 模型相结合的动态极值风险测度模型不仅在样本内表现出优越的风险测度能力,而且在样本外同样具有可靠的预测推广能力．     

On the Screening of Large Numbers of Significance Tests

A brief review is given of procedures for the collective analysis of a large number of significance tests. A simple procedure previously supplied for isolating 'real' effects on the basis of a large number of significance tests is generalized to deal with two-sided tests and is also related more explicitly to the false discovery rate.