Estimating the proportion of true null hypotheses, with application to DNA microarray data

Summary.  We consider the problem of estimating the proportion of true null hypotheses, π ₀, in a multiple-hypothesis set-up. The tests are based on observed p -values. We first review published estimators based on the estimator that was suggested by Schweder and Spjøtvoll. Then we derive new estimators based on nonparametric maximum likelihood estimation of the p -value density, restricting to decreasing and convex decreasing densities. The estimators of π ₀ are all derived under the assumption of independent test statistics. Their performance under dependence is investigated in a simulation study. We find that the estimators are relatively robust with respect to the assumption of independence and work well also for test statistics with moderate dependence.     

An exact distribution-free test comparing two multivariate distributions based on adjacency

Summary.  A new test is proposed comparing two multivariate distributions by using distances between observations. Unlike earlier tests using interpoint distances, the new test statistic has a known exact distribution and is exactly distribution free. The interpoint distances are used to construct an optimal non-bipartite matching, i.e. a matching of the observations into disjoint pairs to minimize the total distance within pairs. The cross-match statistic is the number of pairs containing one observation from the first distribution and one from the second. Distributions that are very different will exhibit few cross-matches. When comparing two discrete distributions with finite support, the test is consistent against all alternatives. The test is applied to a study of brain activation measured by functional magnetic resonance imaging during two linguistic tasks, comparing brains that are impaired by arteriovenous abnormalities with normal controls. A second exact distribution-free test is also discussed: it ranks the pairs and sums the ranks of the cross-matched pairs.     

基于总线观测的微机故障诊断专家系统研究

采用与或树、产生式规则和ＤＢＭＳ相结合的知识表示方法建立专家系统。论述了基于总线观测的知识获取与诊断方法，提出了基于总线观测的可测性分析方法和故障信息的相关性分析方法。该方法为总线测试信息的有效性及故障搜索策略的生成与优化提供了分析和判断依据，使系统有较高的推理效率和诊断分辨率。     

Application of Multivariate Analysis to Increase the Yield of Dry Cell Batteries

In an organization, the manufacturing process of a dry cell battery was suffering from the problem of frequent stoppages in the assembly line. The complete battery manufacturing operation is highly automated and mechanized. It was suspected that excessive variation in overall height of bobbin was the major reason for such stoppages. The bobbin, the inside part of a dry cell battery acting as cathode, is formed by the battery extrusion process. A planned experiment was carried out on the extrusion process that identified the setting of extrusion machines and the amount of water content in the cathode mixture as the parameters causing variation in the bobbin characteristics. The problem of frequent stoppages was eliminated when appropriate action was taken on these two parameters. Finally, multivariate and univariate control schemes were developed for online control of the bobbin characteristics.     

转基因农作物产业化法律问题研究

转基因农作物是随着转基因技术运用到现代农业生产中而产生的一个重要概念。目前世界上产业化种植转基因农作物的国家和其产量都呈一定增长趋势,但是关于转基因农作物的利弊却仍然是科学界乃至整个社会所争论的一个焦点。文章试图从法律角度首先总结西方国家对转基因农作物产业化的立法管理模式,进而分析我国现行法律中有关转基因农作物产业化的具体制度,从而对我国日后转基因产业化发展提供相关的法律支持或建议。     

Kolmogorov-Smirnov Test Statistic and Critical Values for the Erlang-3 and Erlang-4 Distributions

Following a procedure applied to the Erlang-2 distribution in a recent paper, an adjusted Kolmogorov-Smirnov statistic and critical values are developed for the Erlang-3 and -4 cases using data from Monte Carlo simulations. The test statistic produced features of compactness and ease of implementation. It is quite accurate for sample sizes as low as ten.     

基于DEA的交通运输与经济发展的协调性评价

数据包络分析法(DEA)是利用多个输入指标和多个输出指标的数据,对具有可比性的一些"单位"或"部门"(称为"决策单元")进行相对效率评价,应用于对交通运输和经济发展的协调性的动态综合评价,实际是对两个系统相互支持和利用的相对有效性进行动态评价,其评价结果可以通过计量回归模型来验证,即应用Chow's断点(Breakpoint)检验,从交通运输与经济发展计量模型结构发生显著变化的角度,可以进一步验证交通运输与经济发展之间协调性的动态变化趋势.     

对外贸易与经济增长的实证研究——基于江苏和湖南的比较

选取江苏和湖南两省作为研究对象，利用1981—2005年的出口总额、进口总额和地区生产总值等统计数据，在单位根检验和协整检验的基础上建立了误差修正模型．并进行相关的格兰杰因果检验．揭示了江苏和湖南两省的对外贸易与经济增长之间存在长期稳定的关系和短期动态关系。     

Likelihood ratio tests for fuzzy hypotheses testing

In hypotheses testing, such as other statistical problems, we may confront imprecise concepts. One case is a situation in which hypotheses are imprecise. In this paper, we recall and redefine some concepts about fuzzy hypotheses testing, and then we introduce the likelihood ratio test for fuzzy hypotheses testing. Finally, we give some applied examples.     

Testing list effects and diagnosing individual catchabilities in the Rasch model

The Rasch model is useful in the problem of estimating the population size from multiple incomplete lists. It is of great interest to tell whether there are list effects and whether individuals differ in their catchabilities. These two important model selection problems can be easily addressed conditionally. A conditional likelihood ratio test is used to evaluate the list effects and several graphical methods are used to diagnose the individual catchabilities, while neither the unknown population size nor the unknown mixing distribution of individual catchabilities is required to be estimated. Three epidemiological applications are used for illustration.