Statistical analysis of competing risks model from Marshall–Olkin extended Chen distribution under adaptive progressively interval censoring with random removals

In this paper, a new censoring scheme named by adaptive progressively interval censoring scheme is introduced. The competing risks data come from Marshall–Olkin extended Chen distribution under the new censoring scheme with random removals. We obtain the maximum likelihood estimators of the unknown parameters and the reliability function by using the EM algorithm based on the failure data. In addition, the bootstrap percentile confidence intervals and bootstrap-t confidence intervals of the unknown parameters are obtained. To test the equality of the competing risks model, the likelihood ratio tests are performed. Then, Monte Carlo simulation is conducted to evaluate the performance of the estimators under different sample sizes and removal schemes. Finally, a real data set is analyzed for illustration purpose.     

宋代河北书院述论

对于宋代河北书院的研究,从以往的3所扩充到5所,并对5所书院的发展进行了分析,总结了书院师生体现出来的理学家教育理念及方法.对比全国其他区域书院发展的状况,宋代河北的书院发展相对薄弱,与古代后期相较相对滞后,究其原因是战争的影响、行政建制问题以及河北地区遭受的蝗灾、洪灾等方面的影响造成的.     

Control charts for fraction nonconforming in a bivariate binomial process

Many multivariate quality control techniques are used for multivariate variable processes, but few work for multivariate attribute processes. To monitor multivariate attributes, controlling the false alarms (type I errors) and considering the correlation between attributes are two important issues. By taking into account these two issues, a new control chart is presented to monitor a bivariate binomial process. An example is illustrated for the proposed method. To evaluate the performance of the proposed method, a simulation study is conducted to compare the results with those using both the multivariate np chart and skewness reduction approaches. The results show that the correlation is taken into account in the designed chart and the overall false alarm is controlled at the nominal value. Moreover, the process shift can be quickly detected and the variable that is responsible for a signal can be determined.     

Attribute Control Chart for Multivariate Poisson Distribution

In this study, a control chart is constructed to monitor multivariate Poisson count data, called the MP chart. The control limits of the MP chart are developed by an exact probability method based on the sum of defects or non conformities for each quality characteristic. Numerical examples are used to illustrate the MP chart. The MP chart is evaluated by the average run length (ARL) in simulation. The result indicates that the MP chart is more appropriate than the Shewhart-type control chart when the correlation between variables exists.     

Statistical Inference of Type-II Progressively Hybrid Censored Data with Weibull Lifetimes

In this article, we discuss the maximum likelihood estimators and approximate maximum likelihood estimators of the parameters of the Weibull distribution with two different progressively hybrid censoring schemes. We also present the associated expressions of the expected total test time and the expected effective sample size which will be useful for experimental planning purpose. Finally, the efficiency of the point estimation of the parameters based on the two progressive hybrid censoring schemes are compared and the merits of each censoring scheme are discussed.     

Estimating the number of true null hypotheses in multiple hypothesis testing

The overall Type I error computed based on the traditional means may be inflated if many hypotheses are compared simultaneously. The family-wise error rate (FWER) and false discovery rate (FDR) are some of commonly used error rates to measure Type I error under the multiple hypothesis setting. Many controlling FWER and FDR procedures have been proposed and have the ability to control the desired FWER/FDR under certain scenarios. Nevertheless, these controlling procedures become too conservative when only some hypotheses are from the null. Benjamini and Hochberg (J. Educ. Behav. Stat. 25:60–83, 2000) proposed an adaptive FDR-controlling procedure that adapts the information of the number of true null hypotheses (m ₀) to overcome this problem. Since m ₀ is unknown, estimators of m ₀ are needed. Benjamini and Hochberg (J. Educ. Behav. Stat. 25:60–83, 2000) suggested a graphical approach to construct an estimator of m ₀, which is shown to overestimate m ₀ (see Hwang in J. Stat. Comput. Simul. 81:207–220, 2011). Following a similar construction, this paper proposes new estimators of m ₀. Monte Carlo simulations are used to evaluate accuracy and precision of new estimators and the feasibility of these new adaptive procedures is evaluated under various simulation settings.     

高级汉语水平越南学生的趋向补语偏误分析

通过分析高级汉语水平越南学生的作文语料,筛选出了134条趋向补语偏误用例。这些偏误可归为五种类型:(1)趋向补语冗余的偏误;(2)趋向补语之间混淆的偏误;(3)趋向补语遗漏的偏误;(4)趋向补语和其他补语混淆的偏误;(5)趋向补语和宾语错序的偏误。造成偏误的主要原因是母语负迁移,其次是目的语过度泛化。       

向现代化集约化大型企业集团迈进--记沈阳惠天热电股份有限公司

沈阳惠天热电股份有限公司是以城市集中供热为核心,集供暖运行管理、热力设计、工业安装、房地产开发、热力技术研究、非标准结构件制造等多种经营为一体的国家大型上市公司。公司现有供暖面积2470万平方米,供     

Trends in college binge drinking during a period of increased prevention efforts. Findings from 4 Harvard School of Public Health College Alcohol Study surveys: 1993-2001

The 2001 Harvard School of Public Health College Alcohol Study surveyed students at 119 4-year colleges that participated in the 1993, 1997, and 1999 studies. Responses in the 4 survey years were compared to determine trends in heavy alcohol use, alcohol-related problems, and encounters with college and community prevention efforts. In 2001, approximately 2 in 5 (44.4%) college students reported binge drinking, a rate almost identical to rates in the previous 3 surveys. Very little change in overall binge drinking occurred at the individual college level. The percentages of abstainers and frequent binge drinkers increased, a polarization of drinking behavior first noted in 1997. A sharp rise in frequent binge drinking was noted among students attending all-women's colleges. Other significant changes included increases in immoderate drinking and harm among drinkers. More students lived in substance-free housing and encountered college educational efforts and sanctions resulting from their alcohol use.     

Underage college students' drinking behavior, access to alcohol, and the influence of deterrence policies. Findings from the Harvard School of Public Health College Alcohol Study

Underage drinking is a major problem at American colleges, but little is known about the extent of alcohol use in different student groups, in different colleges, and in states with different control policies. We used data from the 2001 and 3 previous Harvard School of Public Health College Alcohol Studies that compared responses of underage students with those of their 21-23-year-old peers. Underage students drank alcohol less frequently but were more likely to drink to excess when they drank. College educational efforts and deterrent policies were limited in their outreach, and half of underage students obtained alcohol very easily. Underage students in states with extensive laws restricting underage and high-volume drinking were less likely to drink and to binge drink. A majority of underage students supported increasing efforts to control underage drinking. The results suggest that additional policy efforts to control underage drinking may be effective and feasible.