新型生育文化的综合性效应论析

新型生育文化的内涵性效应和外延性效应是最基本的两大效应。从综合的角度又可概括出新型生育文化的综合性效应。对其进行分析阐释,可见其在不同领域内产生的新型生育文化的意识形态效应、经济社会发展效应、可持续发展效应、人口现代化效应、制度创新效应和理论创新效应。     

计算机模拟技术在制定月生产计划中的应用

本文设计了一个产品按月出产计划的计算机模拟方案,该方案具有计算机自动调整和人工调整的功能,大大加快了计划的编制速度。     

Stress demands on school administrators in Singapore

This study investigated the use of the Occupational Stress Indicator (OSI) on school administrators in Singapore. The sample of 223 school administrators consisted of the top management group of principals and vice-principals and the middle management group of heads of department. The school administrators reported pressure at work, and consequently, higher levels of mental and physical ill health. They had high locus of control scores, indicating low internal control over their environment. However, they also reported greater use of coping strategies and higher job satisfaction. Psychometrically, the sub-scales of sources of pressure, job satisfaction, and mental and physical ill health were found to be reliable. The items of the scales of type A, locus of control and coping skills had to be re-factor analysed for the Singaporean sample. The new factors were found to have higher reliability. When the stress and job satisfaction levels of the principals/vice-principals and heads of department were compared, the heads of department reported significantly less job satisfaction and higher levels of mental and physical ill health. They perceived less internal control in their work situation.     

A fixed sequence Bonferroni procedure for testing multiple endpoints

A method for controlling the familywise error rate combining the Bonferroni adjustment and fixed testing sequence procedures is proposed. This procedure allots Type I error like the Bonferroni adjustment, but allows the Type I error to accumulate whenever a null hypothesis is rejected. In this manner, power for hypotheses tested later in a prespecified order will be increased. The order of the hypothesis tests needs to be prespecified as in a fixed sequence testing procedure, but unlike the fixed sequence testing procedure all hypotheses can always be tested, allowing for an a priori method of concluding a difference in the various endpoints. An application will be in clinical trials in which mortality is a concern, but it is expected that power to distinguish a difference in mortality will be low. If the effect on mortality is larger than anticipated, this method allows a test with a prespecified method of controlling the Type I error rate. Copyright © 2003 John Wiley & Sons, Ltd.     

Repeated‐measures models in the analysis of QT interval

Because of the recent regulatory emphasis on issues related to drug‐induced cardiac repolarization that can potentially lead to sudden death, QT interval analysis has received much attention in the clinical trial literature. The analysis of QT data is complicated by the fact that the QT interval is correlated with heart rate and other prognostic factors. Several attempts have been made in the literature to derive an optimal method for correcting the QT interval for heart rate; however the QT correction formulae obtained are not universal because of substantial variability observed across different patient populations. It is demonstrated in this paper that the widely used fixed QT correction formulae do not provide an adequate fit to QT and RR data and bias estimates of treatment effect. It is also shown that QT correction formulae derived from baseline data in clinical trials are likely to lead to Type I error rate inflation. This paper develops a QT interval analysis framework based on repeated‐measures models accomodating the correlation between QT interval and heart rate and the correlation among QT measurements collected over time. The proposed method of QT analysis controls the Type I error rate and is at least as powerful as traditional QT correction methods with respect to detecting drug‐related QT interval prolongation. Copyright © 2003 John Wiley & Sons, Ltd.     

Sample size calculation based on risk ratio under multiple matching

To increase the efficiency of comparisons between treatments in clinical trials, we may consider the use of a multiple matching design, in which, for each patient receiving the experimental treatment, we match with more than one patient receiving the standard treatment. To assess the efficacy of the experimental treatment, the risk ratio (RR) of patient responses between two treatments is certainly one of the most commonly used measures. Because the probability of patient responses in clinical trial is often not small, the odds ratio (OR), of which the practical interpretation is not easily understood, cannot approximate RR well. Thus, all sample size formulae in terms of OR for case-control studies with multiple matched controls per case can be of limited use here. In this paper, we develop three sample size formulae based on RR for randomized trials with multiple matching. We propose a test statistic for testing the equality of RR under multiple matching. On the basis of Monte Carlo simulation, we evaluate the performance of the proposed test statistic with respect to Type I error. To evaluate the accuracy and usefulness of the three sample size formulae developed in this paper, we further calculate their simulated powers and compare them with those of the sample size formula ignoring matching and the sample size formula based on OR for multiple matching published elsewhere. Finally, we include an example that employs the multiple matching study design about the use of the supplemental ascorbate in the supportive treatment of terminal cancer patients to illustrate the use of these formulae.     

毛南族“肥套”的符号类型、象征及其功能解析

毛南族“肥套”融合了毛南族的傩歌、傩舞、傩乐、傩诵等形式,是中国傩文化的重要组成部分。毛南族“肥套”在传播中蕴含着大量符号,这些符号类型丰富多样,意义的产生遵循着特定的程序,各种符号具有着多重功能,借助于这些符号,实现毛南族傩文化的沿袭与传承。     

A New Estimation Method Based on Order Statistics in the Families of Symmetric Location-scale Distributions

In this study, new unbiased and nonlinear estimators based on order statistics are proposed for the family of symmetric location-scale distributions and these estimators can be computed from both uncensored and symmetric doubly Type II censored samples. In addition, other relevant unbiased estimators are proposed to estimate standard deviations of these new estimators. A simulation study has been performed to evaluate the performance of the new estimators compared to BLU estimators for small sample sizes. As a result of the simulation study, the new estimators proposed for the location-scale family in general performed nearly as good as BLU estimators. Furthermore, the computational advantage of the proposed estimators over BLU and ML estimators are worthy of notice. In addition, these new estimators have been applied to real data, and the estimation results obtained have been compatible with those of BLUE methods.     

Design of accelerated life test plans under progressive Type II interval censoring with random removals

This paper investigates the design of accelerated life test (ALT) plans under progressive Type II interval censoring with random removals. Units’ lifetimes are assumed to follow a Weibull distribution, and the number of random removals at each inspection is assumed to follow a binomial distribution. The optimal ALT plans, which minimize the asymptotic variance of an estimated quantile at use condition, are determined. The expected duration of the test and the expected number of inspections on each stress level are calculated. A numerical study is conducted to investigate the properties of the derived ALT plans under different parameter values. For illustration purpose, a numerical example is also given.     

Parameter estimation and prediction of order statistics for the Burr Type XII distribution with Type II censoring

This article deals with the statistical inference and prediction on Burr Type XII parameters based on Type II censored sample. It is observed that the maximum likelihood estimators (MLEs) cannot be obtained in closed form. We use the expectation-maximization algorithm to compute the MLEs. We also obtain the Bayes estimators under symmetric and asymmetric loss functions such as squared error and Linex By applying Lindley's approximation and Markov chain Monte Carlo (MCMC) technique. Further, MCMC samples are used to calculate the highest posterior density credible intervals. Monte Carlo simulation study and two real-life data-sets are presented to illustrate all of the methods developed here. Furthermore, we obtain a prediction of future order statistics based on the observed ordered because of its important application in different fields such as medical and engineering sciences. A numerical example carried out to illustrate the procedures obtained for prediction of future order statistics.