Power analysis for clustered non-continuous responses in multicenter trials

Power analysis for multi-center randomized control trials is quite difficult to perform for non-continuous responses when site differences are modeled by random effects using the generalized linear mixed-effects model (GLMM). First, it is not possible to construct power functions analytically, because of the extreme complexity of the sampling distribution of parameter estimates. Second, Monte Carlo (MC) simulation, a popular option for estimating power for complex models, does not work within the current context because of a lack of methods and software packages that would provide reliable estimates for fitting such GLMMs. For example, even statistical packages from software giants like SAS do not provide reliable estimates at the time of writing. Another major limitation of MC simulation is the lengthy running time, especially for complex models such as GLMM, especially when estimating power for multiple scenarios of interest. We present a new approach to address such limitations. The proposed approach defines a marginal model to approximate the GLMM and estimates power without relying on MC simulation. The approach is illustrated with both real and simulated data, with the simulation study demonstrating good performance of the method.     

Stochastic comparisons on sample extremes of dependent and heterogenous observations

Stochastic comparison on order statistics from heterogeneous-dependent observations has been paid lots of attention recently. This paper devotes to investigating the ordering properties of order statistics from dependent observations. We derive the usual stochastic order for sample minimums and the second smallest order statistic, the dispersive order and the star order for minimums of samples having proportional hazards and Archimedean survival copulas. Similar ordering results are also obtained for maximums and the second largest order statistic of samples having proportional reversed hazards and Archimedean copulas. Several examples illustrating the main results are presented as well.     

Functional Partial Linear Single‐index Model

This paper deals with the problem of predicting the real‐valued response variable using explanatory variables containing both multivariate random variable and random curve. The proposed functional partial linear single‐index model treats the multivariate random variable as linear part and the random curve as functional single‐index part, respectively. To estimate the non‐parametric link function, the functional single‐index and the parameters in the linear part, a two‐stage estimation procedure is proposed. Compared with existing semi‐parametric methods, the proposed approach requires no initial estimation and iteration. Asymptotical properties are established for both the parameters in the linear part and the functional single‐index. The convergence rate for the non‐parametric link function is also given. In addition, asymptotical normality of the error variance is obtained that facilitates the construction of confidence region and hypothesis testing for the unknown parameter. Numerical experiments including simulation studies and a real‐data analysis are conducted to evaluate the empirical performance of the proposed method.     

Prevalence and characteristics of sexual violence victimization among U.S. adults, 2001-2003

This article provides the most recent U.S. prevalence estimates of forced sex and unwanted sexual activity. Results of a national telephone survey conducted in 2001-2003 indicate that 1 in 59 U.S. adults (2.7 million women and 978,000 men) experienced unwanted sexual activity in the 12 months preceding the survey and that 1 in 15 U.S. adults (11.7 million women and 2.1 million men) have been forced to have sex during their lifetime. There were 60.4% of females and 69.2% of males who were 17 years old or younger at the time the first forced sex occurred. This study provides an update to the National Violence Against Women Survey with more recent national data. Findings suggest that victimization rates have remained consistent since the 1990s. These findings suggest that a continued effort toward primary prevention of sexual violence, particularly rape of children and adolescents, is needed.     

对职业教育课堂教学优化的探讨

职业院校学生实践能力职业能力是立业之本,创业之基,课堂教学优化是推进职业教育培育技能型人才的基础性工作.加深对课堂教学优化的实践认知,确立课堂教学优化的常态观,是职业教育落实"以就业为导向"的教育方针的必走之路.     

Bayesian t-tests for correlations and partial correlations

In this paper, we develop Bayes factor based testing procedures for the presence of a correlation or a partial correlation. The proposed Bayesian tests are obtained by restricting the class of the alternative hypotheses to maximize the probability of rejecting the null hypothesis when the Bayes factor is larger than a specified threshold. It turns out that they depend simply on the frequentist t-statistics with the associated critical values and can thus be easily calculated by using a spreadsheet in Excel and in fact by just adding one more step after one has performed the frequentist correlation tests. In addition, they are able to yield an identical decision with the frequentist paradigm, provided that the evidence threshold of the Bayesian tests is determined by the significance level of the frequentist paradigm. We illustrate the performance of the proposed procedures through simulated and real-data examples.     

在自我叙事的表象背后--评《紫禁女》

通过对卢新华新作《紫禁女》的文本细读,在分析其感性层面的自我叙事故事基础之上,进而挖掘其理性层面所蕴涵的历史忧患意识。在肯定其梦幻、日记体、意识流等多种表现手法的同时,也中肯地指出其“载道”有余而“文学”不足的缺憾。     

A new tool for urban governance or just rhetoric? The case of participatory budgeting in Taipei City

Increasing interest in participatory budgeting has been observed in local governments around the world. This paper stresses direct citizen participation in the budgeting process leads to good governance, deepens democracy and improves social justice, while also highlighting some challenges in its efficiency and effectiveness. Unlike participatory budgeting, the Sub-borough Chiefs Forum is a community-based representative democratic mechanism; it could be regarded as a form of participatory budgeting in a broad sense. If so, then did the Taipei programme simply duplicate the goals of the Forum or lead to a better governance by making up for the inadequacies of the Chiefs Forum? To find out whether the Taipei participatory budgeting programme made a difference, we carried out qualitative and quantitative comparisons of projects passed under the participatory budgeting process and at the Forum. We also interviewed several participatory budgeting participants and sub-borough chiefs. The findings suggested that participatory budgeting and the Forum generated different proposals and budget requests, and the Taipei programme supplemented the shortcomings of the Forum and therefore led to deeper civic engagement and better urban governance.