On asymptotic posterior normality for controlled branching processes

For a controlled branching process (CBP) with offspring distribution belonging to the power series family, the asymptotic normality of the posterior distribution of the basic parameter and the offspring mean is proved. As practical applications, we calculate asymptotic high probability density credibility sets for the offspring mean and we provide a rule to make inference about the value of this parameter. Moreover, the asymptotic posterior normality of the respective parameters of two classical branching models, namely the standard Galton–Watson process and the Galton–Watson process with immigration, is derived as particular cases of the CBP.     

A new unrelated question randomized response model

In this paper, we extend the work of Gjestvang and Singh [A new randomized response model, J. R. Statist. Soc. Ser. B (Methodological) 68 (2006), pp. 523–530] to propose a new unrelated question randomized response model that can be used for any sampling scheme. The interesting thing is that the estimator based on one sample is free from the use of known proportion of an unrelated character, unlike Horvitz et al. [The unrelated question randomized response model, Social Statistics Section, Proceedings of the American Statistical Association, 1967, pp. 65–72], Greenberg et al. [The unrelated question randomized response model: Theoretical framework, J. Amer. Statist. Assoc. 64 (1969), pp. 520–539] and Mangat et al. [An improved unrelated question randomized response strategy, Calcutta Statist. Assoc. Bull. 42 (1992), pp. 167–168] models. The relative efficiency of the proposed model with respect to the existing competitors has been studied.     

Bayesian sample size determination for phase IIA clinical trials using historical data and semi‐parametric prior's elicitation

The Simon's two‐stage design is the most commonly applied among multi‐stage designs in phase IIA clinical trials. It combines the sample sizes at the two stages in order to minimize either the expected or the maximum sample size. When the uncertainty about pre‐trial beliefs on the expected or desired response rate is high, a Bayesian alternative should be considered since it allows to deal with the entire distribution of the parameter of interest in a more natural way. In this setting, a crucial issue is how to construct a distribution from the available summaries to use as a clinical prior in a Bayesian design. In this work, we explore the Bayesian counterparts of the Simon's two‐stage design based on the predictive version of the single threshold design. This design requires specifying two prior distributions: the analysis prior, which is used to compute the posterior probabilities, and the design prior, which is employed to obtain the prior predictive distribution. While the usual approach is to build beta priors for carrying out a conjugate analysis, we derived both the analysis and the design distributions through linear combinations of B‐splines. The motivating example is the planning of the phase IIA two‐stage trial on anti‐HER2 DNA vaccine in breast cancer, where initial beliefs formed from elicited experts' opinions and historical data showed a high level of uncertainty. In a sample size determination problem, the impact of different priors is evaluated.     

Estimation of finite population mean in stratified sampling using scrambled responses in the presence of measurement errors

This study focuses on the estimation of population mean of a sensitive variable in stratified random sampling based on randomized response technique (RRT) when the observations are contaminated by measurement errors (ME). A generalized estimator of population mean is proposed by using additively scrambled responses for the sensitive variable. The expressions for the bias and mean square error (MSE) of the proposed estimator are derived. The performance of the proposed estimator is evaluated both theoretically and empirically. Results are also applied to a real data set.     

我国民事证据交换制度的反思与完善

证据交换制度作为我国民事审判方式改革进程中的重要内容,对于完善审理结构、提高诉讼效率和质量、实现集中审理具有重要意义.在推进以审判为中心的诉讼制度改革的背景下,针对司法实践中证据交换制度适用率较低的现状,需要进一步完善证据交换制度的程序设计,明确证据交换的实施主体、组织方式及法律效果,从而更好地发挥证据交换制度的作用.     

刑事侦查模式与审判模式的机制冲突

修改后的《刑事诉讼法》第一次出现了'公正审判'一词,在刑事审判阶段大量吸收英美法系当事人主义的审判模式内容,使校辩双方地位趋于平等化。但侦查阶段,我国始终奉行的是职权主义模式,几千年义务本位的法文化背景直接或间接地使犯罪嫌疑人和被告人地位的实际客体化,从而使犯罪嫌疑人和辩护人与国家侦查机关的地位不平等,没有达到'公正侦查',以至于形成'控'、'辩'前提条件不完备的诉讼结构失衡,我们所期待的公正审判将只能是一座空中楼阁。因此笔者试图在我国侦查阶段引入以'弹劾制'侦查现为支撑的当事人主义侦查摸式,使其与当事人主义趋向的庭审相适应、并且适当做好侦查与庭审之间的衔接工作,以完善我国刑事诉讼运行体制。     

A Parametric Estimation Procedure for Relapse Time Distributions

In a relapse clinical trial patients who have recovered from some recurrent disease (e.g.,ulcer or cancer) are examined at a number of predetermined times. A relapse can be detected either at one of these planned inspections or at a spontaneous visit initiated by the patient because of symptoms. In the first case the observations of the time to relapse, X, is interval-censored by two predetermined time-points. In the second case the upper endpoint of the interval is an observation of the time to symptoms,Y . To model the progression of the disease we use a partially observable Markov process. This approach results in a bivariate phase-type distribution for the joint distribution of (X,Y). It is a flexible model which contains several natural distributions for X, and allows the conditional distributions of the marginals to smoothly depend on each other. To estimate the distributions involved we develop an EM-algorithm. The estimation procedure is evaluated and compared with a non-parametric method in a couple of examples based on simulated data.     

试论审判权独立的反向思考

以三权分立思想作为审判权独立的根据在理论上存在不足,三权分立不是法治社会的标志,我国的审判权也不同于西方的司法权。我国的审判权包括普遍意义上的裁判权、具有自身特色的调解权、行政角色浓厚的判决执行权和在政法委统一领导下的政法委决议执行权。从制度功能来看,裁判权、调解权基本等同于司法权,是审判权独立的主体,并且为了防止法官以判逼调,调解权应当独立于裁判权。裁判执行权、政法委决议执行权因不具有居中裁判性质,不是审判权独立的内容。要求审判权完全独立是脱离了中国国情的空想;以审判机构的独立代替审判权独立犯了逻辑上的错误;没有独立地位法官的审判程序将无法克服程序内在的缺陷。审判权独立应当是具有独立地位的办案法官、办案程序与办案保障三者相结合的审判制度。     

论法官在民商事案件证明责任分配中的自由裁量权

充分、有效地与当事人沟通,坚持公平、公正的原则,从而正确运用法官自由裁量权对证明责任进行分配,有利于查清案件事实,促进司法公正。结合审判实际讨论了法官在不同情况下如何坚持一定的原则,根据不同情形,正确运用自由裁量权进行证明责任分配等问题,如在没有法律、法规、及司法解释具体规定的情形下,法官在运用自由裁量权进行证明责任分配时应遵守诚实信用、程序公开透明、公平公正、经验惯例、综合平衡等原则。在双方地位不平等,可能导致显示公平的情形下,法官需要结合具体案情,根据相关原则进行具体证明责任分配。     

Improving precision and power in randomized trials with a two-stage study design: Stratification using clustering method

In a randomized controlled trial (RCT), it is possible to improve precision and power and reduce sample size by appropriately adjusting for baseline covariates. There are multiple statistical methods to adjust for prognostic baseline covariates, such as an ANCOVA method. In this paper, we propose a clustering-based stratification method for adjusting for the prognostic baseline covariates. Clusters (strata) are formed only based on prognostic baseline covariates, not outcome data nor treatment assignment. Therefore, the clustering procedure can be completed prior to the availability of outcome data. The treatment effect is estimated in each cluster, and the overall treatment effect is derived by combining all cluster-specific treatment effect estimates. The proposed implementation of the procedure is described. Simulations studies and an example are presented.