Subgroup Analysis with Time‐to‐Event Data Under a Logistic‐Cox Mixture Model

Subgroup detection has received increasing attention recently in different fields such as clinical trials, public management and market segmentation analysis. In these fields, people often face time‐to‐event data, which are commonly subject to right censoring. This paper proposes a semiparametric Logistic‐Cox mixture model for subgroup analysis when the interested outcome is event time with right censoring. The proposed method mainly consists of a likelihood ratio‐based testing procedure for testing the existence of subgroups. The expectation–maximization iteration is applied to improve the testing power, and a model‐based bootstrap approach is developed to implement the testing procedure. When there exist subgroups, one can also use the proposed model to estimate the subgroup effect and construct predictive scores for the subgroup membership. The large sample properties of the proposed method are studied. The finite sample performance of the proposed method is assessed by simulation studies. A real data example is also provided for illustration.     

Validation of Nonparametric Two-sample Bootstrap in ROC Analysis on Large Datasets

The nonparametric two-sample bootstrap is applied to computing uncertainties of measures in receiver operating characteristic (ROC) analysis on large datasets in areas such as biometrics, speaker recognition, etc. when the analytical method cannot be used. Its validation was studied by computing the standard errors of the area under ROC curve using the well-established analytical Mann–Whitney statistic method and also using the bootstrap. The analytical result is unique. The bootstrap results are expressed as a probability distribution due to its stochastic nature. The comparisons were carried out using relative errors and hypothesis testing. These match very well. This validation provides a sound foundation for such computations.     

Stochastically optimal bootstrap sample size for shrinkage-type statistics

In nonregular problems where the conventional \(n\) out of \(n\) bootstrap is inconsistent, the \(m\) out of \(n\) bootstrap provides a useful remedy to restore consistency. Conventionally, optimal choice of the bootstrap sample size \(m\) is taken to be the minimiser of a frequentist error measure, estimation of which has posed a major difficulty hindering practical application of the \(m\) out of \(n\) bootstrap method. Relatively little attention has been paid to a stronger, stochastic, version of the optimal bootstrap sample size, defined as the minimiser of an error measure calculated directly from the observed sample. Motivated by this stronger notion of optimality, we develop procedures for calculating the stochastically optimal value of \(m\). Our procedures are shown to work under special forms of Edgeworth-type expansions which are typically satisfied by statistics of the shrinkage type. Theoretical and empirical properties of our methods are illustrated with three examples, namely the James–Stein estimator, the ridge regression estimator and the post-model-selection regression estimator.     

英汉“上／下”方位隐喻的认知文化对比分析

许多抽象概念的认知需借助于方位隐喻.由"上/下(up / down)"域产生的隐喻是应用最普遍的一种方位隐喻,它以"上/下(up / down)"的空间意义为核心拓展出一系列丰富的隐喻意义.本文对英汉方位隐喻中的"上/下"源域进行初步探讨,分析其认知基础,并深入剖析英汉语中"上/下"方位隐喻差异及其认知、文化根源     

非营利性民营机构发展的法律规制——以非营利性改制医院为例的分析

我国非营利性民营机构增长迅速,在近年国有企业公司制改革的浪潮中,也有大量公益性机构实行民营化改制,以非营利性民营改制医院最具代表性.因缺失统一的改制规范,全国各地改制结果大多埋下了非营利性定位与出资人权益保护之间矛盾冲突的隐患,并引发一系列司法纠纷,法院裁判的立法和理论依据不足,也很难做到案结事了,甚至增加社会不安定因素,应进行深入研究.承认此类机构出资人离职时享有部分增值权益,甚至可以转变为营利性的公司企业,也许是突破规制困境的可行路径.     

Going it alone and adrift: the socioeconomic profile and parental involvement of single-father and single-mother families in post-industrial Taiwan

In spite of the rising prevalence of marital dissolution in Asia over the past decades, little is known about single-parent families in Asia. The present study aims to contribute to the literature by investigating the changing socioeconomic characteristics and parental involvement (measured by parent–child activities and parental awareness of children) of single-father and single-mother families in Taiwan around the millennium. Using a nationally representative sample of 641 single fathers and 730 single mothers from the Taiwan Social Trend Survey collected in 1998, 2002 and 2006, this study found that the apparent socioeconomic advantage of single-father families over single-mother families has weakened. Parent–child activities and parental awareness are lower for single fathers than for single mothers and married fathers. The association between higher parental education and more parent–child activities and parental awareness is more pronounced among single fathers than among single mothers. The presence of co-residential grandparents is associated with lower parent–child activities with pre-teen children among single mothers. The results warrant greater attention to the wellbeing and development of adults and children from low SES single-father families in post-industrial Taiwan.     

浅析西部民族区域法律文化的培植

当前中国正处在由落后的传统农业社会向先进的现代化工业社会转型的关键时期。改革开放三十年来,我国西部地区经济生活和社会结构发生了巨大的变化,同时,与此相应的法律文化观念也有了一定的提高。但西部地区复杂的民族成分,多样的宗教信仰,保守落后的传统文化等客观或主观方面的不足之处也成为制约区域法律文化成长的障碍。本文针对西部区域民族法律文化的现状、特点,分析其中培植现代法律文化存在的不利因素,并试图找到在西部地区培植区域法律文化的合适路径。     

印度尼西亚佐科政府的粮食自给与粮食安全政策分析

印度尼西亚拥有较好的粮食生产条件,土地肥沃,雨量丰沛,水资源丰富,粮食作物能够一年多熟,印度尼西亚曾经在20世纪80年代实现短暂的粮食自给。但进入20世纪90年代以后,随着人口的不断增长,特别是随着工业化和城市化步伐的加快,粮食自给无法满足。为此,佐科政府推出多项举措,包括制订粮食生产计划,做到粮食作物自给自足;提高农业预算开支,支持农业发展;修复农田灌溉系统,扩大粮食作物种植面积,提高粮食产量;政府发放更多款项,以社会福利计划或现金补助形式来救济贫民;计划在国外开辟种植基地,并改进国内种植方法。同时,加强国际粮食合作确保粮食安全,包括加强国际农业与粮食安全合作,着力加强农业领域外资利用工作,加强与中国的农业合作等。     

海洋钻井隔水管顶张力分析

隔水管系统足海洋钻井的主要设备之-本丈对描述隔水管运动的四阶非线性偏徽分方程和边界条件进行了简化，并应用有限差分法对隔水管的受力情况进行数值分析.作用在隔水管上的顶张力，使用四种海况进行研究，并编制了相应的计算程序.通过实例计葬，与美国应力工程服务奋司的计葬结果进行比较，结果完全-致.末文提供的动态分析方法及计葬程序具有方法简便、精确度高和机时省千优点，对设计和校核隔水管系统具有实用价值.