The Poisson-X family of distributions

ABSTRACT

Recently, Risti? and Nadarajah [A new lifetime distribution. J Stat Comput Simul. 2014;84:135–150] introduced the Poisson generated family of distributions and investigated the properties of a special case named the exponentiated-exponential Poisson distribution. In this paper, we study general mathematical properties of the Poisson-X family in the context of the T-X family of distributions pioneered by Alzaatreh et al. [A new method for generating families of continuous distributions. Metron. 2013;71:63–79], which include quantile, shapes of the density and hazard rate functions, asymptotics and Shannon entropy. We obtain a useful linear representation of the family density and explicit expressions for the ordinary and incomplete moments, mean deviations and generating function. One special lifetime model called the Poisson power-Cauchy is defined and some of its properties are investigated. This model can have flexible hazard rate shapes such as increasing, decreasing, bathtub and upside-down bathtub. The method of maximum likelihood is used to estimate the model parameters. We illustrate the flexibility of the new distribution by means of three applications to real life data sets.     

A Five-Decision Testing Procedure to Infer the Value of a Unidimensional Parameter

ABSTRACT

A statistical test can be seen as a procedure to produce a decision based on observed data, where some decisions consist of rejecting a hypothesis (yielding a significant result) and some do not, and where one controls the probability to make a wrong rejection at some prespecified significance level. Whereas traditional hypothesis testing involves only two possible decisions (to reject or not a null hypothesis), Kaiser’s directional two-sided test as well as the more recently introduced testing procedure of Jones and Tukey, each equivalent to running two one-sided tests, involve three possible decisions to infer the value of a unidimensional parameter. The latter procedure assumes that a point null hypothesis is impossible (e.g., that two treatments cannot have exactly the same effect), allowing a gain of statistical power. There are, however, situations where a point hypothesis is indeed plausible, for example, when considering hypotheses derived from Einstein’s theories. In this article, we introduce a five-decision rule testing procedure, equivalent to running a traditional two-sided test in addition to two one-sided tests, which combines the advantages of the testing procedures of Kaiser (no assumption on a point hypothesis being impossible) and Jones and Tukey (higher power), allowing for a nonnegligible (typically 20%) reduction of the sample size needed to reach a given statistical power to get a significant result, compared to the traditional approach.     

高校思想政治教育网络教育手段的理性分析

网络技术运用于高校思想政治教育,不仅丰富了思想政治教育的途径和方式,而且也有效地拓展了思想政治教育的空间。但是由于思想观念、技术水平的差异性,网络为思想政治教育提供的手段并没有得到充分地开发利用。因此,大胆实施改革创新,不断完善网络教育手段和方式,是促使思想政治教育功能得以最大程度发挥的重要基础。     

Utilizing Bayesian predictive power in clinical trial design

The Bayesian paradigm provides an ideal platform to update uncertainties and carry them over into the future in the presence of data. Bayesian predictive power (BPP) reflects our belief in the eventual success of a clinical trial to meet its goals. In this paper we derive mathematical expressions for the most common types of outcomes, to make the BPP accessible to practitioners, facilitate fast computations in adaptive trial design simulations that use interim futility monitoring, and propose an organized BPP-based phase II-to-phase III design framework.     

同意观念的历史谱系与当代困境

通过提出明示同意与默示同意这两个不同的同意概念并强调有别于集体同意之个体同意的重要性，特别是通过对默示同意的分析和说明，洛克使得近代意义上的同意理论逐渐浮出水面。同意理论在颠覆君权神授理论、确认人民主权思想的过程中有着无可置疑的历史价值。虽然在现当代，同意理论因遭遇到越来越多的诟病而逐渐步入困境，但同意理论并非一无是处。对于当代中国社会来说，强调政府及政府行为必须经过人民的同意这一点，对于政治体制的改革以及政治秩序的合法构建来说仍然具有极为重要且深远的意义。     

中国当下依法治国对孙中山“训政”思想的新发展——关于中国法治现代化阶段论的思考

当前中国特色社会主义法治与孙中山先生的“训政”相比，两者相似之处在于都坚持一党执政，并将此视为法治现代化进程中不可或缺的一个阶段性特征；不同之处在于两者的内容和性质发生了根本变化。内容的变化主要体现在社会基础发生巨大变化和民主成分获得较大增长；性质的变化主要体现在它不再是资本主义而是中国特色社会主义性质。以一党长期执政、不搞西方多党竞争为特点的中国特色社会主义法治长期存在的原因是：中国属于后发的政府主导的赶超型现代化国家，没有形成橄榄形社会结构，需要通过建立能够集中力量办大事的政治体制，实现中国的“富”与“强”。     

Effects of the social dominance orientation on environmental attitudes of Chilean university students / Efectos de la orientación a la dominancia social sobre las actitudes ambientales de universitarios chilenos

By adopting a multidimensional approach to environmental attitudes (apathy, anthropocentrism, connectedness and emotional affinity with nature), this study explores the relationships between these dimensions, social dominance orientation (SDO) and political orientation. Two hundred and sixty-two Chilean university students filled out an ad hoc online questionnaire. Two confirmatory factorial analyses showed the four typologies of environmental attitudes and the two factors for SDO, which are labelled group dominance and opposition to equality. Through hierarchical regressions, group dominance showed higher explanatory power of environmental attitudes than political orientation. Furthermore, using the bootstrap procedure we showed that group dominance mediated between political orientation and attitudes of apathy, anthropocentrism and connectedness, while opposition to equality mediated between apathy and emotional affinity. We conclude that SDO is an important variable for measuring political ideology while also providing new nuances when analysing the relationships with environmental attitudes.     

A decade after the Reform: political activism of the Chinese of West Kalimantan,Indonesia

Political reform after the departure of President Soeharto’s New Order (1966–1998) provided opportunities for previously oppressed social groups to express their concerns and to demand fair recognition. The results of this newly found freedom have been quite immediately visible in Jakarta, where social and political institutions spearheaded by Chinese originally sprouted. In the regions, political participation of ethnic Chinese has also grown; significantly in those regions with a large Chinese population. In West Kalimantan, the number of Chinese being elected to local parliaments in some regions has doubled. They have also contested numerous direct local executive elections since 2003 and have been successful in winning four posts: a mayor, a district head, a deputy district head, and a deputy governor. By looking at the case of West Kalimantan, this article will examine the factors behind the growth in Chinese political activism, the factors contributing to the success of Chinese candidates in elections, how the Chinese have influenced local and provincial politics, and the challenges they are facing.     

Development of predictive signatures for treatment selection in precision medicine with survival outcomes

For survival endpoints in subgroup selection, a score conversion model is often used to convert the set of biomarkers for each patient into a univariate score and using the median of the univariate scores to divide the patients into biomarker‐positive and biomarker‐negative subgroups. However, this may lead to bias in patient subgroup identification regarding the 2 issues: (1) treatment is equally effective for all patients and/or there is no subgroup difference; (2) the median value of the univariate scores as a cutoff may be inappropriate if the sizes of the 2 subgroups are differ substantially. We utilize a univariate composite score method to convert the set of patient's candidate biomarkers to a univariate response score. We propose applying the likelihood ratio test (LRT) to assess homogeneity of the sampled patients to address the first issue. In the context of identification of the subgroup of responders in adaptive design to demonstrate improvement of treatment efficacy (adaptive power), we suggest that subgroup selection is carried out if the LRT is significant. For the second issue, we utilize a likelihood‐based change‐point algorithm to find an optimal cutoff. Our simulation study shows that type I error generally is controlled, while the overall adaptive power to detect treatment effects sacrifices approximately 4.5% for the simulation designs considered by performing the LRT; furthermore, the change‐point algorithm outperforms the median cutoff considerably when the subgroup sizes differ substantially.