The Kumaraswamy modified Weibull distribution: theory and applications

A five-parameter extension of the Weibull distribution capable of modelling a bathtub-shaped hazard rate function is introduced and studied. The beauty and importance of the new distribution lies in its ability to model both monotone and non-monotone failure rates that are quite common in lifetime problems and reliability. The proposed distribution has a number of well-known lifetime distributions as special sub-models, such as the Weibull, extreme value, exponentiated Weibull, generalized Rayleigh and modified Weibull (MW) distributions, among others. We obtain quantile and generating functions, mean deviations, Bonferroni and Lorenz curves and reliability. We provide explicit expressions for the density function of the order statistics and their moments. For the first time, we define the log-Kumaraswamy MW regression model to analyse censored data. The method of maximum likelihood is used for estimating the model parameters and the observed information matrix is determined. Two applications illustrate the potentiality of the proposed distribution.     

Higher order asymptotic computation of Bayesian significance tests for precise null hypotheses in the presence of nuisance parameters

The full Bayesian significance test (FBST) was introduced by Pereira and Stern for measuring the evidence of a precise null hypothesis. The FBST requires both numerical optimization and multidimensional integration, whose computational cost may be heavy when testing a precise null hypothesis on a scalar parameter of interest in the presence of a large number of nuisance parameters. In this paper we propose a higher order approximation of the measure of evidence for the FBST, based on tail area expansions of the marginal posterior of the parameter of interest. When in particular focus is on matching priors, further results are highlighted. Numerical illustrations are discussed.     

Bias Reduction of Likelihood Estimators in Semiparametric Frailty Models

Abstract. Frailty models with a non‐parametric baseline hazard are widely used for the analysis of survival data. However, their maximum likelihood estimators can be substantially biased in finite samples, because the number of nuisance parameters associated with the baseline hazard increases with the sample size. The penalized partial likelihood based on a first‐order Laplace approximation still has non‐negligible bias. However, the second‐order Laplace approximation to a modified marginal likelihood for a bias reduction is infeasible because of the presence of too many complicated terms. In this article, we find adequate modifications of these likelihood‐based methods by using the hierarchical likelihood.     

外来词的语义平面

汉语外来词的语义结构比其他来源的词的语义结构要复杂.把外来词的语义结构视为一个平面,这一平面又包含了若干具有区别性特征的层面隐性/显性,非真实/真实,重合/粘合/接合等.不同的语义结构会对词的稳定性、能产性等产生不同质的影响.     

固定床反应器改进一维模型的参数灵敏性

采用改进的一维模型研究了固定床催化反应器中具有工业意义的气相强放热反应的参数灵敏性行为。用改进的一维模型所预测的参数灵敏性行为与二维模型预测的结果接近。根据固定床反应器改进一维模型的灵敏性行为提出了失控的判据 ,该判据的预测结果合理     

“惧内”现象剖析

:“惧内”是家庭中丈夫处于从属地位 ,而妻子居主权威的社会现象 ,有其存在的理由 ,且有漫长的历史 ,成因和种类也较多 ,爱情是其前提和基础 ,对协调家庭关系具有双重作用     

论文化产业概念与分类

产生于不同背景和条件下的国内外诸多文化产业概念与分类之间有着明显的差异,随着现代科学技术、各国文化经济实践特别是我国文化产业的不断发展,对其进一步研究有着首要的、深远的理论与实践意义.针对文化产业概念与分类的动态发展性,应坚持普遍性和特殊性相结合,体现以人为本特色,坚持发展,尊重实践,利于创新,根据我国的国情与国际竞争状况,文化产业的特征和发展规律,产业细化、融合和兴衰演变规律,进一步完善符合我国实际与未来发展的文化产业概念与分类,以科学指导和促进文化产业的发展.     

A Matching Prior for the Shape Parameter of the Skew‐Normal Distribution

Abstract. This paper deals with the issue of performing a default Bayesian analysis on the shape parameter of the skew‐normal distribution. Our approach is based on a suitable pseudo‐likelihood function and a matching prior distribution for this parameter, when location (or regression) and scale parameters are unknown. This approach is important for both theoretical and practical reasons. From a theoretical perspective, it is shown that the proposed matching prior is proper thus inducing a proper posterior distribution for the shape parameter, also when the likelihood is monotone. From the practical perspective, the proposed approach has the advantages of avoiding the elicitation on the nuisance parameters and the computation of multidimensional integrals.     

论建构和谐文化的可能性

和谐文化是社会和谐的思想灵魂和精神支柱,是社会和谐的文化升华。在以人为本为核心,以科学发展观为统筹指导,建设社会主义和谐社会的时代背景下,应以“和合”思想为思维方式和方法论原则,探讨建构和谐文化可能性之根据、困境和路径。在此基础上建构和谐融洽、平等合作、共生共赢的社会主义文化实践原则。     

Adaptive Step Size Selection for Hessian‐Based Manifold Langevin Samplers

In this paper, I explore the usage of positive definite metric tensors derived from the second derivative information in the context of the simplified manifold Metropolis adjusted Langevin algorithm. I propose a new adaptive step size procedure that resolves the shortcomings of such metric tensors in regions where the log‐target has near zero curvature in some direction. The adaptive step size selection also appears to alleviate the need for different tuning parameters in transient and stationary regimes that is typical of Metropolis adjusted Langevin algorithm. The combination of metric tensors derived from the second derivative information and the adaptive step size selection constitute a large step towards developing reliable manifold Markov chain Monte Carlo methods that can be implemented automatically for models with unknown or intractable Fisher information, and even for target distributions that do not admit factorization into prior and likelihood. Through examples of low to moderate dimension, I show that the proposed methodology performs very well relative to alternative Markov chain Monte Carlo methods.