A new three-parameter lifetime distribution

Many if not most lifetime distributions are motivated only by mathematical interest. Here, a new three-parameter distribution motivated mainly by lifetime issues is introduced. Some properties of the new distribution including estimation procedures are derived. Three real-data applications are described to show superior performance versus at least five of the known lifetime models.     

Multivariate Birnbaum–Saunders distribution: properties and associated inference

The univariate fatigue life distribution proposed by Birnbaum and Saunders [A new family of life distributions. J Appl Probab. 1969;6:319–327] has been used quite effectively to model times to failure for materials subject to fatigue and for modelling lifetime data and reliability problems. In this article, we introduce a Birnbaum–Saunders (BS) distribution in the multivariate setting. The new multivariate model arises in the context of conditionally specified distributions. The proposed multivariate model is an absolutely continuous distribution whose marginals are univariate BS distributions. General properties of the multivariate BS distribution are derived and the estimation of the unknown parameters by maximum likelihood is discussed. Further, the Fisher's information matrix is determined. Applications to real data of the proposed multivariate distribution are provided for illustrative purposes.     

刘将孙生平创作考论

文章根据刘将孙的文集《养吾斋集》，对刘将孙的生平仕履进行了考辨，揭示了其中年出仕、晚年蹭蹬的仕宦经历；对刘将孙的文学思想及诗文创作成就进行了总体的研究，认为刘将孙论诗主“性情”与“辞达”，有纠正江西流弊的意义；其散文风格畅达奇崛，诗歌风格多样，作品开“铁崖体”风气之先。     

基于客户终身价值的流失客户研究

讨论了关于流失客户的各种定义,提出了基于客户终身价值的流失客户预测模型,并通过使用某市移动公司全球通客户的数据对该模型进行了验证.计算结果表明,该模型不仅可以有效预测出流失客户,还可以计算出该客户的终身价值,以期为企业有针对性地采取挽留措施提供依据.     

The Bayesian approach for highly reliable electro-explosive devices using one-shot device testing

Due to the high reliability and high testing cost of electro-explosive devices, even though an accelerated test is performed, one may observe very few failures or even no failures at all due to censoring. In this paper, we consider modelling the reliability of such devices by an exponential lifetime distribution in which the failure rate is assumed to be a function of some covariates and that the observed data are binary. The Bayesian approach, with three different prior settings, is used to develop inference on the failure rate, lifetime and the reliability under some settings. A Monte Carlo simulation study is carried out to show that this approach is quite useful and suitable for analysing data of the considered form, especially when the failure rates are very small. Finally, illustrative data are analysed using this approach.     

Modelling lifetimes by quantile functions using Parzen's score function

The present paper introduces methods of constructing quantile functions as models of lifetimes with monotone and nonmonotone hazard functions. This is accomplished on the basis of the relationships the hazard quantile function has with the score function introduced by Parzen in connection with the tail heaviness of probability distributions. Three models illustrated here contain several existing models as particular cases. The appropriateness of the models in real situations is also demonstrated.     

Characterizations of Distributions Based on Moments of Residual Life

Let T be a random variable having an absolutely continuous distribution function. It is known that linearity of E(T | T > t) can be used to characterize distributions such as exponential, power and Pareto distribution. In this work, we will extend the above results. More precisely, we characterize the distribution of T by using certain relationships of conditional moments of T. Our results can also be used to obtain new characterization of distributions based on adjacent order statistics or record values.     

基于产品寿命次数的闭环供应链生产优化问题研究

本文研究了单一厂商制造/再制造集成系统的多期生产优化问题.首先,基于闭环供应链的全生命周期思想,通过引入产品寿命次数的概念构造了不超过产品寿命次数而能够进行再制造的回收产品与新制造产品之间的数量关系;接着,验证了将可再制造产品全部用于再制造时能够实现利润最大化的目标;然后,给出了几个有关解的性质;最后,通过算例对本文模型的性质和规律作进一步分析.     

The probability of nursing home use over a lifetime in Australia

This article further develops the life table models used in the USA by taking advantage of the superior data available in Australia. The probabilities of nursing home use over a lifetime are estimated for various ages for men and women. The results show that over one-third of the members of a female birth cohort will eventually enter nursing homes for long-term care at least once. The corresponding probability for males is one in five. A woman at age 65 faces a probability as high as 39% of using a nursing home for permanent care before her death compared with 25% for a man at age 65.     

柳永生平订正

柳永的生年、及第时间、宦历与卒葬地等问题,有必要进行重新考察与辨证。柳永生于公元987年,于公元1031年登进士第,其卒后由王安石之弟王安礼与陈朝请共同营葬。《镇江府志》所载泗州判官、著作郎、太常博士诸职,均非柳永生前所任,所谓的《宋故郎中柳公墓志》,乃系一篇伪作。