Age Replacement Policy with a Safety Constraint via the Bayesian Method

Consider a system that is subject to shocks that arrive according to a non homogeneous Poisson process. As the shocks occur, the system has m + 1 failure modes including the following: (i) a non repairable failure (catastrophic) mode that calls for a replacement and (ii) m repairable failure (non catastrophic) modes that are rectified by minimal repairs. In this article, we propose an age-replacement model with minimal repair based on using the natural conjugate prior of Bayesian method. In addition, a safety constraint is considered to control the risk of occurring catastrophic failures in a specified time interval. The minimum-cost replacement policy is studied in terms of its existence and safety constraint. A numerical example is also presented to illustrate the proposed model.     

An Extended Sequential Imperfect Preventive Maintenance Model with Improvement Factors

This article presents a generalization of the imperfect sequential preventive maintenance (PM) policy with minimal repair. As failures occur, the system experiences one of two types of failures: a Type-I failure (minor), rectified by a minimal repair; or a Type-II failure (catastrophic) that calls for an unplanned maintenance. In each maintenance period, the system is maintained following the occurrence of a Type-II failure or at age, whichever takes place first. At the Nth maintenance, the system is replaced rather than maintained. The imperfect PM model adopted in this study incorporates with improvement factors in the hazard-rate function. Taking age-dependent minimal repair costs into consideration, the objective consists of finding the optimal PM and replacement schedule that minimize the expected cost per unit time over an infinite time-horizon.     

Weighted similarity tests for location-scale families of stable distributions

ABSTRACT

The class of stable distributions plays a central role in the study of asymptotic behavior of normalized partial sums, the same role performed by normal distribution among those with finite second moment. In this note, by exploiting the connection between stable laws and regularly varying functions, we present weighted similarity tests for stable location-scale families. The proposed weight functions are based on the 2nd-order Mallows distance between the empirical distribution and the root stable distribution. And the resulting statistics converge weakly to functionals of Brownian bridge.     

Testing Symmetry of a NIG Distribution

Exponential and Weibull models are commonly used models with former being the special case of the latter. In their most general forms, the exponential model involves both threshold and scale parameters whereas the Weibull model involves threshold, scale and shape parameters. The article analyzes the two models in a Bayesian framework and examines the feasibility of generality versus particularity in the sense that it tests for the possibility of (not) having a threshold and/or a shape parameter in the data arising from exponential (Weibull) model. The results are illustrated based on both complete and censored datasets from the models.     

经济全球化过程中的中国特色社会主义

经济全球化是一种以经济方式为杠杠,全方位影响全球经济、政治、文化、社会的现象和历史过程,它对世界经济和其它领域的发展具有双重影响。经济全球化发展对中国特色社会主义的发展,既形成巨大的挑战,也提供了历史上少有的发展机遇。30年来,中国特色社会主义在迎接挑战、把握机遇中获得了空前的发展。     

植物学野外实习教学改革初探

植物学野外实习是高等学校生物类专业教学过程中必不可少的一个实践环节。加强学生的素质教育和能力培养是我国高等教育改革的重点,而实践教学环节则在培养学生基本技能、野外生存合作精神及环保意识等方面都具有重要的作用。     

基于模糊综合评价方法的企业员工绩效评估

企业员工绩效评估中,有定量考评和定性考评两种基本方法。定性考评方法时常带有很大的主观性和不稳定性,从而对考评结果的客观性和准确性造成了很大的影响。如何对定性考评指标进行量化增加结果的可靠性是考评中的一大难点,而采用模糊综合评价方法可较好地解决定性指标的定量化问题。本文首先介绍了模糊综合评价方法的一般原理和步骤,接着通过举例说明如何利用模糊综合评价方法对员工进行绩效评估。     

面子需要概念的维度划分与测量——一项探索性研究

面子问题在中国社会根植已久,它在某种意义上决定了个体的行为表现,从而无所不在地影响着社会交往.然而,鉴于面子概念的复杂性和抽象性,长期以来与面子相关的研究仍然只停留在纸上谈兵的阶段,缺乏系统验证.对面子需要概念的结构与相应的维度划分进行的探索性研究结果表明: (1)面子及面子需要都是多维度的概念,个体的面子需要可以分为三类,即能力性面子需要、关系性面子需要和道德性面子需要,也就是说个体所追求的面子可以根据其来源的不同而区分出能力、人际关系和道德三个维度;(2) 不同的个体对面子有着不同的需要,它不仅表现为强度的区别,同时也表现为类型的差异.     

英国近代文官制度的建立

英国是世界上第一个建立文官制度的国家。工业革命的推进需要建立与之相适应的文官制度;旧的官吏制度越来越成为资本主义发展的桎梏;边沁的功利主义学说和自由平等思想为建立英国近代文官制度提供了理论支持;中国的科举制对其文官制度的建立起了借鉴作用。近代文官制度的建立促进了英国的发展,是对世界政治文明的又一重要贡献。     

当代西方德性伦理视域中德性概念的诠释

自1958年英国哲学家G.E.M.安斯库默发表《现代道德哲学》一文以来,德性伦理在西方伦理学界迅速发展,成为研究的热点。其中,德性的诠释是德性伦理和规范伦理之间斗争的核心。研究德性的不同诠释,我们能够认识德性概念在德性伦理中的重要性,也能通过对德性的不同诠释,深刻理解道德的本质构成,进一步认清伦理学的发展方向。