A multiple warm standby δ-shock system with a repairman having multiple vacations

In this article, a warm standby n-unit system is studied. The system is operational as long as there is one unit normal. The unit online, which has a lifetime distribution governed by a phase-type distribution, is also attacked by a shock from some external causes. Assume that shocks arrive according to a Poisson process. Whenever an interarrival time of shock is less than a threshold, the unit online fails. The lifetimes of the units in warm standby is exponentially distributed. A repairman who can take multiple vacations repairs the failed units based on the “first-in-first-out” rule. The repair times and the vacation times of repairman are governed by different phase-type distributions. For this system, the Markov process governing the system is constructed. The system is studied in a transient and stationary regime; the availability, the reliability, the rates of occurrence of the different types of failures, and the working probability of the repairman are calculated. A numerical application is performed to illustrate the calculations.     

Customizing Generalizations of the Kolmogorov-Smirnov Goodness-of-fit Test

This paper presents a method of customizing goodness-of-fit tests that transforms the empirical distribution function in such a way as to create tests for certain alternatives. Using the @ , g transform described in Blom(1958), one can create non-parametric tests for an assortment of alternative distributions. As examples, three new ( f , g )-corrected Kolmogorov-Smirnov tests for goodness-of-fit are discussed. One of these tests is powerful for testing whether or not the data come from an alternative that is heavier in the tails. Another test identifies whether or not the data come from an alternative which is heavier in the middle of the distribution. The last test identifies if the data come from an alternative in which the first or third quartile is far from the corresponding quartile of the hypothesized distribution. The behavior of the three new tests is investigated through a power study.     

System reliability under δ-shock model

δ-shock model is one of the widely studied shock models in reliability. Under this model, the system fails when the time between two consecutive shocks falls below a fixed threshold δ. In this paper, the survival function and the mean time to failure of the system are obtained when the times between successive shocks follow proportional hazard rate model.     

黄河三角洲C3植物δ13C对盐度变化的响应

通过对黄河三角洲地区C3植物稳定碳同位素组成以及土壤盐分的调查,初步探讨了C3植物δ13C与盐度的关系,揭示了环境因素对植物δ13C的影响.结果显示:黄河三角洲地区C3植物δ13C与盐度之间呈线性正相关关系(P<0.005),且随着盐度的增加,C3植物平均δ13C值呈偏正的趋势(P<0.005),土壤盐分是植物δ13C值的重要影响因素,单个植物种δ13C随盐度上升表现为增加和变化不明显2种模式,这与植物本身的遗传特性、耐盐性强弱等有关.     

论《文讯》的媒介型文学史书写

《文讯》是媒介型文学史,是编年体与纪传体相结合的原生态、遗留态、评价态三合一的台湾文学史,被专家称为＂台湾文学的简史＂：其一,它办刊的历史,再现和浓缩当代台湾文学史：即由威权时代的文宣工作,进入解严前后怀柔的＂文化领导权＂实践,最后转为民营进入文学多元发展时代,它是台湾文坛的＂镜像＂;其二,《文讯》透过史料整理,保存文学历史,对作家的报道,出版、艺文动态的记录,对文学的研究,体现＂写史＂的企图,它是＂遗留态＂的历史;其三,文学期刊与文学历史是＂同型对应＂、＂同源互文＂和＂异构同质＂关系。《文讯》从文类、断代、区域、作家、题材等面向透过专题策划,呈现当代台湾文学众声喧哗、合力书写的历史。     

Moment density estimation for positive random variables

An unknown moment-determinate cumulative distribution function or its density function can be recovered from corresponding moments and estimated from the empirical moments. This method of estimating an unknown density is natural in certain inverse estimation models like multiplicative censoring or biased sampling when the moments of unobserved distribution can be estimated via the transformed moments of the observed distribution. In this paper, we introduce a new nonparametric estimator of a probability density function defined on the positive real line, motivated by the above. Some fundamental properties of proposed estimator are studied. The comparison with traditional kernel density estimator is discussed.     

Standard errors in the multinomial logit model

Asymptotic stmdard errors in the multinomial log it model are derived for efficient estimates of (A) the probability of choosing an alternative , (B) the change in the probability of choosing an alternative given a change in an explanatory variable , (C) the expected response, and (D) the change in the expected response given a change in an explanatory variable. An empirical example illustrates the usefulness of the concepts developed here.     

6西格玛质量管理理念与方法在高校教学质量管理中的应用

借鉴广泛应用于现代工业企业管理中的6西格玛质量管理理念和方法,对高校教学质量管理进行新的尝试。从介绍6西格玛质量管理基本内容入手,就当前高校教学质量管理中的一些突出问题,有针对性地提出应用6西格玛质量管理方法加以改进的意见与措施。