A discrete replacement model for a two-unit parallel system subject to failure rate interaction

In this paper, a repairable two-unit parallel system with failure rate interaction between units is studied. Failure rate interaction between units is described as follows. Unit-1 failure whenever occurs can increase the failure rate of unit-2 of some amount, while unit-2 failure can induce unit-1 into simultaneous failure. We consider a discrete replacement policy N based on the number of unit-1 failure. The system is replaced at the instant of the N-th failure of unit-1 or on simultaneous failure of the system. Our problem is to determine an optimal replacement policy N ^* such that the expected cost rate per unit time is minimized. The explicit expression of the expected cost rate per unit time is derived by introducing relative costs and the corresponding optimal number N* is also verified finite and unique under some specific conditions.     

Bayesian parameter and reliability estimation for a bivariate exponential distribution parallel sampling

The present investigation is concerned with deriving Bayesian statistical inferences for the bivariate exponential (BVE) distribution of Marshall and Olkin (1967) applied as a failure model for a two-component parallel system. In this paper joint posterior distributions for the BVE parameters and marginal posterior densities for individual parameters are developed. The posterior distributions are derived for the case of informative prior knowledge. Bayesian estimators for the BVE parameters and the corresponding reliability are derived in a closed form. Bayesian approximated credibility intervals (‘confidence’ intervals) for parameters are derived by utilizing a gamma approximation to the marginal posterior densities.     

The exact discrete analog to a closed linear mixed-order system

This paper deals with the problem of finding the exact discrete solution that corresponds to a closed linear mixed-order svstem.     

提高电厂PlantScape系统运行的可靠性

文章针对PlantScape系统在实际生产过程中出现的一些问题进行探讨,分析原因,制定对策,取得了良好的使用效果。     

TSI系统运行的可靠性探讨

由于TSI系统在汽轮机中有着重要的保护作用,引起了人们的广泛关注,TSI系统运行的可靠性成为广大学者研究的新课题。文章分析了TSI系统可靠性运行中存在的问题,并针对这些问题,提出了相应的改进措施。     

提高电厂DCS系统运行可靠性的研究

文章介绍了分散控制系统(DCS)的结构特点,进而阐述了DCS在电厂应用中的重要作用,在此基础上具体分析与探讨了如何提高电厂DCS系统运行的可靠性。     

Right censoring in a discrete life model

Although there are many sophisticated models for estimation of failure rate based on censored data in continuous distributions, not much work has been done in the discrete case. We introduce a discrete model for life lengths and consider its properties. For this model, we derive the corresponding maximum likelihood estimators of the parameters under Type I and Type II right-censoring. Received May 2000     

矿用刮板输送机传动系统可靠性刍议

文章对矿用刮板机及其传动系统的可靠性进行了简要介绍,阐述了刮板机传动系统部件的常见故障和问题,并结合笔者自身的工作实践,对刮板机传动系统可靠性的改进和提升提出了见解。     

成型设备增塑剂系统电气控制可靠性探讨

文章通过介绍成型设备增塑剂系统的流程和控制方式,运用可靠性理论,完善其控制和检测,并结合设备的实际情况,提出改进的具体方法。     

The surprising benefits of a parallel universe

Suppose that the successful completion of a project requires performing n tasks, each of which has a probability of success p. The paper establishes under what conditions it may be profitable to engage in parallel multi‐tasking, i.e. tackling each task by following two independent routes. It is found that for ?n>1 parallel multi‐tasking is profitable for a wide range of parameters when costs are linear and is always profitable for convex costs. Copyright © 2008 John Wiley & Sons, Ltd.     

Shortfall risk minimization in a discrete regime switching model

Abstract There have been profound ideas on how to measure risk which have influenced the financial market. Shortfall risk minimization is one of the methods which has attracted considerable attention. This problem has been studied for the binomial model in Runggaldier and Zaccaria (2000) and Runggaldier, Trivellato and Vargiolu (2002) and for the trinomial model in Scagnelatto and Vargiolu (2002). In this paper, we investigate shortfall risk minimization in a discrete regime switching model. In the model, we have two possible regimes, which are both binomial. To fix ideas, we can think of the second regime as being the consequence of the presence of inside information, but this can also be due to other factors. Explicit solutions for one-period models are given.     

离散制造业信息管理系统上线策略及方法的研究与实践

文章以国内一个离散制造型企业ERP系统上线为例,归纳了制造型企业信息管理系统上线策略及方法,给企业实施信息化项目提供了一种适用的方法。     

提高核电厂数字化仪控系统可靠性的途径研究

随着数字化仪控系统在核电厂中的广泛应用,数字化仪控系统的可靠性也引起了各方广泛关注。文章从多个方面全面介绍了如何保证核电厂数字化仪控系统的高可靠性,从而使得核电机组能够安全稳定运行。     

Transaction costs and a redundant security: divergence of individual and social relevance

This paper shows that, in markets with transaction costs, even if a redundant security does not even save individual investors' total costs for their security trading, the prices of the other securities may well be different were it to not be available for trade, resulting in a different equilibrium consumption allocation. In this sense, a redundant security may give rise to the divergence of individual and social relevance in markets with transaction costs. We then show that this divergence may also be a robust phenomenon with respect to perturbations in utility functions, initial endowments, and transaction costs.     

均匀送风系统在除尘系统中的应用

将均匀送风的设计理念引入到除尘系统粉尘的收集上,通过控制产尘区的气流来完成对粉尘的控制及收集,该方法可解决车间粉尘密度小、产尘点不确定且产尘量大的条件下,粉尘收集困难的问题。     

Theory and numerical solution of a discrete queueing problem

Abstract  A queueing problem is considered with one server, independent discrete inter-arrival times, and independent discrete service times. The steady state distribution of the waiting time is approximated by means of the solution of certain linear equations and applying a generalization of the L in -B airstow method for finding quadratic factors of polynomials.     

The reliability of self-reported home values in a developing country context

This paper provides an analysis, in the context of a developing country, of the reliability of homeowners’ estimates of the value of their houses, as obtained through a household survey. We show that non-response to the home value question by the owner is uncorrelated with the appraised value of the house and other demographic characteristics of the respondent. We also document that homeowners with long tenure largely overestimate the value of their home. Moreover, both the bias and the lack of precision in homeowners’ estimates are correlated with tenure, but not with socioeconomic characteristics. However, we also show that self-reported home values from short-tenure homeowners can be used to obtain unbiased and precise estimates of the average house value at the census tract level.     

专业散货码头装卸系统可靠性分析方法

随着大型专业化散货码头装卸工艺系统向着高性能、多功能、大型化方向发展,装卸工艺系统的可靠性问题日益突出。基于复杂系统可靠性分析理论,文中提出了码头装卸工艺系统的主要可靠性指标,利用可靠性框图建立了码头装卸工艺系统可靠性分析模型,并在此模型基础上提出了码头装卸工艺系统主要可靠性指标的计算方法。     

PLC在智能冲水系统中的运用

文章设计了一款自动冲水控制系统,使用FX1S-30MR型三菱可编程逻辑控制器对系统进行控制,保证了系统的稳定性。首先对系统水箱进行设计,添加了高水位检测开关和低水位检测开关,为后期水箱自动冲注水提供了硬件支持。然后对系统进行电路部分设计,画出了电气原理图,并设计了控制面板,实现了人机对话的功能。接着采用MELSOFT系列GX Developer软件对FX1S-30MR型三菱可编程逻辑控制器进行编程,设计出了自动冲水控制系统的梯形图。最后对系统进行仿真。     

Natural estimation of variances in a general finite discrete spectrum linear regression model

The method of “natural” estimation of variances in a general (orthogonal or nonorthogonal) finite discrete spectrum linear regression model of time series is suggested. Using geometrical language of the theory of projectors a form and properties of the estimators are investigated. Obtained results show that in describing the first and second moment properties of the new estimators the central role plays a matrix known in linear algebra as the Schur complement. Illustrative examples with particular regressors demonstrate direct applications of the results.