产品寿命分布的统计推断

对产品的寿命分布做出可信赖的统计推断是可靠性工程界亟待解决的问题之一。本文在结合实际工程问题的基础上，应用数理统计和优化算法理论，对产品寿命分布的统计推断问题进行了，从而提高了一种行之有效的方法。     

无失效数据可靠性分析的贝叶斯方法

Bayes方法是对无失效数据问题进行可靠性分析的有效途径之一。针对某一产品,在确定了其寿命分布类型之后,建立了无失效数据模型,并利用Bayes方法对产品进行了可靠性分析。     

LED组件寿命评估方法的研究

由于LED技术的飞速发展,其应用产品不断扩大到人们生活的各个方面,因此LED产品的可靠性问题也日益受到人们的关注。在可靠性工程常用的寿命分布中,指数分布是应用广泛的一种分布,进入偶然失效期以后都可以认为产品失效分布是指数分布。LED产品的寿命试验有定时截尾和定数截尾2种方式,由于定数结尾需要较长的试验时间,因此采用定时截尾的试验方法来获取试验数据。给出了LED组件的寿命评估方法,该方法对LED模块和应用产品同样适用。     

浅析移动通信系统配套设备的可靠性

本文着重论述了移动通信系统配套设备的可靠性问题，结合寿命指标MTBT论述了移动通信系统配套设备的可靠性分布规律，切实地提出在设计、工程、验收、维护各阶段提高设备可靠性的思想和方法。     

显控台可靠性分析及评定方法研究

本文较系统地研究了显控台的可靠性分析和评定问题，从确定显控台寿命分布类型、建立数据分析模型到寻求失效概率估计值方法和拟合分布曲线方法等都进行了一系列富有成效的探讨，获得了较为满意的结果。     

一种电子设备贝叶斯可靠性评估的新方法

针对贝叶斯方法应用中后验参数的运算复杂性问题,提出了一种电子设备贝叶斯可靠性评估的新方法.基于工程实践中常见的先验信息建立失效率先验分布,通过随机采样构建设备寿命分布参数的离散联合先验分布,结合截尾试验数据,再通过二次随机采样得到分布参数的离散联合后验分布函数.通过实例给出了运算过程,并与其它贝叶斯运算方法进行了比较.结果表明,此方法在确保精度的同时可以大大简化计算过程,在电子设备可靠性评估中有较高的应用价值.     

敏感元件及传感器失效率（寿命）分布类型与分布参数的研究

以Ｈａｌｌ磁敏传感器为研究对象，研究了探讨了通常确定传感器失效分布类型和分布参数的方法，并确定出Ｈａｌｌ磁敏元件的失效率（寿命）分布类型与分布参数数值。其方法和结论可作为今后开发可靠性工作特别是数据处理和确定产品失效分布类型和分布参数时参考。     

丁烷气敏传感器寿命分布研究

通过ＱＭ－Ｙ３型丁烷敏旁热式气敏传感器的工作寿命试验和试验数据处理,获得了该元件的寿命分布及分布参数等信息,了解了该类型元件的可靠性水平,为评价和提高该气敏传感器的可靠性水平提供了依据。     

可靠性寿命试验的动态截尾方法

为节省试验时间和资源，可靠性寿命试验通常采用定数截尾和定时截尾两种方法。但是它们有相同的不足，就是在试验结束后才进行数据分析，无法进行实时的动态控制。为解决这一问题．提出了寿命试验的动态截尾方法，利用该方法研究寿命服从指数型分布产品的可靠性试验．提出了试验动态截尾的数据处理模型及判据。该方法的思想可以推广应用于其它产品的可靠性试验与分析中。     

现场寿命数据分布类型识别方法的研究

在导弹某器件的储存、使用可靠性分析中,确定现场寿命数据分布类型是至关重要的。文章利用数理统计理论、灰色系统理论、模糊逻辑理论分别研究识别最佳寿命分布类型的方法,用实例说明了分析方法和分析过程。结果表明对数正态分布符合该器件的现场数据,同时说明了当前情况下运用单一方法确定最佳分布类型的不足,提出根据实际情况综合运用各种方法的必要性。     

Reliability growth plot - An underutilized tool in reliability analysis

System reliability and performance are improved by continuous improvement effort. The study of the increase in reliability as a function of time is the subject of reliability growth. Although the most well-known reliability growth model, the Duane model, is proposed more than thirty years ago, reliability growth analysis has attracted an increasing interest only recently because of the lack of time for testing and the high reliability of improved products leading to very few failures. In this paper we study a practical approach in reliability growth analysis. Based on the graphical plotting of failure data for some selected models, reliability can easily be estimated and predicted. This approach which is the original idea of the Duane model, overcomes the problem of parameter estimation and model validation that is usually complicated. It is especially useful when the model validation has to be done in order to select a suitable model. The approach, called the First-Model-Validation-Then-Parameter-Estimation approach, is simple and practical for the analysis of reliability growth data. We further develop some models and discuss their applicability in reliability engineering.     

An engineering approach to Bayes estimation for the Weibull distribution

In this paper an engineering approach to Bayes reliability analysis of Weibull failure data collected under a randomly censored sampling is proposed. The posterior distribution of several decision variables, such as the meanlife, the reliability function, the reliable life, and the hazard rate, are derived, when either a prior information on the reliability or a prior information on the hazard rate is available. Point estimates of the selected decision variables are given, by assuming both symmetric and asymmetric loss functions. Finally, numerical examples are presented to illustrate the proposed estimation procedures.     

A discretizing approach for evaluating reliability of complexsystems under stress-strength model

This paper introduces a new discretizing approach for evaluating reliability of any complex system where analytic methods fail to offer a closed-form solution. Numerical analyses on 4 important engineering items have been used to examine the closeness between the proposed reliability estimators and the simulated values. A comparative study between the discretizing approach of English et al. (1996) and ours indicates that our approach is in no way less efficient. It can also retain TFR, DFR, IFRA properties of the original distribution     

基于ML-II方法的k/n-系统Bayes可靠性评估

n中取k系统(简称k/n-系统)是工程实践中应用最广泛的系统类型之一。为了在系统现场试验样本量很小的情况下进行可靠性评估,首先利用次序统计量推导了k/n-系统寿命分布的密度函数,并给出了模型参数的第二类极大似然估计(ML-Ⅱ估计);然后给出了k/n-系统Bayes可靠性评估的一般步骤;仿真实例表明了方法的可行性。     

On/off cycling under multiple stresses

The authors describe an experiment, a model, and an analytic method for on/off vs. continuous policy evaluation. The methodology was developed and verified through experimentation. An experimental life-test of small DC motors was designed and performed; it involved on/off cycling vs. continuous operation under multiple stresses. A stress-factor reliability model based on the two-parameter Weibull proportional-hazards life distribution was fitted to the data. The analysis provides an estimate of the model parameters for the life distribution of the DC motors under two operating policies, while under multiple stresses. The characteristic life was related to the explanatory covariates: voltage, on/off cycling, and load. Due to the proportional hazards (common Weibull shape) nature of the model, acceleration factors were calculated to relate the stress levels. The reliability model was extended to develop a simple rule to aid in a decision between on/off cycling and continuous-run policies (to achieve higher reliability). The proposed model (with covariates) allows a much broader approach to reliability modeling than the usual Weibull model (without covariates) because it predicts the reliability under various environmental combinations     

P波段硅脉冲功率管工程实用化研究

详尽介绍了３ＤＡ５０２ 型硅脉冲功率晶体管工程实用化的研究过程。围绕可靠性综合设计开展六项专题研究, 并辅以用红外热象法监测结温和射频加速寿命试验法, 保证器件的长期使用可靠性, 为雷达全固化创造了基础条件     

A Moment Approach to Evaluation and Optimization of Complex System Reliability

A moment approach to evaluating reliability of complex systems is described. The advantages of this type of model have been discussed in relation to models based simply on probability of failure. The main difficulty of a moment approach is the evaluation of first and second moments of the system failure-time distribution. A proposed theorem considerably alleviates this difficulty. In order to facilitate applying this theorem, approximate expressions for the mean and variance of parallel systems are suggested. The problem of system optimization is then discussed and the technique is illustrated with a bridge network. If the system s-expected life remains unchanged when redundancy is added, the variance of system life always decreases.     

Bayes estimation of component-reliability from masked system-lifedata

This paper estimates component reliability from masked series-system life data, viz, data where the exact component causing system failure might be unknown. It focuses on a Bayes approach which considers prior information on the component reliabilities. In most practical settings, prior engineering knowledge on component reliabilities is extensive. Engineers routinely use prior knowledge and judgment in a variety of ways. The Bayes methodology proposed here provides a formal, realistic means of incorporating such subjective knowledge into the estimation process. In the event that little prior knowledge is available, conservative or even noninformative priors, can be selected. The model is illustrated for a 2-component series system of exponential components. In particular it uses discrete-step priors because of their ease of development and interpretation. By taking advantage of the prior information, the Bayes point-estimates consistently perform well, i.e., are close to the MLE. While the approach is computationally intensive, the calculations can be easily computerized     

Reliability Sampling Plans Under Progressive Type-I Interval Censoring Using Cost Functions

This paper gives a reliability sampling plan for progressively type I interval censored life tests when the lifetime follows the exponential distribution. We use the maximum likelihood method to obtain the point estimation of the parameter of failure time distribution. We provide an approach to establish reliability sampling plans which minimize the total cost of life testing under given consumer's and producer's risks. Some numerical studies are investigated to illustrate the proposed approach.      

Bayes credibility intervals for the left-truncated exponential distribution

In this paper, a Bayes approach for statistical inference on life characteristics is proposed, when the underlying lifetime distribution has the left-truncated exponential density function. The proposed Bayes procedure provides credibility intervals on several life characteristics of great interest to the applied reliability engineer, when the experimental data are collected under a randomly censored sampling. The prior technical knowledge is expressed in the form of a prior density on the reliability level at a prefixed time in conjunction with an upper bound on the location parameter. The statistical properties of the proposed Bayes procedure are compared, via Monte Carlo simulation, with those of the Bayes procedure under the noninformative prior, when both correct and uncorrect prior information on the reliability is available. A numerical example is used for illustration and comparison.