指数型产品的Bayes可靠性鉴定试验

利用可靠性增长模型确定正样产品失效率的先验分布.综合考虑由弃真和存伪风险所造成的试验损失和其他试验费用,建立可靠性鉴定试验的损失评估模型.分别用两种风险准则约束两类决策风险.根据Bayes决策理论,得到失效数和总试验时间的关系,确定使得试验损失函数值最小的鉴定方案.最后通过算例体现方法的有效性,与经典方法和其他Bayes鉴定方法相比较有其优越性.     

指数分布下Bayes鉴定试验方案

在确保使用方利益的前提下，从最大后验风险的角度运用贝叶斯方法制定了可靠性鉴定试验方案。按照此鉴定试验方案，缩短了试验时间，从而降低了鉴定试验所需的费用。     

二项分布下的一种贝叶斯可靠性验收试验方案

为了合理利用先验信息制定可靠性验收试验方案，以降低验收试验的费用，在进行可靠性定型试验的前提下，提出了一种先验信息加工方法，并根据生产与使用双方实际所关心的风险意义，制定了产品可靠性验收试验的一种贝叶斯方案。算例结果证实，该方案在保证了生产方与使用方利益的前提下，减少了试验量，降低了验收试验费用。说明所提出的先验信息利用方式是有效的。     

单线态氧氧化不饱和脂肪酸——前列腺素仿生物合成的研究

本文报道了用单线态氧氧化花生四烯酸得到了具有生物活性的前列腺素.产物经柱层分离,通过薄板层析、高压液体色谱、紫外光谱、红外光谱及质谱进一步提纯鉴定,证明确实得到了前列腺素PGE₂,PGF_2α及PGA₂等.将产品PGE₂及未经柱层分离的混合产品进行药理试验——大白鼠与小白鼠离体子宫收缩试验,大白鼠胃底条试验及妊娠小白鼠的终止妊娠试验均获成功.证明这种方法合成的前列腺素具有良好的生物活性.     

关于失效率试验的一个最小样本容量的选择

假定寿命服从指数分布,当给定两类错误的概率上界时,对于有替换定时截尾试验,本文给出一个简化计算最小受试样本容量的方案。设某批产品的寿命t服从指数分布     

CSP—3—R方案的动态平均检出质量

本文引用８中方法和结果，通过对未检产品数等变量的讨论，首次导出了ＣＰＳ－３－Ｒ方案的动态平均检出质量。     

指数-威布尔分布下基于期望总成本最小的寿命试验抽样方案

对于寿命遵从指数-威布尔分布的产品,在生产商提供优质保修服务的前提下,采用生产商在产品抽验过程中与产品接收后所承担的总成本期望最小的准则,制定寿命试验的最优抽样方案.通过实例,证实指数-威布尔分布适宜作为当前产品的寿命分布,并验证了这种抽样方案的合理性.     

一类利用回归关系的计量指标抽样方案

在产品质量判定的抽样检验问题中,当目标指标需用破坏性试验才能得其值时,更为常用的是用非破坏性试验可得量值的协变指标量来预报它。但在产品抽样验收问题上,未能形成理论较为严密的方法,这是由于预报误差这个关键问题的处理尚未解决得好,即给不出抽样方案的功效计算的正确或是近似性较好的公式。本文通过建立合理的数学模型,把对目标指标的质量要求化为对协变指标量的统计要求,从而利用两者的回归关系,结合两种复杂的抽样方案,给出功效函数的计算公式和计算方法,并进行了分析。     

“失效率等级鉴定抽样方案”原理及其应用

<正> 我们知道,关于可靠性数量指标失效率的规定是电子设备及系统进行可靠性设计和 预测的依据,也是评价产品本身可靠性高低的主要指标.因此,为了使生产和使用单位在考核和鉴定产品的可靠性指标时有共同的标准,就需要有一个统一的考核方案.“失效率等级鉴定方法”的目的是使有可靠性要求的产品失效率鉴定有统一的方法和程序,以方便生产和使用,并促进产品可靠性的不断提高,使得生产单位对产品可靠性高低能够做到心中有数.同时,保证使用单位得到满足失效率规定的电子元器件.     

连续抽样方案CSP—2的动态平均检出质量

本文引入转移概率流向图和转移概率母函数等方法探讨了当产品流长度有限时G8P-2方案的动态平均检出质量。     

Reliability tests for Weibull distribution with variational shape parameter based on sudden death lifetime data

In the traditional design of reliability tests for assuring the mean time to failure (MTTF) in Weibull distribution with shape and scale parameters, it has been assumed that the shape parameter in the acceptable and rejectable populations is the same fixed number. For the purpose of expanding applicability of the reliability testing, Hisada and Arizono have developed a reliability sampling scheme for assuring MTTF in the Weibull distribution under the conditions that shape parameters in the both populations do not necessarily coincide, and are specified as interval values, respectively. Then, their reliability test is designed using the complete lifetime data. In general, the reliability testing based on the complete lifetime data requires the long testing time. As a consequence, the testing cost becomes sometimes expensive. In this paper, for the purpose of an economical plan of the reliability test, we consider the sudden death procedure for assuring MTTF in Weibull distribution with variational shape parameter.     

Optimum step-stress accelerated degradation test for Wiener degradation process under constraints

To assess a product's reliability for subsequent managerial decisions such as designing an extended warranty policy and developing a maintenance schedule, Accelerated Degradation Test (ADT) has been used to obtain reliability information in a timely manner. In particular, Step-Stress ADT (SSADT) is one of the most commonly used stress loadings for shortening test duration and reducing the required sample size. Although it was demonstrated in many previous studies that the optimum SSADT plan is actually a simple SSADT plan using only two stress levels, most of these results were obtained numerically on a case-by-case basis. In this paper, we formally prove that, under the Wiener degradation model with a drift parameter being a linear function of the (transformed) stress level, a multi-level SSADT plan will degenerate to a simple SSADT plan under many commonly used optimization criteria and some practical constraints. We also show that, under our model assumptions, any SSADT plan with more than two distinct stress levels cannot be optimal. These results are useful for searching for an optimum SSADT plan, since one needs to focus only on simple SSADTs. A numerical example is presented to compare the efficiency of the proposed optimum simple SSADT plans and a SSADT plan proposed by a previous study. In addition, a simulation study is conducted for investigating the efficiency of the proposed SSADT plans when the sample size is small.     

定时截尾下指数分布产品可靠性抽样检验方案

本文给出了制订定时截尾下指数分布产品可靠性抽样检验方案的统计方法.检验统计量是平均寿命倒数的极大似然估计.提出了一种选择截尾时间的方法.利用分布分位数的Cornish-Fisher展开近似地确定了样本量和接收常数.模拟结果表明,本文给出的方法是可行的.     

一种估计精度限制下的加速退化试验最优设计

讨论了一类步进应力的加速退化试验,在试验假定下,以退化失效分布平均寿命的极大似然估计与其真值的接近程度为标准得到一个精度限制．然后根据试验的过程得到了试验成本函数的一般表达形式．在估计精度的限制之下,最小化成本函数,以此得出试验的最优设计模型．最后,给出了一个数值例子,展示了优化设计的过程．     

A note on Liu–Iwamura’s dependent-chance programming

Sometimes a complex stochastic decision system undertakes multiple tasks called events, and the decision-maker wishes to maximize the chance functions which are defined as the probabilities of satisfying these events. Originally introduced by Liu and Iwamura [B. Liu, K. Iwamura, Modelling stochastic decision systems using dependent-chance programming, European Journal of Operational Research 101 (1997) 193–203], dependent-chance programming is aimed at maximizing some chance functions of events in an uncertain environment. In this work, we show that the original dependent chance-programming framework needs to be extended in order to capture an exact reliability measure for a given plan.     

淠史杭灌区管理信息系统的网络规划、设计与建设

随着信息技术的迅速发展,信息处理的方式正逐步由手工转向计算机,灌区管理工作对信息传输的可靠性和速度也提出了更高的要求,建设高效、可靠的以计算机网络为支持的灌区管理信息系统已成为发展的必要需求。本文介绍了淠史杭灌区管理信息系统计算机网络的总体规划、设计与建设情况     

Optimal plan for Wiener constant-stress accelerated degradation model

This paper explores inferential procedures for the Wiener constant-stress accelerated degradation model under degradation mechanism invariance. The exact confidence intervals are obtained for the parameters of the proposed accelerated degradation model. The generalized confidence intervals are also proposed for the reliability function and pth quantile of the lifetime at the normal operating stress level. In addition, the prediction intervals are developed for the degradation characteristic, lifetime and remaining useful life of the product at the normal operating stress level. The performance of the proposed generalized confidence intervals and the prediction intervals is assessed by the Monte Carlo simulation. Furthermore, a new optimum criterion is proposed based on minimizing the mean of the upper prediction limit for the degradation characteristic at the design stress level. The exact optimum plan is also derived for the Wiener accelerated degradation model according to the proposed optimal criterion. The proposed interval procedures and optimum plan are the free of the equal testing interval assumption. Finally, two examples are provided to illustrate the proposed interval procedures and exact optimum plan. Specifically, based on the degradation data of LEDs, some interval estimates of quantities related to reliability indicators are obtained. For the degradation data of carbon-film resistors, the optimal allocation of test units is derived in terms of the proposed optimal criterion.     

矿井复杂通风系统技术改造方案的优选

结合实例对矿井复杂通风系统技术改造方案进行了优选,用ＶｉｓｕａｌＢａｓｉｃ３．０ 编制了在Ｗｉｎｄｏｗ ｓ 下运行的计算机程序,该程序具有算法先进、收敛速度快、可靠性好、适用广和使用方便等优点。对矿井日常通风管理和通风长远规划也具有指导意义