逐步Ⅰ型混合截尾下复合Rayleigh分布竞争失效产品部分步加寿命试验的统计分析

本文在逐步Ⅰ型混合截尾下,研究复合Rayleigh分布竞争失效产品部分步加寿命试验的统计分析问题。首先,基于复合Rayleigh分布竞争失效产品和损伤失效率(TFR)模型,运用极大似然理论和渐近似然理论,给出未知参数和加速因子的极大似然估计和渐近置信区间;然后,对未知参数和加速因子选取先验,利用MH抽样算法获得参数和加速因子的Bayes估计和最大后验密度置信区间(HPD);最后,通过Monte Carlo模拟对2种估计方法进行比较。结果表明:贝叶斯估计效果整体优于极大似然估计(MLE),在相同置信水平下,基于Bayes估计的HPD置信区间长度略短于MLE的渐近置信区间长度。

定数截尾步加寿命试验缺失数据下Weibull分布的正常应力水平下特征寿命的近似Bayes估计

当寿命分布为weibull分布时,本文研究定数截尾步加寿命试验缺失数据场合下,当形状参数m已知时,对在正常应力水平S0下的特征寿命η0的一种新的近似Bayes估计.虽然结果形式比较复杂,但可利用数值计算的方法得其近似结果.利用模拟方法研究所给估计的精度,结果显示所给估计的精度是令人满意的.

指数分布下具有随机应力转换时间的截尾步加寿命试验

研究了应力转换时间是随机变量情况下的简单截尾步加寿命试验,并且利用应力转换时间是低应力下次序统计量的信息,给出了简单截尾步加寿命试验的试验模型.在此基础上,以设定应力下对数平均寿命的极大似然估计的渐近方差最小为优化标准,得到了试验的最优设计,最后文中给出的实例证明了该优化设计方案是有效的和可行的.

Weibull分布步加应力寿命试验混合数据的统计分析

对 Weibull分布场合 ,排除形状参数与加速应力无关的限制 ,对步加应力寿命试验的混合数据 ,建立一种可靠性统计分析方法 .给出正常应力水平下寿命分布的参数 。

CE模型下指数分布步加试验的贝叶斯估计

本文利用Gibbs抽样法得到了CE模型下指数分布场合步进应力加速寿命试验的多层Bayes参数估计,最后通过模拟比较表明多层Bayes估计比最大似然估计更加有效而实用。

指数分布基于多重定数截尾样本的近似Bayes估计

该文讨论了指数分布场合具有多重定数截尾样本的一种新的近似Bayes估计,导出了基于寿命试验数据的近似Bayes估计和在步加寿命试验情形基于多重定数截尾样本的近似无偏估计和近似Bayes估计.利用模拟方法研究了所给估计的精度,模拟结果显示所给估计的精度是令人满意的.

Parameter Estimations of the TFR Model Under Exponential Distribution at a Normal Stress

The TFR（Tampered Failure Rate） model was proposed by Bhattacharyya and Soejoeti（1989） for step-stress accelerated life tests, On step-stress completely accelerated test occasions, the paper gives a method of estimating parameters under a normal stress.

Deduction of Design Equations for Durability Performance Improvement of Voice Coil Type Linear Actuator for Servo Valve Operation

The precise hydraulic valve is widely used in various industrial fields like aircraft, automobile and general machinery. Linear actuator is the most important device for driving the precise hydraulic valve. The reliable operation of linear actuator has effects on the overall hydraulic system. The performance of linear actuator relies on frequency response and step response according to arbitrary input signal. In this paper, the analysis for the components of linear actuator is performed to satisfy the reliable operation and response characteristics through the reliability analysis, and also deducted the design equations to realize the reliable operation and fast response characteristics of voice coil type linear actuator for servo valve operation through the empirical knowledge of experts and electromagnetic theories. The design equations are suggested to determine the values of design parameters of linear actuator as like bobbin size, length of yoke and plunger and turn number of coil, and calculated the life test time of linear actuator for verification of reliability of the prototype. In addition, for reducing the life test time, the acceleration model of linear actuator is proposed and the acceleration factor is calculated considering the field operating conditions. And then, the achieved design values are verified through accelerated life test and performance tests using some prototypes of linear actuators adapted in servo valve.