利用条件中位数求指数寿命型元件可靠性近似置信下限

THE APPROXIMATE COMPUTATION OF CONFIDENCE LOWER LIMIT OF RELIABILITY FOR EXPONENTIAL TYPE COMPONENTS

设有参数为λ的指数寿命型元件,λ未知。对于给定的时刻0<t_1<t_2<…<t_k,对此元件的N个随机样本进行寿命试验,得试验数组:(r_1,r_2,…r_k),其中r(?)表示这N个产品中寿命在时间区间[t_(1-19)t_1]内的个数。本文利用条件中位数求λ的点估计,并讨论对于给定的时刻t(t>t_k),在寿命大于t_k的r_(k+1)个样本中在时间区间[t_k,t]内失效个数的预测值。本文还讨论了元件在时刻t_o的可靠性R=e^(-λto)的置信下限的问题。

Suppose that the parameter A of exponential type component A is unknown. Given times t1, t2,..., tk, which satisfy 0<t1<t2...<tk. We make life span test for N random samples and obtain testing number (r1, r2,...,rk), where rf is number of products whose life span is in [ti-1ti). By using conditional median we obtain the point estimate of parameter λand investigate the confidence lower limit of reliability R=e-λt0 of component A when time t=t0.