双参数指数分布可靠性、可靠寿命近似限的研究

Research on Approximate Limits of Reliablity and Reliable Life for Twoparameter Exponential Distribution

对双参数指数分布可靠性、可靠寿命的Ｇｒｕｂｂｓ近似［１］，Ｅｎｇｅｌｈａｒｄｔ＆Ｂａｉｎ［２］的简单近似和正态近似进行了研究，指出简单近似与Ｇｒｕｂｂｓ近似相结合可保证有很高的精度。因正态近似的误差甚大，故Ｌａｗｌｅｓｓ［６］，周源泉等［７］，Ｂａｉｎ＆Ｅｎｇｅｌｈａｒｄｔ［８］推荐使用正态近似是不正确的。

In this paper, Grubbs approximate limits and Engelhardt & Bain′s simple approximate limits and normal approximate limits for the reliability and the reliable life of the twoparameter exponential distribution are studied. The results indicate that the simple approximate limits in combination with Grubbs approximate limits have high accuracy. Since the error of the normal approximate limits is too large, hence it is incorrect that Lawless , Zhou & Weng , Bain & Engelhardt recommend to use the normal approximate limits. 