NBUE分布类在并联结构下的封闭性

CLOSURE PROPERTY OF NBUE DISTRIBUTION CLASS UNDER PARALLEL STRUCTURE

证明了NBUE分布类对于由任何独立元件组成的并联系统封闭,同时用反例说明了DMRL分布类不具有此封闭性,从而在一般情形下解决了Klefsjo提出的公开问题。

The paper has proved that the closure property of NBUE distribution class is preserved under the formation of parallel systems with arbitrary independent NBUE components, the closure property does not hold for DMRL distribution class, so the open question proposed by Klefsjo has been solved in general cases.