The study aims at modelling and assessment of survival probability of a component experiencing two kinds of shocks namely, damage shock and fatal shock. Shocks are occurring randomly in time as events of a Poisson Pro...The study aims at modelling and assessment of survival probability of a component experiencing two kinds of shocks namely, damage shock and fatal shock. Shocks are occurring randomly in time as events of a Poisson Process. The two cases of fixed/random threshold of components are studied. Survival probabilities of proposed models are derived. Maximum likelihood estimators (MLEs) of survival probabilities are obtained using the data from life testing experiments. Fisher information and asymptotic distribution of MLEs of parameters are obtained when a constant threshold is considered. Computation and comparison of estimators of two cases (constant threshold and random threshold) are made through simulation studies. The study recommends the consideration of threshold as a random variable.展开更多
针对离子推力器服役过程中的非预期电击穿对可靠性的影响问题,首先进行了非预期电击穿的失效影响及综合风险评估,然后结合非预期电击穿导致的突发失效特征建立了基于δ冲击模型的离子推力器可靠性评估模型,最后以20 cm Xe离子推力器为例...针对离子推力器服役过程中的非预期电击穿对可靠性的影响问题,首先进行了非预期电击穿的失效影响及综合风险评估,然后结合非预期电击穿导致的突发失效特征建立了基于δ冲击模型的离子推力器可靠性评估模型,最后以20 cm Xe离子推力器为例,在收集地面试验历史数据的基础上计算了考虑非预期电击穿的离子推力器可靠度随服役时间的关系。另外,综合考虑了由于栅极系统性能退化导致的退化型失效和由于非预期电击穿导致的突发型失效共存的情形,对离子推力器的整机可靠性评估进行了分析讨论。展开更多
This paper investigates the comparison problem of the reliability index between a parallel and a cold-standby system,both of which are consisting of two identical units.On the contrary to the general intuitive result,...This paper investigates the comparison problem of the reliability index between a parallel and a cold-standby system,both of which are consisting of two identical units.On the contrary to the general intuitive result,we proved that,under the condition that the system is shocked by a Poisson stream,the life time of the parallel system is longer than that of the cold-standby one in the sense of probability.展开更多
文摘The study aims at modelling and assessment of survival probability of a component experiencing two kinds of shocks namely, damage shock and fatal shock. Shocks are occurring randomly in time as events of a Poisson Process. The two cases of fixed/random threshold of components are studied. Survival probabilities of proposed models are derived. Maximum likelihood estimators (MLEs) of survival probabilities are obtained using the data from life testing experiments. Fisher information and asymptotic distribution of MLEs of parameters are obtained when a constant threshold is considered. Computation and comparison of estimators of two cases (constant threshold and random threshold) are made through simulation studies. The study recommends the consideration of threshold as a random variable.
文摘针对离子推力器服役过程中的非预期电击穿对可靠性的影响问题,首先进行了非预期电击穿的失效影响及综合风险评估,然后结合非预期电击穿导致的突发失效特征建立了基于δ冲击模型的离子推力器可靠性评估模型,最后以20 cm Xe离子推力器为例,在收集地面试验历史数据的基础上计算了考虑非预期电击穿的离子推力器可靠度随服役时间的关系。另外,综合考虑了由于栅极系统性能退化导致的退化型失效和由于非预期电击穿导致的突发型失效共存的情形,对离子推力器的整机可靠性评估进行了分析讨论。
文摘This paper investigates the comparison problem of the reliability index between a parallel and a cold-standby system,both of which are consisting of two identical units.On the contrary to the general intuitive result,we proved that,under the condition that the system is shocked by a Poisson stream,the life time of the parallel system is longer than that of the cold-standby one in the sense of probability.
