中文摘要：

利用区间模型描述根节点的失效可能性,解决根节点的失效可能性不易精确获取的问题;通过引入超椭球模型来界定不确定性参量的取值范围,解决区间贝叶斯网络在求取可靠性指标时计算结果相对保守的问题;定义超椭球贝叶斯网络的灵敏度指标,为找到系统的关键环节提供依据;结合贝叶斯网络双向推理求解出在根节点失效可能性已知的条件下,叶节点的失效可能性、根节点状态的后验可能性;给出了可靠性评估实例。

英文摘要：

Failure probabilities of root nodes were described by interval model to solve the difficulty to obtain the failure probabilities accurately.Hyper-ellipsoid model was utilized to define the ranges of the uncertain parameters to improve the relatively conservative reliability indices calculated by the interval Bayesian networks method.Sensitivity indices of hyper-ellipsoid Bayesian networks were proposed to provide basis for finding the key link of the system.The leaf node＇s failure probability and the root nodes＇ state posterior possibilities were solved by combining with Bayesian networks bidirectional inference under the condition of the root nodes＇ failure probabilities as known.Reliability assessment example was given at last.