Aleatory or epistemic? Does it matter?
Aleatory or epistemic? Does it matter?
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DOI：
10.1016/j.strusafe.2008.06.020
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发表时间：
2009-01-01
影响因子：
5.8
通讯作者：
Didevsen, Ove
中科院分区：
文献类型：
--
作者：
Kiureghian, Armen Der;Didevsen, Ove
讨论了风险和可靠性分析的工程建模中的不确定性的来源和特征。虽然可能存在许多不确定性来源，但它们通常被归类为偶然性或认知性。如果建模者认为有可能通过收集更多数据或改进模型来减少不确定性，那么不确定性就被描述为认知性的。如果建模者没有预见到减少不确定性的可能性，则不确定性被归类为偶然。从务实的角度来看，对模型内的不确定性进行分类是有用的，因为这样就可以清楚哪些不确定性有可能被减少。更重要的是，认知不确定性可能会引入随机事件之间的依赖性，如果不确定性的特征没有正确建模，则可能无法正确注意到这种依赖性。讨论了两类不确定性对可靠性评估、规范化设计、基于性能的工程和基于风险的决策的影响。两个简单的例子证明了认知不确定性引起的统计依赖性对系统和时变可靠性问题的影响。 (c) 2008 Elsevier Ltd. 保留所有权利。
The Sources and characters Of uncertainties in engineering modeling for risk and reliability analyses are discussed. While many sources of uncertainty may exist, they are generally categorized as either aleatory or epistemic. Uncertainties are characterized as epistemic, if the modeler sees a possibility to reduce them by gathering more data or by refining models. Uncertainties are categorized as aleatory if the modeler does not foresee the possibility of reducing them. From a pragmatic standpoint, it is useful to thus categorize the uncertainties within a model, since it then becomes clear as to which uncertainties have the potential of being reduced. More importantly, epistemic uncertainties may introduce dependence among random events, which may not be properly noted if the character of uncertainties is not correctly modeled. Influences of the two types of uncertainties in reliability assessment, codified design, performance-based engineering and risk-based decision-making are discussed. Two simple examples demonstrate the influence of statistical dependence arising from epistemic uncertainties on systems and time-variant reliability problems. (c) 2008 Elsevier Ltd. All rights reserved.