Postprocessing the Hybrid Method for Addressing Uncertainty in Risk Assessments
Publication: Journal of Environmental Engineering
Volume 131, Issue 12
Abstract
In a previous paper in this Journal, a “hybrid method” was proposed for the joint propagation of probability distributions (expressing variability) and possibility distributions (i.e., fuzzy numbers, expressing imprecision or partial ignorance) in the computation of risk. In order to compare the results of the hybrid computation (a random fuzzy set) to a tolerance threshold (a tolerable level of risk), a postprocessing method was proposed. Recent work has highlighted a shortcoming of this postprocessing step which yields overly conservative results. A postprocessing method based on Shafer’s theory of evidence provides a rigorous answer to the problem of comparing a random fuzzy set with a threshold. The principles behind the new postprocessing scheme are presented and illustrated with a synthetic example.
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References
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© 2005 ASCE.
History
Received: Jan 5, 2004
Accepted: Mar 22, 2005
Published online: Dec 1, 2005
Published in print: Dec 2005
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