Research on the influence degree of rare event

A new technique for evaluating influence degree of rare event based on catastrophe theory and rough set reduction theory was proposed. The index set of evaluating influence degree about rare event was established and reduced to a minimum set based on rough set theory. The evaluation method of influence degree about rare event was presented based on the normalization formula of catastrophe theory. The method can incorporate qualitative indexes and quantitative indexes in a model, and avoid the subjective quantification of assessment indexes. The calculated results by an example show feasibility and effectiveness of the method.