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A Study of SIL Allocation with a Multi-Phase Fuzzy Risk Graph Model
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 Title & Authors
A Study of SIL Allocation with a Multi-Phase Fuzzy Risk Graph Model
Yang, Heekap; Lee, Jongwoo;
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This paper introduces a multi-phase fuzzy risk graph model, representing a method for determining for SIL values for railway industry systems. The purpose of this paper is to compensate for the shortcomings of qualitative determination, which are associated with input value ambiguity and the subjectivity problem of expert judgement. The multi-phase fuzzy risk graph model has two phases. The first involves the determination of the conventional risk graph input values of the consequence, exposure, avoidance and demand rates using fuzzy theory. For the first step of fuzzification this paper proposes detailed input parameters. The fuzzy inference and the defuzzification results from the first step will be utilized as input parameters for the second step of the fuzzy model. The second step is to determine the safety integrity level and tolerable hazard rate corresponding to be identified hazard in the railway industry. To validate the results of the proposed the multi-phase fuzzy risk graph, it is compared with the results of a safety analysis of a level crossing system in the CENELEC SC 9XA WG A0 report. This model will be adapted for determining safety requirements at the early concept design stages in the railway business.
Risk graph;SIL(Safety Integrity Level);Fuzzification;Fuzzy Inference;Defuzzification;
 Cited by
H. Yang, J. Lee (2016) A study on the SIL allocation for signalling function with the fuzzy risk graph, Journal of the Korean Society for Railway, to be published.

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