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Interval type-2 defuzzification using uncertainty weights

Runkler, Thomas A.; Coupland, Simon; John, Robert; Chen, Chao


Thomas A. Runkler

Simon Coupland

Robert John


One of the most popular interval type-2 defuzzification methods is the Karnik-Mendel (KM) algorithm. Nie and Tan (NT) have proposed an approximation of the KM method that converts the interval type-2 membership functions to a single type-1 membership function by averaging the upper and lower memberships, and then applies a type-1 centroid defuzzification. In this paper we propose a modification of the NT algorithm which takes into account the uncertainty of the (interval type-2) memberships. We call this method the uncertainty weight (UW) method. Extensive numerical experiments motivated by typical fuzzy controller scenarios compare the KM, NT, and UW methods. The experiments show that (i) in many cases NT can be considered a good approximation of KM with much lower computational complexity, but not for highly unbalanced uncertainties, and (ii) UW yields more reasonable results than KM and NT if more certain decision alternatives should obtain a larger weight than more uncertain alternatives.

Journal Article Type Article
Journal Studies in Computational Intelligence
Print ISSN 1860-949X
Electronic ISSN 1860-949X
Publisher Springer Verlag
Peer Reviewed Peer Reviewed
Volume 739
APA6 Citation Runkler, T. A., Coupland, S., John, R., & Chen, C. (in press). Interval type-2 defuzzification using uncertainty weights. Studies in Computational Intelligence, 739,
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Copyright Statement Copyright information regarding this work can be found at the following address: http://eprints.nottingh.../end_user_agreement.pdf
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Published as: Runkler T.A., Coupland S., John R., Chen C. (2018) Interval Type–2 Defuzzification Using Uncertainty Weights. In: Mostaghim S., Nürnberger A., Borgelt C. (eds) Frontiers in Computational Intelligence. Studies in Computational Intelligence, vol 739. Springer, Cham


type2defuz_v4.pdf (693 Kb)

Copyright Statement
Copyright information regarding this work can be found at the following address:

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