Title
Zadeh’s Extension Principle for Continuous Functions of Non-Interactive Variables: A Parallel Optimization Approach
Abstract
There is a growing interest in the use of fuzzy intervals in many engineering applications. However, a direct implementation of Zadeh’s extension principle, which forms the basis for computing with fuzzy intervals, is still computationally too demanding for practical use. In the case of a continuous function and fuzzy intervals that describe non-interactive variables as inputs, the output is a fuzzy interval as well and can be determined for each $\alpha$-cut separately. The problem, thus, reduces to finding the endpoints of these $\alpha$-cuts, which amounts to a number of interwoven optimization problems. In the case of a non-monotone continuous function, however, these optimization problems are non-trivial. In this paper, different optimization algorithms are applied for that purpose: Gradient Descent based on Sequential Quadratic Programming, Simplex–Simulated Annealing, Particle Swarm Optimization, and Particle Swarm Optimization combined with Gradient Descent. In addition, two approaches are followed to determine a suitable number of $\alpha$-cuts: either a fixed, predetermined number is used, or an initially (very) small number is chosen that is subsequently increased according to a linearity criterion. Both a non-parallel and a parallel implementation are designed. The parallel version is restricted to work with Particle Swarm Optimization and employs communication to optimize its (internal) performance by exploiting the dependence between the various optimization problems. Different configurations are evaluated on a set of benchmark functions in terms of the mean area under the output fuzzy interval and the number of function evaluations. Particle Swarm Optimization combined with Gradient Descent starting from a small number of $\alpha$-cuts leads to the most accurate fuzzy intervals at the cost of a relatively large number of function evaluations.
Year
DOI
Venue
2012
10.1109/TFUZZ.2011.2168406
Fuzzy Systems, IEEE Transactions
Keywords
Field
DocType
particle swarm optimization,fuzzy interval,non-interactive variables,gradient descent,accurate fuzzy interval,output fuzzy interval,suitable number,continuous functions,small number,parallel optimization approach,extension principle,function evaluation,large number,benchmark function,heuristic algorithm,sequential quadratic programming,parallel computing,simulated annealing,interpolation,parallel computer,quadratic programming,fuzzy set theory,optimization problem
Particle swarm optimization,Continuous optimization,Mathematical optimization,Test functions for optimization,Multi-swarm optimization,Artificial intelligence,Random optimization,Fuzzy number,Optimization problem,Machine learning,Mathematics,Metaheuristic
Journal
Volume
Issue
ISSN
20
1
1063-6706
Citations 
PageRank 
References 
8
0.53
15
Authors
3
Name
Order
Citations
PageRank
Karolien Scheerlinck1131.66
Hilde Vernieuwe2767.20
Bernard De Baets32994300.39