Browsing by Author "Gedeon, Tamas D."
Now showing 1 - 3 of 3
Results Per Page
Sort Options
- Bacterial memetic algorithm for fuzzy rule base optimizationPublication . Cabrita, Cristiano Lourenço; Botzheim, J.; Gedeon, Tamas D.; Ruano, Antonio; Kóczy, László T.; Fonseca, C. M.In our previous works model identification methods were discussed. The bacterial evolutionary algorithm for extracting a fuzzy rule base from a training set was presented. The Levenberg-Marquardt method was also proposed for determining membership functions in fuzzy systems. The combination of evolutionary and gradient-based learning techniques – the bacterial memetic algorithm – was also introduced. In this paper an improvement of the bacterial memetic algorithm is shown for fuzzy rule extraction. The new method can optimize not only the rules, but can also find the optimal size of the rule base.
- Fuzzy rule extraction from input/output dataPublication . Kóczy, László T.; Botzheim, J.; Ruano, Antonio; Chong, A.; Gedeon, Tamas D.Several alternative approaches have been discussed: Levenberg-Marquardt - no satisfactory convergence speed + local minimum, Bacterial algorithm - problems with large dimensionality (speed), Clustering - no safe criterion for number of clusters + dimentionality problem.
- Fuzzy rule extraction from input/output dataPublication . Kóczy, László T.; Botzheim, J.; Ruano, Antonio; Gedeon, Tamas D.This paper discusses the question how the membership functions in a fuzzy rule based system can be extracted without human interference. There are several training algorithms, which have been developed initially for neural networks and can be adapted to fuzzy systems. Other algorithms for the extraction of fuzzy rules are inspired by biological evolution. In this paper one of the most successful neural networks training algorithm, the Levenberg-Marquardt algorithm, is discussed, and a very novel evolutionary method, the so-called “bacterial algorithm”, are introduced. The class of membership functions investigated is restricted to the trapezoidal one as it is general enough for practical applications and is anyway the most widely used one. The method can be easily extended to arbitrary piecewise linear functions as well. Apart from the neural networks and evolutional algorithms, fuzzy clustering has also been used for rule extraction. One of the clustering-based rule extraction algorithms that works on the projection of data is also reported in the paper.