Acknowledgments

Abstract

I would like to thank Professor Rita Almeida Ribeiro for inviting me to work at CA3/Uninova in the context of the MODI project and for accepting to co-supervise this thesis. The work developed during this project was the basis of this thesis. Thank you for introducing me to the fuzzy world. I want to express my gratitude to Professor Paula Amaral, for her excellent guidance and important contribution to overcome some of the difficulties encountered through this thesis. To all my family and friends, especially my friends at CA3, thank you for the emotional support that gave me strength to finish the thesis. The purpose of this thesis was to develop algorithms to reduce the number of membership functions in a fuzzy linguistic variable. Groups of similar membership functions to be merged were found using clustering algorithms. By “summarizing ” the information given by a similar group of membership functions into a new membership function we obtain a smaller set of membership functions representing the sam