| Over the last decade fuzzy sets and fuzzy logic introduced in 1965 by Lotfi Zadeh [113] have been used in a wide range of problem domains including process control, image processing, pattern recognition and classification, management, economics and decision making. Specific applications include washing-machine automation, camcorder focusing, TV colour tuning, automobile transmissions and subway operations [29]. We have also been witnessing a rapid development in the area of neural networks (see e.g. [93, 94, 135]). Both fuzzy systems and neural networks, along with probabilistic methods [1, 20, 67], evolutionary algorithms [23, 59], rough sets [69, 70] and uncertain variables [6, 7, 8], constitute a consortium of soft computing techniques [1, 39, 42]. These techniques are often used in combination. For example, fuzzy inference systems are frequently converted into connectionist structures called neuro-fuzzy systems which exhibit advantages of neural networks and fuzzy systems. In literature various neuro fuzzy systems have been developed (see e.g. [11, 12, 13, 15, 18, 24, 25, 26, 34, 35, 37, 40, 49, 50, 52, 53, 54, 55, 60, 61, 65, 72, 75, 76, 80-85, 100]). They combine the natural language description of fuzzy systems and the learning properties of neural networks. Some of them are known in literature under short names such as ANFIS [33], ANNBFIS [15], DENFIS [41], FALCON [51], GARIC [3], NEFCLASS [62], NEFPROX [62, 64], SANFIS [99] and others. |