“…Increasing the quality of the models has been one of the favourite research directions during the last years. This involves the exponential growth of non-conventional modelling based on knowledge-based systems (KBS) tools including fuzzy logic [5,26,29,46,50,55], neural networks [1,33,51,52], genetic algorithms [14,24,38,48], data mining techniques [8,9,36,56] etc., and their merge resulting in hybrid models [2,6,7,25,30,39].…”