JAWADI Fredj University of Paris X - Nanterre -MODEM   200 avenue de la république Batiment G, Bureau 610 A Nanterre Cedex, 92001 France   fredj.jawadi@u-paris10.fr     Biographical Sketch: Mr Fredj JAWADI is a PhD Student at the universty of Paris10-Nanterre (France). He prepares for a doctorate in financial modelling. He is interested on nonlinear modelling and on application of nonlinear models on stock markets.   Primary Research Focus: studies of stock markets dynamics   JEL Areas: C5 : Econometric Modeling: General G1 : General Financial Markets: General (includes Measurement and Data)