20Th European Simulation and Modelling Conference (Esm 2006) in: Modelling And Simulation 2006, OCT 23-25, 2006, Sponsors ETI, EUROSIS, Ghent Univ, Seconda Univ Studi Napoli, Haute Garonne, Conseil Gen, Reg Midi Pyrenees, SIMULA, Univ Malta, Univ Paul Sabatier, LAAS CNRS