1. Department of Information Engineering, Polytechnique University of Marche, 60121 Ancona, Italy
2. Department of Engineering and Geology, University “G. d’Annunzio” of Chieti-Pescara, 65127 Pescara, Italy
3. Next2U s.r.l., 65127 Pescara, Italy
4. Lega F. D’Oro Research Center, 60027 Osimo, Italy