Department of Computer Science, University of Verona, Strada Le Grazie 15 - 37134, Verona.|Department of Computer Science, University of Verona, Strada Le Grazie 15 - 37134, Verona.|Department of Math and Computer Science, University of Catania, Viale a. Doria 6 - 95125, Catania.|Department of Computer Science, University of Verona, Strada Le Grazie 15 - 37134, Verona.|Department of Clinical and Experimental Medicine, University of Catania, via Palermo, 636 - 95122, Catania.|Department of Computer Science, University of Verona, Strada Le Grazie 15 - 37134, Verona Department of Clinical and Experimental Medicine, University of Catania, via Palermo, 636 - 95122, Catania.