1. CERI Numeric Systems, IMT Lille Douai, 59508 Douai, France
2. Dip. Ingegneria Dell’Impresa, University of Rome “Tor Vergata”, 00133 Rome, Italy
3. Department of Computer Science and Engineering (DISI) Alma Mater Studiorum—Università di Bologna, 47522 Cesena, Italy
4. Centre for Intelligent Information Technologies (CETINIA), University Rey Juan Carlos, 28933 Madrid, Spain