1. GREiA Research Group, University of Lleida, Pere de Cabrera s/n, 25001 Lleida, Spain
2. GRIHO Research Group, University of Lleida, Jaume II 69, 25001 Lleida, Spain
3. Department of Engineering, University of Palermo, Viale delle Scienze Edificio 9, 90145 Palermo, Italy