1. a Department of Engineering for Innovation, University of Salento, Via Arnesano, 73100 Lecce, Italy;, Email: giulio.reina@unisalento.it
2. b Mechanical Engineering Department, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
3. c Department of Aerospace Engineering, Tohoku University, Aoba 6-6-01, Sendai 980-8579, Japan
4. d Department of Aerospace Engineering, Tohoku University, Aoba 6-6-01, Sendai 980-8579, Japan