[1] Univ Messina, Dept Math & Comp Sci, Phys Sci & Earth Sci, I-98166 Messina, Italy
[2] FORTH, Inst Appl & Computat Math, GR-70013 Iraklion, Greece
[3] King Abdullah Univ Sci & Technol, Phys Sci & Engn Div, Thuwal 239556900, Saudi Arabia
[4] Univ Messina, Dept Engn, I-98166 Messina, Italy
[5] Polytech Bari, Dept Elect & Informat Engn, I-70125 Bari, Italy
[6] Chinese Acad Sci, Suzhou Inst Nanotech & Nanobion, Key Lab Multifunct Nanomat & Smart Syst, Ruoshui Rd 398, Suzhou 215123, Peoples R China