[1] Shahid Beheshti Univ, Fac Elect Engn, Tehran 69411, Iran
[2] Nottingham Trent Univ, Sch Sci & Technol, Dept Engn, Nottingham NG11 8NS, England
[3] Sharif Univ Technol, Dept Elect Engn, Tehran, Iran
[4] Univ Vaasa, Sch Technol & Innovat, Vaasa 65200, Finland
[5] Univ Porto, Fac Engn, P-4200465 Porto, Portugal
[6] INESC TEC, P-4200465 Porto, Portugal