1. Professorship of Measurement and Sensor Technology, Department of Electrical Engineering and Information Technology, Chemnitz University of Technology, 09126 Chemnitz, Germany
2. Laboratory of Electromechanical Systems, National Engineering School, University of Sfax, Sfax 3038, Tunisia
3. Dipartimento di Ingegneria Elettrica, Elettronica e Informatica, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy