1. Faculty of Electrical Engineering, University of West Bohemia, Univerzitní 22, 306 14 Pilsen, Czech Republic
2. The International Association of Engineers, Hong Kong, China
3. Faculty of Applied Science, University of West Bohemia, Technická 8, 301 00 Pilsen, Czech Republic
4. Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Žižkova 22, 616 62 Brno, Czech Republic