1. Savaria Institute of Technology, Faculty of Informatics, Eötvös Loránd University (ELTE), Károlyi Gáspár tér 4, 9700 Szombathely, Hungary
2. Doctoral School of Physics, Faculty of Natural Sciences, Eötvös Loránd University (ELTE), P.O. Box 32, 1518 Budapest, Hungary