Author(s):
1. Ivana Radonjić Mitić, University of Niš, Faculty of Sciences and Mathematics, Department of Physics, Višegradska 33, Niš, Serbia
2. Milutin Petronijević, University of Niš, Faculty of Electronic Engineering, A. Medvedeva 14, 18000 Niš, Serbia, Serbia
3. Leonid Stoimenov, University of Niš, Faculty of Electronic Engineering, A. Medvedeva 14, 18000 Niš, Serbia, Serbia
4. Dragoljub Mirjanić, Akademija nauka i umjetnosti Republike Srpske, Republic of Srpska, Bosnia and Herzegovina
5. Lana Pantic, University of Niš, Faculty of Sciences and Mathematics, Department of Physics, Višegradska 33, 1800, Serbia
6. Darko Divnić, Akademija nauka i umjetnosti Republike Srpske, Republic of Srpska, Bosnia and Herzegovina

Abstract