[1] Slovak Univ Technol Bratislava, Inst Mat Sci, Jana Bottu 25, Trnava 91724, Slovakia
[2] Sumy State Univ, Dept Complex Syst Modeling, UA-40007 Sumy, Ukraine
[3] Natl Acad Sci Ukraine, Inst Appl Phys, UA-40000 Sumy, Ukraine
[4] Natl Univ Zaporizhzhia Polytech, Comp Sci & Technol Fac, 64, Zhukovskogo Str, UA-69063 Zaporizhzhia, Ukraine
[5] Univ Wurzburg, Fac Phys & Astron EP3, D-97074 Wurzburg, Germany