1. Moscow Technical University of Communications and Informatics; National University of Oil and Gas «Gubkin University»,Moscow,Russia
2. North Ossetian State University named after Kosta Levanovich Khetagurov,Vladikavkaz,Russia
3. Moscow Technical University of Communications and Informatics; Plekhanov Russian University of Economics,Moscow,Russia
4. Moscow Technical University of Communications and Informatics,Moscow,Russia