Lviv Polytecnic National University, 12 Bandery Str.,L'viv 79013, Ukraine;
Lviv Polytecnic National University, 12 Bandery Str.,L'viv 79013, Ukraine;
Lviv Polytecnic National University, 12 Bandery Str.,L'viv 79013, Ukraine;
Lviv Polytecnic National University, 12 Bandery Str.,L'viv 79013, Ukraine;
National Technical University "Kharkiv Polytechnic Institute", 2 Kyrpychova Str., Kharkiv 61002, Ukraine;