1. Ural Federal University; Mira 19 Yekaterinburg 620002 Russia
2. Institute of Industrial Ecology UB RAS; Kovalevskaya St 20 Yekaterinburg 620990 Russia
3. Department of Mathematics, College of Sciences; King Saud University; PO Box 2455 Riyadh 11451 Saudi Arabia
4. Department of Automation Engineering; TEI of Sterea Hellas; Psachna Campus Psachna GR 34400 Greece
5. Section of Mathematics, Department of Civil Engineering; Democritus University of Thrace; Xanthi Greece