1. Prydniprovs'ka State Academy of Civil Engineering and Architecture, 24a Chernyshevskogo Street, Dnipropetrovsk 320005, Ukraine
2. Department of Mathematics, Ukrainian State Chemical Technological University, 8 Gagarina Avenue, Dnipropetrovsk 320005, Ukraine
3. Centre of Mechanics, Institute of Fundamental Technological Research, 21 Swietokrzyska Street, Warsaw 00-049, Poland