1. Institute of General Mechanics, RWTH Aachen, Templergraben 64, Aachen 52062, Germany
2. Department of Automatics and Biomechanics, Technical University of Łódź, 1/15 Stefanowski Street, Łódź 90-924, Poland
3. Pridneprovsk State Academy of Civil Engineering and Architecture, 24a Chernishevskogo Street, Dnepropetrovsk 49005, Ukraine