1. Control and Robotics Group, Silesian University of Technology, Department of Automatic Control and Robotics, Gliwice, Poland, 44-100 (e-mail: artur.babiarz@polsl.pl)
2. Mathematics, Department of Information Technology, National University of Civil Engineering, Ha Noi, Vietnam, 100000 (e-mail: cuonglv2@nuce.edu.vn)
3. Automatic Control, Silesian Technical University, Department of Automatic Control and Robotics, Gliwice, Poland, 44-100 (e-mail: Adam.Czornik@polsl.pl)
4. Probability and Statistics, Vietnam Academy of Science and Technology, Hanoi, Vietnam, 10307 (e-mail: dtson@math.ac.vn)