1. Department of Economics, University of Crete, Rethymnon, Greece
2. Statistical Learning Lab, Institute of Applied and Computational Mathematics, Foundation of Research and Tehchnology Hellas, Herakleion, Greece
3. Department of Mathematics, Northern Border University, Arar, Saudi Arabia
4. Department of Computer Science, University of Crete, Herakleion, Greece
5. Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Bern, Switzerland