1. Department of Computer Science and Engineering, Chongqing University of Technology, Chongqing 400054, China
2. Department of Mathematics and Computer Science, Physical Sciences and Earth Sciences, University of Messina, 98166 Messina, Italy
3. Department of Ancient and Modern Civilizations, University of Messina, 98168 Messina, Italy
4. Department of Cognitive Science, Education and Cultural Studies, University of Messina, 98121 Messina, Italy