1. Centro Vito Volterra, Faculty of Economy, University of Rome (Torvergata) 00133 Rome, Italy
2. International Center for Mathematical Modeling in Physics and Cognitive Sciences, Linnaeus University, Växjö-Kalmar, Sweden
3. Department of Information Sciences, Tokyo University of Science, Yamasaki 2641, Noda-shi, Chiba, 278-8510, Japan