1. Complex Systems and Artificial Intelligence research center, Department of Informatics, Systems and Communication, University of Milano-Bicocca, Italy. E-mails: andrea.gorrini@unimib.it, luca.crociani@unimib.it, giuseppe.vizzari@unimib.it, stefania.bandini@unimib.it
2. Research Center for Advanced Science and Technology, The University of Tokyo, Japan