1. Department of Computer Science, Oslo Metropolitan University, N-0130 Oslo, Norway
2. Department of Applied Mathematics, Lobachevsky University, 603950 Nizhny Novgorod, Russia
3. Center for Theoretical Physics of Complex Systems (IBS), Daejeon 34126, South Korea
4. Institut für Physik, Universität Augsburg, D-86135 Augsburg, Germany