Percolation in the classical blockmodel

Classical blockmodel is known as the simplest among models of networks with community structure. The model can be also seen as an extremely simply example of interconnected networks. For this reason, it is surprising that the percolation transition in the classical blockmodel has not been examined so far, although the phenomenon has been studied in a variety of much more complicated models of interconnected and multiplex networks. In this paper we derive the self-consistent equation for the size the global percolation cluster in the classical blockmodel. We also find the condition for percolation threshold which characterizes the emergence of the giant component. We show that the discussed percolation phenomenon may cause unexpected problems in a simple optimization process of the multilevel network construction. Numerical simulations confirm the correctness of our theoretical derivations.Comment: 7 pages, 6 figure

Taylor’s power law for fluctuation scaling in traffic ∗

In this article, we study transportation network in Minnesota. We show that the system is characterized by Taylor’s power law for fluctuation scaling with nontrivial values of the scaling exponent. We also show that the characteristic exponent does not unequivocally characterize a given road network, as it may differ within the same network if one takes into account location of observation points, season, period of day, or traffic intensity. The results are set against Taylor’s fluctuation scaling in the Nagel-Schreckenberg cellular automaton model for traffic. It is shown that Taylor’s law may serve, beside the fundamental diagram, as an indicator of different traffic phases (free flow, traffic jam etc.). PACS numbers: 89.75.-k, 89.75.Da, 05.40.-a 1