Core-periphery structure at the two resolution levels, G_19×19 and G_125×125.

(a,c) Results found by the stochastic block model, where γ_c is the probability for a node to belong to the core. Core nodes, with γ_c > 0.5, are labeled with red dots. (b,d) Dendrograms showing the hierarchical decomposition of the networks based on the Girvan-Newman algorithm. The core nodes (labeled with red dots) are located towards the inside of the onion structure, while the periphery nodes (labeled with blue dots) are in the outer layers. (e) Graphical representation of the G_125×125 network using a force directed layout. Core nodes are concentrated towards the center. For the lists of core areas at the two resolution levels, see S13 Fig.