Figure 5. Comparing k-shell decomposition and core-periphery analysis in real-world networks.

(a). k-shell decomposition of the karate network: black, blue, green, and red nodes compose, respectively, the 1-to 4-shells. (b, c). For the karate and ppi networks, the k-coreness k_i (i.e., the shell to which the node belongs) and the coreness α_i are compared for each node. Notice that many points coincide: e.g., 20 (over 34) and 996 (over 1458) nodes have α_i = 0 for, respectively, the zachary and ppi network. The blue line is the best linear interpolation.