Y. Maeno and Y. Ohsawa

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The overall network topology is studied. The nodal degree averaged over the all nodes is μ( d ) = 4.6 . Gini coefficient of the nodal degree is 0.33. The clustering coefficient averaged over the all nodes is μ (c) = 0.6 . It is 3.2 times larger than that in the Barabasi-albert model (Barabasi, 1999), a scale-free network, having the same Gini coefficient. Large clustering coefficient indicates that clusters exist as a core structure, but the network takes a less compact form. As qualitatively suggested by (Klerks, 2002),
the terrorists possess a cluster-and-bridge structure, rather than a center-and-periphery