▁hub s ▁in ▁the ▁network , ▁the ▁network ▁would ▁demonstrate ▁the ▁rich - club ▁effect . ▁ ▁App lications ▁ ▁The ▁rich - club ▁coefficient ▁of ▁a ▁network ▁is ▁useful ▁as ▁a ▁he ur istic ▁measurement ▁of ▁the ▁robust ness ▁of ▁a ▁network . ▁A ▁high ▁rich - club ▁coefficient ▁implies ▁that ▁the ▁hub s ▁are ▁well ▁connected , ▁and ▁global ▁connect ivity ▁is ▁res il ient ▁to ▁any ▁one ▁hub ▁being ▁removed . ▁It ▁is ▁also ▁useful ▁for ▁ver ifying ▁theories ▁that ▁general ize ▁to ▁other ▁networks . ▁For ▁example , ▁the ▁consistent ▁observation ▁of ▁high ▁rich - club ▁coefficients ▁for ▁scientific ▁collaboration ▁networks ▁adds ▁evidence ▁to ▁the ▁theory ▁that ▁within ▁social ▁groups , ▁the ▁el ite ▁tend ▁to ▁associate ▁with ▁one ▁another . ▁ ▁Im plement ations ▁▁ ▁The ▁rich - club ▁coefficient ▁has ▁been ▁implemented ▁in ▁Network X , ▁a ▁Python ▁library ▁for ▁network ▁analysis . ▁This ▁implementation ▁includes ▁both ▁the ▁non - normal ized ▁and ▁normal ized ▁forms ▁as ▁described ▁above . ▁ ▁See ▁also ▁Ass ort ativity ▁Pre fer ential ▁attachment ▁Struct ural ▁cut - off ▁ ▁References ▁ ▁External ▁links ▁ ▁Network X ▁Document ation ▁of ▁Rich ▁Club ▁coefficient ▁function ▁ ▁Category : Network s ▁Category : Network ▁theory <0x0A> </s> ▁V P B - 1 9 8 ▁was ▁a ▁Pat rol ▁Bomb ing ▁Squadron ▁of ▁the ▁U . S . ▁Navy . ▁The ▁squad ron ▁was ▁established ▁as ▁Bomb ing ▁Squadron ▁ 1 9 8 ▁( VB - 1 9 8 ) ▁on ▁ 1 2