Table III. Nomenclature List. Notation Details A Adjacency matrix aij An element of A, defining the directed connectivity between nodes i and j a1 Percentage of total population accessing stops on layer a a2 Percentage of total population accessing stops on layer b Ci Local clustering coefficient of node i GC H Average clustering coefficient CD Global clustering coefficient C b (i) Betweenness centrality of a node i C b (e im) Betweenness centrality of an edge eim connecting nodes i and m C c (i) Closeness centrality of a node i cd Cost of a shortest path d Gd H Average path length between two nodes G d tr H Average path length between two nodes considering the number of transfers dij Geodesic path or shortest path between nodes i and j d ij (k) Shortest path between nodes i and j through the node k d max Diameter of the network dm # of points-of-interests of category m DFRl Duplication factor of a bus route R l E or M Set of edges in a network ki Degree of a node i k ia Degree of a node i on layer a k max Maximum degree of a node i k min Minimum degree of a node i k in i In-degree of a node i in a directed network k out i Out-degree of a node i in a directed network k total i Total degree of a node i in a directed network k w i Weighted degree of a node i in w i (k ) Weighted in-degree of a node i in a directed network w (k out i ) Weighted out-degree of a node i in a directed network (k total w i ) Weighted overall degree of a node i in a directed network Average degree of an undirected network Gk H w Gk H Average weighted degree of an undirected network G k in H Average in-degree of a directed network in w G (k ) H Gk out H out w Average weighted in-degree of a directed network Average out-degree of a directed network G (k ) H Average weighted out-degree of a directed network G k total H Average overall degree of a directed network FOURTH QUARTER 2019 (Continued) IEEE CIRCUITS AND SYSTEMS MAGAZINE 45