NONUNIVERSALITY IN SEMI-DIRECTED BARABASI-ALBERT NETWORKS
In usual scale-free networks of Barabasi-Albert type, a newly added node selects randomly m neighbors from the already existing network nodes, proportionally to the number of links these had before. Then the number n(k) of nodes with k links each decays as 1/k(gamma) where gamma = 3 is universal, i.e. independent of m. Now we use a limited directedness in building the network, as a result of which the exponent gamma decreases from 3 to 2 for increasing m.
neighbors general ba directed ba undirected ba fortran programs