Finding the Number of Members with Certain Relationships in Social Networks and Big Size Organizations using Copositive Programming

In social networks and big size organizations, finding the number of members that all of them have a certain relationship w* is an important problem for managers, as well the number of members that none of them has not the relationship (w*). Considering the members as vertices and the relationship as edges, w* and  w* denote the clique number and the number of edges in the independent graph, respectively. w*and w* can be find by solving some optimization models. One of these models is copositive programming. Unfortunately, there is no any polynomial time algorithm for solving these problems. In this paper, we model these problems as a copositive programming then solve them using genetic and particle swarm algorithms. Illustrative examples show the efficiency of our method.