“…In these recent years, the study of the control of complex networks with linear dynamics has gained importance in both science and engineering. Controllability of a dynamical system has being largely studied by several authors and under many different points of view, (see [1], [2], [3], [5], [8], [12], [15] and [20], for example). Between different aspects in which we can study the controllability we have the notion of structural controllability that has been proposed by Lin [18] as a framework for studying the controllability properties of directed complex networks where the dynamics of the system is governed by a linear system:ẋ(t) = Ax(t) + Bu(t) usually the matrix A of the system is linked to the adjacency matrix of the network, x(t) is a time dependent vector of the state variables of the nodes, u(t) is the vector of input signals, and B which defines how the input signals are connected to the nodes of the network and it is the called input matrix.…”