Moltaji

Gravitational search algorithm

This algorithm is a new optimization algorithm based on the law of gravity and is a kind of swarm based algorithm. In a swarm based algorithm, each member executes a series of particular operations and shares its information with others. These operations are almost very simple, however their collective effect, known as swarm intelligence produce a surprising result. Local interactions between agents provide a global result which permit the system to solve the problem without using any central controller. In this case, member operations including randomized search, positive feedback, negative feedback and multiple interactions, conduct to a self-organization situation. In this algorithm agents are considered as objects and their performance is measured by their masses. All these objects attract each other by the gravity force, and this force causes a global movement of all objects towards the objects with heavier masses. Hence, masses cooperate using a direct form of communication, through gravitational force. The heavy masses – which correspond to good solutions – move more slowly than lighter ones. The position of the mass corresponds to a solution of the problem, and its gravitational and inertial masses are determined using a fitness function. In other words, each mass presents a solution, and the algorithm is navigated by properly adjusting the gravitational and inertia masses. By lapse of time, the masses will be attracted by the heaviest mass. This mass will present an optimum solution in the search space.