Synchronous vs Asynchronous Gravitational Search Algorithm

Gravitational search algorithm (GSA) is a new member of swarm intelligence algorithms. It stems from Newtonian law of gravity and mass interaction. Typically the agents in GSA are updated synchronously, where the whole population is updated together after every member´s performance is evaluated. However, asynchronous update of agent has been used by other optimization algorithms. Therefore the performance of asynchronous GSA (A-GSA) is studied in this work. An agent in A-GSA is updated immediately after its performance evaluation. Hence an agent in A-GSA is updated without using complete and updated information of its entire population. Asynchronous update is more attractive from the perspective of parallelization. The results show that improvement to the straight forward implementation of A-GSA is needed.