The overall performance of the PSO can be controlled by the chosen control parameters, i.e. the swarm size s, the inertia weight ω, the maximum number of iterations k max , and the acceleration parameters φ p and φ g . Based on Clerc's constriction method , Eberhart and Shi identified ω = 0.7298 and φ p = φ g = 1.49618 as a reliable set of parameters to obtain well-converged solutions . The choice of the swarm size and the maximum number of iterations depends strongly on the complexity of the optimisation problem and the available computing resources. In general, a larger population size increases the success rate but raises the number of misfit function evaluations .