In this way, the proportion of particles to reset decreases with the number of iterations and thus maintain the convergence property of a PSO. The introduced competitivity parameter γ can control the position of the inflexion point. In general, the choice of the competitivity parameter depends on the optimisation problem, although γ = 1 has proven to be a reasonable initial guess in most cases. For γ = 0, the classical PSO behaviour is preserved, as no particles are reset at any iteration.