Convergence curves for the DE and the hybrid method to the global optimum of the Goodwin problem given by Eqs. (9). a) 0% noise to signal ratio. The left figure shows the value of the objective function as a function of CPU time for different box sizes. CPU time is normalied using the Linpack Benchmark table. The right figure displays the convergence of the hybrid strategy. b) Same as in a) but with 10% noise to signal ratio. The difference between the final value of the cost function in a) and b) is due to the added noise.