Fig. 4

Combining fixed and adaptive approaches during optimization. The fixed approach is used during optimization for 25 epochs. For comparison, the adaptive approach is used starting from the output population of the fixed approach at different generations. The highest fitness is achieved in the case where the adaptive approach is used after 5 epochs of the fixed approach. In the Fitness vs Generations subplots, Y-axis is average fitness of the and calculated as mean over six runs with standard deviations in the order of 0.1–0.2% of mean value. Notice that the adaptive approach starting from the same initial data as the fixed approach achieves a higher fitness after approximately 15 epochs