Fig. 1.

Generated Pareto-optimal fronts after 25, 50, and 75 generations with the NSGA-II (squares), PSO (circles), AMS (+), DE (diamonds), and AMALGAM (x) optimization algorithms for test problem ZDT4. This benchmark problem has 21⁹ different local Pareto-optimal fronts in the search space, of which only one corresponds to the global Pareto-optimal front. Combining the individual algorithms into a simultaneous multimethod search algorithm ensures a faster and more reliable solution to multiobjective optimization problems.