The problem descried has been solved using the above two algorithms and implemented using MATLAB 2017 and run on a PC with the following characteristics: i5 of 2.50 GHz with 4 GB. Each algorithm has been run over ten independent runs. The population size is 20 and the maximum number of iterations is 100. These parameters have been fixed by trial-and-error and based on experience. The weight factors are considered equal, i.e. (w1= w2=w3=0.3333).
Tables 1 and 2 report the results obtained by the PSO and the DE over the ten runs, respectively. The values of the one-scaled objective (Z), the three process performances (Ts, Fs and Is), design variables, number of function evaluations (NFE), CPU time, and standard deviation (σ) are included.
From Table 1, it can be observed that the best value of Z obtained by the PSO is 98.8849 for all runs, except #3, #6 and #7. The fewer NFE corresponds to #5 (1,220) with 12.23 s of CPU time. The optimal values are TS=170.2408 MPa, Fs=125.3889 MPa, Is=1.3162 MJ/m2, whereas the decision variables are A=0.1270 mm, B=7.6880°, C=60°, D=0.4064 mm, and E=0.008 mm. The standard deviation of the ten runs is 2.8E-04.
From Table 2, it can be observed that the best value of Z obtained by the DE is 98.8849 for all runs. The lower NFE corresponds to #9 (440) with 9.89 s of CPU time. The optimal values are TS=170.3954 MPa, Fs=125.2397 MPa, Is=1.3166 MJ/m2, whereas the decision variables are A=0.1270 mm, B=7.6923°, C=60°, D=0.4064 mm, and E=0.008 mm. The standard deviation of the ten runs is 0.
Table 3 summarizes the best results obtained by the PSO and the DE. It can be observed that both algorithms obtained the same value of the one-scale objective (Z=98.8849). However, the performances of the DE have outperformed those of the PSO in terms of number of function evaluations, CPU time, and standard deviation.