Table 2: Parameter setting.
| Parameter | Definitions | Values |
| P | Population size | 20 |
| fmin | Minimum frequency | 0 |
| fmax | Maximum frequency | 5 |
| A0 | The initial loudness | 1 |
| r0 | The initial pulse rate | 0.5 |
| α | The loudness constant | 0.9 |
| γ | The rate of pulse emission constant | 0.9 |
| ε | Step size for checking for decent directions | 10-3 |
| m | Local PS repetition number | 5 |
| ∆0 | Initial mesh size | (Ui - Li)/3 |
| σ | Reduction factor of mesh size | 0.01 |
| m | Local PS repetition number | 5 |
| Maxitr | Maximum iterations number | 2 d |
| Nelite | Number of best solution for final intensification | 1 |