Figure 1:

Figure 2:

Figure 3:

Initial parameter table
| Parameter | Value | 
|---|---|
| Maximum iterations | 200 | 
| Population size | 100 | 
| Optimization parameter number | 2 | 
| Upper limit of optimization parameter | 2−10 | 
| Lower limit of optimization parameter | 210 | 
| Cross-check the number of folds | 5 | 
Model parameter settings
| Algorithm | Parameter | Value range | Optimum value | 
|---|---|---|---|
| SVR | C | / | 10 | 
| g | 0.5 | ||
| SSA-SVR | Alarm value | [0.5, 1] | 0.8 | 
| Safety threshold | [0, 1] | 0.2 | |
| TSSA-SVR | Alarm value | [0.5, 1] | 0.8 | 
| Safety threshold | [0, 1] | 0.2 | 
Quantitative identification results of mixed gases
| Model | RMSE | MAE | R2 | Acc (%) | 
|---|---|---|---|---|
| SVR | 2.626 | 2.336 | 0.095 | 81.80 | 
| SSA-SVR | 1.982 | 1.485 | 0.375 | 87.43 | 
| GA-SVR | 1.892 | 1.367 | 0.482 | 89.67 | 
| PSO-SVR | 1.765 | 1.220 | 0.512 | 90.36 | 
| TSSA-SVR | 0.286 | 0.425 | 0.896 | 94.47 |