[Retracted] Prediction of Concrete Compressive Strength Based on the BP Neural Network Optimized by Random Forest and ISSA

Figure 13

The prediction results of the concrete compressive strength of each model.

(a) RF-BPNN

(b) RF-PSO-BPNN

(c) RF-SSA-BPNN

(d) RF-CSSA-BPNN

(e) RF-ISSA-BPNN

(f) ISSA-BPNN