The Prediction of Metro Shield Construction Cost Based on a Backpropagation Neural Network Improved by Quantum Particle Swarm Optimization

Table 6

Stability of calculation results under different sample numbers.

Model	30	35	40	45
Multiple regression	33.890	27.390	20.11	22.30
BP	1.890	1.631	1.071	0.938
GA-BP	0.817	0.639	0.451	0.381
PSO-BP	0.691	0.588	0.432	0.340
QPSO-BP	0.311	0.273	0.192	0.181