Table 1 Superparameter settings.

From: Prediction method of surface settlement of rectangular pipe jacking tunnel based on improved PSO-BP neural network

Algorithm

Hyperparameter type

Value

BP

Hidden layer nodes

9

Learning rate

0.001

Network target loss value

0.0004

Number of learnings

2000

PSO

Group size

20

Inertia weights \(\omega_{start}\) and \(\omega_{end}\)

0.9 ;0.4

Learning factor \(c_{1}\) and \(c_{2}\)

1.49;1.49

Speed extremes

1.3; − 1.3

Total number of iterations

100

Optimize the target loss value

0.0001