BPNN Back-propagation neural networks 1 Backpropagation 1 Boring machines (machine tools) 1 Compressive strength 1 Construction equipment 1 Fingertip tracking 1 Forecasting 1 Gaussian pyramid 1 Geology 1 Gesture recognition 1 Morse code 1 Neural networks 1 Optimization backs 1 Particle swarm 1 Particle swarm optimization 1 Particle swarm optimization (PSO) 1 Prediction of geological indicator 1 Prediction of geological indicators 1 Rocks 1 SVM (support vector machine) 1 Sample imbalance 1 Surrounding rock grade 1 Swarm optimization 1 TBM 1 Tunnel boring 1 Tunnel boring machine 1 Tunneling (excavation) 1 Tunneling machines 1 Tunnels 1