Machine learning Machine-learning 4 Physical activity 3 accelerometer 3 Accelerometers 2 Bayesian inference 2 Electric batteries 2 Energy 2 Energy ex-penditure 2 Energy expenditure 2 Extreme gradient boosting 2 Gradient boosting 2 Machine learning models 2 Mean square error 2 Physical performance 2 Quantum chemistry 2 Short physical performance battery 2 Walking aids 2 Wrist 2 eXtreme Gradient Boosting 2 energy ex-penditure 2 machine learning 2 physical activity 2 short physical performance battery 2 wrist 2 Accelerometery 1 Accidents 1 Approximate methods 1 Artificial neural network 1 Automatic control engineering 1