New paper accepted

A new paper from the group has been accepted for publication

The paper “Human Activity Recognition by Combining a Small Number of Classifiers ” by Alfredo Nazábal,  Pablo G. MorenoAntonio Artés-Rodríguez and Zoubin Ghahramani has been accepted for publication in IEEE Journal of Biomedical and Health Informatics.
Abtract:
We consider the problem of daily Human Activity Recognition (HAR) using multiple wireless inertial sensors and, specifically, HAR systems with a very low number of sensors, each one providing an estimation of the performed activities. We propose new Bayesian models to combine the output of the sensors. The models are based on a soft outputs combination of individual classifiers to deal with the small number of sensors. We also incorporate the dynamic nature of human activities as a first order homogeneous Markov chain. We develop both inductive and transductive inference methods for each model to be employed in supervised and semi-supervised situations, respectively.Using different real HAR databases, we compare our classifiers combination models against a single classifier that employs all the signals from the sensors. Our models exhibit consistently a reduction of the error rate and an increase of robustness against sensor failures. Our models also outperform other classifiers combination models that do not consider soft outputs and a Markovian structure of the human activities.