“…ULSTER HAR dataset has been collected by following the same protocol of ExtraSensory: 10 volunteer users acting in free-living and unconstrained conditions for a period of 6 weeks. In this case, a mobile application has been used to monitor a small amount of physical smartphone-embedded sensors (i.e., accelerometer, gyroscope, GPS, and light sensor), while more abstract infor- [34,35]; biometric classification and user identification, based on smartphone usage data [36,37,38]; and prediction of users' locations in mobile environments [39]. However, the main limitation of the sensing experiment is related to the homogeneity of the mobile devices.…”