“…It is well-known that body-worn sensors are used for many real-world applications, including but not limited to sleep monitoring [1], environmental perception [2], elderly patient assistance and health assessment [3], etc. Also, wearable-based human activity recognition (HAR) is one of the core research areas in ubiquitous computing, and it plays an essential role in human behaviour understanding, health monitoring, skill assessment, sports training, etc.…”