“…These algorithms are mostly carried out in offline analysis, which also makes the solution impractical. The constraints may also stem from sensor degradation, interconnection failures, and jitter in [91], [96], [98], [140] ACC [90] MIC [95] ACC, GPS [79] ACC, MIC, BT [118], [141] WiFi, GPS [105] ACC,MIC, GPS [76], [82], [89] ACC, MIC, WiFi, GPS Wearable Devices [83], [86], [94], [102] ACC [78] ACC, Proximity [100] ACC,HR [80], [81] ACC, BT Mobile Development Boards [84], [94], [101], [142] ACC [98] ACC,BT [77], [85], [104] ACC, Temperature, Light [80], [93] ACC, MIC, Compass, Temperature, Light -ACC: Accelerometer; BT: Bluetooth; MIC: Microphone; HR: Heart Rate Monitor the sensor placement. Hence, the reduction of sensor dimension is highly important for node interconnection, and make the system stay still unobtrusive.…”