title: Activity Recognition on Streaming Sensor Data.
abstract: Many real-world applications that focus on addressing needs of a human, require information about the activities being performed by the human in real-time. While advances in pervasive computing have lead to the development of wireless and non-intrusive sensors that can capture the necessary activity information, current activity recognition approaches have so far experimented on either a scripted or pre-segmented sequence of sensor events related to activities. In this paper we propose and evaluate a sliding window based approach to perform activity recognition in an on line or streaming fashion; recognizing activities as and when new sensor events are recorded. To account for the fact that different activities can be best characterized by different window lengths of sensor events, we incorporate the time decay and mutual information based weighting of sensor events within a window. Additional contextual information in the form of the previous activity and the activity of the previous window is also appended to the feature describing a sensor window. The experiments conducted to evaluate these techniques on real-world smart home datasets suggests that combining mutual information based weighting of sensor events and adding past contextual information into the feature leads to best performance for streaming activity recognition.
authors.affiliation: School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99164-2752, USA.
authors.forename: Narayanan C
authors.initials: NC
authors.lastname: Krishnan
authors.affiliation: School of Electrical Engineering and Computer Science, Washington State University, Pullman, WA 99164-2752, USA.
authors.forename: Diane J
authors.initials: DJ
authors.lastname: Cook
keywords: activity recognition; mutual information; online; real-time; streaming
references.citation: IEEE Trans Knowl Data Eng. 2011;23(4):527-539
references.pmid: 21617742
references.citation: IEEE Pervasive Comput. 2010;9(1):48
references.pmid: 21258659
references.citation: IEEE Trans Pattern Anal Mach Intell. 2009 Sep;31(9):1685-99
references.pmid: 19574627
references.citation: IEEE Trans Syst Man Cybern B Cybern. 2009 Feb;39(1):56-63
references.pmid: 19068433
references.citation: Int J Biosci Psychiatr Technol IJBSPT. 2009 Jan 1;1(1):25-35
references.pmid: 20019890
references.citation: IEEE Intell Syst. 2010 Sep 9;2010(99):1
references.pmid: 21461133
references.citation: J Ambient Intell Humaniz Comput. 2010 Mar 1;1(1):57-63
references.pmid: 20975986