Michael Buettner Richa Prasad Matthai Philipose David Wetherall Recognizing daily activities with RFID-based sensors. 51-60 2009 UbiComp http://doi.acm.org/10.1145/1620545.1620553 conf/huc/2009 db/conf/huc/ubicomp2009.html#BuettnerPPW09