Date Added: Aug 2009
People-centric sensing and user state recognition can provide rich contextual information for various mobile applications and services. However, continuously capturing this contextual information on mobile devices drains device battery very quickly. In this paper, the authors study the tradeoff between device energy consumption and user state recognition accuracy from a novel perspective. The authors assume the user state evolves as a hidden Discrete Time Markov Chain (DTMC) and an embedded sensor on mobile device discovers user state by performing a sensing observation.