Tatsuo Nakajima Vili Lehdonvirta Eiji Tokunaga Hiroaki Kimura Reflecting human behavior to motivate desirable lifestyle. 405-414 2008 Conference on Designing Interactive Systems http://doi.acm.org/10.1145/1394445.1394489 conf/ACMdis/2008 db/conf/ACMdis/ACMdis2008.html#NakajimaLTK08