User activity understanding from mobile phone sensors

Context acquisition is an important technology for ubiquitous computing. An ideal approach would be easy to deploy and non-intrusive to people's life. Mobile phones equipped with advanced sensors are preferable platform owing to their user-friendliness and freedom from extra costs to deploy. In this study, we propose to use a mobile phone to detect user contexts. We formally define the concept of context and then describe applications that leverage people's long-term activity, which can be inferred from their contexts.