1. A computer-implemented method for recognizing a user's activity pattern, comprising: pre-storing activity data in a computer system; automatically determining locations of one or more sensors on a user's body; obtaining time series of measured activity parameters by the one or more sensors; automatically segmenting the time series of measured activity parameters into two or more activity periods; determining a spatial range of the movement in an activity period; and recognizing an activity in the activity period based at least in part on the measured activity parameters and the pre-stored activity data.