Abstract: An apparatus for modeling user behavior comprising at least one sensor for sensing a parameter, a memory, a processor coupled to the sensor and the memory, wherein the memory contains instructions that when executed by the processor cause the apparatus to collect a first data from the sensor, fuse the sensor data with a time element to obtain a context-feature, determine a first state based on the context-feature, record the first state in a state repository, wherein the state repository is configured to store a plurality of states such that the repository enables time-based pattern identification, and wherein each state corresponds to a user activity, incorporate information stored in the state repository into a behavior model, and predict an expected behavior based on the behavior model.