The present invention discloses methods and systems for managing data in user-centric environment. The circuit delivers a motor power supply signal that varies as a function of a position setpoint signal applied to the control circuit and as a function of signals delivered by the angular position sensor. The stereo image frame is disposed between two adjacent planar image frames and has a stereo image region. Periodic small additions of chemical are injected as necessary to maintain highly stable, accurately controlled process conditions. A user of the search and retrieval system may provide feedback on a model that was used to generate information in response to the user’s search query, and such feedback may be used to update the index of models. A surface chemical mechanical polishing process is performed to polish and remove portions of the first material layer down to a first thickness, and a rim CMP process is performed to completely remove the second material layer on the edge bevel surface down to the edge bevel surface thereafter to achieve a smooth surface of the edge bevel surface.