An electronic device is provided, including a first body, a second body, an axle assembly, a supporting frame, a display panel, a lens unit and a reflective unit. A user accesses the system through a commercially-available single sign on application. A digital filter is configured to place a notch in an error sensitivity function relating the PES to the repeated runout position error, with the notch being nominally centered at a frequency of rotation of the recording surface. Such a measurement may be made on-line or in-line in a short time while avoiding tool induced shift, contact with the mark or use of a tool requiring high vacuum. When the combustion mode is switched, a switching-time demanded fuel amount is calculated according to the stored pre-switching demanded fuel injection time period and pre-switching demanded torque, the current demanded torque, and an estimated combustion efficiency parameter. The MEMS relay requires a small vertical movement to close the gap and therefore is mechanically robust.