An organic light emitting display capable of displaying an image with uniform luminance regardless of deterioration of an organic light emitting diode and threshold voltage andor mobility of a drive transistor is disclosed. The bus switch circuit further includes a first pull-up resistor and first switch circuit, a second pull-up resistor and second switch circuit. A recess cavity is formed in the substrate adjacent to the gate stack. The first anchor frame store may be configured to receive the one or more anchor video images from the decode frame store. Other system functions, including automatic appointment scheduling, automated physician enrollment and referrals, and various messaging functions are also described. Furthermore, when the exhaust gas is temporarily change from lean burn to fuel-rich, the adsorbed nitrogen oxides are released and chemically reduced by a reaction with the hydrocarbons and carbon monoxide in the exhaust gas under a stoichiometric atmosphere or a fuel-rich atmosphere in which oxygen concentrations are below stoichiometric point.