An oral bib includes a thin sheet protective shield portion having resistance to the passage of a sexually transmitted disease microbe therethrough. A selection gate is formed on a p-type well of a semiconductor substrate via a gate insulator, and a memory gate is formed on the p-type well via a laminated film composed of a silicon oxide film, a silicon nitride film, and a silicon oxide film. Between the first sub-electrode and the second sub-electrode, and between the first sub-electrode and the second main electrode are electrically connecting with a first side electrode and a second side electrode, respectively. A brake assembly is connected to the shaft drive arrangement. A variance ratio correcting unit calculates a correction value for suppressing a change of the variance ratio.