In one aspect, an apparatus comprises a substrate, a first electrically-driven device disposed on the substrate, a second electrically-driven device disposed on the substrate, and a composite heat sink device. Magnetic resonance signals are excited by the modified output signal. The apparatus also includes an on-off valve for intermittently supply air to the ports, and a control unit for openingclosing the valve a plurality of times at a predetermined ratio. The drive manager performs the encryption of the data file without corresponding encryption applications being previously loaded on the computer system.