A hard disk drive which moves a transducer across a disk surface so that the transducer has an essentially sinusoidal acceleration trajectory. In one implementation, a method extracts a plurality of service manifest files associated with a web service from a service artifact. The luminescent substance is excited by providing the laser light to the luminescent substance so as to emit light, and the light is reflected by the elliptical reflection mirror. Thus, the assembly working is relatively facilitated, and a production cost can be reduced with the simple construction. Accordingly, since the periphery monitoring performance of each vehicle within the vehicle group is grasped and the arrangement of the vehicles within the vehicle group can be determined on the basis of the periphery monitoring performance of each vehicle, it is possible to efficiently drive the entire vehicle group.