An improved method and device for the reduction of aerodynamic drag and for increased fuel economy of ground vehicles by increasing the pressure on the rear surface of the vehicle with a plurality of vortices generated along the top and side surfaces of the ground vehicle that flow in to the base wake region of the vehicle. In the magnetic sensor element, the exciting pattern, the magnetic thin film pattern for detection, and the detection coil pattern are formed on the substrate. The method comprises receiving a request from a requesting application that requests allocation of the device resource, and determining that the device resource is owned by an owning application.