The present invention is a floor panel structure of a car body where an automobile floor comprises a floor panel that is connected to the frame members of the car body and also has a vibration mode adjusting structure that suppresses the generation of acoustic emission by generating 2\xd71 mode vibration in a predetermined frequency band. The modulator may be connected to the class S amplifier with a fiber optic link. In another implementation, the present invention provides a graphical user interface that provides status icons that efficiently convey status information for corresponding access points. An instruction is received from a service manager specifying an overriding packet destination. The tube can further have a widened end part, the inner diameter of which corresponds with the outer diameter of the co-displacing member arranged round the flexible element. The device also includes an inlet tube connected to the inflatable bladder or pad for feeding intermittent pulses of fluid to the inflatable bladder or pad.