Transactional programming promises to substantially simplify the development and maintenance of correct, scalable, and efficient concurrent programs. The actuating assembly is selectively changeable into a direct drive configuration when the valve is in a lower resistance portion of its stroke. In one vibration system and the other vibration system, voice coils are wound around voice coil bobbins in directions reverse to each other. A storage section stores information on each derived malicious apparatus group. The time duration is also such that reflections on the carrier medium resulting from the propagation of the first delimiter signal decay to a predetermined level prior to propagation of the second delimiter signal.