A method and apparatus for peer-to-peer file sharing is provided. The sense amplifier control signal generating circuit includes a timing control unit that models a transmission path of data from a memory cell to a sense amplifier through a bit line and generates a timing control signal at a sensing timing when the sense amplifier starts a sensing operation. For attaching the joint members 2 in each end of the butt 10 and the shaft 20 jointly connected to form a stick shape, second hollow holes 10b and 20b are bored respectively, and in the second hollow hole 20b of the shaft 20, is received a second weight 22, with which can be adjusted a gravity center, and a joint cylinder body 24 of the joint members 2 being attached therein. The apparatus can also include a bottom bracket, wherein the bottom bracket allows the enclosure to be secured against a bottom surface of the existing surface. The second drive signal may be derived from the first drive signal.