In the conventional file management system, there is a problem that even a file assigned permission information can be processed without considering any permission information. The drive assembly includes a motor including a shaft, the motor adapted to generate rotational power through the shaft at a first rotational speed; and a timing belt coupled to the motor and contactingly engaged with the notched circumferential surfaces of the timing pulleys, the timing belt adapted to transfer the rotational power generated by the motor to the tubes at a second rotational speed. The costs for a variety of input variable partitions are tested to determine an optimal input variable partition. Condensation may be enhanced by cooling the stack, such as with flowing air along the outer walls of the stack or placing a thermoelectric device in contact with the stack. The second switch connects the terminal INS to the ground while the first switch remains connected to the contact for selecting the first memory or the contact for selecting the second memory. The rubber composition can simultaneously satisfy requirements for use as, for example, an automobile grease cup material, that is, heat resistance, ozone resistance, cold resistance, and adhesion to metal or resin.