A system and method for distributing a reference voltage in a system such as an integrated circuit wherein a master reference voltage is distributed via a differential pair of conductors Local reference voltage generators produce local reference voltages proportional to the master reference voltage, but referred to local ground andor a local power supply voltage. The beams each includes an outer peripheral wall having a partition to separate the beam into an outer portion and a inner portion, the outer portion includes an insert engaged in a chamber, to reinforce the outer portion of the beam, and to allow the outer portion of the beam to be solidly coupled to objects. If one user logs into a first image forming device among the image forming devices, a controller of the first image forming device checks for the existence of a second image forming device into which the user has logged. The other end of the resonator duct is closed. 5 or more measuring in concentrated sulfuric acid at a concentration of 1% and at 25\xb0 C. Preferably the switching means is configured so as to be controlled by a characteristic of a received auxiliary analog audio signal, such as its DC level or its AC amplitude level.