Systems and methods for managing a device in a distributed file system are provided. Computing devices include a verifier with a public key that authenticates multiple associated private keys. Occurring errors can be stored as status messages in an error storage device, and if desired, they can be interrogated and corrected at the next service interval. The coupling mechanism is for coupling or separating the holding arm and the casing of the display panel. This composite is mixed with a binder and then molded to obtain an electrode, and this electrode is employed for an electrochemical element. Each of the currents is to be applied to an imaging unit through the contacts between the main body and the imaging unit.