A method determines a location of a single-phase-to-ground fault in an ungrounded power distribution system. This procedure includes encrypting the stored authentication information with the key, transmitting the encrypted authentication information to the server, and then outputting the protected content received from the server for display after transmission of the encrypted authentication information if determined to be valid. The panel, in turn, is connected to the base for movement between a closed position, which prevents access to the storage area and an open position which allows access to the storage area. In the open position, the input and the display face in the same direction to allow simultaneous input of the data and viewing of the information. The present invention prevents distorting of the demodulator’s performance caused by the imbalances to between I and Q components and increases application to high-speed wireless communication. At least one pair of corresponding abutments of said first and second parts has a transverse section which is curvilinearly shaped along a portion of at least half of said transverse section.