In a client-server environment it would be desirable to have a number of servers capable of processing a broad range of applications such as compute intensive applications or graphic operations such as rendering. The apparatus has cells each including first and second electrodes facing each other via a gap; includes a drivingdetecting unit and an external stress applying unit. The input unit receives input to the display area. For each coding technique, the encoded antenna control signals are combined into a total gain and total phase shift control signal, which drives a single phase and gain control device for each antenna element. Precise location of a water leak location is determined by connecting the four conductors to a resistance bridge.