Abstract: A mobile unit navigation system has a position detection unit 10 for a mobile unit, a map information acquisition unit 20, a destination input unit 30, a route search unit 40 for searching for a guide route from the current position to the destination, and an output unit 50 for displaying the found guide route as an image or guiding a user along the found guide route with voice. The unit 40 has a move route extraction unit for extracting a move route of the mobile unit based on a move path of the mobile unit provided by the detection unit 10 and the map information, a differential route registration unit for extracting a differential route different from the guide route from the extracted move route and registering the differential route, and a differential route application unit for applying the registered differential route to searching for the guide route.

Abstract: A gas-insulated switch has separable contacts disposed within a chamber-forming cylinder. The arc drawn between the contacts on opening provides pressurizing of the arc-extinguishing fluid in the chamber, while additional pressurization is provided by an interlocking member which has an interlocked movement with the contacts during the opening operation.