Abstract: The invention discloses a communication system for assisting a user for retrieving geography-associated multimedia information, and the communication system comprises a data processing device and several mobile communication devices. The data processing device receives a first request information including a location term and a time term from a terminal device of the user, and broadcasting a second request information, based on the time term, to the mobile communication devices located within a region relative to the location term. The data processing device receives responding messages and captured audio and/or video data from the mobile communication devices accepting the second request information, and transmitting a location-related information to the terminal device based on the responding messages. The user transmits responding information responsive to the location-related information to the data processing device via the terminal device.

Abstract: A leakproof and fireproof tubing according to the invention comprises an inner tube for guiding a chemical fluid, a heater surrounding the inner tube, a foil enclosing the inner tube which is already surrounded by the heater, and an outer tube surrounding and coaxial with the inner tube. When chemical fluid leakage or a fire caused by a short circuit in the heater is encountered, the tubing can efficiently prevent the chemical fluid leakage and fire from further extending to the outside atmosphere. In coordination with the use of a sensor, the failure of the tubing can be repaired in a timely manner.