Abstract: A sandwich structure does not permit the permeation of water and a sandwich structure repairing method is capable of easily repairing the sandwich structure. A sandwich structure (1) includes a core (4) formed of a closed-cell foam plastic material, and surface plates (2, 3) formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and bonded to the opposite surfaces of the core (4). Water is unable to permeate the sandwich structure.

Abstract: A sandwich structure does not permit the permeation of water and a sandwich structure repairing method is capable of easily repairing the sandwich structure. A sandwich structure (1) includes a core (4) formed of a closed-cell foam plastic material, and surface plates (2, 3) formed of a fiber-reinforced composite material containing hydrophobic inorganic fibers as reinforcing fibers and bonded to the opposite surfaces of the core (4). Water is unable to permeate the sandwich structure.

Abstract: A mobile communication system having a small base station provides radio communications between the small base station and a mobile station. The small base station is connected with a central station via an optical transmission line. The central station includes a modulation section which modulates a time-division multiple signal, an electric/optic converter section which converts an output signal of the modulation section to an optical signal, and sends the optical signal to the optical transmission line. The central station further includes an optic/electric converter section which receives an optical signal from the small base station via the optical transmission line, and converts a received optical signal to an electrical signal, and a demodulation section which demodulates an output signal from the optic/electric converter section.

Abstract: An operator support system comprises an operation guidance generating unit 14 for displaying operation procedures to an operator on the basis of plant monitoring data, and a running operation evaluation processing unit 23 for comparing control object equipment and operation contents of a guidance table generated by the operation guidance generating unit 14 with operation contents selected by the operator and output through an operation selecting unit 22, and for evaluating that the operation contents are correct by coincidence thereof, to prevent an operator's operation error. Accordingly, the operator support system which is capable of evaluating whether or not the operation contents performed by an operator is adequate, and, if an inadequate running operation is performed, of informing the operator of an error without outputting that control output to the controlled plant.