Abstract: This invention provides a plant growth sheet structure which includes a base web layer and a core layer integrally coupled together in this order, a base web layer, a plant seed holding layer and a core layer integrally coupled together in this order, or a base web layer, a core layer, a plant seed holding layer and a cover web layer integrally coupled together in this order, and is provided at its surface with plant protection projections, and also provides a natural turf sheet structure including a natural turf grown on the plant growth sheet structure.

Abstract: A dome shaped roof structure suitable for a stadium for indoor athletic sports is disclosed. The dome shaped roof structure comprises a main frame for covering the inside of the stadium and a reinforcing frame. The reinforcing frame comprises: cables disposed in the inner side of the main frame and extended radially from the central portion of the main frame to the bottom peripheral border; circular cables disposed concentrically about the peripheral border of the main frame; and strut members that have each upper end connected to the steel member of the main frame at an intersecting point of the radiating cables and the circular cables, and the strut members vertically supported by the radiating cables and the circular cables; and wherein tension is introduced to the radiating cables in the direction of the bottom peripheral border and the outer ends of the radiating cables are fixed with the main frame, so that the steel members of the main frame are thrust up by the strut members of the reinforcing frame.

Abstract: The present invention relates to an openable roof having two pairs of half dome openable roofs provided on a ring shaped set roof having a flat upper surface. In the center of the set roof, an aperture is provided; this aperture being opened or closed by these two pairs of openable roofs. Furthermore, either respective pair of these two pairs of openable roofs may be selected and utilized to open and close the aperture as necessary.

Abstract: An operation control system for automated guided vehicles conveying articles along an unmanned conveying system. This operational control system comprises a first travel path loop and a second travel path loop along which a first group and a second group of the automated guided vehicles are automatically travelled. A common travel path is provided along which the automated guided vehicles of both the first and the second group are travelled, to enable a transfer of articles between the groups of automated guided vehicles. Also a correlating unit for correlating one automated guided vehicle of the first group with another automated guided vehicle of the second group, and a transfer control unit for controlling the transfer of the articles between the automated guided vehicles are provided. The transfer control unit permits only a transfer of articles between automated guided vehicles correlated with each other by the correlating unit.