Abstract: A support member and method for supporting the base of a tree. The support member tightens around the base of the tree to support the tree and includes a support member body that can suspend the state where the base of the tree is tightened in a time-dependent manner after a lapse of years corresponding to growth of the tree. The method includes the step of placing the support member around the base of the tree wherein the support member has a support member body that is capable of self-terminating support at the base of the tree in the time-dependent manner to correspond to growth of the tree.

Abstract: A dome-shaped roof structure for a large construction such as an athletic stadium is capable of partly opening according to the environmental conditions such as weather conditions. The dome-shaped roof structure includes a stationary roof section having a central opening and fixedly secured along an outer periphery thereof to the side wall of the large construction, and a movable roof section including a plurality of roof units corresponding to a plurality of divisions of the central opening and each capable of being radially moved between an open position where the roof unit is supported on the stationary roof section and a closed position where the roof unit is supported on a beam in the central opening.

Abstract: A retractable roof structure includes a stationary section having an opening in the central portion thereof and fixedly installed on a side wall constructed on the ground, and a retractable section for covering the opening. The retractable section includes a plurality of movable roof units which correspond to regions defined by dividing radially from a center portion of the opening each of not less than two concentric areas of the opening. The roof units in an inner area are retractable over the roof units in radially adjacent outer area, and the roof units in the outermost area are retractable with the roof units of the inner area retracted thereon over the stationary section.