Abstract: To derive a feasible solution for an operation plan problem for storage tanks for storing liquefied natural gas, which is a complicated mixed-integer non-linear problem, given tank initial state information, reception plan information, and feed plan information, two solving processes are executed alternately two or more times, respectively: a first solving process that replaces a mixed-integer non-linear programming problem with a mixed-integer linear programming problem by linear approximation of a non-linear expression in non-linear constraints containing the non-linear expression, and solves the problem to derive provisional solutions or final solutions for a reception pattern that prescribes a storage tank that is to receive liquefied natural gas, and a discharge pattern that prescribes a storage tank that is to discharge liquefied natural gas, and a second solving process that replaces a mixed-integer non-linear programming problem with a continuous non-linear programming problem by provisionally fixing

Abstract: To derive a feasible solution for an operation plan problem for storage tanks for storing liquefied natural gas, which is a complicated mixed-integer non-linear problem, given tank initial state information, reception plan information, and feed plan information, two solving processes are executed alternately two or more times, respectively: a first solving process that replaces a mixed-integer non-linear programming problem with a mixed-integer linear programming problem by linear approximation of a non-linear expression in non-linear constraints containing the non-linear expression, and solves the problem to derive provisional solutions or final solutions for a reception pattern that prescribes a storage tank that is to receive liquefied natural gas, and a discharge pattern that prescribes a storage tank that is to discharge liquefied natural gas, and a second solving process that replaces a mixed-integer non-linear programming problem with a continuous non-linear programming problem by provisionally fixing

Abstract: The present invention provides a reflex-type screen which is wound up by a winding shaft to be retracted and is unwound from the winding shaft in use. The reflex-type screen comprises a reflection layer which reflects an incident light, a transparent surface protective layer provided on a first surface of the reflection layer, and a back surface protective layer provided on a second surface of the reflection layer, wherein as between the surface protective layer and the back surface protective layer, the one that has a higher loop stiffness value, faces inward when the reflex-type screen is wound up by the shaft.

Abstract: The present invention provides a reflex-type screen which is wound up by a winding shaft to be retracted and is unwound from the winding shaft in use. The reflex-type screen comprises a reflection layer which reflects an incident light, a transparent surface protective layer provided on a first surface of the reflection layer, and a back surface protective layer provided on a second surface of the reflection layer, wherein as between the surface protective layer and the back surface protective layer, the one that has a higher loop stiffness value, faces inward when the reflex-type screen is wound up by the shaft.