A SPECT apparatus has a two-dimensional detector that detects radiations from RIs in a patient via a collimator. The first and second scroll members form a series of pockets. The method includes causing the second storage processor to stop performing the IO requests on the first one or more logical units of the plurality of logical units and a third storage processor to perform the IO requests on the first one or more logical units. A first light source emits a light beam. These grids are then used to forecast when precipitation will start and stop at one or more identified locations with a geographic area. The driving circuit of each light-emitting element is connected to the corresponding current supply, scanning, and data lines.