In accordance with various aspects of the disclosure, a detecting engine for detecting targetsmaterials in hyperspectral scenes is disclosed. The base member has a clock window positioned on the side wall, through which a clock head to write servo track information on the disk is inserted in the disk drive, and a concave adjacent to the clock window and having a predetermined depth relative to an upper surface of the bottom plate, to accommodate the clock head inserted through the clock window. Further, the digital device is configured to detect one or more incidents based on a correlation between at least a first threat event of the one or more threat events and a second threat event of the one or more threat events. Therefore, the air is uniformly blown into the passenger compartment over a wide range of the ceiling.