The present invention provides a file management system and method, and a storage system that can prevent file-multiplexing in a storage apparatus, and efficiently use the storage capacity of the storage apparatus. The developer contains a toner having a volume mean grain size of from 5 to 10 micrometers and a grain size not larger than 5 micrometers accounting for 60 through 80 number percent. The fundamental component with one or more harmonics of the second clock signal does not occupy the same communication channel as the transmission communication signal of the communications device. Such a wave attenuator can comprise a first row of support members extending vertically relative to a seabed and a second row of support members spaced from the first row. The conductive thin film has excellent conductivity, allows the easy adjustment of a work function, also allows easy film formation, and thus can be advantageously used in various electronic elements, such as organic light-emitting devices and organic solar cells. The plurality of LED modules produce a concentrated illuminated area at a pre-determined distance from the front panel as determined by the radius of curvature of the front panel.