A system for estimating the current position of an asset within a location that includes a transponder associated with the asset, a plurality of wireless interface devices provided within the location, and a central computer system in electronic communication with the wireless interface devices. This marking technique is useful in tracking pirated data andor sources, such as CDs or DVDs, to thereby prevent future pirating of data. When transferring data per block, the problem of different potential states between the border of the blocks and an area surrounding it, which is caused by the potential oscillation of the signal line on the border of the blocks, is relieved. The spray heads direct water under pressure onto the sloped screen. A Fe-based amorphous alloy ribbon having no crystalline phase is stably, continuously produced without breakage by this method.