The present invention provides methods for improving cotton fiber quality by modulating transcription factor gene expression. The encoding conditions are controlled so that a total code amount obtained by encoding the image data of the plural objects does not exceed a predetermined code amount. The intensity distribution in the diffraction image in the secondary-beam path is subjected to an autocorrelation, and both the period and the depth of the wave pattern can be calculated from the autocorrelation function. The method may further include deducing, based on information obtained from examining the plurality of metadata fields of the plurality of known-clean- and known-malicious-executable files, metadata-field attributes indicative of malware. When the operating lever is at a raising or holding position, the change of the speed limit from the first speed limit is prohibited.