Abstract: The first storage subsystem, when new data is written in a first memory device beyond a certain timing, writes pre-updated data prior to update by said new data into a pre-updated data memory region and, in addition, updates snapshot management information that expresses a snapshot of a data group within the first memory device to information that expresses the snapshot at the certain timing and, at a later timing than the certain timing, judges, on the basis of the snapshot management information, in which of either the pre-updated data memory region or the first memory device the data constituting the data group at a certain timing exists, acquires data from the one in which the data exists and writes it into the second memory device of the second storage subsystem, and generates the certain timing repeatedly.

Abstract: The invention aims at providing personal identification in environments where non-contact is required, with high accuracy even though using a finger vein pattern images unclear and susceptible to positional deviations, wherein it has: a means for acquiring finger vein patterns without contact; a means for carrying out rotational correction using the outline of a finger as a method of taking out a vein pattern contained in the acquired image; a means for normalizing the position of the finger image with reference to the fingertip; a means for acquiring an overall vein pattern statistically by repetitively tracking regions of dark luminance intensities for a desired length from a desired position in the image; a matching means for comparing regions where vein patterns manifest vivid features; and a means for independent matching of subregions and evaluating positional deviations where matching is recognized.