Abstract: According to one embodiment, a file system includes a hash value calculator, an access controller and a deduplication controller. The hash value calculator calculates a hash value of at least one data block in a file to be stored in storage. The access controller stores, when the at least one data block includes a first data block and when a first hash value of the first data block is calculated, the first data block in a first location of the storage determined based on the first hash value, by using the first hash value as an identifier. The deduplication controller prevents the first data block from being stored in the first location when an effective second data block is already stored in the first location.

Abstract: A plastic film punching apparatus is improved to prevent a waste 15 from being caught in a cylindrical punch blade 2. The apparatus includes a punch blade 2 comprising a saw-toothed edge which includes mountain portions and valley portions formed alternately with each other. A protrusion 5 is disposed internally of the punch blade 2 to protrude beyond the position of height H1 of the bottoms 7 of valley portions and toward the position of height H2 of the tops 6 of mountain portions. An annular clearance 8 is formed between the punch blade 2 and the protrusion 5.

Abstract: A plastic film punching apparatus is improved to prevent a waste 15 from being caught in a cylindrical punch blade 2. The apparatus includes a punch blade 2 comprising a saw-toothed edge which includes mountain portions and valley portions formed alternately with each other. A protrusion 5 is disposed internally of the punch blade 2 to protrude beyond the position of height H1 of the bottoms 7 of valley portions and toward the position of height H2 of the tops 6 of mountain portions. An annular clearance 8 is formed between the punch blade 2 and the protrusion 5.