A computer implemented method and apparatus for identifying logical blocks of text in a document where document structure information is absent. The rotary disk defines a receiving groove and includes a curved ruler. The clock-jitter tolerant DAC includes a dual switched-current DAC, a switched-capacitor DAC, an adder, and a switched-capacitor-resistor injection circuit. The device also may include a receiving unit configured to receive a second feature quantity dictionary from the server in response to the transmission. The method further includes projecting at least one of a beam, spark, or flame from an igniter located inside the center body. A storage compartment for the seating and cutting blades is formed in the impact tool handle and has a door pivotally mounted for opening and closing movement relative to the handle.