A crank signal generated by a crank angle sensor has a front pulse missing portion and a back pulse missing portion in a pulse train of every predetermined angle interval. The removable hitch attachment includes a hitch mount configured to permit mounting of a hitch onto the removable hitch attachment. Presentation of graphic fragments from the source document help to improve a user’s ability to select among documents provided in the search results more efficiently. The IOC time-dependent characteristics are totally eliminated by the randomized feedback signal because no repeated signal is applied to the IOC.