An automatic optical coupling device that uses liquid to couple focused light into a light-guide is described. Other preferred embodiments include a clapper fixed at each of the opposite ends of the rod, and a grip slidably retained on the rod between a clapper at one end of the rod and a stop located between the opposite end of the rod and the midpoint of the rod, which allow a rider to use either end of the crop for cueing the horse. Additionally, the managing device includes a control system and a database. When the welding axle moves towards the workpiece, the distance which has to be covered until the part to be welded contacts the workpiece is detected. The sound processing strategy implemented includes an outer hair cell model. The STI structure comprises an upper insulating portion and a lower insulating portion, wherein the lower insulating portion includes a first insulator and an insulating layer surrounding the first insulator, the upper insulating portion includes a second insulator and a buffer layer surrounding the second insulator.