A micro actuator for moving a head device in a track direction of a recording medium by a magnetic force generated between the magnetic cores. In an embodiment, the mobile wheelchair-assist robot includes a wheelchair interface component configured to exchange control information with a wheelchair controller. The first direction of propagation of the first light does not change relative to the first entity. The full or partial results of the speculative operations are cached in order to allow matching the cryptographic operation to the read data when it arrives. For a larger diameter or square rack column hole, the mounting pins extend completely through the holes where the longer spring element snaps behind the rack column.