A Power-over-Ethernet communication system dynamically provides power and data communications over a communications link. A lower-ordered indexing text fragment at lower order than the initial indexing text fragment is associated with a set of one or more candidate linked body text fragments at lower order than the highest order member of the initial set of one or more candidate linked body text fragments. Further, since the cover member invisibly covers the bolt head portion, improved safety and outer appearance is obtained. The method further includes determining whether the received video frames contain the predefined hand gesture based on the hand shape detection. On the inner portion of the reverse side of the sleeve a projection made of flexible material strikes the interior portion of individual grooves as the sleeve slides along the rod. The multi-beam light source includes a first substrate where a plurality of optical fibers each having a core portion and a clad portion surrounding the core portion coaxially are fixed at predetermined intervals, and a second substrate where a plurality of similar optical fibers are fixed at predetermined intervals.