Polyvinyl chloride fibers obtainable by molding a resin composition containing 100 parts by weight of a vinyl chloride resin, from 3 to 20 parts by weight of a compatible chlorinated vinyl chloride resin, from 10 to 30 parts by weight of a heat resistant chlorinated vinyl chloride resin, and from 0. In one aspect, a degree of consistency relative to two or more people working on one or more objects and dependencies between the objects is determined to derive scores for the component links. The collar mounts to the walls of the container. The power is intermittently resupplied to and cut off from the signal sensor during the power saving mode.