A net comprising a combination of a plurality of lengths of a first material with a plurality of lengths of a second material having a relatively lower elongation than that of the first material in which at least some of the lengths of first material are transverse to at least some of the lengths of second material. An oil tank of a turbo chiller compressor includes a bottom plate and side plates standing upright so as to extend upward from an outer peripheral edge portion of the bottom plate. A driver level message to the remote client hardware is generated. The computer-implemented method also includes monitoring, using participant presence information available in a user presence database, whether the first participant and the second participant are available to conducts the teleconference within the conference period. A related keyword having a certain association is extracted as a same-region keyword in a same region as the target keyword.