| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technique capable of preventing the loss of a portable article by early detecting that the portable article separates from a holder. <P>SOLUTION: A center device determines, by use of a plurality of radio ID readers connected to the center device, whether or not the tag ID of a first radio ID tag mounted on a first object to be held by a holder and the tab ID of a second radio ID tag mounted on a second object to be held by the holder are received within a time regarded as the same time from one radio ID reader of the radio ID readers. When it is determined that the two tag IDs are not received within the time regarded as the same time from the one radio ID reader, a notice is given to the holder. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
