| 摘要 |
PROBLEM TO BE SOLVED: To create a database of data to which a position tag is attached so that, no matter how large the database is, the retrieval performance is optimized to make position-based inquiries on a specific scale and with a specific precision. SOLUTION: A hierarchic index in which the size of a grid and the precision of a coordinate value are correlated with each other is constructed, thereby accurately estimating an entry coordinate value in a database so that precision information is included in a part of a one-dimensional index. COPYRIGHT: (C)2005,JPO&NCIPI
|
