| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce retrieval omissions and nonconforming documents by retrieving a document having geographic relationship even when there is no analyzed geographic information. <P>SOLUTION: The document retrieval device refers to place name storage means on the basis of formal place names including an input prefectural name to a block number to acquire a name recognition degree, and omits place names with recognition degrees lower than a predetermined threshold. Even if the upper hierarchy of the formal place names is omitted, when the residual place names have uniqueness, the upper-hierarchy place name part is omitted. When the recognition degree of place names from which the upper-hierarchy place name part is omitted is higher than the sum of the recognition degrees of the other place names, the place name is extracted as the retrieval object. The document retrieval device thus retrieves a document including an input keyword and at least one of the extracted place names. <P>COPYRIGHT: (C)2013,JPO&INPIT |
