| 摘要 |
<P>PROBLEM TO BE SOLVED: To reduce the size of a retrieval index without decreasing retrieval accuracy in the case of creating the retrieval index in response to a retrieval request for uniquely acquiring a specific position of a specific document. <P>SOLUTION: A position where an index key is extracted is determined based on the feature of a character code expressing a character from the whole or partial area of an inputted document, and an index key configured of the combination of one or more characters lying at the position is extracted from the whole or partial area of the document to associate the index key with an appearance position in the document, where the index key appears, to output to an index DB. Furthermore, a partial area in a certain document is accepted as a search query, and from the search query, a position where the query key is extracted is determined based on the feature of the character code expressing the character and a query key configured of the combination of one or more characters is extracted. The index DB is searched based on the query key, and a search result is outputted. <P>COPYRIGHT: (C)2012,JPO&INPIT |
