JPH0481973A - Document retrieving device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention allows a user to create and input a search condition expression consisting of keywords and logical operators, and to search a document database for documents that match this search condition expression. The present invention relates to a document search device.

Conventional Technology Conventional 1 Document search devices have various search methods, one of which is to use a knowledge base that is a keyword connection table that describes the degree of association between each keyword to enable related keyword searches and ambiguous searches. The present applicant has proposed, for example, Japanese Patent Application No. 8291/1988 "Document Retrieval Apparatus". In such a document search device, even if the user does not remember exact keywords, by performing a vague search using a keyword connection table, an appropriate amount of search results can be obtained.

Problems to be Solved by the Invention However, even with such a fuzzy search method using a keyword connection table, if there are keywords that have different spellings but the same meaning, such as synonyms,
Failure to implement appropriate connection values may result in missed searches. This is of course true for conventional document search devices that do not have keyword connection tables.

Means for Solving the Problem A document search device that creates and inputs a search condition expression that combines keywords and logical operators and searches for documents that match this search condition expression, or a document search device that searches for documents that match this search condition expression, or The system has a described keyword connection table, creates and inputs a search condition expression combining keywords and logical operators when searching for documents, and uses the keyword connection table to search for documents that match this search condition expression. In a document retrieval device, a synonym table is provided that holds a group of synonymous words as a table, and when a keyword in an input search condition expression exists in this synonym table, the synonym is used in the search condition expression. Document selection means is provided for searching documents based on the expanded search conditional expression, which has conditional expression expansion means that performs synonym expansion processing to be incorporated together with a predetermined logical operator.

Groups of words that form action synonyms are held in a synonym table, and when a search condition expression is input, if any keyword among them exists in the synonym table, that synonym will also be included in the search condition expression. By performing the search process after performing the expansion process to incorporate, it is possible to perform a search with fewer omissions. Especially when using keyword connection tables,
By adding the synonym expansion function, the deficiencies of only the keyword connection table can be covered, and the fuzzy search function will be further improved.

Example An embodiment of the present invention will be described based on the drawings.

First, an overview of a document retrieval device to which the present invention is applied will be explained with reference to the block diagram of FIG. This embodiment is applied to the previously proposed content that uses a keyword connection table. When the keyword extraction section 1 receives the registered document 2, it extracts the keyword, and outputs the keyword and information about the registered document 2 to the document information management section 3, the keyword connection table processing section 4, and the inverted file creation section 5. The document information management unit 3 stores the extracted keywords and bibliographic information 6 in a file 7, and creates a database in a format that can be used during a search. The keyword connection table processing unit 4 creates a keyword connection table that describes the necessary keywords as well as the connections between related keywords and their degree of association, and files the file 9.
It is stored in . Here, the keyword connection table has a list structure, for example, and is sorted in descending order of relevance. The inverted file creation section 5 creates an inverted file 10 that associates each keyword with the registered document 2, and stores it in a file 11. That is, the inverted file 10 is a collection of pointers pointing from keywords to documents containing the keywords.

Next, a document selection section (document selection means) 12 is provided. This document selection section 12 is intended to extract document files that are closer to the subject matter/required concept of the search user using a group of keywords. Output to. From there, the user selects the keywords necessary for the requested subject, or selects free keywords, and applies the necessary logical operators (AND, OR, or NOT).
A combined search condition expression is created, and a display search request is input again from the keyboard 13. The document selection section 12 includes a request processing section 15 , a sorting section 16 , a display management section 17 , a keyword correlation speed calculation section 18 , and a document accuracy calculation section 19 . The request processing unit 15 is the keyboard 13
The keywords in the search condition expression received from are transferred to the keyword relationship speed calculation section 18. The keyword relationship speed calculation unit 18 extracts related keywords and their related information regarding the transferred keyword from the keyword connection table 8. The extracted keyword group is sorted by the sorting unit 16 in order of strong relevance and output to the display management unit 17.

The display management unit 17 outputs this related keyword group to the display 14 and displays it to the user. When the user further selects and inputs necessary keywords according to this display, the final keyword group is sent to the request processing unit 15 together with the document selection request.

Upon receiving the document selection request, the request processing section 15 causes the document certainty calculation section 19 to transfer the keyword group.

At the same time, the keyword connection table processing unit 4 is instructed to change the weight of related information regarding the final keyword group. The document probability calculation section 19 calculates the document probability for the file 7 of the registered document 2 using the received keyword group, keyword connection table 8, and inverted file 10, and transfers the result to the sorting section 16. When the necessary document accuracy calculations are completed, the documents are sorted by the sorting unit 16 and displayed on the display 14 as search results.

Accordingly, in this embodiment, as shown in FIG. It is something that has been set.

Here, the synonym table 20 describes two or more word groups that have different notations but the same meaning, and an example of the contents is shown in FIG. 2.

In such a configuration, the keywords in the search condition expression inputted from the keyboard 13 are processed in the document accuracy calculation unit 19 and the keyword relationship speed calculation unit 18 in accordance with the processing request in the request processing unit 15, similar to the content already proposed. However, prior to this, synonym expansion processing using the synonym table 20 is performed. Synonym expansion means that when an arbitrary keyword in the search condition expression exists in the synonym table 20, a word with the same meaning in another notation is combined with the word of this keyword by logical sum (OR). , refers to substituting the corresponding keyword in the original search condition expression. for example,
If the search condition expression before expansion is (AI)*(expert system), the search condition expression after synonym expansion using the synonym table 20 in FIG. 2 is ((AI)+(
Artificial Intelligence)) * ((Expert System) + (ES
)) (“ne” indicates logical product, “+” indicates logical sum)
. The request processing unit 15 transfers the search condition expression expanded into synonyms in this way to the document certainty calculation unit 19 and the keyword correlation speed calculation unit 18, and performs document search processing in the same manner as the already proposed content. Therefore, if there is a synonym that the user is not aware of, even if the synonym is not entered as a search keyword, the search will be performed with the synonym taken into account, which will prevent omissions in the desired document search. It becomes less. Particularly, in the case of the present embodiment, which uses a keyword connection table that enables ambiguous searches, it becomes easy to handle synonyms that are difficult to implement using keyword connections. By adding and combining such a synonym expansion function, the deficiencies caused by only the keyword connection table can be covered, and the ambiguous search function is further improved. 8. Processing such as adding/updating/deleting synonyms in the synonym table 20 can be easily performed.

Effects of the Invention As described above, the present invention stores a group of synonymous words in a synonym table, and when a search condition expression is input, if any keyword among the keywords exists in the synonym table, Since synonyms are also expanded into the search condition expression before the search process is performed, it is possible to perform a search with fewer omissions, especially when using a keyword connection table. By adding the synonym expansion function, the deficiencies of only the keyword connection table can be covered, and the fuzzy search function can be further improved.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and the first part is a block diagram, and the second part is an explanatory diagram showing the contents of a synonym table.

Claims (1)

[Claims] 1. In a document search device that creates and inputs a search condition expression that combines keywords and logical operators, and searches for documents that match this search condition expression, a group of words forming synonyms is used. A synonym table is provided in which a synonym table is held as a table, and when a keyword in an input search condition expression exists in this synonym table, the synonym is incorporated into the search condition expression together with a predetermined logical operator. 1. A document retrieval device, comprising: a conditional expression expansion unit that performs expansion processing; and a document selection unit that searches for documents based on the expanded search conditional expression. 2. Have a keyword connection table that describes the degree of association between keywords, create and input a search condition expression that combines keywords and logical operators when searching documents, and use the keyword connection table to create and input a search condition expression. In a document retrieval device configured to search for documents that match, a synonym table is provided that holds a group of synonymous words as a table, and a keyword in an input search condition expression exists in this synonym table. document selection means for searching documents based on the expanded search condition expression; A document retrieval device characterized in that: