CONTENTS RETRIEVAL DEVICE

• US 20090300011A1
• Filed: 08/05/2008
• Published: 12/03/2009
• Est. Priority Date: 08/09/2007
• Status: Active Grant

• Current Assignee: Intertrust Technologies Corporation (Fidelio Acquisition Co LLC)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Takata, Kazutoyo, Tsuzuki, Takashi, Matsuura, Satoshi
• Granted Patent: US 7,831,610 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/3322 using system suggestions G06F16/3325 takes precedence

Abstract

The contents retrieval device (100) which can present an appropriate related keyword to a user even when the object user wishes to retrieve dynamically changes includes a contents estimation unit (107) which retrieves the contents according to the search keyword, the document space database (103) where the plurality of document spaces according to the occurrence frequency of the keyword is stored, the document space selection unit (104) which selects the narrowing-down document space and the expansion document space from the document space database (103) according to the search keyword and the occurrence frequency of the document space indicating a degree of relevance with the contents according to the search keyword, the related keyword estimation unit (108) which selects the keywords corresponding to the narrowing-down document space and the expansion document space as the narrowing-down keyword and the expansion keyword respectively, and the output unit which displays the selected narrowing-down keyword and the expansion keyword.

Claims

1. A contents retrieval device which displays a related keyword related to a search keyword used for retrieving contents based on a contents database in which each of a plurality of contents is stored with a plurality of keywords, said contents retrieval device comprising:

a keyword acquisition unit configured to acquire the search keyword;

a content retrieval unit configured to retrieve the contents according to the search keyword from the contents database;

a document space storage unit in which document space information is stored, the document space information indicating a degree of relevance between each contents and each keyword, and the document space information being categorized according to an occurrence frequency indicating occurrence of each keyword included in the contents database appears, with respect to each contents in the contents database;

a document space selection unit configured to select (i) second document space information including the keyword used for narrowing down the number of contents to be retrieved and (ii) third document space information used for expanding the number of contents to be retrieved, according to a magnitude relationship of the occurrence frequency of the document space information stored in said document space storage unit, using, as a basis, an occurrence frequency of the keyword in first document space information which indicates a degree of relevance between the search keyword and contents according to the search keyword; and

a display unit configured to display each of keywords which satisfies a predetermined standard in the second document space information and the third document space information selected by said document space selection unit, as the related keyword.

2. The contents retrieval device according to claim 1,

wherein the occurrence frequency of the second document space information or the third document space information is at least equal to or more than the occurrence frequency of the first document space information, or less than the occurrence frequency of the first document space information.

3. The contents retrieval device according to claim 1,

wherein said document space selection unit includes

a first document space selection unit configured to select, as narrowing-down document space information, the second document space information corresponding to the occurrence frequency less than the occurrence frequency of the first document space information, from said document space storage unit, and

said display unit is configured to display a keyword which satisfies a predetermined standard in the narrowing-down space information as the related keyword.

4. The contents retrieval device according to claim 3,

wherein the document space selection information includes

a second document space selection unit configured to select, as expansion document space information, the third document space information corresponding to an occurrence frequency which is equal to or more than the occurrence frequency of the first document space information from said document space storage unit, and

said display unit is configured to display, as the related keyword, (i) a narrowing-down keyword which is the keyword that satisfies the predetermined standard in the narrowing-down document space and (ii) an expansion keyword which is a keyword that satisfies a predetermined standard in the expansion space information.

5. The contents retrieval device according to claim 4, further comprising

a related keyword selection unit configured to select, from the contents database, the narrowing-down keyword and the expansion keyword respectively corresponding to the narrowing-down document space information and the expansion document space information such that a keyword indicating a larger degree of relevance to the contents retrieved by said contents retrieval unit is more likely selected,

wherein said display unit is configured to display the narrowing-down keyword and the expansion keyword as the related keyword, and to display an attribute of the contents retrieved by said contents retrieval unit.

6. The contents retrieval device according to claim 5,

wherein said document space storage unit is configured to store the document space information for each section of the keywords categorized using a DF (Document Frequency) value as the occurrence frequency.

7. The contents retrieval device according to claim 5,

wherein said contents retrieval unit is configured to determine that a narrowing-down search should be performed when said keyword acquisition unit acquires the narrowing-down keyword as the search keyword by a user'"'"'s selection of the narrowing-down keyword displayed by said display unit, and to retrieve the contents according to the search keyword and the other keywords acquired by said keyword acquisition unit before the search keyword.

8. The contents retrieval device according to claim 7,

wherein said contents retrieval unit is configured to determine that an expansion search should be performed when said keyword acquisition unit acquires the expansion keyword as the search keyword by a user'"'"'s selection of the expansion keyword displayed by said display unit, and to retrieve the contents according to the search keyword and the other keywords acquired by said keyword acquisition unit before the search keyword.

9. The contents retrieval device according to claim 8, further comprising:

a search condition determining unit configured to determine (i) that the narrowing-search is performed by said contents retrieval unit when said keyword acquisition unit acquires the narrowing-down keyword by the user'"'"'s selection of the narrowing-down keyword displayed by said display unit, and (ii) that the expansion search should be performed when said keyword acquisition unit acquires the expansion keyword as the search keyword by a user'"'"'s selection of the expansion keyword displayed by said display unit, and to retrieve the contents according to the search keyword and the other keywords acquired by said keyword acquisition unit before the search keyword; and

a ratio determining unit configured to determine a ratio of the number of the narrowing-down keyword and the number of the expansion keyword to be displayed by said display unit, according to a result determined by said search condition determining unit,

wherein said related keyword selection unit is configured to select the narrowing-down keyword and the expansion keyword which are according to the ratio determined by said ratio determining unit in number.

10. The contents retrieval device according to claim 9,

wherein said ratio determining unit is configured to determine a ratio where the number of the narrowing-down keyword is larger than the number of the expansion keyword when said search condition determining unit determines that the narrowing-down search is performed.

11. The contents retrieval device according to claim 9,

wherein said ratio determining unit is configured to determine a ratio where the number of the expansion keyword is larger than the number of the narrowing-down keyword when said search condition determining unit determines that the expansion search is performed.

12. The contents retrieval device according to claim 5,

wherein said contents retrieval unit is configured (i) to determine whether or not the number of overlapping contents between a group of contents according to the search keyword and a group of contents according to another keyword acquired by said keyword acquisition unit before the search keyword is equal to or more than a threshold,

(ii) to retrieve the contents according to the search keyword and the other keyword when it is determined that the number of overlapping contents is equal to or more than the threshold, and

(iii) to retrieve the contents according to the search keyword only when it is determined that the number of overlapping contents is less then the threshold.

13. The contents retrieval device according to claim 5,

wherein said related keyword selection unit is configured to select a keyword indicating a degree of relevance equal to or more than the threshold, as the narrowing-down keyword or the expansion keyword.

14. The contents retrieval device according to claim 5,

wherein said related keyword selection unit is configured to generate a bound related keyword by binding the plurality of narrowing-down keywords or the expansion keywords when said related keyword selection unit selects the plurality of narrowing-down keywords or the expansion keywords, and when the number of overlapping contents in groups of contents each of which corresponds to the plurality of narrowing-down keywords or the expansion keywords,

said display unit is configured to display the bound related keyword instead of the plurality of narrowing-down keyword and the expansion keywords.

15. The contents retrieval device according to claim 5,

wherein, in an associative dictionary indicating a large degree of relevance to the contents retrieved by said contents retrieval unit and indicating relevance between each keyword, said related keyword selection unit is configured to select, from the contents database, the narrowing-down keyword and the expansion keyword respectively corresponding to the narrowing-down document space information and the expansion document space information such that a keyword indicating a larger relevance with the search keyword is more likely selected.

18. The contents retrieval device according to claim 1,

wherein said document space selection unit is configured to select, (i) when narrowing down the number of contents to be retrieved, the document space information having a smaller occurrence frequency than that of the keyword in the first document space information, as the second document space information including the keyword used for narrowing down the number of contents to be retrieved, and (ii) when expanding the number of contents to be retrieved, the document space information having an occurrence frequency equal to or larger than that of the keyword in the first document space information, as the third document space information including the keyword used for expanding the number of contents to be retrieved.

16. A contents retrieval method to display a related keyword related to a search keyword used for retrieving contents based on a contents database in which each of a plurality of contents is stored with a plurality of keywords, said contents retrieval method comprising:

acquiring the search keyword;

retrieving the contents according to the search keyword from the contents database;

using a document space storage unit in which document space information is stored, the document space information indicating a degree of relevance between each contents and each keyword, and the document space information being categorized according to an occurrence frequency indicating occurrence of each keyword included in the contents database appears, with respect to each contents in the contents database;

selecting (i) second document space information including the keyword used for narrowing down the number of contents to be retrieved and (ii) third document space information used for expanding the number of contents to be retrieved, according to a magnitude relationship of the occurrence frequency of the document space information stored in the document space storage unit, using, as a basis, an occurrence frequency of the keyword in first document space information which indicates a degree of relevance between the search keyword and contents according to the search keyword; and

displaying a each of keywords which satisfies a predetermined standard in the second document space information and the third document space information selected by the selecting, as the related keyword.

17. A program to display a related keyword related to a search keyword used for retrieving contents based on a contents database in which each of a plurality of contents is stored with a plurality of keywords, said program causing a computer to execute:

acquiring the search keyword;

retrieving the contents according to the search keyword from the contents database;

using a document space storage unit in which document space information is stored, the document space information indicating a degree of relevance between each contents and each keyword, and the document space information being categorized according to an occurrence frequency indicating occurrence of each keyword included in the contents database appears, with respect to each contents in the contents database;

selecting (i) second document space information including the keyword used for narrowing down the number of contents to be retrieved and (ii) third document space information used for expanding the number of contents to be retrieved, according to a magnitude relationship of the occurrence frequency of the document space information stored in the document space storage unit, using, as a basis, an occurrence frequency of the keyword in first document space information which indicates a degree of relevance between the search keyword and contents according to the search keyword; and

displaying each of keywords which satisfies a predetermined standard in the second document space information and the third document space information selected by the selecting, as the related keyword.