Knowledge based information retrieval system

• US 5,555,408 A
• Filed: 10/25/1993
• Issued: 09/10/1996
• Est. Priority Date: 03/27/1985
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Hatakeyama, Atsushi, Cohn, David, Fujisawa, Hiromichi, Kiuchi, Itsuko
• Primary Examiner(s): Heckler, Thomas M.
• Assistant Examiner(s): Chavis, John Q.
• Application Number:
  US08/141,039
• Time in Patent Office: 1,051 Days
• Field of Search: 395/650, 395/700, 395/600, 395/54, 395/60
• US Class Current: 1/1
• CPC Class Codes: G06F 16/3338 Query expansion
• CPC Class Codes: G06F 16/93 Document management systems
• CPC Class Codes: G06F 40/211 Syntactic parsing, e.g. based on context-free grammar [CFG] or unification grammars
• CPC Class Codes: G06F 40/284 Lexical analysis, e.g. tokenisation or collocates
• CPC Class Codes: G06F 40/30 Semantic analysis
• CPC Class Codes: G06T 11/206 Drawing of charts or graphs
• CPC Class Codes: Y10S 706/934 Information retrieval or Information management
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99935 Query augmenting and refining, e.g. inexact access

Abstract

An information retrieval system with good human-interface methods to give the system ease-of-use having two distinctive features with the first being visual interface and the second being natural language interpretation. The visual interface provides for one is visual interaction for local search and natural language interpretation provides for linguistic interaction for global search. The visual interface provides versatile views onto the contents of the knowledge base that the system has, controlling mechanisms for browsing through the knowledge base, a capability of showing relevant information for the users, and a mechanism for editing a query expression that describes information to retrieve. By using the visual interface for information retrieval, the users can easily create query expressions, by consulting and reacting with the system. The natural language interpretation makes use of a conceptual network as a knowledge-base that stores important concepts and relationships among these concepts. Based on knowledge and information represented in the conceptual network, the meaning of a noun phrase or a nominal compound which is a string of adjectives and nouns with some prepositions can be inferred. The inferred interpretation of such a noun phrase is paraphrased into an expression that the information retrieval system can handle. Therefore, the user of the system can simply describe the desired information in a language to get the desired information.

Claims

1. A knowledge based system for retrieving information by using a concept relation model which expresses knowledge by a plurality of interconnected nodes, each node represents a concept corresponding to information included in said node, said node being connected to other nodes by links, each of said links represents a relation between concepts represented by nodes connected by said link, comprising:

a first memory for storing concept names corresponding to said nodes, each concept name corresponds to a concept;

a second memory for storing information representing subsumption relations between different concepts corresponding to links connected between said concepts;

a third memory for storing information representing definitions of different kinds of relations;

a fourth memory for storing information representing relations between different concepts corresponding to links connected between said concepts; and

relation deducting means for inputting a string of words from a user of said system and deducting both concept names and relations between concepts from said inputted string of words by using knowledge stored in said first to fourth memory; and

retrieval means for retrieving information from at least one of said nodes based on said concept names and said relations between concepts deducted by said relation deducting means.

2. A knowledge base system for retrieving information by using a concept relation model which expresses knowledge y a plurality of interconnected nodes, each node represents a concept corresponding to information included in said node, said node being connected to other nodes by links, each of said links represents a relation between concepts represented by nodes connected by said link, comprising:

a first memory for storing concept names corresponding to said nodes, each concept name corresponds to a concept;

a second memory for storing information representing subsumption relations between different concepts corresponding to links connected between said concepts;

a third memory for storing information representing definitions of different kinds of relations;

a fourth memory for storing information representing relations between different concepts corresponding to links connected between said concepts; and

relation deducting means for inputting concept names from a user of said system and deducting relations between concepts indicated by said inputted concept names by using knowledge stored in said first to fourth memory;

retrieval means for retrieving information from at least one of said nodes based on said inputted concept names and said relations deducted by said relation deducting means;

a fifth memory for storing syntax rules for understanding at least one natural language;

a sixth memory for storing a lexicon, which can be edited based on the content of said first and third memories;

lexical analysis means for effecting lexical analysis by inputting a sentence written in the natural language and referring to information coming from said sixth memory;

syntactic analysis means for forming possible sentence structures based on results of the lexical analysis and information stored in said fifth memory; and

means for extracting and selecting only sentence structures appropriate in meaning relative to the inputted sentence formed based on a result of syntactic analysis by said relation deducting means.

3. A knowledge base system according to claim 2, wherein the inputted sentence written in the natural language consists of a series of nouns and said relation deducting means deducts the relation between different nouns constituting said series of nouns on the basis of an assembly of facts stored in a knowledge base described by the concepts and the relations.

4. A knowledge base system according to claim 2, wherein said syntactic analysis means outputs all the sentence structures, which are possible in view of the syntax rules as results of the syntactic analysis and deducts appropriateness in the meaning based on an assembly of facts stored in a knowledge base described by the concepts and the relations to select and output only those which are appropriate in the meaning, among the results of said syntactic analysis.

5. An information query system for querying desired information by using inputted abstract conceptual expressions expressed by combinations of concepts and relations between the concepts as querying conditions, comprising:

an input device for inputting an abstract conceptual expression as a query expression;

a dialogue window for displaying query expressions;

means for driving said dialogue window to display a network indicating mutual relation between different assemblies of concepts satisfying relations added to a current concept;

means for rewriting said dialogue window representing the network, responding to a modification of said dialogue window displaying query expressions, and rewriting the display of the query expression by replacing said concept by the current concept in the query expression, responding to a modification of the current concept to a certain concept displayed by said dialogue window displaying query expressions; and

means for querying a database containing various types of information according to the rewritten network and the rewritten query expression.

6. An information query system according to claim 5, wherein said means for rewriting the display includes means for searching concepts connected by a generic relationship added to the current concept in the query expression among the concepts connected with the current concept through subsumption relationships, displaying the concepts belonging to the ranks not higher than the concepts of lowest rank in the subsumption relations among these concepts and moving said current concept to a concept within said domain of display.

7. An information query system according to claim 5, wherein said means for rewriting the display includes means for imposing conditions one after another to the concept in the query expression, the current concept moving freely among the concepts in the query expression.

8. An information query system according to claim 5, wherein said means for rewriting the display includes means for adding a root to the concept, which is the object to be queried in the query expression and modifying the concept, which is the object to be queried.

9. An information query system according to claim 5, wherein said means for rewriting the display includes means for making the query of the concepts, to which the condition is imposed, in the query expression, possible one after another.

10. A knowledge based file retrieval system, comprising:

a user interface which inputs from a user a series of words, analyzes said series of words, converts said series of words into an internal query condition based on information related to various concepts and displays responses from said system and information input by said user;

a knowledge base for storing knowledge including said concepts and relations among said concepts;

wherein said stored knowledge is represented by concept nodes and relation links forming a concept network, wherein each of said nodes represents a concept and each of said links represents a relation among said concepts;

information search means for identifying concept nodes that match said internal query condition semantically; and

information retrieval means for retrieving at least one relevant file associated with said identified concept nodes.

11. A knowledge based file retrieval system according to claim 10 wherein said user interface permits said user to edit said internal query condition.

12. A knowledge based file retrieval system according to claim 11 wherein said user interface edits said internal query condition by adding or deleting conditions.

13. A knowledge based file retrieval system according to claim 10 wherein said user interface permits said user to edit said concept network.

14. A knowledge based file retrieval system according to claim 10 wherein said user interface edits said concept network by adding or deleting concept nodes.

15. A knowledge based file retrieval system according to claim 10 wherein said user interface implements operations through a multiwindow function.

16. A knowledge based file retrieval system according to claim 10 wherein said user interface displays said concept network in a hierarchial tree.

17. A knowledge based file retrieval system according to claim 10,

wherein said information storage means stores files representing documents;

wherein said concept nodes represent said documents; and

wherein said information retrieval means retrieves documents associated with said identified concept nodes.

18. A knowledge based file retrieval system according to claim 11,

wherein said information storage means stores files representing documents;

wherein said concept nodes represent said documents; and

wherein said information retrieval means retrieves documents associated with said identified concept nodes.

19. A document based file retrieval system according to claim 17 wherein said user interface permits said user to browse documents associated with said identified concept nodes.

20. A document based file retrieval system according to claim 18 wherein said user interface permits said user to browse documents associated with said identified concept nodes.

26. A knowledge based document retrieval system according to claim 11, wherein said user interface displays said concept network as a hierarchial tree.

21. A knowledge based document retrieval system, comprising:

a user interface which inputs from a user a series of words, creates a query expression and an internal query condition from a dialogue, including said inputted series of words, resulting from interaction by said user with said system, said query expression and said internal query condition being created based on information related to various concepts, and displays responses from said system and information input by said user;

a knowledge base for storing knowledge including said concepts and relations among said concepts, wherein said stored knowledge is represented by concept nodes and relation links forming a concept network, wherein each of said nodes represents a concept and each of said links represents a relation among said concepts;

information search means for identifying concept nodes that match said internal query condition semantically; and

information retrieval means for retrieving at least one document associated with said identified concept nodes.

22. A knowledge based document retrieval system according to claim 21, wherein said user interface permits said user to edit said internal query condition.

23. A knowledge based document retrieval system according to claim 22, wherein said user interface edits said internal query condition by adding or deleting conditions.

24. A knowledge based document retrieval system according to claim 21, wherein said user interface permits said user to edit said concept network.

25. A knowledge based document retrieval system according to claim 24, wherein said user interface edits said concept network by adding or deleting concept nodes.

27. A document retrieval system according to claim 21, wherein each of said documents are included within a file which are retrieved by said information retrieval means.

28. A knowledge based document retrieval system according to claim 21, wherein said user interface permits a user to browse said at least one document associated with said identified concept nodes.

29. A knowledge based document retrieval system according to claim 21 wherein said user interface implements operations through a multi-window function.

30. A knowledge based document retrieval system, comprising:

a user interface which inputs from a user a series of words, creates an internal query condition based on said series of words and displays responses from said system and information input by said user;

a knowledge base for storing knowledge including concepts and relations among said concepts, wherein said stored knowledge is represented by concept nodes and relation links forming a concept network, wherein each of said nodes represents a concept and each of said links represents a relation among said concepts;

information storage means for storing said knowledge base and documents, wherein each document is associated with at least one concept node defined in said knowledge base;

information search means for identifying concept nodes that match said internal query condition represented in terms of concepts and relations defined in said knowledge base; and

information retrieval means for retrieving documents from said information storage means associated with said identified concept nodes.

31. A knowledge based document retrieval system according to claim 30 wherein said user interface permits said user to edit said internal query condition.

32. A knowledge based document retrieval system according to claim 31, wherein said user interface edits said internal query condition by adding or deleting conditions.

33. A knowledge based document retrieval system according to claim 30, wherein said user interface permits said user to edit said concept network.

34. A knowledge based document retrieval system according to claim 33, wherein said user interface edits said concept network by adding or deleting concept nodes.

35. A knowledge based document retrieval system according to claim 30, wherein said user interface displays said concept network as a hierarchial tree.

36. A knowledge based document retrieval system according to claim 30, wherein said user interface implements operations through a multi-window function.

37. A knowledge based document retrieval system according to claim 30, wherein each of said documents are included within a file which are retrieved by said information retrieval means.

38. A knowledge based document retrieval system according to claim 30, wherein said user interface permits said user to browse said documents associated with said identified concept nodes.