SYSTEMS AND METHODS FOR BUILDING AN ELECTRONIC DICTIONARY OF MULTI-WORD NAMES AND FOR PERFORMING FUZZY SEARCHES IN THE DICTIONARY

• US 20080091413A1
• Filed: 09/24/2007
• Published: 04/17/2008
• Est. Priority Date: 10/13/2006
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: El-Shishiny, Hisham, Volkov, Pavel
• Granted Patent: US 8,055,498 B2
• Time in Patent Office: Days
• US Class Current: 704/10
• CPC Class Codes: G06F 16/322 Trees
• CPC Class Codes: G06F 40/242 Dictionaries

Abstract

The present invention automatically builds a contracted dictionary from a given list of multi-word proper names and performs fuzzy searches in the contracted dictionary. The contracted dictionary of proper names includes two linked trie-based dictionaries: a first dictionary is used to store single word names, each word name having an ID number; and a second dictionary is used to store multi-word names encoded with ID numbers. Information related to the multi-word names is also stored as a gloss to the terminal node of the multi-word entry of the trie-based dictionary. An approximate lookup for a multi-word name is conducted first for each word of the multi-word name using an approximate matching technique such as a phonetic proximity or a simple edit distance. Accordingly, N suggestions is determined for each word of the multi-word name under consideration. Then, multi-word candidates are assembled in ID notation. Finally, an approximate search for each assembled candidate is performed based on an edit distance or a n-grams approximate string matching. Edit distances and N-grams are used to measure how similar two strings are. The result is a set of multi-word suggestions in an ID notation. This ID notation is encoded back to the original form using the first trie-based dictionary.

Claims

1. A method for automatically building a contracted dictionary from a given list of multi-word units, comprising:

receiving an input list of original multi-word units;

transforming the original multi-word units into single word elements;

associating an identifier with each single word element to obtain a collection of unique identifiers, each identifier being associated with a single word element;

storing the collection of identifiers and associated single word elements in a letter dictionary based on a trie, wherein;

each entry is a single words element;

letters of the single word elements are nodes of the trie; and

identifiers are glosses attached to the terminal nodes of the trie;

encoding each original multi-word unit in the input list by replacing each single word element within each multi-word unit by the associated identifier;

storing the encoded multi-word units in an identifier trie-based dictionary, wherein each entry is a set of identifiers representing a multi-word unit and each node is an identifier; and

building a contracted dictionary by contracting the letter trie-based dictionary and the identifier trie-based dictionary;

the contracting comprising, for the letter trie-based dictionary and the identifier trie-based dictionary, merging trie nodes while preserving each entry of the letter trie-based dictionary and each entry of the identifier trie-based dictionary.

2. The method according to claim 1, wherein receiving an input list of original multi-word units further comprises:

associating abstract information with each original multi-word unit.

3. The method according to claim 2, wherein storing the encoded multi-word units in an identifier trie-based dictionary further comprises:

attaching to each terminal node, the abstract information associated with the multi-word unit.

4. The method according claim 1, further comprising:

storing in a database the association of unique identifiers with single word elements.

5. The method according claim 2, wherein merging the trie nodes further comprises:

merging trie nodes whenever the trie nodes have identical abstract information.

6. The method according to claim 1, wherein merging the trie nodes further comprises:

merging trie nodes without introducing any additional entry; and

merging trie nodes without losing existing entries.

7. The method according to claim 1, wherein the method is executed in a server;

further comprising;

receiving a list of multi-word units from a client; and

sending back to the client a contracted dictionary.

8. A system for automatically building a contracted dictionary from a given list of multi-word units, comprising:

a system for receiving an input list of original multi-word units;

a system for transforming the original multi-word units into single word elements;

a system for associating an identifier with each single word element to obtain a collection of unique identifiers, each identifier being associated with a single word element;

a system for storing the collection of identifiers and associated single word elements in a letter dictionary based on a trie, wherein;

each entry is a single words element;

letters of the single word elements are nodes of the trie; and

identifiers are glosses attached to the terminal nodes of the trie;

a system for encoding each original multi-word unit in the input list by replacing each single word element within each multi-word unit by the associated identifier;

a system for storing the encoded multi-word units in an identifier trie-based dictionary, wherein each entry is a set of identifiers representing a multi-word unit and each node is an identifier; and

a system for building a contracted dictionary by contracting the letter trie-based dictionary and the identifier trie-based dictionary, the system for building a contracted dictionary further comprising, for the letter trie-based dictionary and the identifier trie-based dictionary, a system for merging trie nodes while preserving each entry of the letter trie-based dictionary and each entry of the identifier trie-based dictionary.

9. A program product stored on a computer readable medium, which when executed, automatically builds a contracted dictionary from a given list of multi-word units, the computer readable medium comprising program code for:

receiving an input list of original multi-word units;

transforming the original multi-word units into single word elements;

associating an identifier with each single word element to obtain a collection of unique identifiers, each identifier being associated with a single word element;

storing the collection of identifiers and associated single word elements in a letter dictionary based on a trie, wherein;

each entry is a single words element;

letters of the single word elements are nodes of the trie; and

identifiers are glosses attached to the terminal nodes of the trie;

encoding each original multi-word unit in the input list by replacing each single word element within each multi-word unit by the associated identifier;

storing the encoded multi-word units in an identifier trie-based dictionary, wherein each entry is a set of identifiers representing a multi-word unit and each node is an identifier; and

building a contracted dictionary by contracting the letter trie-based dictionary and the identifier trie-based dictionary;

the contracting comprising, for the letter trie-based dictionary and the identifier trie-based dictionary, merging trie nodes while preserving each entry of the letter trie-based dictionary and each entry of the identifier trie-based dictionary.

10. A method for performing fuzzy searches in a contracted dictionary of multi-word units, the contracted dictionary comprising two contracted trie-based dictionaries:

a letter trie-based dictionary comprising single word elements, each word element having an identifier, each identifier being associated with a single word element, wherein each entry is a single word element, letters of the single word elements are nodes of the trie, and identifiers are glosses attached to the terminal nodes of the trie; and

an identifier trie-based dictionary comprising multi-word units encoded with the identifiers wherein each entry is a set of identifiers representing a multi-word unit and each node is an identifier;

the method comprising;

receiving a request comprising a multi-word unit;

transforming the multi-word unit into single word elements;

for each single word element, identifying in the letter trie-based dictionary a suggested word element with an identical string of letters and if none exists, applying on the letter trie-based dictionary an approximate matching technique for generating at least one suggested single word element with a letter string as similar as possible to the single word element;

for each suggested word element, extracting from the letter trie-based dictionary the suggested single word element encoded with an identifier, each identifier being associated with a single word element;

generating at least one multi-word unit candidate encoded with identifiers by assembling identifiers of encoded existing and suggested single word elements;

for each encoded multi-word unit candidate, applying on the identifier trie-based dictionary, an approximate matching technique for obtaining at least one suggested multi-word unit encoded with identifiers as similar as possible to the encoded multi-word unit candidate; and

for each encoded suggested multi-word unit, replacing each identifier by the associated single word element.

11. The method according to claim 10, wherein applying on the letter trie-based dictionary an approximate matching technique for generating at least one suggested word element, further comprises:

rejecting and ranking suggested word elements using a proximity factor;

12. The method according to the claim 11, wherein the proximity factor is based on a phonetic proximity.

13. The method according to claim 11, wherein the proximity factor is based on an edit distance.

14. The method according to claim 10, wherein the approximate matching technique is based on an edit distance.

15. The method according claim 10, wherein the approximate matching technique is based on n-gram proximity.

16. The method according to claim 10, wherein the method is executed in a server, further comprising:

receiving from at least one client, at least one request, each request comprising at least one multi-word unit; and

sending back to each client, in response to each request, at least one suggested multi-word unit for each multi-word unit.