Browse Prior Art Database

Method to Define Constrained Grammars

IP.com Disclosure Number: IPCOM000113895D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Daggett, G: AUTHOR [+5]

Abstract

Disclosed is a method to attach "action pointers" to productions in a grammar, and allow incremental redefinition of parts of the grammar to keep the application and recognizer state in tight synchrony.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Method to Define Constrained Grammars

      Disclosed is a method to attach "action pointers" to
productions in a grammar, and allow incremental redefinition of parts
of the grammar to keep the application and recognizer state in tight
synchrony.

      Speech recognition systems often use grammars to constrain the
possible search space.  Constraining the grammar reduces the
computational complexity of the search and generally increases
recognition accuracy.  Typically, the grammar is defined in BNF form,
or as allowable pairs of words.

There are two problems associated with grammars addressed in this
disclosure:
  1.  The application typically receives a string of recognized
      words which must be parsed to determine the appropriate
      actions to execute.  For example, "Do I have any mail?"
      must be parsed before the mail handler can be invoked.
  2.  The closer the coupling between the grammar and the
      application state, the better the recognition accuracy.
      Also, tighter coupling will lower the recognition complexity,
      either increasing recognition speed on a given system
      configuration, or allowing the application to run with
      reduced system resources (CPU cycles, memory).

This disclosure addresses both problems by:
  1.  Allowing the application to attach "action pointers" to
      each production to simplify the post processing of
      recognized strings.
  2.  Incrementally redefine parts of the grammar to keep the
      application and recognizer state in tighter synchrony.

      The key idea is to define grammars as "sentence templates,"
where each template is an allowable sequence of terminal and
non-terminal states.  In defining the permissible set of sentence
templates, the application can associate with each template the
ac...