tailieunhanh - Báo cáo khoa học: "Current Research in the Development of a Spoken Language Understanding System using PARSEC*"

To develop a syntactic and semantic analysis using this framework, a network of the words for a given sentence is constructed. Each word is given some number indicating its position relative to the other words in the sentence. Once a word is entered in the network, the system assigns all of the possible roles the words can have by applying the lexical constraints (which specify legal word categories) and allowing the word to modify all the remaining words in the sentence or no words at all. Each of the arcs in the network has associated with it a matrix. | Current Research in the Development of a Spoken Language Understanding System using PARSEC Carla B. Zoltowski School of Electrical Engineering Purdue University West Lafayette IN 47907 February 28 1991 1 Introduction We are developing a spoken language system which would more effectively merge natural language and speech recognition technology by using a more flexible parsing strategy and utilizing prosody the suprasegmental information in speech such as stress rhythm and intonation. There is a considerable amount of evidence which indicates that prosodic information impacts human speech perception at many different levels 5 . Therefore it is generally agreed that spoken language systems would benefit from its addition to the traditional knowledge sources such as acoustic-phonetic syntactic and semantic information. A recent and novel approach to incorporating prosodic information specifically the relative duration of phonetic segments was developed by Patti Price and John Bear 1 4 . They have developed an algorithm for computing break indices using a hidden Markov model and have modified the context-free grammar rules to incorporate links between non-terminals which corresponded to the break indices. Although incorporation of this information reduced the number of possible parses the processing time increased because of the addition of the link nodes in the grammar. 2 Constraint Dependency Grammar Instead of using context-free grammars we are using a natural language framework based on the Parallel Architecture Sentence Constrainer Constraint Dependency Grammar CDG formalism developed by Maruyama 3 . This framework allows us to handle prosodic information quite easily Rather than coordinating lexical syntactic semantic and contextual modules to develop the meaning of a sentence we apply sets of lexical syntactic prosodic semantic and pragmatic rules to a packed structure containing a developing picture of the structure and meaning of a sentence. The CDG grammar .