Regular Approximation of Context-Free Grammars for Chinese Language

碩士 === 臺灣大學 === 電機工程學研究所 === 95 === As parsing context-free grammars is time-consuming, converting the original grammars into approximated regular languages can reduce the complexity. Based on the approaches, the so-called recursive transition network (RTN, which is an -NFA) is the most adequate ap...

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Bibliographic Details
Main Authors: Chi-Cheng Li, 李奇錚
Other Authors: 顏嗣鈞
Format: Others
Language:en_US
Published: 2007
Online Access:http://ndltd.ncl.edu.tw/handle/90946857305623515968
Description
Summary:碩士 === 臺灣大學 === 電機工程學研究所 === 95 === As parsing context-free grammars is time-consuming, converting the original grammars into approximated regular languages can reduce the complexity. Based on the approaches, the so-called recursive transition network (RTN, which is an -NFA) is the most adequate approximated algorithm. The refinement is parameter RTN, which is more adequate than the original RTN. The suggested parameter is 2. However, the parameter RTN requires large memories, which limits its role in practical applications. In this thesis, we propose a refinement of the parameter RTN which can alleviate the memory requirement effectively. The refined RTN (called group RTN) utilizes the prosperities of Chinese. It classifies the terms into different groups. Based on the different groups of terms, we integrate similar states and transitions of RTN into one. Using this scheme, the memory requirement of the RTN method can be reduced considerably.