一种基于句子分割的文法自动推导算法

Automatic grammar inference based on sentence segmentation for spoken Chinese

信息咨询口语对话系统中的领域文法规则往往需要专家来人工设计。该文针对一种面向汉语口语的上下文无关增强文法,提出了一种基于句子分割的文法自动推导算法。其基本思想是:用初始规则集对训练例句进行分析,若不能得到完整的语法树,则先对分析结果进行消歧和归一化,然后根据顶层成分递归地推导出缺少的规则,并更新已有的规则集。为了提高最终文法的性能,在例句处理顺序和规则更新上对算法基本流程做了改进。在天气预报查询领域进行了实验,结果文法的句法分析准确率在初始规则集为空时达到了64.8%,在初始规则集只包含日期相关规则时达到了86.4%。

The grammar for spoken dialogue systems for information enquiry is often manually designed by experts.Automatic grammar inference method based on sentence segmentation was developed based on an enhanced context free grammar for spoken Chinese.The system parses the training sentences with an initial rule set.If the parsed syntactic tree is incomplete,the top-most constituents are used to recursively infer the missing rules after disambiguation and normalization,and then the rule set is updated.The output grammar is improved by adjusting the processing order of the training sentences to refine the process.Evaluations based on weather forecast enquiries gave a parsing accuracy for the output grammar of 64.8% with an empty initial rule set and 86.4% with an initial rule set including only rules for date descriptions.