Spoken Language Processing by Minimum Total Penalty Dependency Analysis Method

本课题的研究成果可以归结为1.理论基础，2.串串切分和长句切分，3.韵律信息的使用，4.句子压缩，这些都与最小总罚分方法有关。从“最小成本分割问题”的角度对相关性分析进行了研究。结果表明，通过改变代价的定义，可以推导出各种依赖分析算法。会议还明确指出，最小总罚金法允许使用范围广泛的数字信息作为语言知识。在依存关系分析之前，有必要将一个句子切分成花边短语。在这项工作中，决策树方法被应用于这一问题，比传统方法的数据具有更高的分割精度。并将决策树技术应用于长句切分，作为依存分析的前处理。证明了一套分割…该方法能够自动获取更多的规则。为了找出韵律特征中包含的句法信息，建立了韵律特征与短语间依存距离之间的统计模型。然后将该模型整合到最小总惩罚解析器中，以衡量韵律信息对依存分析的有效性。停顿的时间被发现是非常有效的。要利用与音高、功率和语速相关的韵律特征，还需要进一步的研究。针对在线电视字幕生成等应用，提出了一种高效的句子压缩算法。该算法从原始句子中选择最优的花束素子序列，最大化花束素子序列的重要性分数和短语间依存分数之和。未来的工作包括研究更好地定义文氏法重要性分数和阶段间依赖分数。此外，还需要利用大量的测试数据对短句的质量进行评估。较少

Results of this research project can be classified into 1. theoretical basis, 2. bunsetsu segmentation and segmentation of long sentences, 3. use of prosodic information, and 4. sentence compaction, all related to the minimum total penalty method.1. Dependency analysis was investigated from a view point of "minimum cost segmentation problem". It was shown that various dependency analysis algorithms can be derived by changing the definition of the cost. It was also made clear that the minimum total penalty method allows the use of a wide range of numerical information as linguistic knowledge.2. It is necessary to segment a sentence into bunsetsu phrases prior to dependency analysis. In this work, a decision tree method was applied to this problem, giving higher segmentation accuracy than conventional methods data. The decision tree technique was also applied to segmentation of long sentences, which is pre-processing for dependency analysis. It was demonstrated that a set of segmentation … More rules was automatically acquired by this method.3. To find out syntactic information contained in prosodic features, a statistical model was created that represents a relationship between prosodic features and inter-phrase dependency distance. The model was then incorporated into the minimum total penalty parser to measure the effectiveness of prosodic information for dependency analysis. The duration of pause was found to be very effective. Further investigation is necessary to make use of prosodic features related to pitch, power, and speaking rate.4. An efficient sentence compaction algorithm was developed for such application as generation of on-line TV closed-captions. This algorithm selects an optimal bunsetsu subsequence from an original sentence that maximizes the sum of bunsetsu importance scores and inter-phrase dependency scores. Future work includes investigation of better definitions of bunsetsu importance score and inter-phrase dependency score. It is also necessary to evaluate the quality of shortened sentences using large amount of test data. Less