依存关系语义角色标注研究

描述了一个基于依存关系的语义角色标注系统，该系统把依存关系作为语义角色标注的基本单元。通过手工或自动标注出来的依存关系，构造出依存关系树，并从树上抽取特征。用最大熵模型对句中谓词的语义角色进行识别和分类。为了消除不必要的结构化信息，在预处理阶段，依存关系树经过了Xue的剪枝算法处理。通过特征工程，丰富的特征及其组合被应用于系统。最终使用 CoNLL 2008 shared task提供的数据作为训练、开发和测试集，使用手工标注的依存关系，F1值达到了86.25%；使用MSTParser自动产生的依存关系，F1值达到了81.66%。

Semantic role labeling for dependency relations

This paper presents a dependency relations-based semantic role labeling system,which takes dependency relations as the labeled units.Here,a dependency tree is created from a sequence of labeled dependency relations,from which a number of features are extracted.Moreover,the maximum entropy model is trained to identify and classify the predicates'semantic roles.In the pre-processing step,a dependency tree is pruned using Xue's algorithm.With extensive feature engineering,a wide range of features and their com...