基于双向标注融合的汉语最长短语识别方法

汉语最长短语（最长名词短语和介词短语）具有显著的语言学特点.采用基于分类器的确定性标注方法进行双向标注，其结果能够显示最长短语识别在汉语句子正（由左至右）反（由右至左）2个方向上的互补性.基于此，利用确定性的双向标注技术来识别汉语最长短语，并提出了一种基于“分歧点”的概率融合策略以融合该双向标注结果.实验表明，这一融合算法能够有效发掘这2个方向的互补特性，从而获得较好的短语识别效果.

A new approach to identifying Chinese maximal-length phrasesusing bidirectional labeling

Chinese maximal-length phrases (maximal-length noun phrases and prepositional phrases) possess remarkable linguistic properties. Bidirectional labeling results of Chinese maximal-length phrases obtained using sequential classifiers reveal complementary properties in both directions. In this paper, both left-right and right-left sequential labeling were employed to identify the Chinese maximal-length noun phrases and prepositional phrases. Then a novel “fork position” based probabilistic algorithm was developed to fuse the bidirectional results. Experiments were carried out on the Penn Chinese Treebank, a segmented, part-of-speech tagged, and fully bracketed corpus. The results confirmed that the proposed algorithm is able to effectively exploit the complementary strengths of the two directions.