不同粒度层级下的韩语成分结构表示与分析

中文摘要 AI 辅助

韩语成分分析面临表示层面的挑战，因为短语结构树的终端单元无法直接对应简单的表层单词。韩语的eojeol是形态复杂的间隔单元，现有成分资源在表示eojeol内部形态及非显性元素的方式上存在差异。本文比较了从Penn韩语树库衍生出的三种成分分析表示：语素+XPOS、eojeol+XPOS、eojeol+UPOS。我们通过去除空元素、将Penn韩语短语结构与显性eojeol标记对齐、尽可能保留Penn韩语短语标签，并改变终端和前终端层来构建这些表示。随后在统一的建模与评估设置下，评估自上而下、中序、自底向上的经典非二元转换式成分分析器。所有实验均使用黄金标准终端分割和黄金标准前终端标签，因此评估的是基于黄金形态句法标注的成分分析。eojeol终端产生的转换序列更短，但eojeol+UPOS分析的表现显著差于形态更丰富的条件；eojeol+XPOS缩小了这一差距，而语素+XPOS即便在其预测被投影到eojeol终端域后仍给出最强结果。在这些黄金标注条件下，结果表明细粒度的形态和XPOS表示为所评估的分析器提供了有价值的证据。这一实证发现涉及分析可用的信息，本身并不决定语言学上更优的终端域；独立来看，语言学和资源设计考量促使eojeol成为短语结构标注的稳定且可解释的表层域，同时保留语素级和XPOS信息作为对齐的形态句法证据。

英文摘要

Korean constituency parsing raises a representational challenge because the terminal units of a phrase-structure tree do not straightforwardly correspond to simple surface words. Korean eojeols are morphologically complex spacing units, and existing constituency resources differ in how they represent eojeol-internal morphology and non-overt elements. This paper compares three constituency parsing representations derived from the Penn Korean Treebank: Morpheme+XPOS, Eojeol+XPOS, and Eojeol+UPOS. We construct these representations by removing null elements, aligning Penn Korean phrase structure with overt eojeol tokens, preserving Penn Korean phrase labels where possible, and varying the terminal and preterminal layers. We then evaluate canonical non-binary transition-based constituency parsers in top-down, in-order, and bottom-up orders under a shared modeling and evaluation setup. All experiments use gold terminal segmentation and gold preterminal labels and therefore evaluate constituency parsing conditioned on gold morphosyntactic annotation. Eojeol terminals yield shorter transition sequences, but Eojeol+UPOS parsing substantially underperforms the morphologically richer conditions. Eojeol+XPOS narrows this gap, while Morpheme+XPOS gives the strongest results even after its predictions are projected to the eojeol terminal domain. Under these gold-annotation conditions, the results show that fine-grained morphological and XPOS representations provide valuable evidence for the evaluated parsers. This empirical finding concerns the information available for parsing and does not by itself determine the linguistically preferable terminal domain. Independently, linguistic and resource-design considerations motivate eojeol as a stable and interpretable surface domain for phrase-structure annotation, with morpheme-level and XPOS information retained as aligned morphosyntactic evidence.

发表机构

• Korea Advanced Institute of Science & Technology（韩国科学技术院）
• The University of British Columbia（不列颠哥伦比亚大学）
• The Chinese University of Hong Kong（香港中文大学）
• Anyang University（安阳大学）

机构由 AI 辅助整理，请以论文原文为准。