面向政治领域的事理图谱构建

事理图谱是一种描述事件之间顺承、因果等关系的事理演化逻辑有向图,它蕴含了丰富的事件间关系,在各领域都具有重要的研究意义和应用价值。当前研究主要集中于公开域的事件抽取上,而在特定领域,如政治领域,因其事件类型和事件内容较为复杂,相关研究十分有限。该文旨在构建面向政治领域的事理图谱,针对政治事件抽取中存在的语料匮乏、标准缺失等问题,制定了一套面向政治领域的事件分类标准,构建了一套政治领域的事件语料库。同时,该文分别提出了一种融合注意力机制的字嵌入修正神经网络的Pipeline模型和一种基于BERT+BiLSTM的Joint模型进行事件触发词和论元抽取,并在该语料库上进行实验。实验结果表明,两种模型在事件触发词与论元抽取任务中,F₁指标较基线模型均有较大提升。

The Construction of the Eventic Graph for the Political Field

The Eventic Graph(EG) is a directed graph that describes the logic relationship between events, such as continuation and causality, etc. In contrast to the current researches focusing on the event extraction on the open domain. this paper aims at the construction of the eventic graph for the political field. We establish an annotation scheme for political events and construct an event corpus for the political field. Moreover, we present a character embedding based neural network by integrating the attention mechanism and a BERT+BiLSTM framework for political event extraction as the pipeline and the joint model, respectively. Experiments on our constructed corpus show that the porposed method could achieve significant improvement on event classification and argument classification in terms of F₁-score compared with previous neural network based methods.