基于CWHC-AM的实体及关系联合抽取方法

实体及关系抽取是从非结构化自然语言文本中抽取三元组。传统流水线的方法先抽取实体再抽取关系,容易造成误差传播,也忽略了两个子任务的内在联系和依赖关系,抽取多元关系及重叠关系效果较差。针对上述问题,该文首先将多元关系问题转换成多个二元关系问题进行抽取,充分考虑两个子任务之间的联系,提出一种基于CWHC-AM(character word hybrid coding and attention mechanism)的实体及关系联合抽取模型,采用多层指针网络标注方案,将实体及关系联合抽取任务转化为序列标注问题,实现重叠关系抽取。最后,引入对抗训练提高模型的鲁棒性。在百度DuIE 2.0中文数据集上进行实验,结果表明该文方法可有效地同时抽取多元关系及二元关系,取得比基线模型都要好的效果。

Joint Extraction of Entities and Relations Based on CWHC-AM

Entity and relationship extraction is to extract triples from unstructured natural language text. The existing pipeline method extracts entities first and then relations, without capturing the internal relations and dependencies of the two subtasks. This article proposes a joint extraction model of entities and relations based on CWHC-AM, regarding the multiple relationship issue in extraction as multiple binary relationship tasks. The multi-layer pointer network labeling scheme is adopted to transform the joint extraction task of entities and relations into a sequence labeling problem. And the adversarial training is introduced to improve the robustness of the model. Experiments on the Baidu DuIE2.0 Chinese dataset show that the method in this article can effectively extract multiple relations and binary relations at the same time with better results than the baseline model.