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CCML2021+222:融合句法信息的无触发词事件检测方法

汪翠,张亚飞,郭军军,高盛祥,余正涛   

  1. 昆明理工大学
  • 收稿日期:2021-06-03 修回日期:2021-06-17 发布日期:2021-06-17
  • 通讯作者: 张亚飞

CCML2021+222:Event detection incorporating syntactic information and without triggers

  • Received:2021-06-03 Revised:2021-06-17 Online:2021-06-17
  • Contact: Ya-Fei ZHANG

摘要: 摘 要: 事件检测(ED)是信息抽取领域中最重要的任务之一,旨在识别文本中特定事件类型的实例。现有的事件检测方法通常采用邻接矩阵来表示句法依存关系,但是邻接矩阵往往需要借助图卷积网络(GCN)进行编码来获取句法信息,由此增加了模型的复杂度。为此,提出了融合句法信息的无触发词事件检测方法。通过将依赖父词及其上下文转换为位置标记向量,并在模型源端以无参数的方式融入依赖子词的单词嵌入来加强上下文的语义表征,而不需要经过GCN网络进行编码;此外,针对触发词的标注费时费力,设计了基于多头注意力机制的类型感知器,其可以对句子中潜在的触发词进行建模,以实现无触发词的事件检测。为了验证所提方法的性能,本文在ACE2005数据集以及低资源越南语数据集上进行了实验。其中,所提方法在ACE2005数据集上与事件检测模型GTN-ED相比,F1值提升了3.7%;在越南语数据集上,与二分类的基线模型TBNNAM相比, F1值提升了9%。结果表明,通过在Transformer中融入句法信息能有效地连接句子中分散的事件信息来提高事件检测的准确性。

关键词: 事件检测, 句法信息, 无参数, 无触发词, 类型感知器

Abstract: Abstract: Event Detection (ED) is one of the most important tasks in the field of information extraction, aiming to identify instances of specific event types in text. Existing event detection methods usually use adjacency matrix to express syntactic dependency, but the adjacency matrix often needs to use Graph Convolutional Network (GCN) to encode to obtain syntactic information, thereby increasing the complexity of the model. Therefore, we propose a event detection model that convert the parent word and its context into a position marker vector, and at the source of the model, the parent word information is incorporated into the word embedding of the child word in a parameter-free manner to strengthen the semantic representation of the context, without to go through the GCN network for encoding . In addition, considering that the tagging of trigger words is time-consuming and laborious, this paper designs a type perceptron based on a multi-head attention mechanism, which can model potential trigger words in sentences to achieve event detection without triggers. In order to verify the performance of the proposed method, this paper conducted experiments on the ACE2005 data set and the low-resource Vietnamese data set. Among them, compared with the event detection model GTN-ED on the ACE2005 data set, the F1 value increased by 3.7%, and compared with the two-class baseline model TBNNAM, the F1 value has increased by 9%. The results show that the integration of syntactic information into Transformer can effectively connect the scattered event information in the sentence to improve the accuracy of event detection.

Key words: event detection, syntactic information, without parameters, without triggers, type perceptron