journal article·2021-02-06Open access

Syntax-Informed Self-Attention Network for Span-Based Joint Entity and Relation Extraction

Haiyang Zhang, Guanqun Zhang, Ricardo Ma

Applied Sciences· Volume 11· Issue 4

Abstract

Current state-of-the-art joint entity and relation extraction framework is based on span-level entity classification and relation identification between pairs of entity mentions. However, while maintaining an efficient exhaustive search on spans, the importance of syntactic features is not taken into consideration. It will lead to a problem that the prediction of a relation between two entities is related based on corresponding entity types, but in fact they are not related in the sentence. In addition, although previous works have proven that extract local context is beneficial for the task, it still lacks in-depth learning of contextual features in local context. In this paper, we propose to incorporate syntax knowledge into multi-head self-attention by employing part of heads to focus on syntactic parents of each token from pruned dependency trees, and we use it to model the global context to fuse syntactic and semantic features. In addition, in order to get richer contextual features from the local context, we apply local focus mechanism on entity pairs and corresponding context. Based on applying the two strategies, we perform joint entity and relation extraction on span-level. Experimental results show that our model achieves significant improvements on both Conll04 and SciERC dataset compared to strong competitors.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Topic Modeling · Natural Language Processing Techniques · Biomedical Text Mining and Ontologies

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

Affiliations

School of Computer Science, Beijing University of Posts and Telecommunications, Beijing 100876, China

Funding

National Natural Science Foundation of China

References (58)

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