Document-Level Relation Extraction Based on Dual-Granularity Graphs
This study proposes a document-level relation extraction model that addresses the insufficient utilization of document semantics and difficulty in handling noise in unstructured text.The model is based on dual-granularity document graphs and employs a novel graph construction approach along with a noise reduction technique designed at both the inter-and intra-sentence levels.At the inter-sentence level,a rhetorical discourse relation graph,RST-graph,is constructed using rhetorical discourse and entity mention relations,and a Coarse-Grained Document graph(CGD-graph)is generated using an asynchronous noise reduction method.This approach prevents structural mispruning caused by longer inter-sentence relation paths compared with intra-sentence paths.At the intra-sentence level,dependency syntax relations are used to parse sentences in a document,forming a Dependency Syntax Tree(DST)to enhance intra-sentence semantic information.Finally,the DST is connected to the common anchor points in the CGD-graph to form a Fine-Grained Document graph(FGD-graph).Experimental results indicate that compared with the Denoising Graph Inference(DGI)model,the proposed model improves the lgn F1 and F1 value by 0.40 and 0.51 percentage points,respectively.Additionally,it demonstrates a significant improvement in extracting multi-label relations as the number of labels increases.