Weijian Sun


Document-Level Relation Extraction via Pair-Aware and Entity-Enhanced Representation Learning
Xiusheng Huang | Hang Yang | Yubo Chen | Jun Zhao | Kang Liu | Weijian Sun | Zuyu Zhao
Proceedings of the 29th International Conference on Computational Linguistics

Document-level relation extraction aims to recognize relations among multiple entity pairs from a whole piece of article. Recent methods achieve considerable performance but still suffer from two challenges: a) the relational entity pairs are sparse, b) the representation of entity pairs is insufficient. In this paper, we propose Pair-Aware and Entity-Enhanced(PAEE) model to solve the aforementioned two challenges. For the first challenge, we design a Pair-Aware Representation module to predict potential relational entity pairs, which constrains the relation extraction to the predicted entity pairs subset rather than all pairs; For the second, we introduce a Entity-Enhanced Representation module to assemble directional entity pairs and obtain a holistic understanding of the entire document. Experimental results show that our approach can obtain state-of-the-art performance on four benchmark datasets DocRED, DWIE, CDR and GDA.


Named Entity Recognition via Noise Aware Training Mechanism with Data Filter
Xiusheng Huang | Yubo Chen | Shun Wu | Jun Zhao | Yuantao Xie | Weijian Sun
Findings of the Association for Computational Linguistics: ACL-IJCNLP 2021


FedED: Federated Learning via Ensemble Distillation for Medical Relation Extraction
Dianbo Sui | Yubo Chen | Jun Zhao | Yantao Jia | Yuantao Xie | Weijian Sun
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)

Unlike other domains, medical texts are inevitably accompanied by private information, so sharing or copying these texts is strictly restricted. However, training a medical relation extraction model requires collecting these privacy-sensitive texts and storing them on one machine, which comes in conflict with privacy protection. In this paper, we propose a privacy-preserving medical relation extraction model based on federated learning, which enables training a central model with no single piece of private local data being shared or exchanged. Though federated learning has distinct advantages in privacy protection, it suffers from the communication bottleneck, which is mainly caused by the need to upload cumbersome local parameters. To overcome this bottleneck, we leverage a strategy based on knowledge distillation. Such a strategy uses the uploaded predictions of ensemble local models to train the central model without requiring uploading local parameters. Experiments on three publicly available medical relation extraction datasets demonstrate the effectiveness of our method.

Global-to-Local Neural Networks for Document-Level Relation Extraction
Difeng Wang | Wei Hu | Ermei Cao | Weijian Sun
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)

Relation extraction (RE) aims to identify the semantic relations between named entities in text. Recent years have witnessed it raised to the document level, which requires complex reasoning with entities and mentions throughout an entire document. In this paper, we propose a novel model to document-level RE, by encoding the document information in terms of entity global and local representations as well as context relation representations. Entity global representations model the semantic information of all entities in the document, entity local representations aggregate the contextual information of multiple mentions of specific entities, and context relation representations encode the topic information of other relations. Experimental results demonstrate that our model achieves superior performance on two public datasets for document-level RE. It is particularly effective in extracting relations between entities of long distance and having multiple mentions.

PathQG: Neural Question Generation from Facts
Siyuan Wang | Zhongyu Wei | Zhihao Fan | Zengfeng Huang | Weijian Sun | Qi Zhang | Xuanjing Huang
Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)

Existing research for question generation encodes the input text as a sequence of tokens without explicitly modeling fact information. These models tend to generate irrelevant and uninformative questions. In this paper, we explore to incorporate facts in the text for question generation in a comprehensive way. We present a novel task of question generation given a query path in the knowledge graph constructed from the input text. We divide the task into two steps, namely, query representation learning and query-based question generation. We formulate query representation learning as a sequence labeling problem for identifying the involved facts to form a query and employ an RNN-based generator for question generation. We first train the two modules jointly in an end-to-end fashion, and further enforce the interaction between these two modules in a variational framework. We construct the experimental datasets on top of SQuAD and results show that our model outperforms other state-of-the-art approaches, and the performance margin is larger when target questions are complex. Human evaluation also proves that our model is able to generate relevant and informative questions.

Automatic Term Name Generation for Gene Ontology: Task and Dataset
Yanjian Zhang | Qin Chen | Yiteng Zhang | Zhongyu Wei | Yixu Gao | Jiajie Peng | Zengfeng Huang | Weijian Sun | Xuanjing Huang
Findings of the Association for Computational Linguistics: EMNLP 2020

Terms contained in Gene Ontology (GO) have been widely used in biology and bio-medicine. Most previous research focuses on inferring new GO terms, while the term names that reflect the gene function are still named by the experts. To fill this gap, we propose a novel task, namely term name generation for GO, and build a large-scale benchmark dataset. Furthermore, we present a graph-based generative model that incorporates the relations between genes, words and terms for term name generation, which exhibits great advantages over the strong baselines.