scholarly journals Joint Extraction of Entities and Overlapping Relations Using Position-Attentive Sequence Labeling

2019 ◽  
Vol 33 ◽  
pp. 6300-6308 ◽  
Author(s):  
Dai Dai ◽  
Xinyan Xiao ◽  
Yajuan Lyu ◽  
Shan Dou ◽  
Qiaoqiao She ◽  
...  
Keyword(s):  
Long Range ◽  
State Of The Art ◽  
Relation Extraction ◽  
Attention Mechanism ◽  
Single Model ◽  
Sequence Labeling ◽  
Word Position ◽  
Query Word ◽  
Public Datasets ◽  
Extraction Model

Joint entity and relation extraction is to detect entity and relation using a single model. In this paper, we present a novel unified joint extraction model which directly tags entity and relation labels according to a query word position p, i.e., detecting entity at p, and identifying entities at other positions that have relationship with the former. To this end, we first design a tagging scheme to generate n tag sequences for an n-word sentence. Then a position-attention mechanism is introduced to produce different sentence representations for every query position to model these n tag sequences. In this way, our method can simultaneously extract all entities and their type, as well as all overlapping relations. Experiment results show that our framework performances significantly better on extracting overlapping relations as well as detecting long-range relation, and thus we achieve state-of-the-art performance on two public datasets.

scholarly journals A Relation-Specific Attention Network for Joint Entity and Relation Extraction

2020 ◽  
Author(s):  
Yue Yuan ◽  
Xiaofei Zhou ◽  
Shirui Pan ◽  
Qiannan Zhu ◽  
Zeliang Song ◽  
...  
Keyword(s):  
Natural Language Processing ◽  
Natural Language ◽  
Language Processing ◽  
State Of The Art ◽  
Relation Extraction ◽  
Attention Mechanism ◽  
Important Task ◽  
Entity Recognition ◽  
Attention Network ◽  
Public Datasets

Joint extraction of entities and relations is an important task in natural language processing (NLP), which aims to capture all relational triplets from plain texts. This is a big challenge due to some of the triplets extracted from one sentence may have overlapping entities. Most existing methods perform entity recognition followed by relation detection between every possible entity pairs, which usually suffers from numerous redundant operations. In this paper, we propose a relation-specific attention network (RSAN) to handle the issue. Our RSAN utilizes relation-aware attention mechanism to construct specific sentence representations for each relation, and then performs sequence labeling to extract its corresponding head and tail entities. Experiments on two public datasets show that our model can effectively extract overlapping triplets and achieve state-of-the-art performance.

scholarly journals Attention as Relation: Learning Supervised Multi-head Self-Attention for Relation Extraction

2020 ◽  
Author(s):  
Jie Liu ◽  
Shaowei Chen ◽  
Bingquan Wang ◽  
Jiaxin Zhang ◽  
Na Li ◽  
...  
Keyword(s):  
Natural Language Processing ◽  
Natural Language ◽  
Language Processing ◽  
State Of The Art ◽  
Relation Extraction ◽  
Attention Mechanism ◽  
Entity Extraction ◽  
Relation Type ◽  
Benchmark Datasets ◽  
Relation Learning

Joint entity and relation extraction is critical for many natural language processing (NLP) tasks, which has attracted increasing research interest. However, it is still faced with the challenges of identifying the overlapping relation triplets along with the entire entity boundary and detecting the multi-type relations. In this paper, we propose an attention-based joint model, which mainly contains an entity extraction module and a relation detection module, to address the challenges. The key of our model is devising a supervised multi-head self-attention mechanism as the relation detection module to learn the token-level correlation for each relation type separately. With the attention mechanism, our model can effectively identify overlapping relations and flexibly predict the relation type with its corresponding intensity. To verify the effectiveness of our model, we conduct comprehensive experiments on two benchmark datasets. The experimental results demonstrate that our model achieves state-of-the-art performances.

scholarly journals SpanBERT: Improving Pre-training by Representing and Predicting Spans

2020 ◽  
Vol 8 ◽  
pp. 64-77 ◽  
Author(s):  
Mandar Joshi ◽  
Danqi Chen ◽  
Yinhan Liu ◽  
Daniel S. Weld ◽  
Luke Zettlemoyer ◽  
...  
Keyword(s):  
Question Answering ◽  
State Of The Art ◽  
Relation Extraction ◽  
Training Data ◽  
Coreference Resolution ◽  
Single Model ◽  
Model Size ◽  
Boundary Representations ◽  
Selection Tasks ◽  
The Individual

We present SpanBERT, a pre-training method that is designed to better represent and predict spans of text. Our approach extends BERT by (1) masking contiguous random spans, rather than random tokens, and (2) training the span boundary representations to predict the entire content of the masked span, without relying on the individual token representations within it. SpanBERT consistently outperforms BERT and our better-tuned baselines, with substantial gains on span selection tasks such as question answering and coreference resolution. In particular, with the same training data and model size as BERTlarge, our single model obtains 94.6% and 88.7% F1 on SQuAD 1.1 and 2.0 respectively. We also achieve a new state of the art on the OntoNotes coreference resolution task (79.6% F1), strong performance on the TACRED relation extraction benchmark, and even gains on GLUE. 1

scholarly journals Document-level medical relation extraction via edge-oriented graph neural network based on document structure and external knowledge

2021 ◽  
Vol 21 (S7) ◽  
Author(s):  
Tao Li ◽  
Ying Xiong ◽  
Xiaolong Wang ◽  
Qingcai Chen ◽  
Buzhou Tang
Keyword(s):  
Neural Network ◽  
Language Processing ◽  
State Of The Art ◽  
Relation Extraction ◽  
Oriented Graph ◽  
Document Structure ◽  
External Knowledge ◽  
Novel Method ◽  
Public Datasets ◽  
Document Level

Abstract Objective Relation extraction (RE) is a fundamental task of natural language processing, which always draws plenty of attention from researchers, especially RE at the document-level. We aim to explore an effective novel method for document-level medical relation extraction. Methods We propose a novel edge-oriented graph neural network based on document structure and external knowledge for document-level medical RE, called SKEoG. This network has the ability to take full advantage of document structure and external knowledge. Results We evaluate SKEoG on two public datasets, that is, Chemical-Disease Relation (CDR) dataset and Chemical Reactions dataset (CHR) dataset, by comparing it with other state-of-the-art methods. SKEoG achieves the highest F1-score of 70.7 on the CDR dataset and F1-score of 91.4 on the CHR dataset. Conclusion The proposed SKEoG method achieves new state-of-the-art performance. Both document structure and external knowledge can bring performance improvement in the EoG framework. Selecting proper methods for knowledge node representation is also very important.

scholarly journals Translating Embeddings for Knowledge Graph Completion with Relation Attention Mechanism

2018 ◽  
Author(s):  
Wei Qian ◽  
Cong Fu ◽  
Yu Zhu ◽  
Deng Cai ◽  
Xiaofei He
Keyword(s):  
State Of The Art ◽  
Graph Embedding ◽  
Attention Mechanism ◽  
Human Cognition ◽  
Knowledge Graph ◽  
People First ◽  
Public Datasets ◽  
The Right ◽  
The Given ◽  
Essential Problem

Knowledge graph embedding is an essential problem in knowledge extraction. Recently, translation based embedding models (e.g., TransE) have received increasingly attentions. These methods try to interpret the relations among entities as translations from head entity to tail entity and achieve promising performance on knowledge graph completion. Previous researchers attempt to transform the entity embedding concerning the given relation for distinguishability. Also, they naturally think the relation-related transforming should reflect attention mechanism, which means it should focus on only a part of the attributes. However, we found previous methods are failed with creating attention mechanism, and the reason is that they ignore the hierarchical routine of human cognition. When predicting whether a relation holds between two entities, people first check the category of entities, then they focus on fined-grained relation-related attributes to make the decision. In other words, the attention should take effect on entities filtered by the right category. In this paper, we propose a novel knowledge graph embedding method named TransAt to learn the translation based embedding, relation-related categories of entities and relation-related attention simultaneously. Extensive experiments show that our approach outperforms state-of-the-art methods significantly on public datasets, and our method can learn the true attention varying among relations.

scholarly journals Utilizing Entity-Based Gated Convolution and Multilevel Sentence Attention to Improve Distantly Supervised Relation Extraction

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Qian Yi ◽  
Guixuan Zhang ◽  
Shuwu Zhang
Keyword(s):  
Selective Attention ◽  
Large Scale ◽  
State Of The Art ◽  
Relation Extraction ◽  
Benchmark Dataset ◽  
Experimental Results ◽  
Fine Grained ◽  
Convolution Operation ◽  
Distant Supervision ◽  
Extraction Model

Distant supervision is an effective method to automatically collect large-scale datasets for relation extraction (RE). Automatically constructed datasets usually comprise two types of noise: the intrasentence noise and the wrongly labeled noisy sentence. To address issues caused by the above two types of noise and improve distantly supervised relation extraction, this paper proposes a novel distantly supervised relation extraction model, which consists of an entity-based gated convolution sentence encoder and a multilevel sentence selective attention (Matt) module. Specifically, we first apply an entity-based gated convolution operation to force the sentence encoder to extract entity-pair-related features and filter out useless intrasentence noise information. Furthermore, the multilevel attention schema fuses the bag information to obtain a fine-grained bag-specific query vector, which can better identify valid sentences and reduce the influence of wrongly labeled sentences. Experimental results on a large-scale benchmark dataset show that our model can effectively reduce the influence of the above two types of noise and achieves state-of-the-art performance in relation extraction.

scholarly journals Joint Extraction of Entity and Relation with Information Redundancy Elimination

2020 ◽  
Author(s):  
Yuanhao Shen ◽  
Jungang Han
Keyword(s):  
Language Model ◽  
Named Entity Recognition ◽  
Relation Extraction ◽  
Entity Recognition ◽  
Redundant Information ◽  
Named Entity ◽  
Lstm Network ◽  
Relation Classification ◽  
Public Datasets ◽  
Extraction Model

To solve the problem of redundant information and overlapping relations of the entity and relation extraction model, we propose a joint extraction model. This model can directly extract multiple pairs of related entities without generating unrelated redundant information. We also propose a recurrent neural network named Encoder-LSTM that enhances the ability of recurrent units to model sentences. Specifically, the joint model includes three sub-modules: the Named Entity Recognition sub-module consisted of a pre-trained language model and an LSTM decoder layer, the Entity Pair Extraction sub-module which uses Encoder-LSTM network to model the order relationship between related entity pairs, and the Relation Classification submodule including Attention mechanism. We conducted experiments on the public datasets ADE and CoNLL04 to evaluate the effectiveness of our model. The results show that the proposed model achieves good performance in the task of entity and relation extraction and can greatly reduce the amount of redundant information.

scholarly journals Relation Extraction Exploiting Full Dependency Forests

2020 ◽  
Vol 34 (05) ◽  
pp. 8034-8041
Author(s):  
Lifeng Jin ◽  
Linfeng Song ◽  
Yue Zhang ◽  
Kun Xu ◽  
Wei-Yun Ma ◽  
...  
Keyword(s):  
Error Propagation ◽  
State Of The Art ◽  
Relation Extraction ◽  
Extraction Performance ◽  
Dependency Syntax ◽  
Extraction Model

Dependency syntax has long been recognized as a crucial source of features for relation extraction. Previous work considers 1-best trees produced by a parser during preprocessing. However, error propagation from the out-of-domain parser may impact the relation extraction performance. We propose to leverage full dependency forests for this task, where a full dependency forest encodes all possible trees. Such representations of full dependency forests provide a differentiable connection between a parser and a relation extraction model, and thus we are also able to study adjusting the parser parameters based on end-task loss. Experiments on three datasets show that full dependency forests and parser adjustment give significant improvements over carefully designed baselines, showing state-of-the-art or competitive performances on biomedical or newswire benchmarks.

Named Entity Recognition and Relation Extraction

2021 ◽  
Vol 54 (1) ◽  
pp. 1-39
Author(s):  
Zara Nasar ◽  
Syed Waqar Jaffry ◽  
Muhammad Kamran Malik
Keyword(s):  
Deep Learning ◽  
State Of The Art ◽  
Named Entity Recognition ◽  
Relation Extraction ◽  
The State ◽  
Entity Recognition ◽  
Joint Models ◽  
Named Entity ◽  
Textual Data ◽  
Benchmark Datasets

With the advent of Web 2.0, there exist many online platforms that result in massive textual-data production. With ever-increasing textual data at hand, it is of immense importance to extract information nuggets from this data. One approach towards effective harnessing of this unstructured textual data could be its transformation into structured text. Hence, this study aims to present an overview of approaches that can be applied to extract key insights from textual data in a structured way. For this, Named Entity Recognition and Relation Extraction are being majorly addressed in this review study. The former deals with identification of named entities, and the latter deals with problem of extracting relation between set of entities. This study covers early approaches as well as the developments made up till now using machine learning models. Survey findings conclude that deep-learning-based hybrid and joint models are currently governing the state-of-the-art. It is also observed that annotated benchmark datasets for various textual-data generators such as Twitter and other social forums are not available. This scarcity of dataset has resulted into relatively less progress in these domains. Additionally, the majority of the state-of-the-art techniques are offline and computationally expensive. Last, with increasing focus on deep-learning frameworks, there is need to understand and explain the under-going processes in deep architectures.

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