关系提取(RE)是指在输入文本中提取关系三元组。现有的基于神经工作的系统在很大程度上依赖于手动标记的培训数据,但是仍然有很多域中不存在足够的标记数据。受到基于距离的几弹性实体识别方法的启发,我们根据序列标记的关节提取方法提出了几个弹出任务的定义,并为任务提出了一些弹出框架。此外,我们将两个实际的序列标记模型应用于我们的框架(称为少数Tplinker和几杆Bitt),并在从公共数据集构建的两个少量RE任务上实现了可靠的结果。
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联合医疗关系提取是指由单个模型从医学文本中提取由实体和关系组成的三元组。解决方案之一是将此任务转换为顺序标记任务。但是,在现有的作品中,以线性方式表示和标记三元组的方法失败了,而将三元组组织为图形的方法面临着大量计算工作的挑战。在本文中,受到医学文本中类似树状的关系结构的启发,我们提出了一个名为“双向树”标签(BITT)的新颖方案,将医疗关系三元组成两条两条二进制树,并将树转换为单词级别的标签序列。基于BITT方案,我们开发了一个联合关系提取模型,以预测BITT标签并进一步提取医疗三元三元。我们的模型在两个医疗数据集上的最佳基准在F1分中优于2.0 \%和2.5 \%。更重要的是,我们的BITT方案的模型还可以在其他域的三个公共数据集中获得有希望的结果。
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几个名称的实体识别(NER)使我们能够使用很少的标记示例为新域构建一个NER系统。但是,该任务的现有原型网络具有大致估计的标签依赖性和紧密分布的原型,因此经常导致错误分类。为了解决上述问题,我们提出了EP-NET,这是一个实体级原型网络,通过分散分布的原型增强。EP-NET构建实体级原型,并认为文本跨度为候选实体,因此它不再需要标签依赖性。此外,EP-NET从头开始训练原型,以分散分配它们,并使用空间投影将跨度与嵌入空间中的原型对齐。两项评估任务和少量网络设置的实验结果表明,EP-NET在整体性能方面始终优于先前的强大模型。广泛的分析进一步验证了EP-NET的有效性。
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Metric-based meta-learning is one of the de facto standards in few-shot learning. It composes of representation learning and metrics calculation designs. Previous works construct class representations in different ways, varying from mean output embedding to covariance and distributions. However, using embeddings in space lacks expressivity and cannot capture class information robustly, while statistical complex modeling poses difficulty to metric designs. In this work, we use tensor fields (``areas'') to model classes from the geometrical perspective for few-shot learning. We present a simple and effective method, dubbed hypersphere prototypes (HyperProto), where class information is represented by hyperspheres with dynamic sizes with two sets of learnable parameters: the hypersphere's center and the radius. Extending from points to areas, hyperspheres are much more expressive than embeddings. Moreover, it is more convenient to perform metric-based classification with hypersphere prototypes than statistical modeling, as we only need to calculate the distance from a data point to the surface of the hypersphere. Following this idea, we also develop two variants of prototypes under other measurements. Extensive experiments and analysis on few-shot learning tasks across NLP and CV and comparison with 20+ competitive baselines demonstrate the effectiveness of our approach.
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Few-shot relation extraction (FSRE) aims at recognizing unseen relations by learning with merely a handful of annotated instances. To generalize to new relations more effectively, this paper proposes a novel pipeline for the FSRE task based on queRy-information guided Attention and adaptive Prototype fuSion, namely RAPS. Specifically, RAPS first derives the relation prototype by the query-information guided attention module, which exploits rich interactive information between the support instances and the query instances, in order to obtain more accurate initial prototype representations. Then RAPS elaborately combines the derived initial prototype with the relation information by the adaptive prototype fusion mechanism to get the integrated prototype for both train and prediction. Experiments on the benchmark dataset FewRel 1.0 show a significant improvement of our method against state-of-the-art methods.
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Practices in the built environment have become more digitalized with the rapid development of modern design and construction technologies. However, the requirement of practitioners or scholars to gather complicated professional knowledge in the built environment has not been satisfied yet. In this paper, more than 80,000 paper abstracts in the built environment field were obtained to build a knowledge graph, a knowledge base storing entities and their connective relations in a graph-structured data model. To ensure the retrieval accuracy of the entities and relations in the knowledge graph, two well-annotated datasets have been created, containing 2,000 instances and 1,450 instances each in 29 relations for the named entity recognition task and relation extraction task respectively. These two tasks were solved by two BERT-based models trained on the proposed dataset. Both models attained an accuracy above 85% on these two tasks. More than 200,000 high-quality relations and entities were obtained using these models to extract all abstract data. Finally, this knowledge graph is presented as a self-developed visualization system to reveal relations between various entities in the domain. Both the source code and the annotated dataset can be found here: https://github.com/HKUST-KnowComp/BEKG.
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关系提取是一项重要但具有挑战性的任务,旨在从文本中提取所有隐藏的关系事实。随着深层语言模型的发展,关系提取方法在各种基准上都取得了良好的性能。但是,我们观察到以前方法的两个缺点:首先,在各种关系提取设置下没有统一的框架可以很好地工作;其次,有效利用外部知识作为背景信息。在这项工作中,我们提出了一种知识增强的生成模型来减轻这两个问题。我们的生成模型是一个统一的框架,可在各种关系提取设置下依次生成关系三胞胎,并明确利用来自知识图(KG)的相关知识来解决歧义。我们的模型在包括WebNLG,NYT10和Tacred在内的多个基准和设置上实现了卓越的性能。
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大多数NER方法都依赖于广泛的标记数据进行模型培训,这些数据在低资源场景中挣扎,培训数据有限。与资源丰富的源域相比,现有的主要方法通常会遇到目标域具有不同标签集的挑战,该标签集可以作为类传输和域转移得出的结论。在本文中,我们通过可拔出的提示(Lightner)提出了一个轻巧的调整范式,用于低资源。具体而言,我们构建了实体类别的统一可学习的语言器,以生成实体跨度序列和实体类别,而无需任何标签特定的分类器,从而解决了类转移问题。我们通过将可学习的参数纳入自我发言层作为指导,进一步提出了一个可插入的指导模块,该参数可以重新调节注意力并调整预训练的权重。请注意,我们仅通过修复了预训练的语言模型的整个参数来调整那些插入的模块,从而使我们的方法轻巧且灵活地适合低资源场景,并且可以更好地跨域传输知识。实验结果表明,Lightner可以在标准监督环境中获得可比的性能,并且在低资源设置中优于强大基线。代码在https://github.com/zjunlp/deepke/tree/main/main/example/ner/few-shot中。
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当大型训练数据集不可用于低资源域时,命名实体识别(NER)模型通常表现不佳。最近,预先训练大规模语言模型已成为应对数据稀缺问题的有希望的方向。然而,语言建模和ner任务之间的潜在差异可能会限制模型的性能,并且由于收集的网数据集通常很小或大而是低质量,因此已经研究了NER任务的预训练。在本文中,我们构建了一个具有相对高质量的大规模核心语料库,我们基于创建的数据集预先列车。实验结果表明,我们的预训练模型可以显着优于八大域的低资源场景中的百合形和其他强基线。此外,实体表示的可视化进一步指示Ner-BERT用于对各种实体进行分类的有效性。
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我们提出了一个零射门学习关系分类(ZSLRC)框架,通过其识别训练数据中不存在的新颖关系的能力来提高最先进的框架。零射击学习方法模仿人类学习和识别新概念的方式,没有先前的知识。为此,ZSLRC使用修改的高级原型网络来利用加权侧(辅助)信息。 ZSLRC的侧面信息是由关键字,名称实体的高度和标签及其同义词构建的。 ZSLRC还包括一个自动高义的提取框架,可直接从Web获取各种名称实体的高型。 ZSLRC提高了最先进的少量学习关系分类方法,依赖于标记的培训数据,因此即使在现实世界方案中也适用于某些关系对相应标记的培训示例。我们在两种公共数据集(NYT和NEREREL)上使用广泛的实验显示结果,并显示ZSLRC显着优于最先进的方法对监督学习,少量学习和零射击学习任务。我们的实验结果还展示了我们所提出的模型的有效性和稳健性。
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Modern supervised learning neural network models require a large amount of manually labeled data, which makes the construction of domain-specific knowledge graphs time-consuming and labor-intensive. In parallel, although there has been much research on named entity recognition and relation extraction based on distantly supervised learning, constructing a domain-specific knowledge graph from large collections of textual data without manual annotations is still an urgent problem to be solved. In response, we propose an integrated framework for adapting and re-learning knowledge graphs from one coarse domain (biomedical) to a finer-define domain (oncology). In this framework, we apply distant-supervision on cross-domain knowledge graph adaptation. Consequently, no manual data annotation is required to train the model. We introduce a novel iterative training strategy to facilitate the discovery of domain-specific named entities and triples. Experimental results indicate that the proposed framework can perform domain adaptation and construction of knowledge graph efficiently.
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Pre-trained Language Models (PLMs) have been applied in NLP tasks and achieve promising results. Nevertheless, the fine-tuning procedure needs labeled data of the target domain, making it difficult to learn in low-resource and non-trivial labeled scenarios. To address these challenges, we propose Prompt-based Text Entailment (PTE) for low-resource named entity recognition, which better leverages knowledge in the PLMs. We first reformulate named entity recognition as the text entailment task. The original sentence with entity type-specific prompts is fed into PLMs to get entailment scores for each candidate. The entity type with the top score is then selected as final label. Then, we inject tagging labels into prompts and treat words as basic units instead of n-gram spans to reduce time complexity in generating candidates by n-grams enumeration. Experimental results demonstrate that the proposed method PTE achieves competitive performance on the CoNLL03 dataset, and better than fine-tuned counterparts on the MIT Movie and Few-NERD dataset in low-resource settings.
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三重提取是自然语言处理和知识图构建信息提取的重要任务。在本文中,我们重新审视了序列生成的端到端三重提取任务。由于生成三重提取可能难以捕获长期依赖性并产生不忠的三元组,因此我们引入了一种新型模型,即与生成变压器的对比度三重提取。具体而言,我们为基于编码器的生成引入了一个共享的变压器模块。为了产生忠实的结果,我们提出了一个新颖的三胞胎对比训练对象。此外,我们引入了两种机制,以进一步提高模型性能(即,批处理动态注意力掩盖和三个方面的校准)。在三个数据集(即NYT,WebNLG和MIE)上进行的实验结果表明,我们的方法比基线的方法更好。
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我们研究了很少的细粒实体键入(FET)的问题,其中只有几个带注释的实体对每种实体类型提供了上下文。最近,基于及时的调整通过将实体类型分类任务作为“填补空白”的问题来表明在几次射击方案中表现出优越的性能。这允许有效利用预训练的语言模型(PLM)的强语建模能力。尽管当前基于及时的调整方法成功了,但仍有两个主要挑战:(1)提示中的口头化器要么是由外部知识基础手动设计或构建的,而无需考虑目标语料库和标签层次结构信息,而且(2)当前方法主要利用PLM的表示能力,但没有通过广泛的通用域预训练来探索其产生的功率。在这项工作中,我们为由两个模块组成的几个弹药fet提出了一个新颖的框架:(1)实体类型标签解释模块自动学习将类型标签与词汇联系起来,通过共同利用几个播放实例和标签层次结构和标签层次结构,以及(2)基于类型的上下文化实例生成器根据给定实例生成新实例,以扩大培训集以更好地概括。在三个基准数据集上,我们的模型优于大量利润的现有方法。可以在https://github.com/teapot123/fine-graining-entity-typing上找到代码。
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Cross-domain few-shot relation extraction poses a great challenge for the existing few-shot learning methods and domain adaptation methods when the source domain and target domain have large discrepancies. This paper proposes a method by combining the idea of few-shot learning and domain adaptation to deal with this problem. In the proposed method, an encoder, learned by optimizing a representation loss and an adversarial loss, is used to extract the relation of sentences in the source and target domain. The representation loss, including a cross-entropy loss and a contrastive loss, makes the encoder extract the relation of the source domain and keep the geometric structure of the classes in the source domain. And the adversarial loss is used to merge the source domain and target domain. The experimental results on the benchmark FewRel dataset demonstrate that the proposed method can outperform some state-of-the-art methods.
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几乎没有命名的实体识别(NER)对于在有限的资源领域中标记的实体标记至关重要,因此近年来受到了适当的关注。现有的几声方法主要在域内设置下进行评估。相比之下,对于这些固有的忠实模型如何使用一些标记的域内示例在跨域NER中执行的方式知之甚少。本文提出了一种两步以理性为中心的数据增强方法,以提高模型的泛化能力。几个数据集中的结果表明,与先前的最新方法相比,我们的模型无形方法可显着提高跨域NER任务的性能,包括反事实数据增强和及时调用方法。我们的代码可在\ url {https://github.com/lifan-yuan/factmix}上获得。
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开放信息提取是一个重要的NLP任务,它针对从非结构化文本中提取结构化信息的目标,而无需限制关系类型或文本域。该调查文件涵盖了2007年至2022年的开放信息提取技术,重点是以前的调查未涵盖的新模型。我们从信息角度来源提出了一种新的分类方法,以适应最近的OIE技术的开发。此外,我们根据任务设置以及当前流行的数据集和模型评估指标总结了三种主要方法。鉴于全面的审查,从数据集,信息来源,输出表格,方法和评估指标方面显示了几个未来的方向。
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Neural language representation models such as BERT pre-trained on large-scale corpora can well capture rich semantic patterns from plain text, and be fine-tuned to consistently improve the performance of various NLP tasks. However, the existing pre-trained language models rarely consider incorporating knowledge graphs (KGs), which can provide rich structured knowledge facts for better language understanding. We argue that informative entities in KGs can enhance language representation with external knowledge. In this paper, we utilize both large-scale textual corpora and KGs to train an enhanced language representation model (ERNIE), which can take full advantage of lexical, syntactic, and knowledge information simultaneously. The experimental results have demonstrated that ERNIE achieves significant improvements on various knowledge-driven tasks, and meanwhile is comparable with the state-of-the-art model BERT on other common NLP tasks. The source code and experiment details of this paper can be obtained from https:// github.com/thunlp/ERNIE.
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Information Extraction (IE) aims to extract structured information from heterogeneous sources. IE from natural language texts include sub-tasks such as Named Entity Recognition (NER), Relation Extraction (RE), and Event Extraction (EE). Most IE systems require comprehensive understandings of sentence structure, implied semantics, and domain knowledge to perform well; thus, IE tasks always need adequate external resources and annotations. However, it takes time and effort to obtain more human annotations. Low-Resource Information Extraction (LRIE) strives to use unsupervised data, reducing the required resources and human annotation. In practice, existing systems either utilize self-training schemes to generate pseudo labels that will cause the gradual drift problem, or leverage consistency regularization methods which inevitably possess confirmation bias. To alleviate confirmation bias due to the lack of feedback loops in existing LRIE learning paradigms, we develop a Gradient Imitation Reinforcement Learning (GIRL) method to encourage pseudo-labeled data to imitate the gradient descent direction on labeled data, which can force pseudo-labeled data to achieve better optimization capabilities similar to labeled data. Based on how well the pseudo-labeled data imitates the instructive gradient descent direction obtained from labeled data, we design a reward to quantify the imitation process and bootstrap the optimization capability of pseudo-labeled data through trial and error. In addition to learning paradigms, GIRL is not limited to specific sub-tasks, and we leverage GIRL to solve all IE sub-tasks (named entity recognition, relation extraction, and event extraction) in low-resource settings (semi-supervised IE and few-shot IE).
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近年来,人们对少量知识图(FKGC)的兴趣日益增加,该图表旨在推断出关于该关系的一些参考三元组,从而推断出不见了的查询三倍。现有FKGC方法的主要重点在于学习关系表示,可以反映查询和参考三元组共享的共同信息。为此,这些方法从头部和尾部实体的直接邻居中学习实体对表示,然后汇总参考实体对的表示。但是,只有从直接邻居那里学到的实体对代表可能具有较低的表现力,当参与实体稀疏直接邻居或与其他实体共享一个共同的当地社区。此外,仅仅对头部和尾部实体的语义信息进行建模不足以准确推断其关系信息,尤其是当它们具有多个关系时。为了解决这些问题,我们提出了一个特定于关系的上下文学习(RSCL)框架,该框架利用了三元组的图形上下文,以学习全球和本地关系特定的表示形式,以使其几乎没有相关关系。具体而言,我们首先提取每个三倍的图形上下文,这可以提供长期实体关系依赖性。为了编码提取的图形上下文,我们提出了一个分层注意网络,以捕获三元组的上下文信息并突出显示实体的有价值的本地邻里信息。最后,我们设计了一个混合注意聚合器,以评估全球和本地级别的查询三元组的可能性。两个公共数据集的实验结果表明,RSCL的表现优于最先进的FKGC方法。
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