The typical way for relation extraction is fine-tuning large pre-trained language models on task-specific datasets, then selecting the label with the highest probability of the output distribution as the final prediction. However, the usage of the Top-k prediction set for a given sample is commonly overlooked. In this paper, we first reveal that the Top-k prediction set of a given sample contains useful information for predicting the correct label. To effectively utilizes the Top-k prediction set, we propose Label Graph Network with Top-k Prediction Set, termed as KLG. Specifically, for a given sample, we build a label graph to review candidate labels in the Top-k prediction set and learn the connections between them. We also design a dynamic $k$-selection mechanism to learn more powerful and discriminative relation representation. Our experiments show that KLG achieves the best performances on three relation extraction datasets. Moreover, we observe that KLG is more effective in dealing with long-tailed classes.

Sequence generation demonstrates promising performance in recent information extraction efforts, by incorporating large-scale pre-trained Seq2Seq models. This paper investigates the merits of employing sequence generation in relation extraction, finding that with relation names or synonyms as generation targets, their textual semantics and the correlation (in terms of word sequence pattern) among them affect model performance. We then propose Relation Extraction with Label Augmentation (RELA), a Seq2Seq model with automatic label augmentation for RE. By saying label augmentation, we mean prod semantically synonyms for each relation name as the generation target. Besides, we present an in-depth analysis of the Seq2Seq model's behavior when dealing with RE. Experimental results show that RELA achieves competitive results compared with previous methods on four RE datasets.

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。

Relation extraction (RE), which has relied on structurally annotated corpora for model training, has been particularly challenging in low-resource scenarios and domains. Recent literature has tackled low-resource RE by self-supervised learning, where the solution involves pretraining the relation embedding by RE-based objective and finetuning on labeled data by classification-based objective. However, a critical challenge to this approach is the gap in objectives, which prevents the RE model from fully utilizing the knowledge in pretrained representations. In this paper, we aim at bridging the gap and propose to pretrain and finetune the RE model using consistent objectives of contrastive learning. Since in this kind of representation learning paradigm, one relation may easily form multiple clusters in the representation space, we further propose a multi-center contrastive loss that allows one relation to form multiple clusters to better align with pretraining. Experiments on two document-level RE datasets, BioRED and Re-DocRED, demonstrate the effectiveness of our method. Particularly, when using 1% end-task training data, our method outperforms PLM-based RE classifier by 10.5% and 5.8% on the two datasets, respectively.

预训练的语言模型（PLM）在各种自然语言理解任务上取得了巨大的成功。另一方面，对PLM的简单微调对于特定于领域的任务可能是次优的，因为它们不可能涵盖所有域中的知识。尽管PLM的自适应预培训可以帮助他们获得特定于领域的知识，但需要大量的培训成本。此外，自适应预训练可能会通过造成灾难性忘记其常识来损害PLM在下游任务上的表现。为了克服PLM适应性适应性预训练的这种局限性，我们提出了一个新颖的域名适应框架，用于将PLMS创造为知识增强语言模型适应性（KALA），该框架调节了PLM的中间隐藏表示与域中的中间隐藏表示，由实体和实体和实体和实体和实体构成他们的关系事实。我们验证了Kala在问题答案中的性能，并在各个域的多个数据集上命名实体识别任务。结果表明，尽管在计算上有效，但我们的Kala在很大程度上优于适应性预训练。代码可在以下网址获得：https：//github.com/nardien/kala/。

放射学报告的印象部分总结了调查结果部分中最突出的观察结果，是放射科医生与医生进行交流的最重要部分。总结发现很耗时，对于缺乏经验的放射科医生可能会出错，因此自动印象产生引起了很大的关注。通过编码器框架，大多数先前的研究都探讨了纳入额外知识（例如，静态预定义的临床本体或额外的背景信息）。然而，他们通过单独的编码器对这种知识进行编码，以将其视为其模型的额外输入，这在利用其与原始发现的关系方面受到限制。为了解决限制，我们提出了一个统一的框架，以综合的方式利用额外的知识和原始发现，以便可以以适当的方式提取关键信息（即关键词及其关系），以促进印象产生。详细说明，对于每个输入发现，它是由文本编码器编码的，并且图形是通过其实体和依赖树构造的。然后，采用图形编码器（例如，图形神经网络（GNNS））在构造的图中模拟关系信息。最后，为了强调调查结果中的关键词，引入了对比度学习以映射正面样本（通过掩盖非钥匙单词构建）更紧密，并将负面的样本推开（通过掩盖关键词构建）。 Openi和Mimic-CXR的实验结果证实了我们提出的方法的有效性。

知识增强的预训练预审语言模型（Keplms）是预先接受的模型，具有从知识图中注入的关系三元组，以提高语言理解能力。为了保证有效的知识注入，之前的研究将模型与知识编码器集成，以表示从知识图表中检索的知识。知识检索和编码的操作带来了重要的计算负担，限制了在需要高推理速度的现实应用程序中使用这些模型。在本文中，我们提出了一种名为DKPLM的新型KEPLM，其在预训练，微调和推理阶段进行了预先训练的语言模型的知识注射过程，这有助于KEPLMS在现实世界场景中的应用。具体而言，我们首先检测知识感知的长尾实体作为知识注射的目标，增强了Keplms的语义理解能力，避免注入冗余信息。长尾实体的嵌入式被相关知识三元组形成的“伪令牌表示”取代。我们进一步设计了用于预培训的关系知识解码任务，以强制模型通过关系三重重建来真正了解注入的知识。实验表明，我们的模型在零拍摄知识探测任务和多种知识意识语言理解任务中显着优于其他KEPLS。我们进一步表明，由于分解机制，DKPLM具有比其他竞争模型更高的推理速度。

Machine-Generated Text (MGT) detection, a task that discriminates MGT from Human-Written Text (HWT), plays a crucial role in preventing misuse of text generative models, which excel in mimicking human writing style recently. Latest proposed detectors usually take coarse text sequence as input and output some good results by fine-tune pretrained models with standard cross-entropy loss. However, these methods fail to consider the linguistic aspect of text (e.g., coherence) and sentence-level structures. Moreover, they lack the ability to handle the low-resource problem which could often happen in practice considering the enormous amount of textual data online. In this paper, we present a coherence-based contrastive learning model named CoCo to detect the possible MGT under low-resource scenario. Inspired by the distinctiveness and permanence properties of linguistic feature, we represent text as a coherence graph to capture its entity consistency, which is further encoded by the pretrained model and graph neural network. To tackle the challenges of data limitations, we employ a contrastive learning framework and propose an improved contrastive loss for making full use of hard negative samples in training stage. The experiment results on two public datasets prove our approach outperforms the state-of-art methods significantly.

预训练的语言模型在对话任务上取得了长足的进步。但是，这些模型通常在表面对话文本上进行训练，因此被证明在理解对话环境的主要语义含义方面是薄弱的。我们研究抽象含义表示（AMR）作为预训练模型的明确语义知识，以捕获预训练期间对话中的核心语义信息。特别是，我们提出了一个基于语义的前训练框架，该框架通过三个任务来扩展标准的预训练框架（Devlin等，2019）。根据AMR图表示。关于聊天聊天和面向任务的对话的理解的实验表明了我们的模型的优势。据我们所知，我们是第一个利用深层语义表示进行对话预训练的人。

将电子健康记录（EHR）自动分为诊断代码对NLP社区的挑战。最先进的方法将此问题视为多标签分类问题，并提出了各种架构来对此问题进行建模。但是，这些系统并未利用验证的语言模型的出色性能，这在自然语言理解任务上实现了出色的性能。先前的工作表明，经常使用的填充方案在此任务上表现不佳。因此，本文旨在分析表现不佳的原因，并通过验证的语言模型为自动编码开发一个框架。我们通过实验发现了三个主要问题：1）大标签空间，2）长输入序列和3）域预读和微调之间的域不匹配。我们提出了PLMICD，该框架通过各种策略来应对挑战。实验结果表明，我们提出的框架可以在基准模拟数据上以多个指标来克服挑战和实现最新性能。源代码可从https://github.com/miulab/plm-icd获得

We present Pre-trained Machine Reader (PMR), a novel method to retrofit Pre-trained Language Models (PLMs) into Machine Reading Comprehension (MRC) models without acquiring labeled data. PMR is capable of resolving the discrepancy between model pre-training and downstream fine-tuning of existing PLMs, and provides a unified solver for tackling various extraction tasks. To achieve this, we construct a large volume of general-purpose and high-quality MRC-style training data with the help of Wikipedia hyperlinks and design a Wiki Anchor Extraction task to guide the MRC-style pre-training process. Although conceptually simple, PMR is particularly effective in solving extraction tasks including Extractive Question Answering and Named Entity Recognition, where it shows tremendous improvements over previous approaches especially under low-resource settings. Moreover, viewing sequence classification task as a special case of extraction task in our MRC formulation, PMR is even capable to extract high-quality rationales to explain the classification process, providing more explainability of the predictions.

Document-level relation extraction faces two overlooked challenges: long-tail problem and multi-label problem. Previous work focuses mainly on obtaining better contextual representations for entity pairs, hardly address the above challenges. In this paper, we analyze the co-occurrence correlation of relations, and introduce it into DocRE task for the first time. We argue that the correlations can not only transfer knowledge between data-rich relations and data-scarce ones to assist in the training of tailed relations, but also reflect semantic distance guiding the classifier to identify semantically close relations for multi-label entity pairs. Specifically, we use relation embedding as a medium, and propose two co-occurrence prediction sub-tasks from both coarse- and fine-grained perspectives to capture relation correlations. Finally, the learned correlation-aware embeddings are used to guide the extraction of relational facts. Substantial experiments on two popular DocRE datasets are conducted, and our method achieves superior results compared to baselines. Insightful analysis also demonstrates the potential of relation correlations to address the above challenges.

立场检测旨在确定文本的作者是否赞成，反对或中立。这项任务的主要挑战是两个方面的：由于不同目标以及缺乏目标的上下文信息而产生的几乎没有学习。现有作品主要通过设计基于注意力的模型或引入嘈杂的外部知识来解决第二期，而第一个问题仍未探索。在本文中，受到预训练的语言模型（PLM）的潜在能力（PLM）的启发，我们建议介绍基于立场检测的及时基于迅速的微调。 PLM可以为目标提供基本的上下文信息，并通过提示启用几次学习。考虑到目标在立场检测任务中的关键作用，我们设计了目标感知的提示并提出了一种新颖的语言。我们的语言器不会将每个标签映射到具体单词，而是将每个标签映射到矢量，并选择最能捕获姿势与目标之间相关性的标签。此外，为了减轻通过单人工提示来处理不同目标的可能缺陷，我们建议将信息从多个提示中学到的信息提炼。实验结果表明，我们提出的模型在全数据和少数场景中的表现出色。

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。

与伯特（Bert）等语言模型相比，已证明知识增强语言表示的预培训模型在知识基础构建任务（即〜关系提取）中更有效。这些知识增强的语言模型将知识纳入预训练中，以生成实体或关系的表示。但是，现有方法通常用单独的嵌入表示每个实体。结果，这些方法难以代表播出的实体和大量参数，在其基础代币模型之上（即〜变压器），必须使用，并且可以处理的实体数量为由于内存限制，实践限制。此外，现有模型仍然难以同时代表实体和关系。为了解决这些问题，我们提出了一个新的预培训模型，该模型分别从图书中学习实体和关系的表示形式，并分别在文本中跨越跨度。通过使用SPAN模块有效地编码跨度，我们的模型可以代表实体及其关系，但所需的参数比现有模型更少。我们通过从Wikipedia中提取的知识图对我们的模型进行了预训练，并在广泛的监督和无监督的信息提取任务上进行了测试。结果表明，我们的模型比基线学习对实体和关系的表现更好，而在监督的设置中，微调我们的模型始终优于罗伯塔，并在信息提取任务上取得了竞争成果。

基于方面的情感分析（ABSA）是一项精细的情感分析任务，它的重点是检测句子中的情感极性。但是，它始终对多方面的挑战敏感，在句子中，多个方面的特征将相互影响。为了减轻此问题，我们设计了一个新颖的培训框架，称为对比度跨通道数据增强（C3 DA），该框架利用了一个内域的发电机来构建更多的多种相应样本，然后通过对比度模型通过对比度学习的稳健性，从而通过对比度学习的稳健性这些生成的数据。实际上，鉴于生成预审预测的语言模型和一些有限的ABSA标记数据，我们首先采用一些参数效率的方法来执行内域微调。然后，所获得的内域发生器用于从两个通道（即方面增强通道和极性增强通道）生成合成句子，该句子分别在给定的方面和极性上生成句子条件。具体而言，我们的C3 DA以跨渠道的方式执行句子生成以获取更多句子，并提出了熵最小化过滤器以滤除低质量生成的样品。广泛的实验表明，我们的C3 DA可以在准确性和宏观上胜过约1％的基准，而不会增加1％。代码和数据在https://github.com/wangbing1416/c3da中发布。

句子级别的关系提取（RE）旨在确定句子中两个实体之间的关系。许多努力都致力于这个问题，而最佳性能方法仍然远非完美。在本文中，我们重新审视了影响现有RE模型的性能的两个问题，即实体表示和嘈杂或定义不明的标签。我们的改进的重新基线与带有键入标记的实体表示形式合并，在Tacred上获得了74.6％的F1，显着胜过以前的SOTA方法。此外，提出的新基线在精致的重新鉴定数据集上达到了91.1％的F1，这表明审计的语言模型（PLMS）在此任务上实现了高性能。我们将代码发布给社区以进行未来的研究。

Triplet extraction aims to extract entities and their corresponding relations in unstructured text. Most existing methods train an extraction model on high-quality training data, and hence are incapable of extracting relations that were not observed during training. Generalizing the model to unseen relations typically requires fine-tuning on synthetic training data which is often noisy and unreliable. In this paper, we argue that reducing triplet extraction to a template filling task over a pre-trained language model can equip the model with zero-shot learning capabilities and enable it to leverage the implicit knowledge in the language model. Embodying these ideas, we propose a novel framework, ZETT (ZEro-shot Triplet extraction by Template infilling), that is based on end-to-end generative transformers. Our experiments show that without any data augmentation or pipeline systems, ZETT can outperform previous state-of-the-art models with 25% less parameters. We further show that ZETT is more robust in detecting entities and can be incorporated with automatically generated templates for relations.

Script event prediction aims to predict the subsequent event given the context. This requires the capability to infer the correlations between events. Recent works have attempted to improve event correlation reasoning by using pretrained language models and incorporating external knowledge~(e.g., discourse relations). Though promising results have been achieved, some challenges still remain. First, the pretrained language models adopted by current works ignore event-level knowledge, resulting in an inability to capture the correlations between events well. Second, modeling correlations between events with discourse relations is limited because it can only capture explicit correlations between events with discourse markers, and cannot capture many implicit correlations. To this end, we propose a novel generative approach for this task, in which a pretrained language model is fine-tuned with an event-centric pretraining objective and predicts the next event within a generative paradigm. Specifically, we first introduce a novel event-level blank infilling strategy as the learning objective to inject event-level knowledge into the pretrained language model, and then design a likelihood-based contrastive loss for fine-tuning the generative model. Instead of using an additional prediction layer, we perform prediction by using sequence likelihoods generated by the generative model. Our approach models correlations between events in a soft way without any external knowledge. The likelihood-based prediction eliminates the need to use additional networks to make predictions and is somewhat interpretable since it scores each word in the event. Experimental results on the multi-choice narrative cloze~(MCNC) task demonstrate that our approach achieves better results than other state-of-the-art baselines. Our code will be available at \url{https://github.com/zhufq00/mcnc}.

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.