事实证明,信息提取方法可有效从结构化或非结构化数据中提取三重。以(头部实体,关系,尾部实体)形式组织这样的三元组的组织称为知识图(kgs)。当前的大多数知识图都是不完整的。为了在下游任务中使用kgs,希望预测kgs中缺少链接。最近,通过将实体和关系嵌入到低维的矢量空间中,旨在根据先前访问的三元组来预测三元组,从而对KGS表示不同的方法。根据如何独立或依赖对三元组进行处理,我们将知识图完成的任务分为传统和图形神经网络表示学习,并更详细地讨论它们。在传统的方法中,每个三重三倍将独立处理,并在基于GNN的方法中进行处理,三倍也考虑了他们的当地社区。查看全文
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Knowledge graphs (KG) have served as the key component of various natural language processing applications. Commonsense knowledge graphs (CKG) are a special type of KG, where entities and relations are composed of free-form text. However, previous works in KG completion and CKG completion suffer from long-tail relations and newly-added relations which do not have many know triples for training. In light of this, few-shot KG completion (FKGC), which requires the strengths of graph representation learning and few-shot learning, has been proposed to challenge the problem of limited annotated data. In this paper, we comprehensively survey previous attempts on such tasks in the form of a series of methods and applications. Specifically, we first introduce FKGC challenges, commonly used KGs, and CKGs. Then we systematically categorize and summarize existing works in terms of the type of KGs and the methods. Finally, we present applications of FKGC models on prediction tasks in different areas and share our thoughts on future research directions of FKGC.
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Knowledge graph reasoning (KGR), aiming to deduce new facts from existing facts based on mined logic rules underlying knowledge graphs (KGs), has become a fast-growing research direction. It has been proven to significantly benefit the usage of KGs in many AI applications, such as question answering and recommendation systems, etc. According to the graph types, the existing KGR models can be roughly divided into three categories, \textit{i.e.,} static models, temporal models, and multi-modal models. The early works in this domain mainly focus on static KGR and tend to directly apply general knowledge graph embedding models to the reasoning task. However, these models are not suitable for more complex but practical tasks, such as inductive static KGR, temporal KGR, and multi-modal KGR. To this end, multiple works have been developed recently, but no survey papers and open-source repositories comprehensively summarize and discuss models in this important direction. To fill the gap, we conduct a survey for knowledge graph reasoning tracing from static to temporal and then to multi-modal KGs. Concretely, the preliminaries, summaries of KGR models, and typical datasets are introduced and discussed consequently. Moreover, we discuss the challenges and potential opportunities. The corresponding open-source repository is shared on GitHub: https://github.com/LIANGKE23/Awesome-Knowledge-Graph-Reasoning.
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Knowledge graph (KG) embedding is to embed components of a KG including entities and relations into continuous vector spaces, so as to simplify the manipulation while preserving the inherent structure of the KG. It can benefit a variety of downstream tasks such as KG completion and relation extraction, and hence has quickly gained massive attention. In this article, we provide a systematic review of existing techniques, including not only the state-of-the-arts but also those with latest trends. Particularly, we make the review based on the type of information used in the embedding task. Techniques that conduct embedding using only facts observed in the KG are first introduced. We describe the overall framework, specific model design, typical training procedures, as well as pros and cons of such techniques. After that, we discuss techniques that further incorporate additional information besides facts. We focus specifically on the use of entity types, relation paths, textual descriptions, and logical rules. Finally, we briefly introduce how KG embedding can be applied to and benefit a wide variety of downstream tasks such as KG completion, relation extraction, question answering, and so forth.
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链接预测的任务旨在解决由于难以从现实世界中收集事实而引起的不完整知识的问题。基于GCN的模型由于其复杂性而广泛应用于解决链接预测问题,但基于GCN的模型在结构和培训过程中遇到了两个问题。 1)GCN层的转化方法在基于GCN的知识表示模型中变得越来越复杂; 2)由于知识图收集过程的不完整,标记为负样本中有许多未收集的真实事实。因此,本文研究了相邻节点的信息聚合系数(自我注意)的特征,并重新设计了GAT结构的自我注意力。同时,受到人类思维习惯的启发,我们在预训练的模型上设计了一种半监督的自训练方法。基准数据集FB15K-237和WN18RR上的实验结果表明,我们提出的自我发项机制和半监督的自我训练方法可以有效地提高链接预测任务的性能。例如,如果您查看FB15K-237,则建议的方法将@1的命中率提高了约30%。
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In knowledge graph completion (KGC), predicting triples involving emerging entities and/or relations, which are unseen when the KG embeddings are learned, has become a critical challenge. Subgraph reasoning with message passing is a promising and popular solution. Some recent methods have achieved good performance, but they (i) usually can only predict triples involving unseen entities alone, failing to address more realistic fully inductive situations with both unseen entities and unseen relations, and (ii) often conduct message passing over the entities with the relation patterns not fully utilized. In this study, we propose a new method named RMPI which uses a novel Relational Message Passing network for fully Inductive KGC. It passes messages directly between relations to make full use of the relation patterns for subgraph reasoning with new techniques on graph transformation, graph pruning, relation-aware neighborhood attention, addressing empty subgraphs, etc., and can utilize the relation semantics defined in the ontological schema of KG. Extensive evaluation on multiple benchmarks has shown the effectiveness of techniques involved in RMPI and its better performance compared with the existing methods that support fully inductive KGC. RMPI is also comparable to the state-of-the-art partially inductive KGC methods with very promising results achieved. Our codes and data are available at https://github.com/zjukg/RMPI.
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知识图(kgs)在许多应用程序中越来越重要的基础架构,同时患有不完整问题。 KG完成任务(KGC)自动根据不完整的KG预测缺失的事实。但是,现有方法在现实情况下表现不佳。一方面,他们的性能将巨大的降解,而kg的稀疏性越来越大。另一方面,预测的推理过程是一个不可信的黑匣子。本文提出了一个稀疏kgc的新型可解释模型,将高阶推理组合到图形卷积网络中,即HOGRN。它不仅可以提高减轻信息不足问题的概括能力,而且还可以在保持模型的有效性和效率的同时提供可解释性。有两个主要组件无缝集成以进行关节优化。首先,高阶推理成分通过捕获关系之间的内源性相关性来学习高质量的关系表示。这可以反映逻辑规则,以证明更广泛的事实是合理的。其次,更新组件的实体利用无重量的图形卷积网络(GCN)有效地模拟具有可解释性的KG结构。与常规方法不同,我们在没有其他参数的情况下在关系空间中进行实体聚合和基于设计组成的注意。轻巧的设计使HOGRN更适合稀疏设置。为了进行评估,我们进行了广泛的实验 - HOGRN对几个稀疏KG的结果表现出了令人印象深刻的改善(平均为9%的MRR增益)。进一步的消融和案例研究证明了主要成分的有效性。我们的代码将在接受后发布。
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Knowledge graph embedding (KGE) is a increasingly popular technique that aims to represent entities and relations of knowledge graphs into low-dimensional semantic spaces for a wide spectrum of applications such as link prediction, knowledge reasoning and knowledge completion. In this paper, we provide a systematic review of existing KGE techniques based on representation spaces. Particularly, we build a fine-grained classification to categorise the models based on three mathematical perspectives of the representation spaces: (1) Algebraic perspective, (2) Geometric perspective, and (3) Analytical perspective. We introduce the rigorous definitions of fundamental mathematical spaces before diving into KGE models and their mathematical properties. We further discuss different KGE methods over the three categories, as well as summarise how spatial advantages work over different embedding needs. By collating the experimental results from downstream tasks, we also explore the advantages of mathematical space in different scenarios and the reasons behind them. We further state some promising research directions from a representation space perspective, with which we hope to inspire researchers to design their KGE models as well as their related applications with more consideration of their mathematical space properties.
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图表可以表示实体之间的关系信息,图形结构广泛用于许多智能任务,例如搜索,推荐和问题应答。然而,实际上大多数图形结构数据都遭受了不完整性,因此链路预测成为一个重要的研究问题。虽然提出了许多模型来用于链路预测,但以下两个问题仍然仍然较少:(1)大多数方法在不利用相关链路中使用丰富的信息,大多数方法都独立模型,并且(2)现有型号主要基于关联设计学习并没有考虑推理。通过这些问题,在本文中,我们提出了图表协作推理(GCR),它可以使用邻居与逻辑推理视角的关系中的关系推理。我们提供了一种简单的方法来将图形结构转换为逻辑表达式,以便链路预测任务可以转换为神经逻辑推理问题。我们应用逻辑受限的神经模块根据逻辑表达式构建网络架构,并使用反向传播以有效地学习模型参数,这在统一架构中桥接可分辨率的学习和象征性推理。为了展示我们工作的有效性,我们对图形相关任务进行实验,例如基于常用的基准数据集的链路预测和推荐,我们的图表合作推理方法实现了最先进的性能。
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Knowledge graphs enable a wide variety of applications, including question answering and information retrieval. Despite the great effort invested in their creation and maintenance, even the largest (e.g., Yago, DBPedia or Wikidata) remain incomplete. We introduce Relational Graph Convolutional Networks (R-GCNs) and apply them to two standard knowledge base completion tasks: Link prediction (recovery of missing facts, i.e. subject-predicate-object triples) and entity classification (recovery of missing entity attributes). R-GCNs are related to a recent class of neural networks operating on graphs, and are developed specifically to deal with the highly multi-relational data characteristic of realistic knowledge bases. We demonstrate the effectiveness of R-GCNs as a stand-alone model for entity classification. We further show that factorization models for link prediction such as DistMult can be significantly improved by enriching them with an encoder model to accumulate evidence over multiple inference steps in the relational graph, demonstrating a large improvement of 29.8% on FB15k-237 over a decoder-only baseline. * Equal contribution.
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机器学习方法尤其是深度神经网络取得了巨大的成功,但其中许多往往依赖于一些标记的样品进行训练。在真实世界的应用中,我们经常需要通过例如具有新兴预测目标和昂贵的样本注释的动态上下文来解决样本短缺。因此,低资源学习,旨在学习具有足够资源(特别是培训样本)的强大预测模型,现在正在被广泛调查。在所有低资源学习研究中,许多人更喜欢以知识图(kg)的形式利用一些辅助信息,这对于知识表示变得越来越受欢迎,以减少对标记样本的依赖。在这项调查中,我们非常全面地审查了90美元的报纸关于两个主要的低资源学习设置 - 零射击学习(ZSL)的预测,从未出现过训练,而且很少拍摄的学习(FSL)预测的新类仅具有可用的少量标记样本。我们首先介绍了ZSL和FSL研究中使用的KGS以及现有的和潜在的KG施工解决方案,然后系统地分类和总结了KG感知ZSL和FSL方法,将它们划分为不同的范例,例如基于映射的映射,数据增强,基于传播和基于优化的。我们接下来呈现了不同的应用程序,包括计算机视觉和自然语言处理中的kg增强预测任务,还包括kg完成的任务,以及每个任务的一些典型评估资源。我们最终讨论了一些关于新学习和推理范式的方面的一些挑战和未来方向,以及高质量的KGs的建设。
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The development of deep neural networks has improved representation learning in various domains, including textual, graph structural, and relational triple representations. This development opened the door to new relation extraction beyond the traditional text-oriented relation extraction. However, research on the effectiveness of considering multiple heterogeneous domain information simultaneously is still under exploration, and if a model can take an advantage of integrating heterogeneous information, it is expected to exhibit a significant contribution to many problems in the world. This thesis works on Drug-Drug Interactions (DDIs) from the literature as a case study and realizes relation extraction utilizing heterogeneous domain information. First, a deep neural relation extraction model is prepared and its attention mechanism is analyzed. Next, a method to combine the drug molecular structure information and drug description information to the input sentence information is proposed, and the effectiveness of utilizing drug molecular structures and drug descriptions for the relation extraction task is shown. Then, in order to further exploit the heterogeneous information, drug-related items, such as protein entries, medical terms and pathways are collected from multiple existing databases and a new data set in the form of a knowledge graph (KG) is constructed. A link prediction task on the constructed data set is conducted to obtain embedding representations of drugs that contain the heterogeneous domain information. Finally, a method that integrates the input sentence information and the heterogeneous KG information is proposed. The proposed model is trained and evaluated on a widely used data set, and as a result, it is shown that utilizing heterogeneous domain information significantly improves the performance of relation extraction from the literature.
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Relational machine learning studies methods for the statistical analysis of relational, or graph-structured, data. In this paper, we provide a review of how such statistical models can be "trained" on large knowledge graphs, and then used to predict new facts about the world (which is equivalent to predicting new edges in the graph). In particular, we discuss two fundamentally different kinds of statistical relational models, both of which can scale to massive datasets. The first is based on latent feature models such as tensor factorization and multiway neural networks. The second is based on mining observable patterns in the graph. We also show how to combine these latent and observable models to get improved modeling power at decreased computational cost. Finally, we discuss how such statistical models of graphs can be combined with text-based information extraction methods for automatically constructing knowledge graphs from the Web. To this end, we also discuss Google's Knowledge Vault project as an example of such combination.
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Pre-publication draft of a book to be published byMorgan & Claypool publishers. Unedited version released with permission. All relevant copyrights held by the author and publisher extend to this pre-publication draft.
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知识图嵌入(KGE)旨在将实体和关系映射到低维空间,并成为知识图完成的\ textit {de-facto}标准。大多数现有的KGE方法都受到稀疏挑战的困扰,在这种挑战中,很难预测在知识图中频繁的实体。在这项工作中,我们提出了一个新颖的框架KRACL,以减轻具有图表和对比度学习的KG中广泛的稀疏性。首先,我们建议知识关系网络(KRAT)通过同时将相邻的三元组投射到不同的潜在空间,并通过注意机制共同汇总信息来利用图形上下文。 KRAT能够捕获不同上下文三联的微妙的语义信息和重要性,并利用知识图中的多跳信息。其次,我们通过将对比度损失与跨熵损失相结合,提出知识对比损失,这引入了更多的负样本,从而丰富了对稀疏实体的反馈。我们的实验表明,KRACL在各种标准知识基准中取得了卓越的结果,尤其是在WN18RR和NELL-995上,具有大量低级内实体。广泛的实验还具有KRACL在处理稀疏知识图和鲁棒性三元组的鲁棒性方面的有效性。
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外部知识(A.K.A.侧面信息)在零拍摄学习(ZSL)中起着关键作用,该角色旨在预测从未出现在训练数据中的看不见的类。已被广泛调查了几种外部知识,例如文本和属性,但他们独自受到不完整的语义。因此,一些最近的研究提出了由于其高度富有效力和代表知识的兼容性而使用知识图表(千克)。但是,ZSL社区仍然缺乏用于学习和比较不同外部知识设置和基于不同的KG的ZSL方法的标准基准。在本文中,我们提出了六个资源,涵盖了三个任务,即零拍摄图像分类(ZS-IMGC),零拍摄关系提取(ZS-RE)和零拍KG完成(ZS-KGC)。每个资源都有一个正常的zsl基准标记和包含从文本到属性的kg的kg,从关系知识到逻辑表达式。我们已清楚地介绍了这些资源,包括其建设,统计数据格式和使用情况W.r.t.不同的ZSL方法。更重要的是,我们进行了一项全面的基准研究,具有两个通用和最先进的方法,两种特定方法和一种可解释方法。我们讨论并比较了不同的ZSL范式W.R.T.不同的外部知识设置,并发现我们的资源具有开发更高级ZSL方法的巨大潜力,并为应用KGS进行增强机学习的更多解决方案。所有资源都可以在https://github.com/china-uk-zsl/resources_for_kzsl上获得。
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图形神经网络(GNN)在解决图形结构数据(即网络)方面的各种分析任务方面已广受欢迎。典型的gnns及其变体遵循一种消息的方式,该方式通过网络拓扑沿网络拓扑的特征传播过程获得网络表示,然而,它们忽略了许多现实世界网络中存在的丰富文本语义(例如,局部单词序列)。现有的文本丰富网络方法通过主要利用内部信息(例如主题或短语/单词)来整合文本语义,这些信息通常无法全面地挖掘文本语义,从而限制了网络结构和文本语义之间的相互指导。为了解决这些问题,我们提出了一个具有外部知识(TEKO)的新型文本富裕的图形神经网络,以充分利用文本丰富的网络中的结构和文本信息。具体而言,我们首先提出一个灵活的异质语义网络,该网络结合了文档和实体之间的高质量实体和互动。然后,我们介绍两种类型的外部知识,即结构化的三胞胎和非结构化实体描述,以更深入地了解文本语义。我们进一步为构建的异质语义网络设计了互惠卷积机制,使网络结构和文本语义能够相互协作并学习高级网络表示。在四个公共文本丰富的网络以及一个大规模的电子商务搜索数据集上进行了广泛的实验结果,这说明了Teko优于最先进的基线。
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知识图(kg)对齐 - 指识别不同kgs中同一件事的实体的任务 - 被认为是KG构造领域中最重要的操作之一。然而,现有的对齐技术通常假设输入kgs是完整的并且同性的,这是由于域,大小和稀疏性的现实世界异质性而不是真实。在这项工作中,我们解决了与代表学习对齐不完整的KG对齐的问题。我们的KG嵌入式框架利用了两个特征频道:基于传输型和基于接近的。前者通过翻译路径捕获实体之间的一致性约束,而后者通过注意引导关系感知图形神经网络捕获KG的邻域结构。两个特征频道共同学习以在输入kgs之间交换重要特征,同时强制在同一嵌入空间中强制输入kg的输出表示。此外,我们开发了缺失的链接检测器,该探测器发现并恢复培训过程中输入kgs中的缺失链接,这有助于减轻不完整性问题,从而提高学习象征的兼容性。然后将嵌入的熔合融合以生成对准结果,并且高置信匹配节点对被更新为预先调整的监控数据以逐渐改善嵌入。经验结果表明,我们的型号比SOTA更准确,而且对不同级别的不完整性较高,高达15.2 \%。我们还证明了KGS之间交换的知识有助于揭示知识图表(A.K.A.知识完成)的看不见的事实,结果比SOTA知识图形完成技术高3.5 \%。
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学术知识图(KGS)提供了代表科学出版物编码的知识的丰富的结构化信息来源。随着出版的科学文学的庞大,包括描述科学概念的过多的非均匀实体和关系,这些公斤本质上是不完整的。我们呈现Exbert,一种利用预先训练的变压器语言模型来执行学术知识图形完成的方法。我们将知识图形的三元组模型为文本并执行三重分类(即,属于KG或不属于KG)。评估表明,在三重分类,链路预测和关系预测的任务中,Exbert在三个学术kg完成数据集中表现出其他基线。此外,我们将两个学术数据集作为研究界的资源,从公共公共公报和在线资源中收集。
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Knowledge graph (KG) link prediction aims to infer new facts based on existing facts in the KG. Recent studies have shown that using the graph neighborhood of a node via graph neural networks (GNNs) provides more useful information compared to just using the query information. Conventional GNNs for KG link prediction follow the standard message-passing paradigm on the entire KG, which leads to over-smoothing of representations and also limits their scalability. On a large scale, it becomes computationally expensive to aggregate useful information from the entire KG for inference. To address the limitations of existing KG link prediction frameworks, we propose a novel retrieve-and-read framework, which first retrieves a relevant subgraph context for the query and then jointly reasons over the context and the query with a high-capacity reader. As part of our exemplar instantiation for the new framework, we propose a novel Transformer-based GNN as the reader, which incorporates graph-based attention structure and cross-attention between query and context for deep fusion. This design enables the model to focus on salient context information relevant to the query. Empirical results on two standard KG link prediction datasets demonstrate the competitive performance of the proposed method.
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