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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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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Link prediction for knowledge graphs is the task of predicting missing relationships between entities. Previous work on link prediction has focused on shallow, fast models which can scale to large knowledge graphs. However, these models learn less expressive features than deep, multi-layer modelswhich potentially limits performance. In this work we introduce ConvE, a multi-layer convolutional network model for link prediction, and report state-of-the-art results for several established datasets. We also show that the model is highly parameter efficient, yielding the same performance as DistMult and R-GCN with 8x and 17x fewer parameters. Analysis of our model suggests that it is particularly effective at modelling nodes with high indegree -which are common in highlyconnected, complex knowledge graphs such as Freebase and YAGO3. In addition, it has been noted that the WN18 and FB15k datasets suffer from test set leakage, due to inverse relations from the training set being present in the test sethowever, the extent of this issue has so far not been quantified. We find this problem to be severe: a simple rule-based model can achieve state-of-the-art results on both WN18 and FB15k. To ensure that models are evaluated on datasets where simply exploiting inverse relations cannot yield competitive results, we investigate and validate several commonly used datasets -deriving robust variants where necessary. We then perform experiments on these robust datasets for our own and several previously proposed models, and find that ConvE achieves state-of-the-art Mean Reciprocal Rank across most datasets.
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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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知识图(kgs)因其学习单一关系事实的表示能力而获得了突出。最近,研究重点是建模超级关系的事实,这些事实超出了单一关系事实的限制,使我们能够代表更复杂和现实的信息。但是,现有的超级关系中学习表征的方法主要集中于增强从预选赛到基础三元组的沟通,同时忽略了从基本三重限制者到资格赛的信息流。这可能会导致次级预选赛表示,尤其是在提出大量预选赛时。它促使我们设计一个利用多个聚合器来学习超级关系事实的表示框架:从基本三重的角度来看,一个框架从资格符的角度来看。实验证明了我们框架对多个数据集的超相关知识图完成的有效性。此外,我们进行了一项消融研究,以验证各个组件在我们的框架中的重要性。可以在\ url {https://github.com/harryshomer/quad}找到复制我们的结果的代码。
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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 statistical relational learning, the link prediction problem is key to automatically understand the structure of large knowledge bases. As in previous studies, we propose to solve this problem through latent factorization. However, here we make use of complex valued embeddings. The composition of complex embeddings can handle a large variety of binary relations, among them symmetric and antisymmetric relations. Compared to state-of-the-art models such as Neural Tensor Network and Holographic Embeddings, our approach based on complex embeddings is arguably simpler, as it only uses the Hermitian dot product, the complex counterpart of the standard dot product between real vectors. Our approach is scalable to large datasets as it remains linear in both space and time, while consistently outperforming alternative approaches on standard link prediction benchmarks. 1
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In this paper we show the surprising effectiveness of a simple observed features model in comparison to latent feature models on two benchmark knowledge base completion datasets, FB15K and WN18. We also compare latent and observed feature models on a more challenging dataset derived from FB15K, and additionally coupled with textual mentions from a web-scale corpus. We show that the observed features model is most effective at capturing the information present for entity pairs with textual relations, and a combination of the two combines the strengths of both model types.
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最近公布的知识图形嵌入模型的实施,培训和评估的异质性已经公平和彻底的比较困难。为了评估先前公布的结果的再现性,我们在Pykeen软件包中重新实施和评估了21个交互模型。在这里,我们概述了哪些结果可以通过其报告的超参数再现,这只能以备用的超参数再现,并且无法再现,并且可以提供洞察力,以及为什么会有这种情况。然后,我们在四个数据集上进行了大规模的基准测试,其中数千个实验和24,804 GPU的计算时间。我们展示了最佳实践,每个模型的最佳配置以及可以通过先前发布的最佳配置进行改进的洞察。我们的结果强调了模型架构,训练方法,丢失功能和逆关系显式建模的组合对于模型的性能来说至关重要,而不仅由模型架构决定。我们提供了证据表明,在仔细配置时,若干架构可以获得对最先进的结果。我们制定了所有代码,实验配置,结果和分析,导致我们在https://github.com/pykeen/pykeen和https://github.com/pykeen/benchmarking中获得的解释
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最近,链接预测问题,也称为知识图完成,已经吸引了大量的研究。即使最近的型号很少试图通过在低维度中嵌入知识图表来实现相对良好的性能,即目前最先进的模型的最佳结果是以大大提高嵌入的维度的成本赚取的。然而,这导致在巨大知识库的情况下导致过度舒服和更重要的可扩展性问题。灵感灵感来自变压器模型的变体提供的深度学习的进步,因为它的自我关注机制,在本文中,我们提出了一种基于IT的模型来解决上述限制。在我们的模型中,自我关注是将查询依赖预测应用于实体和关系的关键,并捕获它们之间的相互信息,以获得来自低维嵌入的高度富有表现力的表现。两种标准链路预测数据集,FB15K-237和WN18RR的经验结果表明,我们的模型比我们三个最近最近期的最新竞争对手实现了相当的性能或更好的性能,其维度的重大减少了76.3%平均嵌入。
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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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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 (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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知识图的归纳链路预测旨在预测未见实体之间的缺失联系,而那些未在训练阶段显示的实体。大多数以前的作品都学习实体的特定实体嵌入,这些实体无法处理看不见的实体。最近的几种方法利用封闭子图来获得归纳能力。但是,所有这些作品仅在没有完整的邻近关系的情况下考虑子图的封闭部分,这导致了忽略部分邻近关系的问题,并且很难处理稀疏的子图。为了解决这个问题,我们提出了SNRI子图邻近关系Infomax,它足够从两个方面利用完整的相邻关系:节点特征的相邻关系特征和稀疏子图的相邻关系路径。为了进一步以全球方式建模邻近关系,我们对知识图进行创新的相互信息(MI)最大化。实验表明,SNRI在归纳链路预测任务上的大幅度优于现有的最新方法,并验证以全局方式探索完整的邻近关系的有效性,以表征节点特征和在稀疏子分类上的理由。
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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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Machine learning on graphs is an important and ubiquitous task with applications ranging from drug design to friendship recommendation in social networks. The primary challenge in this domain is finding a way to represent, or encode, graph structure so that it can be easily exploited by machine learning models. Traditionally, machine learning approaches relied on user-defined heuristics to extract features encoding structural information about a graph (e.g., degree statistics or kernel functions). However, recent years have seen a surge in approaches that automatically learn to encode graph structure into low-dimensional embeddings, using techniques based on deep learning and nonlinear dimensionality reduction. Here we provide a conceptual review of key advancements in this area of representation learning on graphs, including matrix factorization-based methods, random-walk based algorithms, and graph neural networks. We review methods to embed individual nodes as well as approaches to embed entire (sub)graphs. In doing so, we develop a unified framework to describe these recent approaches, and we highlight a number of important applications and directions for future work.
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多跳跃逻辑推理是在知识图(KGS)上学习领域的一个已建立问题。它涵盖了单跳连接预测以及其他更复杂的逻辑查询类型。现有的算法仅在经典的三重基图上运行,而现代KG经常采用超相关的建模范式。在此范式中,键入的边缘可能具有几对键值对,称为限定符,可为事实提供细粒度的环境。在查询中,此上下文修改了关系的含义,通常会减少答案集。经常在现实世界中的应用程序中观察到超相关的查询,并且现有的近似查询答案方法无法使用预选赛对。在这项工作中,我们弥合了这一差距,并将多跳的推理问题扩展到了超级关系的KG,允许解决这一新类型的复杂查询。在图形神经网络和查询嵌入技术的最新进展之下,我们研究了如何嵌入和回答超相关的连词查询。除此之外,我们还提出了一种回答此类查询并在我们的实验中证明的方法,即预选赛可以改善对各种查询模式的查询回答。
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在本文中,我们介绍了一种新的基于GNN的知识图形嵌入模型,命名为WGE,以捕获聚焦的图形结构和关联的图形结构。特别是,鉴于知识图形,WGE构建一个无向实体的聚焦图,该图形将实体视为节点。此外,WGE还从关联的约束构造另一个无向图形,将实体和关系视为节点。然后,WGE提出了一种新的架构,即直接在这两个单个图表上使用两个vanilla GNNS,以更好地更新实体和关系的矢量表示,然后是加权得分函数来返回三重分数。实验结果表明,WGE在三个新的和具有挑战性的基准数据集Codex上获得最先进的表演,用于知识图形完成。
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