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.

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

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.

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.

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

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.

Graph is an important data representation which appears in a wide diversity of real-world scenarios. Effective graph analytics provides users a deeper understanding of what is behind the data, and thus can benefit a lot of useful applications such as node classification, node recommendation, link prediction, etc. However, most graph analytics methods suffer the high computation and space cost. Graph embedding is an effective yet efficient way to solve the graph analytics problem. It converts the graph data into a low dimensional space in which the graph structural information and graph properties are maximumly preserved. In this survey, we conduct a comprehensive review of the literature in graph embedding. We first introduce the formal definition of graph embedding as well as the related concepts. After that, we propose two taxonomies of graph embedding which correspond to what challenges exist in different graph embedding problem settings and how the existing work address these challenges in their solutions. Finally, we summarize the applications that graph embedding enables and suggest four promising future research directions in terms of computation efficiency, problem settings, techniques and application scenarios.

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.

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。

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.

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。

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。

Recent years have witnessed the resurgence of knowledge engineering which is featured by the fast growth of knowledge graphs. However, most of existing knowledge graphs are represented with pure symbols, which hurts the machine's capability to understand the real world. The multi-modalization of knowledge graphs is an inevitable key step towards the realization of human-level machine intelligence. The results of this endeavor are Multi-modal Knowledge Graphs (MMKGs). In this survey on MMKGs constructed by texts and images, we first give definitions of MMKGs, followed with the preliminaries on multi-modal tasks and techniques. We then systematically review the challenges, progresses and opportunities on the construction and application of MMKGs respectively, with detailed analyses of the strength and weakness of different solutions. We finalize this survey with open research problems relevant to MMKGs.

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

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。

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。

知识图嵌入（KGE）方法已从广泛的AI社区（包括自然语言处理（NLP））中引起了极大的关注，用于文本生成，分类和上下文诱导。用少数维度嵌入大量的相互关系，需要在认知和计算方面进行适当的建模。最近，开发了有关自然语言的认知和计算方面的许多目标功能。其中包括最新的线性方法，双线性，具有歧管的内核，投影 - 空间和类似推断。但是，这种模型的主要挑战在于它们的损失函数，将关系嵌入的维度与相应的实体维度相关联。当错误估计对应物时，这导致对实体之间相应关系的预测不准确。 Bordes等人发表的Proje Kge由于计算复杂性低和模型改进的高潜力，在所有翻译和双线性相互作用的同时，在捕获实体非线性的同时，都改善了这项工作。基准知识图（KGS）（例如FB15K和WN18）的实验结果表明，所提出的方法使用线性和双线性方法以及其他最新功能的方法在实体预测任务中的最新模型优于最先进的模型。另外，为该模型提出了平行处理结构，以提高大型kg的可伸缩性。还解释了不同自适应聚类和新提出的抽样方法的影响，这被证明可以有效提高知识图完成的准确性。

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。

知识基础问题回答（KBQA）旨在通过知识库（KB）回答问题。早期研究主要集中于回答有关KB的简单问题，并取得了巨大的成功。但是，他们在复杂问题上的表现远非令人满意。因此，近年来，研究人员提出了许多新颖的方法，研究了回答复杂问题的挑战。在这项调查中，我们回顾了KBQA的最新进展，重点是解决复杂问题，这些问题通常包含多个主题，表达复合关系或涉及数值操作。详细说明，我们从介绍复杂的KBQA任务和相关背景开始。然后，我们描述用于复杂KBQA任务的基准数据集，并介绍这些数据集的构建过程。接下来，我们提出两个复杂KBQA方法的主流类别，即基于语义解析的方法（基于SP）的方法和基于信息检索的方法（基于IR）。具体而言，我们通过流程设计说明了他们的程序，并讨论了它们的主要差异和相似性。之后，我们总结了这两类方法在回答复杂问题时会遇到的挑战，并解释了现有工作中使用的高级解决方案和技术。最后，我们结论并讨论了与复杂的KBQA有关的几个有希望的方向，以进行未来的研究。

知识图表（KGS）是真实世界事实的结构化表示，是融合人类知识的智能数据库，可以帮助机器模仿人类问题的方法。然而，由于快速迭代的性质以及数据的不完整，KGs通常是巨大的，并且在公斤上有不可避免的事实。对于知识图链接的预测是针对基于现有的知识推理来完成缺少事实的任务。广泛研究了两个主要的研究流：一个学习可以捕获潜在模式的实体和关系的低维嵌入，以及通过采矿逻辑规则的良好解释性。不幸的是，以前的研究很少关注异质的KG。在本文中，我们提出了一种将基于嵌入的学习和逻辑规则挖掘结合的模型，以推断在KG上。具体地，我们研究了从节点程度的角度涉及各种类型的实体和关系的异构kg中的缺失链接的问题。在实验中，我们证明了我们的DegreEmbed模型优于对现实世界的数据集的国家的最先进的方法。同时，我们模型开采的规则具有高质量和可解释性。