近年来,对图表的研究受到了极大的关注。但是,到目前为止,大多数研究都集中在单层图的嵌入上。涉及多层结构的表示问题问题的少数研究取决于以下强烈的假设:层间链接是已知的,这限制了可能的应用范围。在这里,我们提出了多层,这是允许嵌入多重网络的图形算法的概括。我们表明,多层能够重建层内和层间连接性,超过了图形,该图是为简单图形而设计的。接下来,通过全面的实验分析,我们还以简单和多重网络中的嵌入性能阐明,表明图的密度或链接的随机性都会强烈影响嵌入的质量。
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Clustering is a fundamental problem in network analysis that finds closely connected groups of nodes and separates them from other nodes in the graph, while link prediction is to predict whether two nodes in a network are likely to have a link. The definition of both naturally determines that clustering must play a positive role in obtaining accurate link prediction tasks. Yet researchers have long ignored or used inappropriate ways to undermine this positive relationship. In this article, We construct a simple but efficient clustering-driven link prediction framework(ClusterLP), with the goal of directly exploiting the cluster structures to obtain connections between nodes as accurately as possible in both undirected graphs and directed graphs. Specifically, we propose that it is easier to establish links between nodes with similar representation vectors and cluster tendencies in undirected graphs, while nodes in a directed graphs can more easily point to nodes similar to their representation vectors and have greater influence in their own cluster. We customized the implementation of ClusterLP for undirected and directed graphs, respectively, and the experimental results using multiple real-world networks on the link prediction task showed that our models is highly competitive with existing baseline models. The code implementation of ClusterLP and baselines we use are available at https://github.com/ZINUX1998/ClusterLP.
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链接预测是一项重要的任务,在各个域中具有广泛的应用程序。但是,大多数现有的链接预测方法都假定给定的图遵循同质的假设,并设计基于相似性的启发式方法或表示学习方法来预测链接。但是,许多现实世界图是异性图,同义假设不存在,这挑战了现有的链接预测方法。通常,在异性图中,有许多引起链接形成的潜在因素,并且两个链接的节点在一个或两个因素中往往相似,但在其他因素中可能是不同的,导致总体相似性较低。因此,一种方法是学习每个节点的分离表示形式,每个矢量捕获一个因子上的节点的潜在表示,这铺平了一种方法来模拟异性图中的链接形成,从而导致更好的节点表示学习和链接预测性能。但是,对此的工作非常有限。因此,在本文中,我们研究了一个新的问题,该问题是在异性图上进行链接预测的分离表示学习。我们提出了一种新颖的框架分解,可以通过建模链接形成并执行感知因素的消息来学习以促进链接预测来学习解开的表示形式。在13个现实世界数据集上进行的广泛实验证明了Disenlink对异性恋和血友病图的链接预测的有效性。我们的代码可从https://github.com/sjz5202/disenlink获得
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网络完成是一个比链接预测更难的问题,因为它不仅尝试推断丢失的链接,还要推断节点。已经提出了不同的方法来解决此问题,但是很少有人使用结构信息 - 局部连接模式的相似性。在本文中,我们提出了一个名为C-GIN的模型,以根据图形自动编码器框架从网络的观察到的部分捕获局部结构模式,该框架配备了图形同构网络模型,并将这些模式推广到完成整个图形。对来自不同领域的合成和现实世界网络的实验和分析表明,C-Gin可以实现竞争性能,而所需的信息较少,并且在大多数情况下,与基线预测模型相比,可以获得更高的准确性。我们进一步提出了一个基于网络结构的“可达聚类系数(CC)”。实验表明,我们的模型在具有较高可及的CC的网络上表现更好。
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图表表示学习是一种快速增长的领域,其中一个主要目标是在低维空间中产生有意义的图形表示。已经成功地应用了学习的嵌入式来执行各种预测任务,例如链路预测,节点分类,群集和可视化。图表社区的集体努力提供了数百种方法,但在所有评估指标下没有单一方法擅长,例如预测准确性,运行时间,可扩展性等。该调查旨在通过考虑算法来评估嵌入方法的所有主要类别的图表变体,参数选择,可伸缩性,硬件和软件平台,下游ML任务和多样化数据集。我们使用包含手动特征工程,矩阵分解,浅神经网络和深图卷积网络的分类法组织了图形嵌入技术。我们使用广泛使用的基准图表评估了节点分类,链路预测,群集和可视化任务的这些类别算法。我们在Pytorch几何和DGL库上设计了我们的实验,并在不同的多核CPU和GPU平台上运行实验。我们严格地审查了各种性能指标下嵌入方法的性能,并总结了结果。因此,本文可以作为比较指南,以帮助用户选择最适合其任务的方法。
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图形嵌入是图形节点到一组向量的转换。良好的嵌入应捕获图形拓扑,节点与节点的关系以及有关图,其子图和节点的其他相关信息。如果实现了这些目标,则嵌入是网络中有意义的,可理解的,可理解的压缩表示形式,可用于其他机器学习工具,例如节点分类,社区检测或链接预测。主要的挑战是,需要确保嵌入很好地描述图形的属性。结果,选择最佳嵌入是一项具有挑战性的任务,并且通常需要领域专家。在本文中,我们在现实世界网络和人为生成的网络上进行了一系列广泛的实验,并使用选定的图嵌入算法进行了一系列的实验。根据这些实验,我们制定了两个一般结论。首先,如果需要在运行实验之前选择一种嵌入算法,则Node2Vec是最佳选择,因为它在我们的测试中表现最好。话虽如此,在所有测试中都没有单一的赢家,此外,大多数嵌入算法都具有应该调整并随机分配的超参数。因此,如果可能的话,我们对从业者的主要建议是生成几个问题的嵌入,然后使用一个通用框架,该框架为无监督的图形嵌入比较提供了工具。该框架(最近在文献中引入并在GitHub存储库中很容易获得)将分歧分数分配给嵌入,以帮助区分好的分数和不良的分数。
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Inferring missing links or detecting spurious ones based on observed graphs, known as link prediction, is a long-standing challenge in graph data analysis. With the recent advances in deep learning, graph neural networks have been used for link prediction and have achieved state-of-the-art performance. Nevertheless, existing methods developed for this purpose are typically discriminative, computing features of local subgraphs around two neighboring nodes and predicting potential links between them from the perspective of subgraph classification. In this formalism, the selection of enclosing subgraphs and heuristic structural features for subgraph classification significantly affects the performance of the methods. To overcome this limitation, this paper proposes a novel and radically different link prediction algorithm based on the network reconstruction theory, called GraphLP. Instead of sampling positive and negative links and heuristically computing the features of their enclosing subgraphs, GraphLP utilizes the feature learning ability of deep-learning models to automatically extract the structural patterns of graphs for link prediction under the assumption that real-world graphs are not locally isolated. Moreover, GraphLP explores high-order connectivity patterns to utilize the hierarchical organizational structures of graphs for link prediction. Our experimental results on all common benchmark datasets from different applications demonstrate that the proposed method consistently outperforms other state-of-the-art methods. Unlike the discriminative neural network models used for link prediction, GraphLP is generative, which provides a new paradigm for neural-network-based link prediction.
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复杂网络分析的最新进展为不同领域的应用开辟了广泛的可能性。网络分析的功能取决于节点特征。基于拓扑的节点特征是对局部和全局空间关系和节点连接结构的实现。因此,收集有关节点特征的正确信息和相邻节点的连接结构在复杂网络分析中在节点分类和链接预测中起着最突出的作用。目前的工作介绍了一种新的特征抽象方法,即基于嵌入匿名随机步行向量上的匿名随机步行,即过渡概率矩阵(TPM)。节点特征向量由从预定义半径中的一组步行中获得的过渡概率组成。过渡概率与局部连接结构直接相关,因此正确嵌入到特征向量上。在节点识别/分类中测试了建议的嵌入方法的成功,并在三个常用的现实世界网络上进行了链接预测。在现实世界网络中,具有相似连接结构的节点很常见。因此,从类似网络中获取新网络预测的信息是一种显着特征,它使所提出的算法在跨网络概括任务方面优于最先进的算法。
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图表表示学习已经成为许多情景中的无处不在的组成部分,从社会网络分析到智能电网的能量预测。在几个应用程序中,确保关于某些受保护属性的节点(或图形)表示的公平对其正确部署至关重要。然而,图表深度学习的公平仍然在探索,很少有解决方案。特别地,在若干真实世界图(即同声源性)上相似节点对簇的趋势可以显着恶化这些程序的公平性。在本文中,我们提出了一种新颖的偏见边缘辍学算法(Fairdrop)来反击精神剧并改善图形表示学习中的公平性。 Fairdrop可以在许多现有算法上轻松插入,具有高效,适应性,并且可以与其他公平诱导的解决方案结合。在描述了一般算法之后,我们在两个基准任务中展示其应用,具体地,作为用于生产节点嵌入的随机步道模型,以及用于链路预测的图形卷积网络。我们证明,所提出的算法可以成功地改善所有型号的公平,直到精度小或可忽略的降低,并与现有的最先进的解决方案相比。在一个消融研究中,我们证明我们的算法可以灵活地在偏置公平性和无偏见的边缘辍学之间插入。此外,为了更好地评估增益,我们提出了一种新的二元组定义,以测量与基于组的公平度量配对时的链路预测任务的偏差。特别是,我们扩展了用于测量节点嵌入的偏差的指标,以考虑图形结构。
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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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Graph Neural Networks (GNNs) have become increasingly important in recent years due to their state-of-the-art performance on many important downstream applications. Existing GNNs have mostly focused on learning a single node representation, despite that a node often exhibits polysemous behavior in different contexts. In this work, we develop a persona-based graph neural network framework called PersonaSAGE that learns multiple persona-based embeddings for each node in the graph. Such disentangled representations are more interpretable and useful than a single embedding. Furthermore, PersonaSAGE learns the appropriate set of persona embeddings for each node in the graph, and every node can have a different number of assigned persona embeddings. The framework is flexible enough and the general design helps in the wide applicability of the learned embeddings to suit the domain. We utilize publicly available benchmark datasets to evaluate our approach and against a variety of baselines. The experiments demonstrate the effectiveness of PersonaSAGE for a variety of important tasks including link prediction where we achieve an average gain of 15% while remaining competitive for node classification. Finally, we also demonstrate the utility of PersonaSAGE with a case study for personalized recommendation of different entity types in a data management platform.
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Graph AutoCododers(GAE)和变分图自动编码器(VGAE)作为链接预测的强大方法出现。他们的表现对社区探测问题的印象不那么令人印象深刻,根据最近和同意的实验评估,它们的表现通常超过了诸如louvain方法之类的简单替代方案。目前尚不清楚可以通过GAE和VGAE改善社区检测的程度,尤其是在没有节点功能的情况下。此外,不确定是否可以在链接预测上同时保留良好的性能。在本文中,我们表明,可以高精度地共同解决这两个任务。为此,我们介绍和理论上研究了一个社区保留的消息传递方案,通过在计算嵌入空间时考虑初始图形结构和基于模块化的先验社区来掺杂我们的GAE和VGAE编码器。我们还提出了新颖的培训和优化策略,包括引入一个模块化的正规器,以补充联合链路预测和社区检测的现有重建损失。我们通过对各种现实世界图的深入实验验证,证明了方法的经验有效性,称为模块化感知的GAE和VGAE。
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在过去的二十年中,我们目睹了以图形或网络形式构建的有价值的大数据的大幅增长。为了将传统的机器学习和数据分析技术应用于此类数据,有必要将图形转换为基于矢量的表示,以保留图形最重要的结构属性。为此,文献中已经提出了大量的图形嵌入方法。它们中的大多数产生了适用于各种应用的通用嵌入,例如节点聚类,节点分类,图形可视化和链接预测。在本文中,我们提出了两个新的图形嵌入算法,这些算法是基于专门为节点分类问题设计的随机步道。已设计算法的随机步行采样策略旨在特别注意集线器 - 高度节点,这些节点在大规模图中具有最关键的作用。通过分析对现实世界网络嵌入的三种分类算法的分类性能,对所提出的方法进行实验评估。获得的结果表明,与当前最流行的随机步行方法相比,我们的方法可大大提高所检查分类器的预测能力(NODE2VEC)。
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Learning fair graph representations for downstream applications is becoming increasingly important, but existing work has mostly focused on improving fairness at the global level by either modifying the graph structure or objective function without taking into account the local neighborhood of a node. In this work, we formally introduce the notion of neighborhood fairness and develop a computational framework for learning such locally fair embeddings. We argue that the notion of neighborhood fairness is more appropriate since GNN-based models operate at the local neighborhood level of a node. Our neighborhood fairness framework has two main components that are flexible for learning fair graph representations from arbitrary data: the first aims to construct fair neighborhoods for any arbitrary node in a graph and the second enables adaption of these fair neighborhoods to better capture certain application or data-dependent constraints, such as allowing neighborhoods to be more biased towards certain attributes or neighbors in the graph.Furthermore, while link prediction has been extensively studied, we are the first to investigate the graph representation learning task of fair link classification. We demonstrate the effectiveness of the proposed neighborhood fairness framework for a variety of graph machine learning tasks including fair link prediction, link classification, and learning fair graph embeddings. Notably, our approach achieves not only better fairness but also increases the accuracy in the majority of cases across a wide variety of graphs, problem settings, and metrics.
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能够推荐在线社交网络中用户之间的链接对于用户与志趣相投的个人以及利用社交媒体信息发展业务的平台本身和第三方联系很重要。预测通常基于无监督或监督的学习,通常利用简单而有效的图形拓扑信息,例如普通邻居的数量。但是,我们认为有关个人个人社会结构的更丰富信息可能会带来更好的预测。在本文中,我们建议利用良好的社会认知理论来提高链接预测绩效。根据这些理论,个人平均将自己的社会关系安排在五个同心圆下,以减少亲密关系。我们假设不同圈子中的关系在预测新链接方面具有不同的重要性。为了验证这一主张,我们专注于流行的功能萃取预测算法(既无监督和监督),并将其扩展到包括社交圈的意识。我们验证了这些圆圈感知算法对几个基准测试的预测性能(包括其基线版本以及基于节点的链接和GNN链接预测),利用了两个Twitter数据集,其中包括一个视频游戏玩家和通用用户的社区。我们表明,社会意识通常可以在预测绩效方面有重大改进,击败了Node2Vec和Seal等最新解决方案,而不会增加计算复杂性。最后,我们表明可以使用社交意识来代替针对特定类别用户的分类器(可能是昂贵或不切实际)的。
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图表可以模拟实体之间的复杂交互,它在许多重要的应用程序中自然出现。这些应用程序通常可以投入到标准图形学习任务中,其中关键步骤是学习低维图表示。图形神经网络(GNN)目前是嵌入方法中最受欢迎的模型。然而,邻域聚合范例中的标准GNN患有区分\ EMPH {高阶}图形结构的有限辨别力,而不是\ EMPH {低位}结构。为了捕获高阶结构,研究人员求助于主题和开发的基于主题的GNN。然而,现有的基于主基的GNN仍然仍然遭受较少的辨别力的高阶结构。为了克服上述局限性,我们提出了一个新颖的框架,以更好地捕获高阶结构的新框架,铰接于我们所提出的主题冗余最小化操作员和注射主题组合的新颖框架。首先,MGNN生成一组节点表示W.R.T.每个主题。下一阶段是我们在图案中提出的冗余最小化,该主题在彼此相互比较并蒸馏出每个主题的特征。最后,MGNN通过组合来自不同图案的多个表示来执行节点表示的更新。特别地,为了增强鉴别的功率,MGNN利用重新注射功能来组合表示的函数w.r.t.不同的主题。我们进一步表明,我们的拟议体系结构增加了GNN的表现力,具有理论分析。我们展示了MGNN在节点分类和图形分类任务上的七个公共基准上表现出最先进的方法。
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异质图卷积网络在解决异质网络数据的各种网络分析任务方面已广受欢迎,从链接预测到节点分类。但是,大多数现有作品都忽略了多型节点之间的多重网络的关系异质性,而在元路径中,元素嵌入中关系的重要性不同,这几乎无法捕获不同关系跨不同关系的异质结构信号。为了应对这一挑战,这项工作提出了用于异质网络嵌入的多重异质图卷积网络(MHGCN)。我们的MHGCN可以通过多层卷积聚合自动学习多重异质网络中不同长度的有用的异质元路径相互作用。此外,我们有效地将多相关结构信号和属性语义集成到学习的节点嵌入中,并具有无监督和精选的学习范式。在具有各种网络分析任务的五个现实世界数据集上进行的广泛实验表明,根据所有评估指标,MHGCN与最先进的嵌入基线的优势。
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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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越来越多的语义资源提供了人类知识的宝贵储存;但是,错误条目的概率随着尺寸的增加而增加。因此,识别给定知识库的潜在虚假部分的方法正在成为越来越重要的感兴趣领域。在这项工作中,我们展示了对仅结构的链接分析方法的系统评估是否可以提供可扩展手段,以检测可能的异常,以及潜在的有趣的新颖关系候选者。在八种不同的语义资源中评估十三方法,包括基因本体,食品本体,海洋本体论和类似,我们证明了仅限结构的链接分析可以为数据集的子集提供可扩展的异常检测。此外,我们证明,通过考虑符号节点嵌入,可以获得预测(链接)的说明,使得该方法的该分支可能比黑盒更有价值。据我们所知,这是目前,来自不同域的语义资源的不同类型链路分析方法的适用性最广泛的系统研究之一。
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Link prediction is a key problem for network-structured data. Link prediction heuristics use some score functions, such as common neighbors and Katz index, to measure the likelihood of links. They have obtained wide practical uses due to their simplicity, interpretability, and for some of them, scalability. However, every heuristic has a strong assumption on when two nodes are likely to link, which limits their effectiveness on networks where these assumptions fail. In this regard, a more reasonable way should be learning a suitable heuristic from a given network instead of using predefined ones. By extracting a local subgraph around each target link, we aim to learn a function mapping the subgraph patterns to link existence, thus automatically learning a "heuristic" that suits the current network. In this paper, we study this heuristic learning paradigm for link prediction. First, we develop a novel γ-decaying heuristic theory. The theory unifies a wide range of heuristics in a single framework, and proves that all these heuristics can be well approximated from local subgraphs. Our results show that local subgraphs reserve rich information related to link existence. Second, based on the γ-decaying theory, we propose a new method to learn heuristics from local subgraphs using a graph neural network (GNN). Its experimental results show unprecedented performance, working consistently well on a wide range of problems.
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