在现实世界中,签名的定向网络无处不在。但是,对于分析此类网络的方法,较少的工作提出了频谱图神经网络(GNN)方法。在这里,我们介绍了一个签名的定向拉普拉斯矩阵,我们称之为磁性签名的laplacian,作为在签名的图表上签名的laplacian的自然概括,在有向图上的磁Laplacian。然后,我们使用此矩阵来构建一种新型的光谱GNN结构,并在节点聚类和链接预测任务上进行广泛的实验。在这些实验中,我们考虑了与签名信息有关的任务,与定向信息相关的任务以及与签名和定向信息有关的任务。我们证明,我们提出的光谱GNN有效地合并了签名和定向信息,并在广泛的数据集中获得领先的性能。此外,我们提供了一种新颖的合成网络模型,我们称之为签名的定向随机块模型,以及许多基于财务时间序列中铅滞后关系的新型现实世界数据集。
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网络在许多现实世界应用程序中无处不在(例如,编码信任/不信任关系的社交网络,由时间序列数据引起的相关网络)。尽管许多网络都是签名或指示的,或者两者都在图形神经网络(GNN)上缺少统一的软件包,专门为签名和定向网络设计。在本文中,我们提出了Pytorch几何签名的指示,这是一个填补此空白的软件包。在此过程中,我们还提供了简短的审查调查,以分析签名和定向网络的分析,讨论相关实验中使用的数据,提供提出的方法概述,并通过实验评估实施方法。深度学习框架包括易于使用的GNN模型,合成和现实世界数据,以及针对签名和定向网络的特定任务评估指标和损失功能。作为Pytorch几何形状的扩展库,我们提出的软件由开源版本,详细文档,连续集成,单位测试和代码覆盖范围检查维护。我们的代码可在\ url {https://github.com/sherylhyx/pytorch_geometric_signed_directed}上公开获得。
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This paper introduces SigMaNet, a generalized Graph Convolutional Network (GCN) capable of handling both undirected and directed graphs with weights not restricted in sign nor magnitude. The cornerstone of SigMaNet is the Sign-Magnetic Laplacian ($L^{\sigma}$), a new Laplacian matrix that we introduce ex novo in this work. $L^{\sigma}$ allows us to bridge a gap in the current literature by extending the theory of spectral GCNs to (directed) graphs with both positive and negative weights. $L^{\sigma}$ exhibits several desirable properties not enjoyed by other Laplacian matrices on which several state-of-the-art architectures are based, among which encoding the edge direction and weight in a clear and natural way that is not negatively affected by the weight magnitude. $L^{\sigma}$ is also completely parameter-free, which is not the case of other Laplacian operators such as, e.g., the Magnetic Laplacian. The versatility and the performance of our proposed approach is amply demonstrated via computational experiments. Indeed, our results show that, for at least a metric, SigMaNet achieves the best performance in 15 out of 21 cases and either the first- or second-best performance in 21 cases out of 21, even when compared to architectures that are either more complex or that, due to being designed for a narrower class of graphs, should -- but do not -- achieve a better performance.
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图形卷积网络(GCN)及其变体是为仅包含正链的无符号图设计的。许多现有的GCN来自位于(未签名)图的信号的光谱域分析,在每个卷积层中,它们对输入特征进行低通滤波,然后进行可学习的线性转换。它们扩展到具有正面和负面链接的签名图,引发了多个问题,包括计算不规则性和模棱两可的频率解释,从而使计算有效的低通滤波器的设计具有挑战性。在本文中,我们通过签名图的光谱分析来解决这些问题,并提出了两个不同的图形神经网络,一个人仅保留低频信息,并且还保留了高频信息。我们进一步引入了磁性签名的拉普拉斯式,并使用其特征成分进行定向签名图的光谱分析。我们在签名图上测试了节点分类的方法,并链接符号预测任务并实现最先进的性能。
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根据数据的性质,有几种类型的图形。定向图具有链接的方向,签名的图具有链接类型,例如正和负面。签名的定向图是两者兼有的最复杂和信息的。签名有向图的图形卷积尚未得到太多。尽管已经提供了许多图形卷积研究,但大多数是为无方向或未签名设计的。在本文中,我们研究了一个用于签名的有向图的光谱图卷积网络。我们提出了一个新型的复杂居式邻接矩阵,该矩阵通过复数字编码图形信息。复数数字代表通过阶段和大小的链路方向,符号和连通性。然后,我们定义了带有Hermitian基质的磁性laplacian,并证明其阳性半限体性质。最后,我们介绍了签名的有向图卷积网络(SD-GCN)。据我们所知,这是带有符号的图形的第一频谱卷积。此外,与专为特定图形类型设计的现有卷积不同,该模型具有可应用于任何图的通用性,包括无方向性,指示或签名。用四个现实世界图评估了所提出的模型的性能。在链接标志预测的任务中,它的表现优于所有其他最新图形卷积。
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图表神经网络(GNNS)在各种机器学习任务中获得了表示学习的提高。然而,应用邻域聚合的大多数现有GNN通常在图中的图表上执行不良,其中相邻的节点属于不同的类。在本文中,我们示出了在典型的异界图中,边缘可以被引导,以及是否像是处理边缘,也可以使它们过度地影响到GNN模型的性能。此外,由于异常的限制,节点对来自本地邻域之外的类似节点的消息非常有益。这些激励我们开发一个自适应地学习图表的方向性的模型,并利用潜在的长距离相关性节点之间。我们首先将图拉普拉斯概括为基于所提出的特征感知PageRank算法向数字化,该算法同时考虑节点之间的图形方向性和长距离特征相似性。然后,Digraph Laplacian定义了一个图形传播矩阵,导致一个名为{\ em diglaciangcn}的模型。基于此,我们进一步利用节点之间的通勤时间测量的节点接近度,以便在拓扑级别上保留节点的远距离相关性。具有不同级别的10个数据集的广泛实验,同意级别展示了我们在节点分类任务任务中对现有解决方案的有效性。
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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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Deep learning has revolutionized many machine learning tasks in recent years, ranging from image classification and video processing to speech recognition and natural language understanding. The data in these tasks are typically represented in the Euclidean space. However, there is an increasing number of applications where data are generated from non-Euclidean domains and are represented as graphs with complex relationships and interdependency between objects. The complexity of graph data has imposed significant challenges on existing machine learning algorithms. Recently, many studies on extending deep learning approaches for graph data have emerged. In this survey, we provide a comprehensive overview of graph neural networks (GNNs) in data mining and machine learning fields. We propose a new taxonomy to divide the state-of-the-art graph neural networks into four categories, namely recurrent graph neural networks, convolutional graph neural networks, graph autoencoders, and spatial-temporal graph neural networks. We further discuss the applications of graph neural networks across various domains and summarize the open source codes, benchmark data sets, and model evaluation of graph neural networks. Finally, we propose potential research directions in this rapidly growing field.
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从成对比较中恢复全球排名从时间同步到运动队排名的广泛应用。对应于竞争中匹配的成对比较可以解释为有向图(Digraph)中的边缘,其节点代表例如竞争对手的排名未知。在本文中,我们通过提出所谓的Gnnrank,这是一种基于Digraph嵌入的基于训练的GNN框架,将神经网络引入排名恢复问题。此外,设计了新的目标来编码排名upsess/违规行为。该框架涉及一种排名得分估计方法,并通过展开从可学习的相似性矩阵构建的图形的fiedler矢量计算来增加电感偏差。广泛数据集的实验结果表明,我们的方法具有竞争性,并且通常对基准的表现卓越,并且表现出了有希望的转移能力。代码和预处理数据为:\ url {https://github.com/sherylhyx/gnnrank}。
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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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在过去十年中,图形内核引起了很多关注,并在结构化数据上发展成为一种快速发展的学习分支。在过去的20年中,该领域发生的相当大的研究活动导致开发数十个图形内核,每个图形内核都对焦于图形的特定结构性质。图形内核已成功地成功地在广泛的域中,从社交网络到生物信息学。本调查的目标是提供图形内核的文献的统一视图。特别是,我们概述了各种图形内核。此外,我们对公共数据集的几个内核进行了实验评估,并提供了比较研究。最后,我们讨论图形内核的关键应用,并概述了一些仍有待解决的挑战。
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几何深度学习取得了长足的进步,旨在概括从传统领域到非欧几里得群岛的结构感知神经网络的设计,从而引起图形神经网络(GNN),这些神经网络(GNN)可以应用于形成的图形结构数据,例如社会,例如,网络,生物化学和材料科学。尤其是受欧几里得对应物的启发,尤其是图形卷积网络(GCN)通过提取结构感知功能来成功处理图形数据。但是,当前的GNN模型通常受到各种现象的限制,这些现象限制了其表达能力和推广到更复杂的图形数据集的能力。大多数模型基本上依赖于通过本地平均操作对图形信号的低通滤波,从而导致过度平滑。此外,为了避免严重的过度厚度,大多数流行的GCN式网络往往是较浅的,并且具有狭窄的接收场,导致侵犯。在这里,我们提出了一个混合GNN框架,该框架将传统的GCN过滤器与通过几何散射定义的带通滤波器相结合。我们进一步介绍了一个注意框架,该框架允许该模型在节点级别上从不同过滤器的组合信息进行本地参与。我们的理论结果确定了散射过滤器的互补益处,以利用图表中的结构信息,而我们的实验显示了我们方法对各种学习任务的好处。
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Graph classification is an important area in both modern research and industry. Multiple applications, especially in chemistry and novel drug discovery, encourage rapid development of machine learning models in this area. To keep up with the pace of new research, proper experimental design, fair evaluation, and independent benchmarks are essential. Design of strong baselines is an indispensable element of such works. In this thesis, we explore multiple approaches to graph classification. We focus on Graph Neural Networks (GNNs), which emerged as a de facto standard deep learning technique for graph representation learning. Classical approaches, such as graph descriptors and molecular fingerprints, are also addressed. We design fair evaluation experimental protocol and choose proper datasets collection. This allows us to perform numerous experiments and rigorously analyze modern approaches. We arrive to many conclusions, which shed new light on performance and quality of novel algorithms. We investigate application of Jumping Knowledge GNN architecture to graph classification, which proves to be an efficient tool for improving base graph neural network architectures. Multiple improvements to baseline models are also proposed and experimentally verified, which constitutes an important contribution to the field of fair model comparison.
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图形卷积网络(GCN)已被证明是一个有力的概念,在过去几年中,已成功应用于许多领域的各种任务。在这项工作中,我们研究了为GCN定义铺平道路的理论,包括经典图理论的相关部分。我们还讨论并在实验上证明了GCN的关键特性和局限性,例如由样品的统计依赖性引起的,该图由图的边缘引入,这会导致完整梯度的估计值偏置。我们讨论的另一个限制是Minibatch采样对模型性能的负面影响。结果,在参数更新期间,在整个数据集上计算梯度,从而破坏了对大图的可扩展性。为了解决这个问题,我们研究了替代方法,这些方法允许在每次迭代中仅采样一部分数据,可以安全地学习良好的参数。我们重现了KIPF等人的工作中报告的结果。并提出一个灵感签名的实现,这是一种无抽样的minibatch方法。最终,我们比较了基准数据集上的两个实现,证明它们在半监督节点分类任务的预测准确性方面是可比的。
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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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散射变换是一种基于小波的多层转换,最初是作为卷积神经网络(CNN)的模型引入的,它在我们对这些网络稳定性和不变性属性的理解中发挥了基础作用。随后,人们普遍兴趣将CNN的成功扩展到具有非欧盟结构的数据集,例如图形和歧管,从而导致了几何深度学习的新兴领域。为了提高我们对这个新领域中使用的体系结构的理解,几篇论文提出了对非欧几里得数据结构(如无方向的图形和紧凑的Riemannian歧管)的散射转换的概括。在本文中,我们介绍了一个通用的统一模型,用于测量空间上的几何散射。我们提出的框架包括以前的几何散射作品作为特殊情况,但也适用于更通用的设置,例如有向图,签名图和带边界的歧管。我们提出了一个新标准,该标准可以识别哪些有用表示应该不变的组,并表明该标准足以确保散射变换具有理想的稳定性和不变性属性。此外,我们考虑从随机采样未知歧管获得的有限度量空间。我们提出了两种构造数据驱动图的方法,在该图上相关的图形散射转换近似于基础歧管上的散射变换。此外,我们使用基于扩散图的方法来证明这些近似值之一的收敛速率的定量估计值,因为样品点的数量趋向于无穷大。最后,我们在球形图像,有向图和高维单细胞数据上展示了方法的实用性。
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Recently, graph neural networks (GNNs) have revolutionized the field of graph representation learning through effectively learned node embeddings, and achieved state-of-the-art results in tasks such as node classification and link prediction. However, current GNN methods are inherently flat and do not learn hierarchical representations of graphs-a limitation that is especially problematic for the task of graph classification, where the goal is to predict the label associated with an entire graph. Here we propose DIFFPOOL, a differentiable graph pooling module that can generate hierarchical representations of graphs and can be combined with various graph neural network architectures in an end-to-end fashion. DIFFPOOL learns a differentiable soft cluster assignment for nodes at each layer of a deep GNN, mapping nodes to a set of clusters, which then form the coarsened input for the next GNN layer. Our experimental results show that combining existing GNN methods with DIFFPOOL yields an average improvement of 5-10% accuracy on graph classification benchmarks, compared to all existing pooling approaches, achieving a new state-of-the-art on four out of five benchmark data sets.
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Deep learning has been shown to be successful in a number of domains, ranging from acoustics, images, to natural language processing. However, applying deep learning to the ubiquitous graph data is non-trivial because of the unique characteristics of graphs. Recently, substantial research efforts have been devoted to applying deep learning methods to graphs, resulting in beneficial advances in graph analysis techniques. In this survey, we comprehensively review the different types of deep learning methods on graphs. We divide the existing methods into five categories based on their model architectures and training strategies: graph recurrent neural networks, graph convolutional networks, graph autoencoders, graph reinforcement learning, and graph adversarial methods. We then provide a comprehensive overview of these methods in a systematic manner mainly by following their development history. We also analyze the differences and compositions of different methods. Finally, we briefly outline the applications in which they have been used and discuss potential future research directions.
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Graphs are ubiquitous in nature and can therefore serve as models for many practical but also theoretical problems. For this purpose, they can be defined as many different types which suitably reflect the individual contexts of the represented problem. To address cutting-edge problems based on graph data, the research field of Graph Neural Networks (GNNs) has emerged. Despite the field's youth and the speed at which new models are developed, many recent surveys have been published to keep track of them. Nevertheless, it has not yet been gathered which GNN can process what kind of graph types. In this survey, we give a detailed overview of already existing GNNs and, unlike previous surveys, categorize them according to their ability to handle different graph types and properties. We consider GNNs operating on static and dynamic graphs of different structural constitutions, with or without node or edge attributes. Moreover, we distinguish between GNN models for discrete-time or continuous-time dynamic graphs and group the models according to their architecture. We find that there are still graph types that are not or only rarely covered by existing GNN models. We point out where models are missing and give potential reasons for their absence.
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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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