图形卷积网络是一类流行的深神经网络算法，在许多关系学习任务中都表现出成功。尽管它们取得了成功，但图形卷积网络仍表现出许多特殊的特征，包括偏见学习过度平滑和同质性功能，由于这些算法的复杂性质，这些功能不容易被诊断出来。我们建议通过研究捆卷卷积网络的神经切线内核来弥合这一差距，这是图形卷积网络的拓扑概括。为此，我们得出了捆卷卷网络的神经切线内核的参数化，该内部的卷积网络将函数分为两个部分：一个由图形确定的正向扩散过程驱动，另一个由节点对节点激活的复合效应确定的部分。输出层。这种以几何为重点的推导产生了许多直接见解，我们会详细讨论。

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.

近年来，基于Weisfeiler-Leman算法的算法和神经架构，是一个众所周知的Graph同构问题的启发式问题，它成为具有图形和关系数据的机器学习的强大工具。在这里，我们全面概述了机器学习设置中的算法的使用，专注于监督的制度。我们讨论了理论背景，展示了如何将其用于监督的图形和节点表示学习，讨论最近的扩展，并概述算法的连接（置换 - ）方面的神经结构。此外，我们概述了当前的应用和未来方向，以刺激进一步的研究。

图形内核是历史上最广泛使用的图形分类任务的技术。然而，由于图的手工制作的组合特征，这些方法具有有限的性能。近年来，由于其性能卓越，图形神经网络（GNNS）已成为与下游图形相关任务的最先进的方法。大多数GNN基于消息传递神经网络（MPNN）框架。然而，最近的研究表明，MPNN不能超过Weisfeiler-Lehman（WL）算法在图形同构术中的力量。为了解决现有图形内核和GNN方法的限制，在本文中，我们提出了一种新的GNN框架，称为\ Texit {内核图形神经网络}（Kernnns），该框架将图形内核集成到GNN的消息传递过程中。通过卷积神经网络（CNNS）中的卷积滤波器的启发，KERGNNS采用可训练的隐藏图作为绘图过滤器，该绘图过滤器与子图组合以使用图形内核更新节点嵌入式。此外，我们表明MPNN可以被视为Kergnns的特殊情况。我们将Kergnns应用于多个与图形相关的任务，并使用交叉验证来与基准进行公平比较。我们表明，与现有的现有方法相比，我们的方法达到了竞争性能，证明了增加GNN的表现能力的可能性。我们还表明，KERGNNS中的训练有素的图形过滤器可以揭示数据集的本地图形结构，与传统GNN模型相比，显着提高了模型解释性。

Many scientific fields study data with an underlying structure that is a non-Euclidean space. Some examples include social networks in computational social sciences, sensor networks in communications, functional networks in brain imaging, regulatory networks in genetics, and meshed surfaces in computer graphics. In many applications, such geometric data are large and complex (in the case of social networks, on the scale of billions), and are natural targets for machine learning techniques. In particular, we would like to use deep neural networks, which have recently proven to be powerful tools for a broad range of problems from computer vision, natural language processing, and audio analysis. However, these tools have been most successful on data with an underlying Euclidean or grid-like structure, and in cases where the invariances of these structures are built into networks used to model them.Geometric deep learning is an umbrella term for emerging techniques attempting to generalize (structured) deep neural models to non-Euclidean domains such as graphs and manifolds. The purpose of this paper is to overview different examples of geometric deep learning problems and present available solutions, key difficulties, applications, and future research directions in this nascent field.

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.

尽管在深度学习的其他应用领域中取得了非常深的架构，但流行的图神经网络是浅层模型。这降低了建模能力，并使模型无法捕获远程关系。浅设计的主要原因是过度平滑的，这导致节点状态随着深度的增加而变得更加相似。我们建立在GNNS和Pagerank之间的紧密联系的基础上，为此，个性化的Pagerank介绍了对个性化向量的考虑。通过这个想法，我们提出了个性化的Pagerank图神经网络（PPRGNN），该神经网络将图形卷积网络扩展到无限深度模型，该模型有机会将邻居聚集重置回每个迭代中的初始状态。我们引入了一个很好的解释调整，以重置重置并证明我们的方法与独特解决方案的收敛性，而无需放置任何限制，即使无限地进行了许多邻居聚集。与个性化的Pagerank一样，我们的结果不会过度光滑。在这样做的同时，在我们保持内存复杂性恒定的同时，时间复杂性保持线性，而与网络的深度无关，使其比较大图。我们从经验上展示了方法对各种节点和图形分类任务的有效性。在几乎所有情况下，PPRGNN优于可比较的方法。

图表是一个宇宙数据结构，广泛用于组织现实世界中的数据。像交通网络，社交和学术网络这样的各种实际网络网络可以由图表代表。近年来，目睹了在网络中代表顶点的快速发展，进入低维矢量空间，称为网络表示学习。表示学习可以促进图形数据上的新算法的设计。在本调查中，我们对网络代表学习的当前文献进行了全面审查。现有算法可以分为三组：浅埋模型，异构网络嵌入模型，图形神经网络的模型。我们为每个类别审查最先进的算法，并讨论这些算法之间的基本差异。调查的一个优点是，我们系统地研究了不同类别的算法底层的理论基础，这提供了深入的见解，以更好地了解网络表示学习领域的发展。

A prominent paradigm for graph neural networks is based on the message passing framework. In this framework, information communication is realized only between neighboring nodes. The challenge of approaches that use this paradigm is to ensure efficient and accurate \textit{long distance communication} between nodes, as deep convolutional networks are prone to over-smoothing. In this paper, we present a novel method based on time derivative graph diffusion (TIDE), with a learnable time parameter. Our approach allows to adapt the spatial extent of diffusion across different tasks and network channels, thus enabling medium and long-distance communication efficiently. Furthermore, we show that our architecture directly enables local message passing and thus inherits from the expressive power of local message passing approaches. We show that on widely used graph benchmarks we achieve comparable performance and on a synthetic mesh dataset we outperform state-of-the-art methods like GCN or GRAND by a significant margin.

分层神经网络（SNN）是一种在捆上运行的图形神经网络（GNN），该对象是在这些空间之间在其节点和边缘和线性图上与矢量空间配合矢量空间的对象。 SNN已被证明具有有用的理论特性，可帮助解决异性和光滑过度引起的问题。这些模型固有的一种并发症是找到解决任务的良好支架。先前的作品提出了两种截然相反的方法：基于域知识手动构建捆扎，并使用基于梯度的方法端对端学习捆绑。但是，域知识通常不足，而学习捆绑可能会导致过度拟合和重要的计算开销。在这项工作中，我们提出了一种计算带动束带的新型方法，它从黎曼几何形状中汲取灵感：我们利用歧管假设来计算流形和图形感知的正交图，从而最佳地对齐相邻数据点的切线空间。我们表明，与以前的SNN模型相比，这种方法的计算开销较少。总体而言，这项工作提供了代数拓扑结构与差异几何形状之间的有趣联系，我们希望它能朝这个方向引发未来的研究。

简单的复合物可以看作是图形的高维概括，这些图表一次在不同分辨率下的顶点之间明确编码多路有序关系。这个概念是检测数据的较高拓扑特征的核心，图形仅编码成对关系的图形仍然遗忘。尽管已尝试将图形神经网络（GNN）扩展到简单复杂设置，但这些方法并未固有地利用网络的基本拓扑结构。我们提出了一个图形卷积模型，用于学习由简单复合物的$ K $学术特征参数化的学习功能。通过频谱操纵其组合$ k $二维的霍奇laplacians，提议的模型可以实现基础简单复合物的学习拓扑特征，特别是，每个$ k $ simplex的距离与最接近的“最佳” $ k $ k $ - $ k $ - $ k $ - th $ k $ - ，有效地提供同源性本地化的替代方案。

散射变换是一种基于多层的小波的深度学习架构，其充当卷积神经网络的模型。最近，几种作品引入了非欧几里德设置的散射变换的概括，例如图形。我们的工作通过基于非常一般的非对称小波来引入图形的窗口和非窗口几何散射变换来构建这些结构。我们表明，这些不对称的图形散射变换具有许多与其对称对应的相同的理论保证。结果，所提出的结构统一并扩展了许多现有图散射架构的已知理论结果。在这样做时，这项工作有助于通过引入具有可提供稳定性和不变性保证的大型网络，帮助弥合几何散射和其他图形神经网络之间的差距。这些结果为未来的图形结构数据奠定了基础，对具有学习过滤器的图形结构数据，并且还可以证明具有理想的理论特性。

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。

Graph Neural Networks (graph NNs) are a promising deep learning approach for analyzing graph-structured data. However, it is known that they do not improve (or sometimes worsen) their predictive performance as we pile up many layers and add non-lineality. To tackle this problem, we investigate the expressive power of graph NNs via their asymptotic behaviors as the layer size tends to infinity. Our strategy is to generalize the forward propagation of a Graph Convolutional Network (GCN), which is a popular graph NN variant, as a specific dynamical system. In the case of a GCN, we show that when its weights satisfy the conditions determined by the spectra of the (augmented) normalized Laplacian, its output exponentially approaches the set of signals that carry information of the connected components and node degrees only for distinguishing nodes. Our theory enables us to relate the expressive power of GCNs with the topological information of the underlying graphs inherent in the graph spectra. To demonstrate this, we characterize the asymptotic behavior of GCNs on the Erdős -Rényi graph. We show that when the Erdős -Rényi graph is sufficiently dense and large, a broad range of GCNs on it suffers from the "information loss" in the limit of infinite layers with high probability. Based on the theory, we provide a principled guideline for weight normalization of graph NNs. We experimentally confirm that the proposed weight scaling enhances the predictive performance of GCNs in real data 1 .

图形神经网络（GNNS）对图表上的半监督节点分类展示了卓越的性能，结果是它们能够同时利用节点特征和拓扑信息的能力。然而，大多数GNN隐含地假设曲线图中的节点和其邻居的标签是相同或一致的，其不包含在异质图中，其中链接节点的标签可能不同。因此，当拓扑是非信息性的标签预测时，普通的GNN可以显着更差，而不是在每个节点上施加多层Perceptrons（MLPS）。为了解决上述问题，我们提出了一种新的$ -laplacian基于GNN模型，称为$ ^ P $ GNN，其消息传递机制来自离散正则化框架，并且可以理论上解释为多项式图的近似值在$ p $ -laplacians的频谱域上定义过滤器。光谱分析表明，新的消息传递机制同时用作低通和高通滤波器，从而使$ ^ P $ GNNS对同性恋和异化图有效。关于现实世界和合成数据集的实证研究验证了我们的调查结果，并证明了$ ^ P $ GNN明显优于异交基准的几个最先进的GNN架构，同时在同性恋基准上实现竞争性能。此外，$ ^ p $ gnns可以自适应地学习聚合权重，并且对嘈杂的边缘具有强大。

许多现代神经架构的核心的卷积运算符可以有效地被视为在输入矩阵和滤波器之间执行点产品。虽然这很容易适用于诸如图像的数据，其可以在欧几里德空间中表示为常规网格，延伸卷积操作者以在图形上工作，而是由于它们的不规则结构而被证明更具有挑战性。在本文中，我们建议使用图形内部产品的图形内核，即在图形上计算内部产品，以将标准卷积运算符扩展到图形域。这使我们能够定义不需要计算输入图的嵌入的完全结构模型。我们的架构允许插入任何类型和数量的图形内核，并具有在培训过程中学到的结构面具方面提供一些可解释性的额外益处，类似于传统卷积神经网络中的卷积掩模发生的事情。我们执行广泛的消融研究，调查模型超参数的影响，我们表明我们的模型在标准图形分类数据集中实现了竞争性能。

Deploying graph neural networks (GNNs) on whole-graph classification or regression tasks is known to be challenging: it often requires computing node features that are mindful of both local interactions in their neighbourhood and the global context of the graph structure. GNN architectures that navigate this space need to avoid pathological behaviours, such as bottlenecks and oversquashing, while ideally having linear time and space complexity requirements. In this work, we propose an elegant approach based on propagating information over expander graphs. We leverage an efficient method for constructing expander graphs of a given size, and use this insight to propose the EGP model. We show that EGP is able to address all of the above concerns, while requiring minimal effort to set up, and provide evidence of its empirical utility on relevant graph classification datasets and baselines in the Open Graph Benchmark. Importantly, using expander graphs as a template for message passing necessarily gives rise to negative curvature. While this appears to be counterintuitive in light of recent related work on oversquashing, we theoretically demonstrate that negatively curved edges are likely to be required to obtain scalable message passing without bottlenecks. To the best of our knowledge, this is a previously unstudied result in the context of graph representation learning, and we believe our analysis paves the way to a novel class of scalable methods to counter oversquashing in GNNs.

最新提出的基于变压器的图形模型的作品证明了香草变压器用于图形表示学习的不足。要了解这种不足，需要研究变压器的光谱分析是否会揭示其对其表现力的见解。类似的研究已经确定，图神经网络（GNN）的光谱分析为其表现力提供了额外的观点。在这项工作中，我们系统地研究并建立了变压器领域中的空间和光谱域之间的联系。我们进一步提供了理论分析，并证明了变压器中的空间注意机制无法有效捕获所需的频率响应，因此，固有地限制了其在光谱空间中的表现力。因此，我们提出了feta，该框架旨在在整个图形频谱（即图形的实际频率成分）上进行注意力类似于空间空间中的注意力。经验结果表明，FETA在标准基准的所有任务中为香草变压器提供均匀的性能增益，并且可以轻松地扩展到具有低通特性的基于GNN的模型（例如GAT）。

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.

Existing popular methods for semi-supervised learning with Graph Neural Networks (such as the Graph Convolutional Network) provably cannot learn a general class of neighborhood mixing relationships. To address this weakness, we propose a new model, MixHop, that can learn these relationships, including difference operators, by repeatedly mixing feature representations of neighbors at various distances. MixHop requires no additional memory or computational complexity, and outperforms on challenging baselines. In addition, we propose sparsity regularization that allows us to visualize how the network prioritizes neighborhood information across different graph datasets. Our analysis of the learned architectures reveals that neighborhood mixing varies per datasets. 1 We use "like", as graph edges are not axis-aligned.