Node classification on graph data is a major problem, and various graph neural networks (GNNs) have been proposed. Variants of GNNs such as H2GCN and CPF outperform graph convolutional networks (GCNs) by improving on the weaknesses of the traditional GNN. However, there are some graph data which these GNN variants fail to perform well than other GNNs in the node classification task. This is because H2GCN has a feature thinning on graph data with high average degree, and CPF gives rise to a problem about label-propagation suitability. Accordingly, we propose a hierarchical model selection framework (HMSF) that selects an appropriate GNN model by analyzing the indicators of each graph data. In the experiment, we show that the model selected by our HMSF achieves high performance on node classification for various types of graph data.
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Various graph neural networks (GNNs) have been proposed to solve node classification tasks in machine learning for graph data. GNNs use the structural information of graph data by aggregating the features of neighboring nodes. However, they fail to directly characterize and leverage the structural information. In this paper, we propose multi-duplicated characterization of graph structures using information gain ratio (IGR) for GNNs (MSI-GNN), which enhances the performance of node classification by using an i-hop adjacency matrix as the structural information of the graph data. In MSI-GNN, the i-hop adjacency matrix is adaptively adjusted by two methods: (i) structural features in the matrix are selected based on the IGR, and (ii) the selected features in (i) for each node are duplicated and combined flexibly. In an experiment, we show that our MSI-GNN outperforms GCN, H2GCN, and GCNII in terms of average accuracies in benchmark graph datasets.
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图形神经网络(GNNS)在节点分类,回归和推荐任务中取得了最新的最新性能。当可提供高质量和丰富的连接结构时,GNNS工作好。但是,在许多真实世界图中,该要求在节点度具有幂律分布的许多真实世界中,因为许多节点具有较少或嘈杂的连接。这种情况的极端情况是节点可能没有邻居,称为严格的冷启动(SCS)场景。这会强制预测模型依赖于节点的输入特征。与通过蒸馏方法相比,我们提出冷啤酒以解决SCS和嘈杂的邻居设置。我们介绍了功能贡献比(FCR),测量使用电感GNN解决SCS问题的可行性,并选择SCS泛化的最佳体系结构。我们通过实验显示FCR Disentangles图数据集的各种组成部分的贡献,并展示了几个公共基准和专有电子商务数据集上的冷啤酒的优越性。我们方法的源代码可用于:https://github.com/amazon-research/gnn-tail-一致化。
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图形神经网络(GNNS)在各种基于图形的应用中显示了优势。大多数现有的GNNS假设图形结构的强大奇妙并应用邻居的置换不变本地聚合以学习每个节点的表示。然而,它们未能概括到异质图,其中大多数相邻节点具有不同的标签或特征,并且相关节点远处。最近的几项研究通过组合中央节点的隐藏表示(即,基于多跳的方法)的多个跳数来解决这个问题,或者基于注意力分数对相邻节点进行排序(即,基于排名的方法)来解决这个问题。结果,这些方法具有一些明显的限制。一方面,基于多跳的方法没有明确区分相关节点的大量多跳社区,导致严重的过平滑问题。另一方面,基于排名的模型不与结束任务进行联合优化节点排名,并导致次优溶液。在这项工作中,我们呈现图表指针神经网络(GPNN)来解决上述挑战。我们利用指针网络从大量的多跳邻域选择最相关的节点,这根据与中央节点的关系来构造有序序列。然后应用1D卷积以从节点序列中提取高级功能。 GPNN中的基于指针网络的Ranker是以端到端的方式与其他部件进行联合优化的。在具有异质图的六个公共节点分类数据集上进行了广泛的实验。结果表明,GPNN显着提高了最先进方法的分类性能。此外,分析还揭示了拟议的GPNN在过滤出无关邻居并减少过平滑的特权。
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图形神经网络已成为从图形结构数据学习的不可缺少的工具之一,并且它们的实用性已在各种各样的任务中显示。近年来,建筑设计的巨大改进,导致各种预测任务的性能更好。通常,这些神经架构在同一层中使用可知的权重矩阵组合节点特征聚合和特征转换。这使得分析从各种跳过的节点特征和神经网络层的富有效力来挑战。由于不同的图形数据集显示在特征和类标签分布中的不同级别和异常级别,因此必须了解哪些特征对于没有任何先前信息的预测任务是重要的。在这项工作中,我们将节点特征聚合步骤和深度与图形神经网络分离,并经验分析了不同的聚合特征在预测性能中发挥作用。我们表明,并非通过聚合步骤生成的所有功能都很有用,并且通常使用这些较少的信息特征可能对GNN模型的性能有害。通过我们的实验,我们表明学习这些功能的某些子集可能会导致各种数据集的性能更好。我们建议使用Softmax作为常规器,并从不同跳距的邻居聚合的功能的“软选择器”;和L2 - GNN层的标准化。结合这些技术,我们呈现了一个简单浅的模型,特征选择图神经网络(FSGNN),并经验展示所提出的模型比九个基准数据集中的最先进的GNN模型实现了可比或甚至更高的准确性节点分类任务,具有显着的改进,可达51.1%。
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知识蒸馏(KD)证明了其有效性,可以提高图形神经网络(GNN)的性能,其目标是将知识从更深的教师gnn蒸馏成较浅的学生GNN。但是,由于众所周知的过度参数和过度光滑的问题,实际上很难培训令人满意的教师GNN,从而导致实际应用中的知识转移无效。在本文中,我们通过对GNN的加强学习(称为FreeKD)提出了第一个自由方向知识蒸馏框架,而这不再需要提供更深入的良好优化的教师GNN。我们工作的核心思想是协作建立两个较浅的GNN,以通过以层次结构方式通过加强学习来交流知识。正如我们观察到的一个典型的GNN模型在训练过程中通常在不同节点的表现更好,更差的表现,我们设计了一种动态和自由方向的知识转移策略,该策略由两个级别的动作组成:1)节点级别的动作决定了知识的方向。两个网络的相应节点之间的传输;然后2)结构级的动作确定了要传播的节点级别生成的局部结构。从本质上讲,我们的FreeKD是一个一般且原则性的框架,可以自然与不同架构的GNN兼容。在五个基准数据集上进行的广泛实验表明,我们的FreeKD在很大的边距上优于两个基本GNN,并显示了其对各种GNN的功效。更令人惊讶的是,我们的FreeKD比传统的KD算法具有可比性甚至更好的性能,这些KD算法将知识从更深,更强大的教师GNN中提取。
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众所周知,图形神经网络(GNN)的成功高度依赖于丰富的人类通知数据,这在实践中努力获得,并且并非总是可用的。当只有少数标记的节点可用时,如何开发高效的GNN仍在研究。尽管已证明自我训练对于半监督学习具有强大的功能,但其在图形结构数据上的应用可能会失败,因为(1)不利用较大的接收场来捕获远程节点相互作用,这加剧了传播功能的难度 - 标记节点到未标记节点的标签模式; (2)有限的标记数据使得在不同节点类别中学习良好的分离决策边界而不明确捕获基本的语义结构,这是一项挑战。为了解决捕获信息丰富的结构和语义知识的挑战,我们提出了一个新的图数据增强框架,AGST(增强图自训练),该框架由两个新的(即结构和语义)增强模块构建。 GST骨干。在这项工作中,我们研究了这个新颖的框架是否可以学习具有极有限标记节点的有效图预测模型。在有限标记节点数据的不同情况下,我们对半监督节点分类进行全面评估。实验结果证明了新的数据增强框架对节点分类的独特贡献,几乎没有标记的数据。
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由于学术和工业领域的异质图无处不在,研究人员最近提出了许多异质图神经网络(HGNN)。在本文中,我们不再采用更强大的HGNN模型,而是有兴趣设计一个多功能的插件模块,该模块解释了从预先训练的HGNN中提取的关系知识。据我们所知,我们是第一个在异质图上提出高阶(雇用)知识蒸馏框架的人,无论HGNN的模型体系结构如何,它都可以显着提高预测性能。具体而言,我们的雇用框架最初执行一阶节点级知识蒸馏,该蒸馏曲线及其预测逻辑编码了老师HGNN的语义。同时,二阶关系级知识蒸馏模仿了教师HGNN生成的不同类型的节点嵌入之间的关系相关性。在各种流行的HGNN模型和三个现实世界的异质图上进行了广泛的实验表明,我们的方法获得了一致且相当大的性能增强,证明了其有效性和泛化能力。
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现代图形神经网络(GNNS)通过多层本地聚合学习节点嵌入,并在各种图形应用中取得巨大成功。但是,对辅音图的任务通常需要非局部聚合。此外,我们发现本地聚合对某些抵消图表甚至有害。在这项工作中,我们提出了一个简单但有效的非本地聚合框架,具有高效的GNN的关注排序。基于它,我们开发各种非本地GNN。我们进行彻底的实验,以分析Disasstative图数据集并评估我们的非本地GNN。实验结果表明,在模型性能和效率方面,我们的非本地GNN在七个基准数据集上显着优于七个基准数据集。
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Graph neural networks (GNNs) have been widely used under semi-supervised settings. Prior studies have mainly focused on finding appropriate graph filters (e.g., aggregation schemes) to generalize well for both homophilic and heterophilic graphs. Even though these approaches are essential and effective, they still suffer from the sparsity in initial node features inherent in the bag-of-words representation. Common in semi-supervised learning where the training samples often fail to cover the entire dimensions of graph filters (hyperplanes), this can precipitate over-fitting of specific dimensions in the first projection matrix. To deal with this problem, we suggest a simple and novel strategy; create additional space by flipping the initial features and hyperplane simultaneously. Training in both the original and in the flip space can provide precise updates of learnable parameters. To the best of our knowledge, this is the first attempt that effectively moderates the overfitting problem in GNN. Extensive experiments on real-world datasets demonstrate that the proposed technique improves the node classification accuracy up to 40.2 %
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Graph Neural Networks (GNNs) achieve state-of-the-art performance on graph-structured data across numerous domains. Their underlying ability to represent nodes as summaries of their vicinities has proven effective for homophilous graphs in particular, in which same-type nodes tend to connect. On heterophilous graphs, in which different-type nodes are likely connected, GNNs perform less consistently, as neighborhood information might be less representative or even misleading. On the other hand, GNN performance is not inferior on all heterophilous graphs, and there is a lack of understanding of what other graph properties affect GNN performance. In this work, we highlight the limitations of the widely used homophily ratio and the recent Cross-Class Neighborhood Similarity (CCNS) metric in estimating GNN performance. To overcome these limitations, we introduce 2-hop Neighbor Class Similarity (2NCS), a new quantitative graph structural property that correlates with GNN performance more strongly and consistently than alternative metrics. 2NCS considers two-hop neighborhoods as a theoretically derived consequence of the two-step label propagation process governing GCN's training-inference process. Experiments on one synthetic and eight real-world graph datasets confirm consistent improvements over existing metrics in estimating the accuracy of GCN- and GAT-based architectures on the node classification task.
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由于它们对处理图形结构数据的显着功率,图表卷积网络(GCNS)已广泛应用于各个领域。典型的GCN及其变体在同声源性假设下工作(即,具有相同类的节点容易彼此连接),同时忽略许多真实网络中存在的异源性(即,具有不同类别的节点倾向于形成边缘) 。现有方法通过主要聚集高阶邻域或梳理即时表示来处理异常的方法,这导致结果导致噪声和无关的信息。但这些方法没有改变在同性恋假设下工作的传播机制(这是GCN的基本部分)。这使得难以区分不同类别的节点的表示。为了解决这个问题,在本文中,我们设计了一种新的传播机制,可以根据节点对之间自动或异常改变传播和聚合过程。为了自适应地学习传播过程,我们在节点对之间引入两个奇妙程度的两个测量,这分别基于拓扑和属性信息来学习。然后,我们将学习的同音源于Graph卷积框架纳入图形卷积框架,该框架在端到端的架构中培训,使其能够超越奇妙的假设。更重要的是,我们理论上证明我们的模型可以根据他们的同意程度来限制节点之间的表示的相似性。 7个现实世界数据集的实验表明,这种新方法在异常或低意识下表现出最先进的方法,并在精梳性下获得竞争性能。
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Graph Neural Networks (GNNs) have been a prevailing technique for tackling various analysis tasks on graph data. A key premise for the remarkable performance of GNNs relies on complete and trustworthy initial graph descriptions (i.e., node features and graph structure), which is often not satisfied since real-world graphs are often incomplete due to various unavoidable factors. In particular, GNNs face greater challenges when both node features and graph structure are incomplete at the same time. The existing methods either focus on feature completion or structure completion. They usually rely on the matching relationship between features and structure, or employ joint learning of node representation and feature (or structure) completion in the hope of achieving mutual benefit. However, recent studies confirm that the mutual interference between features and structure leads to the degradation of GNN performance. When both features and structure are incomplete, the mismatch between features and structure caused by the missing randomness exacerbates the interference between the two, which may trigger incorrect completions that negatively affect node representation. To this end, in this paper we propose a general GNN framework based on teacher-student distillation to improve the performance of GNNs on incomplete graphs, namely T2-GNN. To avoid the interference between features and structure, we separately design feature-level and structure-level teacher models to provide targeted guidance for student model (base GNNs, such as GCN) through distillation. Then we design two personalized methods to obtain well-trained feature and structure teachers. To ensure that the knowledge of the teacher model is comprehensively and effectively distilled to the student model, we further propose a dual distillation mode to enable the student to acquire as much expert knowledge as possible.
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We investigate the representation power of graph neural networks in the semisupervised node classification task under heterophily or low homophily, i.e., in networks where connected nodes may have different class labels and dissimilar features. Many popular GNNs fail to generalize to this setting, and are even outperformed by models that ignore the graph structure (e.g., multilayer perceptrons). Motivated by this limitation, we identify a set of key designs-ego-and neighbor-embedding separation, higher-order neighborhoods, and combination of intermediate representations-that boost learning from the graph structure under heterophily. We combine them into a graph neural network, H 2 GCN, which we use as the base method to empirically evaluate the effectiveness of the identified designs. Going beyond the traditional benchmarks with strong homophily, our empirical analysis shows that the identified designs increase the accuracy of GNNs by up to 40% and 27% over models without them on synthetic and real networks with heterophily, respectively, and yield competitive performance under homophily.
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尽管图神经网络(GNNS)已经证明了它们在处理非欧国人结构数据方面的功效,但由于多跳数据依赖性施加的可伸缩性约束,因此很难将它们部署在实际应用中。现有方法试图通过使用训练有素的GNN的标签训练多层感知器(MLP)来解决此可伸缩性问题。即使可以显着改善MLP的性能,但两个问题仍能阻止MLP的表现优于GNN并在实践中使用:图形结构信息的无知和对节点功能噪声的敏感性。在本文中,我们建议在图(NOSMOG)上学习噪声稳定结构感知的MLP,以克服挑战。具体而言,我们首先将节点内容与位置功能进行补充,以帮助MLP捕获图形结构信息。然后,我们设计了一种新颖的表示相似性蒸馏策略,以将结构节点相似性注入MLP。最后,我们介绍了对抗性功能的扩展,以确保稳定的学习能力噪声,并进一步提高性能。广泛的实验表明,在七个数据集中,NOSMOG在转导和归纳环境中均优于GNN和最先进的方法,同时保持竞争性推理效率。
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知识蒸馏最近成为一种流行的技术,以改善卷积神经网络的模型泛化能力。然而,它对图形神经网络的影响小于令人满意的,因为图形拓扑和节点属性可能以动态方式改变,并且在这种情况下,静态教师模型引导学生培训不足。在本文中,我们通过在在线蒸馏时期同时培训一组图形神经网络来解决这一挑战,其中组知识发挥作用作为动态虚拟教师,并且有效地捕获了图形神经网络的结构变化。为了提高蒸馏性能,在学生之间转移两种知识,以增强彼此:在图形拓扑和节点属性中反映信息的本地知识,以及反映课程预测的全局知识。随着香草知识蒸馏等,在利用有效的对抗性循环学习框架,将全球知识与KL分歧转移。广泛的实验验证了我们提出的在线对抗蒸馏方法的有效性。
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图形神经网络(GNNS)显着改善了图形结构数据的表示功率。尽管最近GNN的成功,大多数GNN的图表卷积都有两个限制。由于图形卷积在输入图上的小本地邻域中执行,因此固有地无法捕获距离节点之间的远程依赖性。另外,当节点具有属于不同类别的邻居时,即,异常,来自它们的聚合消息通常会影响表示学习。为了解决图表卷积的两个常见问题,在本文中,我们提出了可变形的图形卷积网络(可变形GCNS),可在多个潜在空间中自适应地执行卷积并捕获节点之间的短/远程依赖性。与节点表示(特征)分开,我们的框架同时学习节点位置嵌入式嵌入式(坐标)以确定节点之间以端到端的方式之间的关系。根据节点位置,卷积内核通过变形向量变形并将不同的变换应用于其邻居节点。我们广泛的实验表明,可变形的GCNS灵活地处理异常的处理,并在六个异化图数据集中实现节点分类任务中的最佳性能。
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学习图形结构与图形神经网络(GNN)的数据被涌现为一个重要领域,因为它在生物信息学,化疗,社交网络分析和数据挖掘中的广泛适用性。最近的GNN算法基于神经消息传递,这使得GNN能够递归地集成本地结构和节点特征。然而,基于1跳邻域神经消息传递的过去的GNN算法暴露于对局部结构和关系的信息丢失的风险。在本文中,我们提出了邻居边缘聚合器(近),这是通过边缘聚集在邻域中的节点之间的关系的框架。近的,可以与图同构网络(GIN)正交结合,提供描述邻域中的节点的集成信息。因此,接近可以在1跳邻域中反映每个节点的局部结构的局部结构的附加信息。多图分类任务的实验结果表明,我们的算法在基于GNN的其他基于GNN的基于GNN的算法中取得了良好的改进。
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Recent years have witnessed great success in handling graph-related tasks with Graph Neural Networks (GNNs). Despite their great academic success, Multi-Layer Perceptrons (MLPs) remain the primary workhorse for practical industrial applications. One reason for this academic-industrial gap is the neighborhood-fetching latency incurred by data dependency in GNNs, which make it hard to deploy for latency-sensitive applications that require fast inference. Conversely, without involving any feature aggregation, MLPs have no data dependency and infer much faster than GNNs, but their performance is less competitive. Motivated by these complementary strengths and weaknesses, we propose a Graph Self-Distillation on Neighborhood (GSDN) framework to reduce the gap between GNNs and MLPs. Specifically, the GSDN framework is based purely on MLPs, where structural information is only implicitly used as prior to guide knowledge self-distillation between the neighborhood and the target, substituting the explicit neighborhood information propagation as in GNNs. As a result, GSDN enjoys the benefits of graph topology-awareness in training but has no data dependency in inference. Extensive experiments have shown that the performance of vanilla MLPs can be greatly improved with self-distillation, e.g., GSDN improves over stand-alone MLPs by 15.54\% on average and outperforms the state-of-the-art GNNs on six datasets. Regarding inference speed, GSDN infers 75X-89X faster than existing GNNs and 16X-25X faster than other inference acceleration methods.
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The core operation of current Graph Neural Networks (GNNs) is the aggregation enabled by the graph Laplacian or message passing, which filters the neighborhood information of nodes. Though effective for various tasks, in this paper, we show that they are potentially a problematic factor underlying all GNN models for learning on certain datasets, as they force the node representations similar, making the nodes gradually lose their identity and become indistinguishable. Hence, we augment the aggregation operations with their dual, i.e. diversification operators that make the node more distinct and preserve the identity. Such augmentation replaces the aggregation with a two-channel filtering process that, in theory, is beneficial for enriching the node representations. In practice, the proposed two-channel filters can be easily patched on existing GNN methods with diverse training strategies, including spectral and spatial (message passing) methods. In the experiments, we observe desired characteristics of the models and significant performance boost upon the baselines on 9 node classification tasks.
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