灵感来自深度学习的广泛成功,已经提出了图表神经网络(GNNS)来学习表达节点表示,并在各种图形学习任务中表现出有希望的性能。然而,现有的努力主要集中在提供相对丰富的金色标记节点的传统半监督设置。虽然数据标签是难以忍受的事实令人生畏的事实并且需要强化领域知识,但特别是在考虑图形结构数据的异质性时,它通常是不切实际的。在几次半监督的环境下,大多数现有GNN的性能不可避免地受到过度装备和过天际问题的破坏,在很大程度上由于标记数据的短缺。在本文中,我们提出了一种配备有新型元学习算法的解耦的网络架构来解决这个问题。从本质上讲,我们的框架META-PN通过META学习的标签传播策略在未标记节点上乘坐高质量的伪标签,这有效增强了稀缺标记的数据,同时在培训期间启用大型接受领域。广泛的实验表明,与各种基准数据集上的现有技术相比,我们的方法提供了简单且实质性的性能。
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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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图形广泛用于建模数据的关系结构,并且图形机器学习(ML)的研究具有广泛的应用,从分子图中的药物设计到社交网络中的友谊建议。图形ML的流行方法通常需要大量的标记实例来实现令人满意的结果,这在现实世界中通常是不可行的,因为在图形上标记了新出现的概念的数据(例如,在图形上的新分类)是有限的。尽管已将元学习应用于不同的几个图形学习问题,但大多数现有的努力主要假设所有所见类别的数据都是金标记的,而当这些方法弱标记时,这些方法可能会失去疗效严重的标签噪声。因此,我们旨在研究一个新的问题,即弱监督图元学习,以改善知识转移的模型鲁棒性。为了实现这一目标,我们提出了一个新的图形学习框架 - 本文中的图形幻觉网络(Meta-GHN)。基于一种新的鲁棒性增强的情节训练,元研究将从弱标记的数据中幻觉清洁节点表示,并提取高度可转移的元知识,这使该模型能够快速适应不见了的任务,几乎没有标记的实例。广泛的实验表明,元基因与现有图形学习研究的优越性有关弱监督的少数弹性分类的任务。
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图形神经网络(GNN)在许多基于图的任务中表现出强大的表示能力。具体而言,由于其简单性和性能优势,GNN(例如APPNP)的解耦结构变得流行。但是,这些GNN的端到端培训使它们在计算和记忆消耗方面效率低下。为了应对这些局限性,在这项工作中,我们为图形神经网络提供了交替的优化框架,不需要端到端培训。在不同设置下进行的广泛实验表明,所提出的算法的性能与现有的最新算法相当,但具有更好的计算和记忆效率。此外,我们表明我们的框架可以利用优势来增强现有的脱钩GNN。
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Graph Contrastive Learning (GCL) has recently drawn much research interest for learning generalizable node representations in a self-supervised manner. In general, the contrastive learning process in GCL is performed on top of the representations learned by a graph neural network (GNN) backbone, which transforms and propagates the node contextual information based on its local neighborhoods. However, nodes sharing similar characteristics may not always be geographically close, which poses a great challenge for unsupervised GCL efforts due to their inherent limitations in capturing such global graph knowledge. In this work, we address their inherent limitations by proposing a simple yet effective framework -- Simple Neural Networks with Structural and Semantic Contrastive Learning} (S^3-CL). Notably, by virtue of the proposed structural and semantic contrastive learning algorithms, even a simple neural network can learn expressive node representations that preserve valuable global structural and semantic patterns. Our experiments demonstrate that the node representations learned by S^3-CL achieve superior performance on different downstream tasks compared with the state-of-the-art unsupervised GCL methods. Implementation and more experimental details are publicly available at \url{https://github.com/kaize0409/S-3-CL.}
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Graph Neural Networks (GNNs) have been widely applied in the semi-supervised node classification task, where a key point lies in how to sufficiently leverage the limited but valuable label information. Most of the classical GNNs solely use the known labels for computing the classification loss at the output. In recent years, several methods have been designed to additionally utilize the labels at the input. One part of the methods augment the node features via concatenating or adding them with the one-hot encodings of labels, while other methods optimize the graph structure by assuming neighboring nodes tend to have the same label. To bring into full play the rich information of labels, in this paper, we present a label-enhanced learning framework for GNNs, which first models each label as a virtual center for intra-class nodes and then jointly learns the representations of both nodes and labels. Our approach could not only smooth the representations of nodes belonging to the same class, but also explicitly encode the label semantics into the learning process of GNNs. Moreover, a training node selection technique is provided to eliminate the potential label leakage issue and guarantee the model generalization ability. Finally, an adaptive self-training strategy is proposed to iteratively enlarge the training set with more reliable pseudo labels and distinguish the importance of each pseudo-labeled node during the model training process. Experimental results on both real-world and synthetic datasets demonstrate our approach can not only consistently outperform the state-of-the-arts, but also effectively smooth the representations of intra-class nodes.
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鉴于在现实世界应用中大规模图的流行率,训练神经模型的存储和时间引起了人们的关注。为了减轻关注点,我们提出和研究图形神经网络(GNNS)的图形凝结问题。具体而言,我们旨在将大型原始图凝结成一个小的,合成的和高度信息的图,以便在小图和大图上训练的GNN具有可比性的性能。我们通过优化梯度匹配损失并设计一种凝结节点期货和结构信息的策略来模仿原始图上的GNN训练轨迹,以解决凝结问题。广泛的实验证明了所提出的框架在将不同的图形数据集凝结成信息较小的较小图中的有效性。特别是,我们能够在REDDIT上近似于95.3%的原始测试准确性,Flickr的99.8%和CiteSeer的99.0%,同时将其图形尺寸降低了99.9%以上,并且可以使用冷凝图来训练各种GNN架构Code在https://github.com/chandlerbang/gcond上发布。
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图形神经网络是一种强大的深度学习工具,用于建模图形结构化数据,在众多图形学习任务上表现出了出色的性能。为了解决深图学习中的数据噪声和数据稀缺性问题,最近有关图形数据的研究已加剧。但是,常规数据增强方法几乎无法处理具有多模式性的非欧几里得空间中定义的图形结构化数据。在这项调查中,我们正式提出了图数据扩展的问题,并进一步审查了代表性技术及其在不同深度学习问题中的应用。具体而言,我们首先提出了图形数据扩展技术的分类法,然后通过根据增强信息方式对相关工作进行分类,从而提供结构化的审查。此外,我们总结了以数据为中心的深图学习中两个代表性问题中图数据扩展的应用:(1)可靠的图形学习,重点是增强输入图的实用性以及通过图数据增强的模型容量; (2)低资源图学习,其针对通过图数据扩大标记的训练数据量表的目标。对于每个问题,我们还提供层次结构问题分类法,并审查与图数据增强相关的现有文献。最后,我们指出了有希望的研究方向和未来研究的挑战。
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数据增强已广泛用于图像数据和语言数据,但仍然探索图形神经网络(GNN)。现有方法专注于从全局视角增强图表数据,并大大属于两个类型:具有特征噪声注入的结构操纵和对抗训练。但是,最近的图表数据增强方法忽略了GNNS“消息传递机制的本地信息的重要性。在这项工作中,我们介绍了本地增强,这通过其子图结构增强了节点表示的局部。具体而言,我们将数据增强模拟为特征生成过程。鉴于节点的功能,我们的本地增强方法了解其邻居功能的条件分布,并生成更多邻居功能,以提高下游任务的性能。基于本地增强,我们进一步设计了一个新颖的框架:La-GNN,可以以即插即用的方式应用于任何GNN模型。广泛的实验和分析表明,局部增强一致地对各种基准的各种GNN架构始终如一地产生性能改进。
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图形神经网络(GNN),图数据上深度神经网络的概括已被广泛用于各个领域,从药物发现到推荐系统。但是,当可用样本很少的情况下,这些应用程序的GNN是有限的。元学习一直是解决机器学习中缺乏样品的重要框架,近年来,研究人员已经开始将元学习应用于GNNS。在这项工作中,我们提供了对涉及GNN的不同元学习方法的综合调查,这些方法在各种图表中显示出使用这两种方法的力量。我们根据提出的架构,共享表示和应用程序分类文献。最后,我们讨论了几个激动人心的未来研究方向和打开问题。
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Graph neural networks have shown significant success in the field of graph representation learning. Graph convolutions perform neighborhood aggregation and represent one of the most important graph operations. Nevertheless, one layer of these neighborhood aggregation methods only consider immediate neighbors, and the performance decreases when going deeper to enable larger receptive fields. Several recent studies attribute this performance deterioration to the over-smoothing issue, which states that repeated propagation makes node representations of different classes indistinguishable. In this work, we study this observation systematically and develop new insights towards deeper graph neural networks. First, we provide a systematical analysis on this issue and argue that the key factor compromising the performance significantly is the entanglement of representation transformation and propagation in current graph convolution operations. After decoupling these two operations, deeper graph neural networks can be used to learn graph node representations from larger receptive fields. We further provide a theoretical analysis of the above observation when building very deep models, which can serve as a rigorous and gentle description of the over-smoothing issue. Based on our theoretical and empirical analysis, we propose Deep Adaptive Graph Neural Network (DAGNN) to adaptively incorporate information from large receptive fields. A set of experiments on citation, coauthorship, and co-purchase datasets have confirmed our analysis and insights and demonstrated the superiority of our proposed methods. CCS CONCEPTS• Mathematics of computing → Graph algorithms; • Computing methodologies → Artificial intelligence; Neural networks.
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逐步学习新课程的能力对于所有现实世界的人工智能系统至关重要。像社交媒体,推荐系统,电子商务平台等的大部分高冲击应用都可以由图形模型表示。在本文中,我们调查了挑战但实际问题,图表几次拍摄的类增量(图形FCL)问题,其中图形模型是任务,以对新遇到的类和以前学习的类进行分类。为此目的,我们通过从基类循环地采样任务来提出图形伪增量学习范例,以便为我们的模型产生任意数量的培训集,以练习增量学习技能。此外,我们设计了一种基于分层的图形元学习框架,Hag-Meta。我们介绍了一个任务敏感的常规程序,从任务级关注和节点类原型计算,以缓解到新颖或基本类上的过度拟合。为了采用拓扑知识,我们添加了一个节点级注意模块来调整原型表示。我们的模型不仅达到了旧知识整合的更大稳定性,而且还可以获得对具有非常有限的数据样本的新知识的有利适应性。在三个现实世界数据集上进行广泛的实验,包括亚马逊服装,Reddit和DBLP,表明我们的框架与基线和其他相关最先进的方法相比,展示了显着的优势。
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图表分类是一种非常有影响力的任务,在多数世界应用中起着至关重要的作用,例如分子性质预测和蛋白质函数预测。以有限标记的图表处理新课程,几次拍摄图形分类已成为一座桥梁现有图分类解决方案与实际使用。这项工作探讨了基于度量的元学习的潜力,用于解决少量图形分类。我们突出了考虑解决方案结构特征的重要性,并提出了一种明确考虑全球结构的新框架和输入图的局部结构。在两个数据集,Chembl和三角形上测试了名为SMF-GIN的GIN的实施,其中广泛的实验验证了所提出的方法的有效性。 ChemBl构造成填补缺乏几次拍摄图形分类评估的大规模基准的差距,与SMF-GIN的实施一起释放:https://github.com/jiangshunyu/smf-ing。
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Graph Neural Networks (GNNs) have been predominant for graph learning tasks; however, recent studies showed that a well-known graph algorithm, Label Propagation (LP), combined with a shallow neural network can achieve comparable performance to GNNs in semi-supervised node classification on graphs with high homophily. In this paper, we show that this approach falls short on graphs with low homophily, where nodes often connect to the nodes of the opposite classes. To overcome this, we carefully design a combination of a base predictor with LP algorithm that enjoys a closed-form solution as well as convergence guarantees. Our algorithm first learns the class compatibility matrix and then aggregates label predictions using LP algorithm weighted by class compatibilities. On a wide variety of benchmarks, we show that our approach achieves the leading performance on graphs with various levels of homophily. Meanwhile, it has orders of magnitude fewer parameters and requires less execution time. Empirical evaluations demonstrate that simple adaptations of LP can be competitive in semi-supervised node classification in both homophily and heterophily regimes.
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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。
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Few-shot node classification is tasked to provide accurate predictions for nodes from novel classes with only few representative labeled nodes. This problem has drawn tremendous attention for its projection to prevailing real-world applications, such as product categorization for newly added commodity categories on an E-commerce platform with scarce records or diagnoses for rare diseases on a patient similarity graph. To tackle such challenging label scarcity issues in the non-Euclidean graph domain, meta-learning has become a successful and predominant paradigm. More recently, inspired by the development of graph self-supervised learning, transferring pretrained node embeddings for few-shot node classification could be a promising alternative to meta-learning but remains unexposed. In this work, we empirically demonstrate the potential of an alternative framework, \textit{Transductive Linear Probing}, that transfers pretrained node embeddings, which are learned from graph contrastive learning methods. We further extend the setting of few-shot node classification from standard fully supervised to a more realistic self-supervised setting, where meta-learning methods cannot be easily deployed due to the shortage of supervision from training classes. Surprisingly, even without any ground-truth labels, transductive linear probing with self-supervised graph contrastive pretraining can outperform the state-of-the-art fully supervised meta-learning based methods under the same protocol. We hope this work can shed new light on few-shot node classification problems and foster future research on learning from scarcely labeled instances on graphs.
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Neural message passing algorithms for semi-supervised classification on graphs have recently achieved great success. However, for classifying a node these methods only consider nodes that are a few propagation steps away and the size of this utilized neighborhood is hard to extend. In this paper, we use the relationship between graph convolutional networks (GCN) and PageRank to derive an improved propagation scheme based on personalized PageRank. We utilize this propagation procedure to construct a simple model, personalized propagation of neural predictions (PPNP), and its fast approximation, APPNP. Our model's training time is on par or faster and its number of parameters on par or lower than previous models. It leverages a large, adjustable neighborhood for classification and can be easily combined with any neural network. We show that this model outperforms several recently proposed methods for semi-supervised classification in the most thorough study done so far for GCN-like models. Our implementation is available online. 1
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属性网络上的节点分类是一项半监督任务,对于网络分析至关重要。通过将图形卷积网络(GCN)中的两个关键操作解耦,即具有转换和邻域聚合,截断的GCN的一些最新作品可以支持这些信息,以更深入地传播并实现高级性能。但是,它们遵循GCN的传统结构感知的传播策略,因此很难捕获节点的属性相关性,并对由两个端点属于不同类别的边缘描述的结构噪声敏感。为了解决这些问题,我们提出了一种新方法,称为“裂开式”传播,然后训练(PAMT)。关键思想是将属性相似性掩码整合到结构感知的传播过程中。这样,PAMT可以在传播过程中保留相邻节点的属性相关性,并有效地减少结构噪声的影响。此外,我们开发了一种迭代改进机制,以在改善培训性能的培训过程中更新相似性面罩。在四个现实世界数据集上进行的广泛实验证明了PAMT的出色性能和鲁棒性。
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图形神经网络(GNNS)在建模图形结构数据方面表明了它们的能力。但是,实际图形通常包含结构噪声并具有有限的标记节点。当在这些图表中培训时,GNN的性能会显着下降,这阻碍了许多应用程序的GNN。因此,与有限标记的节点开发抗噪声GNN是重要的。但是,这是一个相当有限的工作。因此,我们研究了在具有有限标记节点的嘈杂图中开发鲁棒GNN的新问题。我们的分析表明,嘈杂的边缘和有限的标记节点都可能损害GNN的消息传递机制。为减轻这些问题,我们提出了一种新颖的框架,该框架采用嘈杂的边缘作为监督,以学习去噪和密集的图形,这可以减轻或消除嘈杂的边缘,并促进GNN的消息传递,以缓解有限标记节点的问题。生成的边缘还用于规则地将具有标记平滑度的未标记节点的预测规范化,以更好地列车GNN。实验结果对现实世界数据集展示了在具有有限标记节点的嘈杂图中提出框架的稳健性。
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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。
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