最近,网络钓鱼诈骗对块线构成了重大威胁。网络钓鱼探测器指导他们在狩猎网络钓鱼地址方面的努力。大多数检测器通过随机行走或构建静态子图提取目标地址的交易行为特征。随机行走方法,遗憾的是,由于采样序列长度有限,通常会错过结构信息,而静态子图方法倾向于忽略在不断变化的交易行为中忽略时间的时间特征。更重要的是,当恶意用户故意隐藏网络钓鱼行为时,它们的性能经历严重退化。为了解决这些挑战,我们提出了一种动态图分类,从事务演变图(TEGS)中了解了一种动态图形分类器。首先,我们将交易系列转换为多个时间片,在不同时段中捕获目标地址的交易行为。然后,我们提供快速非参数的网络钓鱼检测器,以缩小可疑地址的搜索空间。最后,TEGDetector认为空间和时间的演变,朝着不断变化的交易行为的完整表征。此外,TEGDetector利用了自适应的学习时间系数来向不同的关注点关注不同的时期,这提供了几个新颖的洞察力。大型Etereum Transaction DataSet上的广泛实验表明,该方法实现了最先进的检测性能。
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图表神经网络(GNNS)已成功利用在许多现实世界应用中的图形分析任务中。攻击和防御方法之间的竞争也增强了GNN的鲁棒性。在这次竞争中,对抗性培训方法的发展提出了对攻击例子的多样性要求。相比之下,大多数具有特定攻击策略的攻击方法难以满足这种要求。为了解决这个问题,我们提出了GraphAtcher,这是一种新型通用图形攻击框架,可根据图分析任务灵活地调整结构和攻击策略。通过在三个关键组件上的替代培训:基于生成对冲网络(GaN)的多策略攻击发生器(MAG),相似性鉴别器(SD)和攻击鉴别器(AD),产生对手示例。此外,考虑到节点相似性分布的变化,我们介绍了一种新颖的相似性修改率SMR来进行隐秘的攻击。在各种基准数据集上的实验表明,GraphAtcker可以在节点分类,图形分类和链路预测的图形分析任务上实现最先进的攻击性能,无论是否进行了对抗性培训。此外,我们还分析了每个任务的独特特征及其在统一攻击框架中的特定响应。项目代码可在https://github.com/honoluluuuu/graphatter处获得。
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由于其独立性与标签及其稳健性的独立性,自我监督的学习最近引起了很多关注。目前关于本主题的研究主要使用诸如图形结构的静态信息,但不能很好地捕获诸如边缘时间戳的动态信息。现实图形通常是动态的,这意味着节点之间的交互发生在特定时间。本文提出了一种自我监督的动态图形表示学习框架(DYSUBC),其定义了一个时间子图对比学学习任务,以同时学习动态图的结构和进化特征。具体地,首先提出了一种新的时间子图采样策略,其将动态图的每个节点作为中心节点提出,并使用邻域结构和边缘时间戳来采样相应的时间子图。然后根据在编码每个子图中的节点之后,根据中心节点上的邻域节点的影响设计子图表示功能。最后,定义了结构和时间对比损失,以最大化节点表示和时间子图表示之间的互信息。五个现实数据集的实验表明(1)DySubc比下游链路预测任务中的两个图形对比学习模型和四个动态图形表示学习模型更好地表现出更好的相关基线,(2)使用时间信息不能使用只有更有效的子图,还可以通过时间对比损失来学习更好的表示。
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保持个人特征和复杂的关系,广泛利用和研究了图表数据。通过更新和聚合节点的表示,能够捕获结构信息,图形神经网络(GNN)模型正在获得普及。在财务背景下,该图是基于实际数据构建的,这导致复杂的图形结构,因此需要复杂的方法。在这项工作中,我们在最近的财务环境中对GNN模型进行了全面的审查。我们首先将普通使用的财务图分类并总结每个节点的功能处理步骤。然后,我们总结了每个地图类型的GNN方法,每个区域的应用,并提出一些潜在的研究领域。
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准确的交通状况预测为车辆环境协调和交通管制任务提供了坚实的基础。由于道路网络数据在空间分布中的复杂性以及深度学习方法的多样性,有效定义流量数据并充分捕获数据中复杂的空间非线性特征变得具有挑战性。本文将两种分层图池方法应用于流量预测任务,以减少图形信息冗余。首先,本文验证了流量预测任务中层次图池方法的有效性。分层图合并方法与其他基线在预测性能上形成鲜明对比。其次,应用了两种主流分层图池方法,节点群集池和节点下降池,用于分析流量预测中的优势和弱点。最后,对于上述图神经网络,本文比较了不同图网络输入对流量预测准确性的预测效应。分析和汇总定义图网络的有效方法。
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随着传感技术的进步,多元时间序列分类(MTSC)最近受到了相当大的关注。基于深度学习的MTSC技术主要依赖于卷积或经常性神经网络,主要涉及单时间序列的时间依赖性。结果,他们努力直接在多变量变量中表达成对依赖性。此外,基于图形神经网络(GNNS)的当前空间 - 时间建模(例如,图形分类)方法本质上是平的,并且不能以分层方式聚合集线器数据。为了解决这些限制,我们提出了一种基于新的图形汇集框架MTPOOL,以获得MTS的表现力全球表示。我们首先通过采用通过图形结构学习模块的相互作用来将MTS切片转换为曲线图,并通过时间卷积模块获得空间 - 时间图节点特征。为了获得全局图形级表示,我们设计了基于“编码器 - 解码器”的变形图池池模块,用于为群集分配创建自适应质心。然后我们将GNN和我们所提出的变分图层汇集层组合用于联合图表示学习和图形粗糙化,之后该图逐渐赋予一个节点。最后,可差异化的分类器将此粗糙的表示来获取最终预测的类。 10个基准数据集的实验表明MTPOOL优于MTSC任务中最先进的策略。
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社交机器人被称为社交网络上的自动帐户,这些帐户试图像人类一样行事。尽管图形神经网络(GNNS)已大量应用于社会机器人检测领域,但大量的领域专业知识和先验知识大量参与了最先进的方法,以设计专门的神经网络体系结构,以设计特定的神经网络体系结构。分类任务。但是,在模型设计中涉及超大的节点和网络层,通常会导致过度平滑的问题和缺乏嵌入歧视。在本文中,我们提出了罗斯加斯(Rosgas),这是一种新颖的加强和自我监督的GNN Architecture搜索框架,以适应性地指出了最合适的多跳跃社区和GNN体系结构中的层数。更具体地说,我们将社交机器人检测问题视为以用户为中心的子图嵌入和分类任务。我们利用异构信息网络来通过利用帐户元数据,关系,行为特征和内容功能来展示用户连接。 Rosgas使用多代理的深钢筋学习(RL)机制来导航最佳邻域和网络层的搜索,以分别学习每个目标用户的子图嵌入。开发了一种用于加速RL训练过程的最接近的邻居机制,Rosgas可以借助自我监督的学习来学习更多的判别子图。 5个Twitter数据集的实验表明,Rosgas在准确性,训练效率和稳定性方面优于最先进的方法,并且在处理看不见的样本时具有更好的概括。
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Due to the issue that existing wireless sensor network (WSN)-based anomaly detection methods only consider and analyze temporal features, in this paper, a self-supervised learning-based anomaly node detection method based on an autoencoder is designed. This method integrates temporal WSN data flow feature extraction, spatial position feature extraction and intermodal WSN correlation feature extraction into the design of the autoencoder to make full use of the spatial and temporal information of the WSN for anomaly detection. First, a fully connected network is used to extract the temporal features of nodes by considering a single mode from a local spatial perspective. Second, a graph neural network (GNN) is used to introduce the WSN topology from a global spatial perspective for anomaly detection and extract the spatial and temporal features of the data flows of nodes and their neighbors by considering a single mode. Then, the adaptive fusion method involving weighted summation is used to extract the relevant features between different models. In addition, this paper introduces a gated recurrent unit (GRU) to solve the long-term dependence problem of the time dimension. Eventually, the reconstructed output of the decoder and the hidden layer representation of the autoencoder are fed into a fully connected network to calculate the anomaly probability of the current system. Since the spatial feature extraction operation is advanced, the designed method can be applied to the task of large-scale network anomaly detection by adding a clustering operation. Experiments show that the designed method outperforms the baselines, and the F1 score reaches 90.6%, which is 5.2% higher than those of the existing anomaly detection methods based on unsupervised reconstruction and prediction. Code and model are available at https://github.com/GuetYe/anomaly_detection/GLSL
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时间网络链接预测是网络科学领域的重要任务,并且在实际情况下具有广泛的应用。揭示网络的进化机制对于链接预测至关重要,如何有效利用历史信息来实现时间链接并有效提取网络结构的高阶模式仍然是一个至关重要的挑战。为了解决这些问题,在本文中,我们提出了一个具有调整后的Sigmoid函数和2-Simplex结构(TLPSS)的新型时间链接预测模型。调整后的Sigmoid衰减模式考虑了活跃,衰减和稳定的边缘状态,这适当适合信息的生命周期。此外,引入了由单纯形高阶结构组成的潜在矩阵序列,以增强链接预测方法的性能,因为它在稀疏网络中非常可行。结合信息的生命周期和单纯级结构,通过满足动态网络中时间和结构信息的一致性来实现TLPS的整体性能。六个现实世界数据集的实验结果证明了TLPS的有效性,与其他基线方法相比,我们提出的模型平均提高了链接预测的性能15%。
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Graph Neural Networks (GNNs) have been widely applied to different tasks such as bioinformatics, drug design, and social networks. However, recent studies have shown that GNNs are vulnerable to adversarial attacks which aim to mislead the node or subgraph classification prediction by adding subtle perturbations. Detecting these attacks is challenging due to the small magnitude of perturbation and the discrete nature of graph data. In this paper, we propose a general adversarial edge detection pipeline EDoG without requiring knowledge of the attack strategies based on graph generation. Specifically, we propose a novel graph generation approach combined with link prediction to detect suspicious adversarial edges. To effectively train the graph generative model, we sample several sub-graphs from the given graph data. We show that since the number of adversarial edges is usually low in practice, with low probability the sampled sub-graphs will contain adversarial edges based on the union bound. In addition, considering the strong attacks which perturb a large number of edges, we propose a set of novel features to perform outlier detection as the preprocessing for our detection. Extensive experimental results on three real-world graph datasets including a private transaction rule dataset from a major company and two types of synthetic graphs with controlled properties show that EDoG can achieve above 0.8 AUC against four state-of-the-art unseen attack strategies without requiring any knowledge about the attack type; and around 0.85 with knowledge of the attack type. EDoG significantly outperforms traditional malicious edge detection baselines. We also show that an adaptive attack with full knowledge of our detection pipeline is difficult to bypass it.
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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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Anomaly analytics is a popular and vital task in various research contexts, which has been studied for several decades. At the same time, deep learning has shown its capacity in solving many graph-based tasks like, node classification, link prediction, and graph classification. Recently, many studies are extending graph learning models for solving anomaly analytics problems, resulting in beneficial advances in graph-based anomaly analytics techniques. In this survey, we provide a comprehensive overview of graph learning methods for anomaly analytics tasks. We classify them into four categories based on their model architectures, namely graph convolutional network (GCN), graph attention network (GAT), graph autoencoder (GAE), and other graph learning models. The differences between these methods are also compared in a systematic manner. Furthermore, we outline several graph-based anomaly analytics applications across various domains in the real world. Finally, we discuss five potential future research directions in this rapidly growing field.
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图形神经网络(GNN)在学习强大的节点表示中显示了令人信服的性能,这些表现在保留节点属性和图形结构信息的强大节点表示中。然而,许多GNNS在设计有更深的网络结构或手柄大小的图形时遇到有效性和效率的问题。已经提出了几种采样算法来改善和加速GNN的培训,但他们忽略了解GNN性能增益的来源。图表数据中的信息的测量可以帮助采样算法来保持高价值信息,同时消除冗余信息甚至噪声。在本文中,我们提出了一种用于GNN的公制引导(MEGUIDE)子图学习框架。 MEGUIDE采用两种新颖的度量:功能平滑和连接失效距离,以指导子图采样和迷你批次的培训。功能平滑度专为分析节点的特征而才能保留最有价值的信息,而连接失败距离可以测量结构信息以控制子图的大小。我们展示了MEGUIDE在多个数据集上培训各种GNN的有效性和效率。
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Temporal networks are an important type of network whose topological structure changes over time. Compared with methods on static networks, temporal network embedding (TNE) methods are facing three challenges: 1) it cannot describe the temporal dependence across network snapshots; 2) the node embedding in the latent space fails to indicate changes in the network topology; and 3) it cannot avoid a lot of redundant computation via parameter inheritance on a series of snapshots. To this end, we propose a novel temporal network embedding method named Dynamic Cluster Structure Constraint model (DyCSC), whose core idea is to capture the evolution of temporal networks by imposing a temporal constraint on the tendency of the nodes in the network to a given number of clusters. It not only generates low-dimensional embedding vectors for nodes but also preserves the dynamic nonlinear features of temporal networks. Experimental results on multiple realworld datasets have demonstrated the superiority of DyCSC for temporal graph embedding, as it consistently outperforms competing methods by significant margins in multiple temporal link prediction tasks. Moreover, the ablation study further validates the effectiveness of the proposed temporal constraint.
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图表神经网络(GNNS)最近提出了用于处理图形结构数据的神经网络结构。由于他们所采用的邻国聚合策略,现有的GNNS专注于捕获节点级信息并忽略高级信息。因此,现有的GNN受到本地置换不变性(LPI)问题引起的代表性限制。为了克服这些限制并丰富GNN捕获的特征,我们提出了一种新的GNN框架,称为两级GNN(TL-GNN)。这与节点级信息合并子图级信息。此外,我们提供了对LPI问题的数学分析,这表明子图级信息有利于克服与LPI相关的问题。还提出了一种基于动态编程算法的子图计数方法,并且该具有时间复杂度是O(n ^ 3),n是图的节点的数量。实验表明,TL-GNN优于现有的GNN,实现了最先进的性能。
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Graph Neural Networks (GNNs) have attracted increasing attention in recent years and have achieved excellent performance in semi-supervised node classification tasks. The success of most GNNs relies on one fundamental assumption, i.e., the original graph structure data is available. However, recent studies have shown that GNNs are vulnerable to the complex underlying structure of the graph, making it necessary to learn comprehensive and robust graph structures for downstream tasks, rather than relying only on the raw graph structure. In light of this, we seek to learn optimal graph structures for downstream tasks and propose a novel framework for semi-supervised classification. Specifically, based on the structural context information of graph and node representations, we encode the complex interactions in semantics and generate semantic graphs to preserve the global structure. Moreover, we develop a novel multi-measure attention layer to optimize the similarity rather than prescribing it a priori, so that the similarity can be adaptively evaluated by integrating measures. These graphs are fused and optimized together with GNN towards semi-supervised classification objective. Extensive experiments and ablation studies on six real-world datasets clearly demonstrate the effectiveness of our proposed model and the contribution of each component.
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Providing accurate estimated time of package delivery on users' purchasing pages for e-commerce platforms is of great importance to their purchasing decisions and post-purchase experiences. Although this problem shares some common issues with the conventional estimated time of arrival (ETA), it is more challenging with the following aspects: 1) Inductive inference. Models are required to predict ETA for orders with unseen retailers and addresses; 2) High-order interaction of order semantic information. Apart from the spatio-temporal features, the estimated time also varies greatly with other factors, such as the packaging efficiency of retailers, as well as the high-order interaction of these factors. In this paper, we propose an inductive graph transformer (IGT) that leverages raw feature information and structural graph data to estimate package delivery time. Different from previous graph transformer architectures, IGT adopts a decoupled pipeline and trains transformer as a regression function that can capture the multiplex information from both raw feature and dense embeddings encoded by a graph neural network (GNN). In addition, we further simplify the GNN structure by removing its non-linear activation and the learnable linear transformation matrix. The reduced parameter search space and linear information propagation in the simplified GNN enable the IGT to be applied in large-scale industrial scenarios. Experiments on real-world logistics datasets show that our proposed model can significantly outperform the state-of-the-art methods on estimation of delivery time. The source code is available at: https://github.com/enoche/IGT-WSDM23.
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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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Recently, graph anomaly detection has attracted increasing attention in data mining and machine learning communities. Apart from existing attribute anomalies, graph anomaly detection also captures suspicious topological-abnormal nodes that differ from the major counterparts. Although massive graph-based detection approaches have been proposed, most of them focus on node-level comparison while pay insufficient attention on the surrounding topology structures. Nodes with more dissimilar neighborhood substructures have more suspicious to be abnormal. To enhance the local substructure detection ability, we propose a novel Graph Anomaly Detection framework via Multi-scale Substructure Learning (GADMSL for abbreviation). Unlike previous algorithms, we manage to capture anomalous substructures where the inner similarities are relatively low in dense-connected regions. Specifically, we adopt a region proposal module to find high-density substructures in the network as suspicious regions. Their inner-node embedding similarities indicate the anomaly degree of the detected substructures. Generally, a lower degree of embedding similarities means a higher probability that the substructure contains topology anomalies. To distill better embeddings of node attributes, we further introduce a graph contrastive learning scheme, which observes attribute anomalies in the meantime. In this way, GADMSL can detect both topology and attribute anomalies. Ultimately, extensive experiments on benchmark datasets show that GADMSL greatly improves detection performance (up to 7.30% AUC and 17.46% AUPRC gains) compared to state-of-the-art attributed networks anomaly detection algorithms.
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作为图理论中最基本的任务之一,子图匹配是许多领域的关键任务,范围从信息检索,计算机视觉,生物学,化学和自然语言处理。然而,子图匹配问题仍然是NP完整问题。这项研究提出了一种基于端到端学习的近似近似方法,用于匹配任务,称为子图匹配网络(子GMN)。所提出的子-GMN首先使用图表表示学习将节点映射到节点级嵌入。然后,它结合了度量学习和注意机制,以模拟数据图和查询图中匹配节点之间的关系。为了测试所提出方法的性能,我们将方法应用于两个数据库。我们使用了两种现有方法,即GNN和FGNN作为基线进行比较。我们的实验表明,在数据集1上,平均而言,亚GMN的准确性分别比GNN和FGNN高12.21 \%和3.2 \%。平均运行时间次-GMN的运行速度比FGNN快20-40倍。此外,所有数据集2的实验中sub-gmn的平均F1得分达到0.95,这表明sub-gmn输出更正确的节点到节点匹配。与以前的基于GNNS的子图匹配任务相比,我们提出的子GMN允许在测试/应用程序阶段进行改变的查询和数据图,而大多数以前基于GNN的方法只能在数据图中在数据图中找到匹配的子图片,在训练阶段使用的相同查询图的测试/应用。我们提出的子-GMN的另一个优点是,它可以输出节点到节点匹配的列表,而大多数现有的基于端GNN的方法无法提供匹配的节点对。
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