最近,图形神经网络(GNN)已被广泛用于文档分类。但是,大多数现有方法都基于没有句子级信息的静态词共同发生图,它构成了三个挑战:(1)字歧义,(2)字同义词和(3)动态上下文依赖性。为解决这些挑战,我们提出了一种用于归纳文档分类的新型GNN的稀疏结构学习模型。具体地,文档级图最初由句子级字共有图的不相交联盟生成。我们的模型收集了一系列连接句子之间的脱节单词的可训练边,并采用结构学习稀疏地选择具有动态上下文依赖性的边缘。具有稀疏结构的图形可以通过GNN共同利用文档中的本地和全局上下文信息。对于归纳学习,精致的文档图进一步馈入以端到端的方式的图形级分类和优化的一般读出函数。在几个现实世界数据集上的广泛实验表明,所提出的模型优于最先进的结果,并揭示了学习每个文档的稀疏结构的必要性。
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文本分类是自然语言处理(NLP)的主要任务。最近,图神经网络(GNN)已迅速发展,并应用于文本分类任务。作为一种特殊的图形数据,该树具有更简单的数据结构,可以为文本分类提供丰富的层次结构信息。受结构熵的启发,我们通过最小化结构熵并提出提示来构造图形的编码树,该提示旨在充分利用文本中包含的文本中包含的层次信息,以完成文本分类的任务。具体来说,我们首先为每个文本建立依赖关系解析图。然后,我们设计了一种结构熵最小化算法来解码图中的关键信息,并将每个图转换为其相应的编码树。基于编码树的层次结构,通过逐层更新编码树中的非叶子节点的表示来获得整个图的表示。最后,我们介绍了层次信息在文本分类中的有效性。实验结果表明,在具有简单的结构和很少的参数的同时,提示在流行基准测试上的最新方法优于最先进的方法。
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Text classification is an important and classical problem in natural language processing. There have been a number of studies that applied convolutional neural networks (convolution on regular grid, e.g., sequence) to classification. However, only a limited number of studies have explored the more flexible graph convolutional neural networks (convolution on non-grid, e.g., arbitrary graph) for the task. In this work, we propose to use graph convolutional networks for text classification. We build a single text graph for a corpus based on word co-occurrence and document word relations, then learn a Text Graph Convolutional Network (Text GCN) for the corpus. Our Text GCN is initialized with one-hot representation for word and document, it then jointly learns the embeddings for both words and documents, as supervised by the known class labels for documents. Our experimental results on multiple benchmark datasets demonstrate that a vanilla Text GCN without any external word embeddings or knowledge outperforms state-of-the-art methods for text classification. On the other hand, Text GCN also learns predictive word and document embeddings. In addition, experimental results show that the improvement of Text GCN over state-of-the-art comparison methods become more prominent as we lower the percentage of training data, suggesting the robustness of Text GCN to less training data in text classification.
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文本分类任务的关键是语言表示和重要信息提取,并且有许多相关研究。近年来,文本分类中的图形神经网络(GNN)的研究逐渐出现并显示出其优势,但现有模型主要集中于直接将单词作为图形节点直接输入GNN模型,而忽略了不同级别的语义结构信息。样品。为了解决该问题,我们提出了一个新的层次图神经网络(HIEGNN),该图分别从Word级,句子级别和文档级别提取相应的信息。与几种基线方法相比,几个基准数据集的实验结果取得更好或相似的结果,这表明我们的模型能够从样品中获得更多有用的信息。
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最近,基于图形神经网络(GNN)的文本分类模型引起了越来越多的关注。大多数这些模型采用类似的网络范例,即使用预训练节点嵌入初始化和两层图卷积。在这项工作中,我们提出了Textrgnn,一种改进的GNN结构,它引入了剩余连接以加深卷积网络深度。我们的结构可以获得更广泛的节点接收领域,有效地抑制节点特征的过平滑。此外,我们将概率语言模型集成到图形节点嵌入的初始化中,从而可以更好地提取非图形语义信息。实验结果表明,我们的模型是一般和高效的。无论是语料库级别还是文本级别,它都可以显着提高分类准确性,并在各种文本分类数据集中实现SOTA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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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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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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文档级关系提取(DRE)旨在识别两个实体之间的关系。实体可以对应于超越句子边界的多个提升。以前很少有研究已经调查了提及集成,这可能是有问题的,因为库鲁弗提到对特定关系没有同样有贡献。此外,事先努力主要关注实体级的推理,而不是捕获实体对之间的全局相互作用。在本文中,我们提出了两种新颖的技术,上下文指导的集成和交互推理(CGM2IR),以改善DRE。而不是简单地应用平均池,而是利用上下文来指导在加权和方式中的经验提升的集成。另外,对实体对图的相互作用推理在实体对图上执行迭代算法,以模拟关系的相互依赖性。我们在三个广泛使用的基准数据集中评估我们的CGM2IR模型,即Docred,CDR和GDA。实验结果表明,我们的模型优于以前的最先进的模型。
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Short text classification is a crucial and challenging aspect of Natural Language Processing. For this reason, there are numerous highly specialized short text classifiers. However, in recent short text research, State of the Art (SOTA) methods for traditional text classification, particularly the pure use of Transformers, have been unexploited. In this work, we examine the performance of a variety of short text classifiers as well as the top performing traditional text classifier. We further investigate the effects on two new real-world short text datasets in an effort to address the issue of becoming overly dependent on benchmark datasets with a limited number of characteristics. Our experiments unambiguously demonstrate that Transformers achieve SOTA accuracy on short text classification tasks, raising the question of whether specialized short text techniques are necessary.
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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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图表学习目的旨在将节点内容与图形结构集成以学习节点/图表示。然而,发现许多现有的图形学习方法在具有高异性级别的数据上不能很好地工作,这是不同类标签之间很大比例的边缘。解决这个问题的最新努力集中在改善消息传递机制上。但是,尚不清楚异质性是否确实会损害图神经网络(GNNS)的性能。关键是要展现一个节点与其直接邻居之间的关系,例如它们是异性还是同质性?从这个角度来看,我们在这里研究了杂质表示在披露连接节点之间的关系之前/之后的杂音表示的作用。特别是,我们提出了一个端到端框架,该框架既学习边缘的类型(即异性/同质性),并利用边缘类型的信息来提高图形神经网络的表现力。我们以两种不同的方式实施此框架。具体而言,为了避免通过异质边缘传递的消息,我们可以通过删除边缘分类器鉴定的异性边缘来优化图形结构。另外,可以利用有关异性邻居的存在的信息进行特征学习,因此,设计了一种混合消息传递方法来汇总同质性邻居,并根据边缘分类使异性邻居多样化。广泛的实验表明,在整个同质级别的多个数据集上,通过在多个数据集上提出的框架对GNN的绩效提高了显着提高。
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Graph neural networks (GNNs) have been utilized for various natural language processing (NLP) tasks lately. The ability to encode corpus-wide features in graph representation made GNN models popular in various tasks such as document classification. One major shortcoming of such models is that they mainly work on homogeneous graphs, while representing text datasets as graphs requires several node types which leads to a heterogeneous schema. In this paper, we propose a transductive hybrid approach composed of an unsupervised node representation learning model followed by a node classification/edge prediction model. The proposed model is capable of processing heterogeneous graphs to produce unified node embeddings which are then utilized for node classification or link prediction as the downstream task. The proposed model is developed to classify stock market technical analysis reports, which to our knowledge is the first work in this domain. Experiments, which are carried away using a constructed dataset, demonstrate the ability of the model in embedding extraction and the downstream tasks.
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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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Recent years have witnessed the emerging success of graph neural networks (GNNs) for modeling structured data. However, most GNNs are designed for homogeneous graphs, in which all nodes and edges belong to the same types, making them infeasible to represent heterogeneous structures. In this paper, we present the Heterogeneous Graph Transformer (HGT) architecture for modeling Web-scale heterogeneous graphs. To model heterogeneity, we design node-and edge-type dependent parameters to characterize the heterogeneous attention over each edge, empowering HGT to maintain dedicated representations for different types of nodes and edges. To handle dynamic heterogeneous graphs, we introduce the relative temporal encoding technique into HGT, which is able to capture the dynamic structural dependency with arbitrary durations. To handle Web-scale graph data, we design the heterogeneous mini-batch graph sampling algorithm-HGSampling-for efficient and scalable training. Extensive experiments on the Open Academic Graph of 179 million nodes and 2 billion edges show that the proposed HGT model consistently outperforms all the state-of-the-art GNN baselines by 9%-21% on various downstream tasks. The dataset and source code of HGT are publicly available at https://github.com/acbull/pyHGT.
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近年来,图表表示学习越来越多地引起了越来越长的关注,特别是为了在节点和图表水平上学习对分类和建议任务的低维嵌入。为了能够在现实世界中的大规模图形数据上学习表示,许多研究专注于开发不同的抽样策略,以方便培训过程。这里,我们提出了一种自适应图策略驱动的采样模型(GPS),其中通过自适应相关计算实现了本地邻域中每个节点的影响。具体地,邻居的选择是由自适应策略算法指导的,直接贡献到消息聚合,节点嵌入更新和图级读出步骤。然后,我们从各种角度对图表分类任务进行全面的实验。我们所提出的模型在几个重要的基准测试中优于现有的3%-8%,实现了现实世界数据集的最先进的性能。
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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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Machine reading comprehension (MRC) is a long-standing topic in natural language processing (NLP). The MRC task aims to answer a question based on the given context. Recently studies focus on multi-hop MRC which is a more challenging extension of MRC, which to answer a question some disjoint pieces of information across the context are required. Due to the complexity and importance of multi-hop MRC, a large number of studies have been focused on this topic in recent years, therefore, it is necessary and worth reviewing the related literature. This study aims to investigate recent advances in the multi-hop MRC approaches based on 31 studies from 2018 to 2022. In this regard, first, the multi-hop MRC problem definition will be introduced, then 31 models will be reviewed in detail with a strong focus on their multi-hop aspects. They also will be categorized based on their main techniques. Finally, a fine-grain comprehensive comparison of the models and techniques will be presented.
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基于方面的情感分析(ABSA)是一项精细的情感分析任务,旨在使特定方面的情感极性推断对齐方面和相应的情感。这是具有挑战性的,因为句子可能包含多个方面或复杂(例如,有条件,协调或逆境)的关系。最近,使用图神经网络利用依赖性语法信息是最受欢迎的趋势。尽管取得了成功,但在很大程度上依赖依赖树的方法在准确地建模方面的对准及其单词方面构成了挑战,因为依赖树可能会提供无关的关联的嘈杂信号(例如,“ conj”之间的关系“ conj”之间的关系。图2中的“伟大”和“可怕”。在本文中,为了减轻这个问题,我们提出了一个双轴法意识到的图形注意网络(BISYN-GAT+)。具体而言,bisyn-gat+完全利用句子组成树的语法信息(例如,短语分割和层次结构),以建模每个方面的情感感知环境(称为内在文章)和跨方面的情感关系(称为跨性别的情感)称为Inter-Contept)学习。四个基准数据集的实验表明,BISYN-GAT+的表现始终超过最新方法。
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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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