Traditional network embedding primarily focuses on learning a continuous vector representation for each node, preserving network structure and/or node content information, such that off-the-shelf machine learning algorithms can be easily applied to the vector-format node representations for network analysis. However, the learned continuous vector representations are inefficient for large-scale similarity search, which often involves finding nearest neighbors measured by distance or similarity in a continuous vector space. In this paper, we propose a search efficient binary network embedding algorithm called BinaryNE to learn a binary code for each node, by simultaneously modeling node context relations and node attribute relations through a three-layer neural network. BinaryNE learns binary node representations through a stochastic gradient descent based online learning algorithm. The learned binary encoding not only reduces memory usage to represent each node, but also allows fast bit-wise comparisons to support faster node similarity search than using Euclidean distance or other distance measures. Extensive experiments and comparisons demonstrate that BinaryNE not only delivers more than 25 times faster search speed, but also provides comparable or better search quality than traditional continuous vector based network embedding methods. The binary codes learned by BinaryNE also render competitive performance on node classification and node clustering tasks. The source code of this paper is available at https://github.com/daokunzhang/BinaryNE.

链接预测旨在推断网络/图中的一对节点对之间的链接存在。尽管应用了广泛的应用，但传统链接预测算法的成功受到了三个主要挑战（链接稀疏，节点属性噪声和动态变化）的影响，这些挑战受到许多现实世界网络所面临的。为了应对这些挑战，我们提出了一个上下文化的自我监督学习（CSSL）框架，该框架充分利用了链接预测的结构上下文预测。提出的CSSL框架学习了一个链接编码器，以从配对的节点嵌入中推断链接存在概率，这些嵌入是通过节点属性上的转换构建的。为了生成链接预测的信息节点嵌入，结构上下文预测被用作自我监督的学习任务，以提高链接预测性能。研究了两种类型的结构上下文，即从随机步行和上下文子图收集的上下文节点。 CSSL框架可以以端到端的方式进行训练，并通过通过链接预测和自我监督的学习任务来监督模型参数的学习。提出的CSSL是一个通用且灵活的框架，因为它可以同时处理属性和非属性网络，并且在跨性和归纳性链接预测设置下进行操作。对七个现实世界基准网络进行的广泛实验和消融研究表明，在转化和归纳性环境下，在不同类型的网络上，提出的基于自学的链接链路预测算法优于最先进的基线。拟议的CSSL还可以从大规模网络上的节点属性噪声和可扩展性方面产生竞争性能。

图表表示学习是一种快速增长的领域，其中一个主要目标是在低维空间中产生有意义的图形表示。已经成功地应用了学习的嵌入式来执行各种预测任务，例如链路预测，节点分类，群集和可视化。图表社区的集体努力提供了数百种方法，但在所有评估指标下没有单一方法擅长，例如预测准确性，运行时间，可扩展性等。该调查旨在通过考虑算法来评估嵌入方法的所有主要类别的图表变体，参数选择，可伸缩性，硬件和软件平台，下游ML任务和多样化数据集。我们使用包含手动特征工程，矩阵分解，浅神经网络和深图卷积网络的分类法组织了图形嵌入技术。我们使用广泛使用的基准图表评估了节点分类，链路预测，群集和可视化任务的这些类别算法。我们在Pytorch几何和DGL库上设计了我们的实验，并在不同的多核CPU和GPU平台上运行实验。我们严格地审查了各种性能指标下嵌入方法的性能，并总结了结果。因此，本文可以作为比较指南，以帮助用户选择最适合其任务的方法。

Graph is an important data representation which appears in a wide diversity of real-world scenarios. Effective graph analytics provides users a deeper understanding of what is behind the data, and thus can benefit a lot of useful applications such as node classification, node recommendation, link prediction, etc. However, most graph analytics methods suffer the high computation and space cost. Graph embedding is an effective yet efficient way to solve the graph analytics problem. It converts the graph data into a low dimensional space in which the graph structural information and graph properties are maximumly preserved. In this survey, we conduct a comprehensive review of the literature in graph embedding. We first introduce the formal definition of graph embedding as well as the related concepts. After that, we propose two taxonomies of graph embedding which correspond to what challenges exist in different graph embedding problem settings and how the existing work address these challenges in their solutions. Finally, we summarize the applications that graph embedding enables and suggest four promising future research directions in terms of computation efficiency, problem settings, techniques and application scenarios.

在低维空间中节点的学习表示是一项至关重要的任务，在网络分析中具有许多有趣的应用，包括链接预测，节点分类和可视化。解决此问题的两种流行方法是矩阵分解和基于步行的随机模型。在本文中，我们旨在将两全其美的最好的人融合在一起，以学习节点表示。特别是，我们提出了一个加权矩阵分解模型，该模型编码有关网络节点的随机步行信息。这种新颖的表述的好处是，它使我们能够利用内核函数，而无需意识到确切的接近矩阵，从而增强现有矩阵分解方法的表达性，并减轻其计算复杂性。我们通过多个内核学习公式扩展了方法，该公式提供了学习内核作为以数据驱动方式的词典的线性组合的灵活性。我们在现实世界网络上执行经验评估，表明所提出的模型优于基线节点嵌入下游机器学习任务中的算法。

异质图卷积网络在解决异质网络数据的各种网络分析任务方面已广受欢迎，从链接预测到节点分类。但是，大多数现有作品都忽略了多型节点之间的多重网络的关系异质性，而在元路径中，元素嵌入中关系的重要性不同，这几乎无法捕获不同关系跨不同关系的异质结构信号。为了应对这一挑战，这项工作提出了用于异质网络嵌入的多重异质图卷积网络（MHGCN）。我们的MHGCN可以通过多层卷积聚合自动学习多重异质网络中不同长度的有用的异质元路径相互作用。此外，我们有效地将多相关结构信号和属性语义集成到学习的节点嵌入中，并具有无监督和精选的学习范式。在具有各种网络分析任务的五个现实世界数据集上进行的广泛实验表明，根据所有评估指标，MHGCN与最先进的嵌入基线的优势。

This paper studies the problem of embedding very large information networks into low-dimensional vector spaces, which is useful in many tasks such as visualization, node classification, and link prediction. Most existing graph embedding methods do not scale for real world information networks which usually contain millions of nodes. In this paper, we propose a novel network embedding method called the "LINE," which is suitable for arbitrary types of information networks: undirected, directed, and/or weighted. The method optimizes a carefully designed objective function that preserves both the local and global network structures. An edge-sampling algorithm is proposed that addresses the limitation of the classical stochastic gradient descent and improves both the effectiveness and the efficiency of the inference. Empirical experiments prove the effectiveness of the LINE on a variety of real-world information networks, including language networks, social networks, and citation networks. The algorithm is very efficient, which is able to learn the embedding of a network with millions of vertices and billions of edges in a few hours on a typical single machine. The source code of the LINE is available online. 1

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。

Machine learning on graphs is an important and ubiquitous task with applications ranging from drug design to friendship recommendation in social networks. The primary challenge in this domain is finding a way to represent, or encode, graph structure so that it can be easily exploited by machine learning models. Traditionally, machine learning approaches relied on user-defined heuristics to extract features encoding structural information about a graph (e.g., degree statistics or kernel functions). However, recent years have seen a surge in approaches that automatically learn to encode graph structure into low-dimensional embeddings, using techniques based on deep learning and nonlinear dimensionality reduction. Here we provide a conceptual review of key advancements in this area of representation learning on graphs, including matrix factorization-based methods, random-walk based algorithms, and graph neural networks. We review methods to embed individual nodes as well as approaches to embed entire (sub)graphs. In doing so, we develop a unified framework to describe these recent approaches, and we highlight a number of important applications and directions for future work.

网络表示学习（NRL）方法在过去几年中受到了重大关注，因此由于它们在几个图形分析问题中的成功，包括节点分类，链路预测和聚类。这种方法旨在以一种保留网络的结构信息的方式将网络的每个顶点映射到低维空间中。特别感兴趣的是基于随机行走的方法;这些方法将网络转换为节点序列的集合，旨在通过预测序列内每个节点的上下文来学习节点表示。在本文中，我们介绍了一种通用框架，以增强通过基于主题信息的随机行走方法获取的节点的嵌入。类似于自然语言处理中局部单词嵌入的概念，所提出的模型首先将每个节点分配给潜在社区，并有利于各种统计图模型和社区检测方法，然后了解增强的主题感知表示。我们在两个下游任务中评估我们的方法：节点分类和链路预测。实验结果表明，通过纳入节点和社区嵌入，我们能够以广泛的广泛的基线NRL模型表明。

时间图代表实体之间的动态关系，并发生在许多现实生活中的应用中，例如社交网络，电子商务，通信，道路网络，生物系统等。他们需要根据其生成建模和表示学习的研究超出与静态图有关的研究。在这项调查中，我们全面回顾了近期针对处理时间图提出的神经时间依赖图表的学习和生成建模方法。最后，我们确定了现有方法的弱点，并讨论了我们最近发表的论文提格的研究建议[24]。

Prediction tasks over nodes and edges in networks require careful effort in engineering features used by learning algorithms. Recent research in the broader field of representation learning has led to significant progress in automating prediction by learning the features themselves. However, present feature learning approaches are not expressive enough to capture the diversity of connectivity patterns observed in networks.Here we propose node2vec, an algorithmic framework for learning continuous feature representations for nodes in networks. In node2vec, we learn a mapping of nodes to a low-dimensional space of features that maximizes the likelihood of preserving network neighborhoods of nodes. We define a flexible notion of a node's network neighborhood and design a biased random walk procedure, which efficiently explores diverse neighborhoods. Our algorithm generalizes prior work which is based on rigid notions of network neighborhoods, and we argue that the added flexibility in exploring neighborhoods is the key to learning richer representations.We demonstrate the efficacy of node2vec over existing state-ofthe-art techniques on multi-label classification and link prediction in several real-world networks from diverse domains. Taken together, our work represents a new way for efficiently learning stateof-the-art task-independent representations in complex networks.

Network embedding is an important method to learn low-dimensional representations of vertexes in networks, aiming to capture and preserve the network structure. Almost all the existing network embedding methods adopt shallow models. However, since the underlying network structure is complex, shallow models cannot capture the highly non-linear network structure, resulting in sub-optimal network representations. Therefore, how to find a method that is able to effectively capture the highly non-linear network structure and preserve the global and local structure is an open yet important problem. To solve this problem, in this paper we propose a Structural Deep Network Embedding method, namely SDNE. More specifically, we first propose a semi-supervised deep model, which has multiple layers of non-linear functions, thereby being able to capture the highly non-linear network structure. Then we propose to exploit the first-order and second-order proximity jointly to preserve the network structure. The second-order proximity is used by the unsupervised component to capture the global network structure. While the first-order proximity is used as the supervised information in the supervised component to preserve the local network structure. By jointly optimizing them in the semi-supervised deep model, our method can preserve both the local and global network structure and is robust to sparse networks. Empirically, we conduct the experiments on five real-world networks, including a language network, a citation network and three social networks. The results show that compared to the baselines, our method can reconstruct the original network significantly better and achieves substantial gains in three applications, i.e. multi-label classification, link prediction and visualization.

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.

大量的现实数据可以由大规模网络自然表示，该网络需要高效有效的学习算法。同时，标签可能仅适用于某些网络，这要求这些算法能够适应未标记的网络。域自适应哈希学习在许多实际任务中在计算机视觉社区中取得了巨大的成功，因为在检索时间和存储足迹中的成本较低。但是，它尚未应用于多域网络。在这项工作中，我们通过为网络（称为Udah）开发无监督的域自适应哈希学习方法来弥合这一差距。具体而言，我们开发了四个{特定于任务但相关的}组件：（1）通过硬组对比损失进行网络结构保存，（2）无放松的监督哈希，（3）跨域相交的歧视者和（4）语义中心对齐。我们进行了广泛的实验，以评估我们方法对包括链接预测，节点分类和邻居建议在内的一系列任务的有效性和效率。我们的评估结果表明，我们的模型比所有任务上最先进的常规离散嵌入方法的性能更好。

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.

图表学习方法为解决图形所代表的复杂的现实世界问题打开了新的可能性。但是，这些应用程序中使用的许多图包括数百万节点和数十亿个边缘，并且超出了当前方法和软件实现的功能。我们提供葡萄，这是一种用于图形处理和表示学习的软件资源，能够通过使用专业和智能数据结构，算法和快速并行实现来通过大图扩展。与最先进的软件资源相比，葡萄显示出经验空间和时间复杂性的数量级的改善，以及边缘预测和节点标签预测性能的实质和统计学上的显着改善。此外，葡萄提供了来自文献和其他来源的80,000多种图，标准化界面允许直接整合第三方库，61个节点嵌入方法，25个推理模型和3个模块化管道，以允许公平且可重复的方法比较以及用于图形处理和嵌入的库。

通过提取和利用来自异构信息网络（HIN）的高阶信息的提取和利用模拟异质性，近年来一直在吸引巨大的研究关注。这种异构网络嵌入（HNE）方法有效地利用小规模旋流的异质性。然而，在现实世界中，随着新节点和不同类型的链路的连续引入，何种素数量呈指数级增长，使其成为十亿尺度的网络。在这种关链接上的学习节点嵌入式为现有的HNE方法进行了性能瓶颈，这些方法通常是集中的，即完成数据，并且模型都在单机上。为了满足强大的效率和有效性保障的大型HNE任务，我们呈现\纺织{分散嵌入框架的异构信息网络}（Dehin）。在Dehin中，我们生成一个分布式并行管道，它利用超图来注入到HNE任务中的并行化。 Dehin呈现了一种上下文保留的分区机制，可创新地将大HIN作为超图制定，其超高频连接语义相似的节点。我们的框架然后采用分散的策略来通过采用类似的树形管道来有效地分隔帖。然后，每个结果的子网被分配给分布式工作人员，该工作者采用深度信息最大化定理，从其接收的分区本地学习节点嵌入。我们进一步设计了一种新颖的嵌入对准方案，将独立学习的节点嵌入从所有子网嵌入到公共向量空间上的新颖嵌入对准方案，从而允许下游任务等链路预测和节点分类。

图表上的表示学习（也称为图形嵌入）显示了其对一系列机器学习应用程序（例如分类，预测和建议）的重大影响。但是，现有的工作在很大程度上忽略了现代应用程序中图和边缘的属性（或属性）中包含的丰富信息，例如，属性图表示的节点和边缘。迄今为止，大多数现有的图形嵌入方法要么仅关注具有图形拓扑的普通图，要么仅考虑节点上的属性。我们提出了PGE，这是一个图形表示学习框架，该框架将节点和边缘属性都包含到图形嵌入过程中。 PGE使用节点聚类来分配偏差来区分节点的邻居，并利用多个数据驱动的矩阵来汇总基于偏置策略采样的邻居的属性信息。 PGE采用了流行的邻里聚合归纳模型。我们通过显示PGE如何实现更好的嵌入结果的详细分析，并验证PGE的性能，而不是最新的嵌入方法嵌入方法在基准应用程序上的嵌入方法，例如节点分类和对现实世界中的链接预测数据集。

Graph neural networks (GNNs) have received remarkable success in link prediction (GNNLP) tasks. Existing efforts first predefine the subgraph for the whole dataset and then apply GNNs to encode edge representations by leveraging the neighborhood structure induced by the fixed subgraph. The prominence of GNNLP methods significantly relies on the adhoc subgraph. Since node connectivity in real-world graphs is complex, one shared subgraph is limited for all edges. Thus, the choices of subgraphs should be personalized to different edges. However, performing personalized subgraph selection is nontrivial since the potential selection space grows exponentially to the scale of edges. Besides, the inference edges are not available during training in link prediction scenarios, so the selection process needs to be inductive. To bridge the gap, we introduce a Personalized Subgraph Selector (PS2) as a plug-and-play framework to automatically, personally, and inductively identify optimal subgraphs for different edges when performing GNNLP. PS2 is instantiated as a bi-level optimization problem that can be efficiently solved differently. Coupling GNNLP models with PS2, we suggest a brand-new angle towards GNNLP training: by first identifying the optimal subgraphs for edges; and then focusing on training the inference model by using the sampled subgraphs. Comprehensive experiments endorse the effectiveness of our proposed method across various GNNLP backbones (GCN, GraphSage, NGCF, LightGCN, and SEAL) and diverse benchmarks (Planetoid, OGB, and Recommendation datasets). Our code is publicly available at \url{https://github.com/qiaoyu-tan/PS2}