它是由Thom和Palm所说的,稀疏连接的神经网络(SCNS)显示出完全连接的网络(FCN)的改进性能。超常规网络(SRNS)是由一组堆叠稀疏层组成的神经网络(epsilon,delta) - 常规对和随机置换的节点顺序组成。使用爆破引理,我们证明,由于每对层的各个超规律性,SRNS保证了许多属性,使它们为许多任务提供适用于FCN的替代品。这些保证包括所有大足够大的子集,最小节点内和OUT度,输入 - 输出灵敏度以及嵌入预培训构造的能力的边缘均匀性。实际上,SRNS具有像FCN一样行动的能力,并消除对耗时的昂贵正则化方案的需求。我们表明SRNS通过易于可重复的实验表现出与X-NET相似,并提供更大的保证和对网络结构的控制。
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消息传递神经网络(MPNNS)是由于其简单性和可扩展性而大部分地进行图形结构数据的深度学习的领先架构。不幸的是,有人认为这些架构的表现力有限。本文提出了一种名为Comifariant Subgraph聚合网络(ESAN)的新颖框架来解决这个问题。我们的主要观察是,虽然两个图可能无法通过MPNN可区分,但它们通常包含可区分的子图。因此,我们建议将每个图形作为由某些预定义策略导出的一组子图,并使用合适的等分性架构来处理它。我们为图同构同构同构造的1立维Weisfeiler-Leman(1-WL)测试的新型变体,并在这些新的WL变体方面证明了ESAN的表达性下限。我们进一步证明,我们的方法增加了MPNNS和更具表现力的架构的表现力。此外,我们提供了理论结果,描述了设计选择诸如子图选择政策和等效性神经结构的设计方式如何影响我们的架构的表现力。要处理增加的计算成本,我们提出了一种子图采样方案,可以将其视为我们框架的随机版本。关于真实和合成数据集的一套全面的实验表明,我们的框架提高了流行的GNN架构的表现力和整体性能。
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Graph clustering is a fundamental problem in unsupervised learning, with numerous applications in computer science and in analysing real-world data. In many real-world applications, we find that the clusters have a significant high-level structure. This is often overlooked in the design and analysis of graph clustering algorithms which make strong simplifying assumptions about the structure of the graph. This thesis addresses the natural question of whether the structure of clusters can be learned efficiently and describes four new algorithmic results for learning such structure in graphs and hypergraphs. All of the presented theoretical results are extensively evaluated on both synthetic and real-word datasets of different domains, including image classification and segmentation, migration networks, co-authorship networks, and natural language processing. These experimental results demonstrate that the newly developed algorithms are practical, effective, and immediately applicable for learning the structure of clusters in real-world data.
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在处理大规模网络和关系数据时,降低图是基本的。它们可以通过在粗糙的结构中求解它们来缩小高度计算影响的尺寸。同时,图减少起着在图神经网络中合并层的作用,从结构中提取多分辨率表示。在这些情况下,还原机制保留距离关系和拓扑特性的能力似乎是基本的,以及可扩展性,使其能够应用于实际大小的问题。在本文中,我们基于最大重量$ k $独立的集合的图理论概念引入了图形粗化机制,从而提供了一种贪婪的算法,该算法允许在GPU上有效地并行实现。我们的方法是常规数据(图像,序列)中的第一个图形结构化对应物。我们证明了在路径长度上的失真界限的理论保证,以及在污垢图中保留关键拓扑特性的能力。我们利用这些概念来定义我们在图形分类任务中经验评估的图表合并机制,表明它与文献中的合并方法进行了比较。
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图形上的分层聚类是数据挖掘和机器学习中的一项基本任务,并在系统发育学,社交网络分析和信息检索等领域中进行了应用。具体而言,我们考虑了由于Dasgupta引起的层次聚类的最近普及的目标函数。以前(大约)最小化此目标函数的算法需要线性时间/空间复杂性。在许多应用程序中,底层图的大小可能很大,即使使用线性时间/空间算法,也可以在计算上具有挑战性。结果,人们对设计只能使用sublinear资源执行全局计算的算法有浓厚的兴趣。这项工作的重点是在三个经过良好的sublinear计算模型下研究大量图的层次聚类,分别侧重于时空,时间和通信,作为要优化的主要资源:(1)(动态)流模型。边缘作为流,(2)查询模型表示,其中使用邻居和度查询查询图形,(3)MPC模型,其中图边缘通过通信通道连接的几台机器进行了分区。我们在上面的所有三个模型中设计用于层次聚类的sublinear算法。我们算法结果的核心是图表中的剪切方面的视图,这使我们能够使用宽松的剪刀示意图进行分层聚类,同时仅引入目标函数中的较小失真。然后,我们的主要算法贡献是如何在查询模型和MPC模型中有效地构建所需形式的切割稀疏器。我们通过建立几乎匹配的下限来补充我们的算法结果,该界限排除了在每个模型中设计更好的算法的可能性。
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$ N $ -Quens配置是$ N \ Times N $ Chessboard的$ N $相互非攻击座位的位置。Nauck在1850年介绍的$ N $ -Queens完井问题是决定是否可以将给定的部分配置完成为$ N $ -Queens配置。在本文中,我们研究了这个问题的极端方面,即:部分配置必须小心,以便完成完成?我们表明,可以完成任何最多$ N / 60 $相互非攻击Queens的展示。我们还提供了大约N / 4 $ Queens的部分配置,不能完成,并制定一些有趣的问题。我们的证据将Queens问题与二角形图中的彩虹匹配连接,并使用概率参数以及线性编程二元性。
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This article explores and analyzes the unsupervised clustering of large partially observed graphs. We propose a scalable and provable randomized framework for clustering graphs generated from the stochastic block model. The clustering is first applied to a sub-matrix of the graph's adjacency matrix associated with a reduced graph sketch constructed using random sampling. Then, the clusters of the full graph are inferred based on the clusters extracted from the sketch using a correlation-based retrieval step. Uniform random node sampling is shown to improve the computational complexity over clustering of the full graph when the cluster sizes are balanced. A new random degree-based node sampling algorithm is presented which significantly improves upon the performance of the clustering algorithm even when clusters are unbalanced. This framework improves the phase transitions for matrix-decomposition-based clustering with regard to computational complexity and minimum cluster size, which are shown to be nearly dimension-free in the low inter-cluster connectivity regime. A third sampling technique is shown to improve balance by randomly sampling nodes based on spatial distribution. We provide analysis and numerical results using a convex clustering algorithm based on matrix completion.
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近年来,基于Weisfeiler-Leman算法的算法和神经架构,是一个众所周知的Graph同构问题的启发式问题,它成为具有图形和关系数据的机器学习的强大工具。在这里,我们全面概述了机器学习设置中的算法的使用,专注于监督的制度。我们讨论了理论背景,展示了如何将其用于监督的图形和节点表示学习,讨论最近的扩展,并概述算法的连接(置换 - )方面的神经结构。此外,我们概述了当前的应用和未来方向,以刺激进一步的研究。
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近年来,在平衡(超级)图分配算法的设计和评估中取得了重大进展。我们调查了过去十年的实用算法的趋势,用于平衡(超级)图形分区以及未来的研究方向。我们的工作是对先前有关该主题的调查的更新。特别是,该调查还通过涵盖了超图形分区和流算法来扩展先前的调查,并额外关注并行算法。
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我们考虑了从节点观测值估算多个网络拓扑的问题,其中假定这些网络是从相同(未知)随机图模型中绘制的。我们采用图形作为我们的随机图模型,这是一个非参数模型,可以从中绘制出潜在不同大小的图形。图形子的多功能性使我们能够解决关节推理问题,即使对于要恢复的图形包含不同数量的节点并且缺乏整个图形的精确比对的情况。我们的解决方案是基于将最大似然惩罚与Graphon估计方案结合在一起,可用于增强现有网络推理方法。通过引入嘈杂图抽样信息的强大方法,进一步增强了所提出的联合网络和图形估计。我们通过将其性能与合成和实际数据集中的竞争方法进行比较来验证我们提出的方法。
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在过去十年中,图形内核引起了很多关注,并在结构化数据上发展成为一种快速发展的学习分支。在过去的20年中,该领域发生的相当大的研究活动导致开发数十个图形内核,每个图形内核都对焦于图形的特定结构性质。图形内核已成功地成功地在广泛的域中,从社交网络到生物信息学。本调查的目标是提供图形内核的文献的统一视图。特别是,我们概述了各种图形内核。此外,我们对公共数据集的几个内核进行了实验评估,并提供了比较研究。最后,我们讨论图形内核的关键应用,并概述了一些仍有待解决的挑战。
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In the past few years, neural architecture search (NAS) has become an increasingly important tool within the deep learning community. Despite the many recent successes of NAS, however, most existing approaches operate within highly structured design spaces, and hence explore only a small fraction of the full search space of neural architectures while also requiring significant manual effort from domain experts. In this work, we develop techniques that enable efficient NAS in a significantly larger design space. To accomplish this, we propose to perform NAS in an abstract search space of program properties. Our key insights are as follows: (1) the abstract search space is significantly smaller than the original search space, and (2) architectures with similar program properties also have similar performance; thus, we can search more efficiently in the abstract search space. To enable this approach, we also propose a novel efficient synthesis procedure, which accepts a set of promising program properties, and returns a satisfying neural architecture. We implement our approach, $\alpha$NAS, within an evolutionary framework, where the mutations are guided by the program properties. Starting with a ResNet-34 model, $\alpha$NAS produces a model with slightly improved accuracy on CIFAR-10 but 96% fewer parameters. On ImageNet, $\alpha$NAS is able to improve over Vision Transformer (30% fewer FLOPS and parameters), ResNet-50 (23% fewer FLOPS, 14% fewer parameters), and EfficientNet (7% fewer FLOPS and parameters) without any degradation in accuracy.
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分层聚类研究将数据集的递归分区设置为连续较小尺寸的簇,并且是数据分析中的基本问题。在这项工作中,我们研究了Dasgupta引入的分层聚类的成本函数,并呈现了两个多项式时间近似算法:我们的第一个结果是高度电导率图的$ O(1)$ - 近似算法。我们简单的建筑绕过了在文献中已知的稀疏切割的复杂递归常规。我们的第二个和主要结果是一个US(1)$ - 用于展示群集明确结构的宽族图形的近似算法。该结果推出了以前的最先进的,该现有技术仅适用于从随机模型产生的图表。通过对合成和现实世界数据集的实证分析,我们所呈现的算法的实证分析表明了我们的工作的重要性,以其具有明确定义的集群结构的先前所提出的图表算法。
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已经提出了多种寻找属于种植的致密子图的顶点的方法,以随机致密的$ G(n,p)$图表,重点是种植的派系。这些方法可以识别多项式时间中的种植的子图,但全部限于几个子图结构。这里,我们呈现Pygon,这是一种基于图的神经网络的算法,这对种植子图的结构不敏感。这是第一个使用高级学习工具来恢复密集子图的算法。我们表明Pygon可以恢复尺寸$ \ theta \ left的派系(\ sqrt {n}右)$,其中$ n $是背景图的大小,与现有技术相当。我们还表明,相同的算法可以在指向和无向图形中恢复左转(\ sqrt {n \右)$的尺寸尺寸的其他种植的子图。我们建议一个猜想,没有多项式时间PAC学习算法可以检测尺寸小于$ o \ lex的种植的密集子图(\ sqrt {n}右)$,即使原则上也可以找到对数尺寸的密集子图。
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Deploying graph neural networks (GNNs) on whole-graph classification or regression tasks is known to be challenging: it often requires computing node features that are mindful of both local interactions in their neighbourhood and the global context of the graph structure. GNN architectures that navigate this space need to avoid pathological behaviours, such as bottlenecks and oversquashing, while ideally having linear time and space complexity requirements. In this work, we propose an elegant approach based on propagating information over expander graphs. We leverage an efficient method for constructing expander graphs of a given size, and use this insight to propose the EGP model. We show that EGP is able to address all of the above concerns, while requiring minimal effort to set up, and provide evidence of its empirical utility on relevant graph classification datasets and baselines in the Open Graph Benchmark. Importantly, using expander graphs as a template for message passing necessarily gives rise to negative curvature. While this appears to be counterintuitive in light of recent related work on oversquashing, we theoretically demonstrate that negatively curved edges are likely to be required to obtain scalable message passing without bottlenecks. To the best of our knowledge, this is a previously unstudied result in the context of graph representation learning, and we believe our analysis paves the way to a novel class of scalable methods to counter oversquashing in GNNs.
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Kernel matrices, as well as weighted graphs represented by them, are ubiquitous objects in machine learning, statistics and other related fields. The main drawback of using kernel methods (learning and inference using kernel matrices) is efficiency -- given $n$ input points, most kernel-based algorithms need to materialize the full $n \times n$ kernel matrix before performing any subsequent computation, thus incurring $\Omega(n^2)$ runtime. Breaking this quadratic barrier for various problems has therefore, been a subject of extensive research efforts. We break the quadratic barrier and obtain $\textit{subquadratic}$ time algorithms for several fundamental linear-algebraic and graph processing primitives, including approximating the top eigenvalue and eigenvector, spectral sparsification, solving linear systems, local clustering, low-rank approximation, arboricity estimation and counting weighted triangles. We build on the recent Kernel Density Estimation framework, which (after preprocessing in time subquadratic in $n$) can return estimates of row/column sums of the kernel matrix. In particular, we develop efficient reductions from $\textit{weighted vertex}$ and $\textit{weighted edge sampling}$ on kernel graphs, $\textit{simulating random walks}$ on kernel graphs, and $\textit{importance sampling}$ on matrices to Kernel Density Estimation and show that we can generate samples from these distributions in $\textit{sublinear}$ (in the support of the distribution) time. Our reductions are the central ingredient in each of our applications and we believe they may be of independent interest. We empirically demonstrate the efficacy of our algorithms on low-rank approximation (LRA) and spectral sparsification, where we observe a $\textbf{9x}$ decrease in the number of kernel evaluations over baselines for LRA and a $\textbf{41x}$ reduction in the graph size for spectral sparsification.
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现代的神经网络是著名的,但也高度多余和可压缩。在深度学习文献中存在许多修剪策略,这些策略产生了超过90%的稀疏子网,这些子网已全面训练,密集的体系结构,同时仍保持其原始精度。不过,在这些方法中,由于其概念上的简单性,易于实施和功效 - 迭代幅度修剪(IMP)在实践中占主导地位,并且实际上是在修剪社区中击败的基线。但是,关于为什么像IMP这样的简单方法完全有限的理论解释是很少且有限的。在这项工作中,我们利用持续的同源性的概念来了解IMP的运作,并表明它本质地鼓励保留那些保留受过训练的网络中拓扑信息的权重。随后,我们还提供有关在完美保留其零订单拓扑特征的同时可以修剪多少不同网络的界限,并为IMP的修改版本提供了相同的操作。
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我们根据计算一个扎根于每个顶点的某个加权树的家族而构成的相似性得分提出了一种有效的图形匹配算法。对于两个erd \ h {o} s-r \'enyi图$ \ mathcal {g}(n,q)$,其边缘通过潜在顶点通信相关联,我们表明该算法正确地匹配了所有范围的范围,除了所有的vertices分数外,有了很高的概率,前提是$ nq \ to \ infty $,而边缘相关系数$ \ rho $满足$ \ rho^2> \ alpha \ ailpha \大约0.338 $,其中$ \ alpha $是Otter的树木计数常数。此外,在理论上是必需的额外条件下,可以精确地匹配。这是第一个以显式常数相关性成功的多项式图匹配算法,并适用于稀疏和密集图。相比之下,以前的方法要么需要$ \ rho = 1-o(1)$,要么仅限于稀疏图。该算法的症结是一个经过精心策划的植根树的家族,称为吊灯,它可以有效地从同一树的计数中提取图形相关性,同时抑制不同树木之间的不良相关性。
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Low-dimensional embeddings of nodes in large graphs have proved extremely useful in a variety of prediction tasks, from content recommendation to identifying protein functions. However, most existing approaches require that all nodes in the graph are present during training of the embeddings; these previous approaches are inherently transductive and do not naturally generalize to unseen nodes. Here we present GraphSAGE, a general inductive framework that leverages node feature information (e.g., text attributes) to efficiently generate node embeddings for previously unseen data. Instead of training individual embeddings for each node, we learn a function that generates embeddings by sampling and aggregating features from a node's local neighborhood. Our algorithm outperforms strong baselines on three inductive node-classification benchmarks: we classify the category of unseen nodes in evolving information graphs based on citation and Reddit post data, and we show that our algorithm generalizes to completely unseen graphs using a multi-graph dataset of protein-protein interactions. * The two first authors made equal contributions. 1 While it is common to refer to these data structures as social or biological networks, we use the term graph to avoid ambiguity with neural network terminology.
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我们提供了通过线性激活的多渠道卷积神经网络中的$ \ ell_2 $标准来最大程度地减少$ \ ell_2 $标准而产生的功能空间表征,并经验测试了我们对使用梯度下降训练的Relu网络的假设。我们将功能空间中的诱导正规化程序定义为实现函数所需的网络权重规范的最小$ \ ell_2 $。对于具有$ C $输出频道和内核尺寸$ K $的两个层线性卷积网络,我们显示以下内容:(a)如果网络的输入是单个渠道,则任何$ k $的诱导正规器都与数字无关输出频道$ c $。此外,我们得出正常化程序是由半决赛程序(SDP)给出的规范。 (b)相比之下,对于多通道输入,仅实现所有矩阵值值线性函数而需要多个输出通道,因此归纳偏置确实取决于$ c $。但是,对于足够大的$ c $,诱导的正规化程序再次由独立于$ c $的SDP给出。特别是,$ k = 1 $和$ k = d $(输入维度)的诱导正规器以封闭形式作为核标准和$ \ ell_ {2,1} $ group-sparse Norm,线性预测指标的傅立叶系数。我们通过对MNIST和CIFAR-10数据集的实验来研究理论结果对从线性和RELU网络上梯度下降的隐式正则化的更广泛的适用性。
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