论文标题
在不均匀的几何图中揭示采样密度
Unveiling the Sampling Density in Non-Uniform Geometric Graphs
论文作者
论文摘要
研究图形的一个有力的框架是将它们视为几何图:节点是从基本的度量空间中随机采样的,并且如果它们的距离小于指定的邻域半径,则任何一对节点都可以连接。目前,文献主要集中于均匀的采样和持续的邻域半径。但是,现实图形可能会以一个模型更好地表示,在该模型中,采样密度和邻域半径都可以在潜在空间上变化。例如,在社交网络社区中,可以将其建模为密集采样区域,而枢纽则为邻域半径较大的节点。在这项工作中,我们首先对(更通用)模型类别进行严格的数学分析,包括所得图形移动运算符的推导。关键的见解是,应纠正图形移位算子,以避免不均匀采样引入潜在的扭曲。然后,我们开发了以自我监督的方式估算未知采样密度的方法。最后,我们提出了模范应用程序,其中学习的密度用于1)纠正图形移动操作员并改善各种任务的性能,2)改进汇总,3)从网络中提取知识。我们的实验发现支持我们的理论,并为我们的模型提供了有力的证据。
A powerful framework for studying graphs is to consider them as geometric graphs: nodes are randomly sampled from an underlying metric space, and any pair of nodes is connected if their distance is less than a specified neighborhood radius. Currently, the literature mostly focuses on uniform sampling and constant neighborhood radius. However, real-world graphs are likely to be better represented by a model in which the sampling density and the neighborhood radius can both vary over the latent space. For instance, in a social network communities can be modeled as densely sampled areas, and hubs as nodes with larger neighborhood radius. In this work, we first perform a rigorous mathematical analysis of this (more general) class of models, including derivations of the resulting graph shift operators. The key insight is that graph shift operators should be corrected in order to avoid potential distortions introduced by the non-uniform sampling. Then, we develop methods to estimate the unknown sampling density in a self-supervised fashion. Finally, we present exemplary applications in which the learnt density is used to 1) correct the graph shift operator and improve performance on a variety of tasks, 2) improve pooling, and 3) extract knowledge from networks. Our experimental findings support our theory and provide strong evidence for our model.