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arXiv 2202.03580cs.LGcs.AI
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重新审视基于切比雪夫近似的图卷积神经网络

Convolutional Neural Networks on Graphs with Chebyshev Approximation, Revisited

Renmin University of China(中国人民大学)

Mingguo He, Zhewei Wei, Ji-Rong Wen

AI总结:

针对ChebNet等切比雪夫基谱图卷积性能反直觉弱于其他基的问题,研究者指出其性能差源于非法系数导致的过拟合,提出基于切比雪夫插值的ChebNetII模型,在节点分类任务及十亿级ogbn-papers100M数据集上均取得优异表现。

摘要:

设计谱卷积网络是图学习领域的一个挑战性问题。作为早期尝试之一,ChebNet(切比雪夫图卷积网络)使用切比雪夫多项式近似谱图卷积。GCN(图卷积网络)仅利用前两个切比雪夫多项式简化了ChebNet,却仍在真实数据集上表现更优。GPR-GNN和BernNet表明,在学习谱图卷积方面,单项式基和伯恩斯坦基的表现也优于切比雪夫基。这类结论在逼近论领域是反直觉的——该领域已证实切比雪夫多项式在函数逼近中能达到最优收敛速度。\n本文重新探讨了用切比雪夫多项式近似谱图卷积的问题。我们发现,ChebNet性能不佳的主要原因是其在逼近解析滤波器函数时学习到的系数不合法,进而导致过拟合。随后我们提出了ChebNetII,这是一种基于切比雪夫插值的新型GNN(图神经网络)模型,它在减少龙格现象的同时增强了原始切比雪夫多项式近似效果。我们开展了广泛的实验研究,证明ChebNetII能够学习任意图卷积,并且在全监督和半监督节点分类任务中均能取得优异性能。最值得注意的是,我们将ChebNetII扩展到十亿级图数据集ogbn-papers100M上,证明了基于谱方法的GNN具有优越性能。我们的代码可在https://github.com/ivam-he/ChebNetII 获取。

英文摘要:

Designing spectral convolutional networks is a challenging problem in graph learning. ChebNet, one of the early attempts, approximates the spectral graph convolutions using Chebyshev polynomials. GCN simplifies ChebNet by utilizing only the first two Chebyshev polynomials while still outperforming it on real-world datasets. GPR-GNN and BernNet demonstrate that the Monomial and Bernstein bases also outperform the Chebyshev basis in terms of learning the spectral graph convolutions. Such conclusions are counter-intuitive in the field of approximation theory, where it is established that the Chebyshev polynomial achieves the optimum convergent rate for approximating a function. In this paper, we revisit the problem of approximating the spectral graph convolutions with Chebyshev polynomials. We show that ChebNet's inferior performance is primarily due to illegal coefficients learnt by ChebNet approximating analytic filter functions, which leads to over-fitting. We then propose ChebNetII, a new GNN model based on Chebyshev interpolation, which enhances the original Chebyshev polynomial approximation while reducing the Runge phenomenon. We conducted an extensive experimental study to demonstrate that ChebNetII can learn arbitrary graph convolutions and achieve superior performance in both full- and semi-supervised node classification tasks. Most notably, we scale ChebNetII to a billion graph ogbn-papers100M, showing that spectral-based GNNs have superior performance. Our code is available at https://github.com/ivam-he/ChebNetII.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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