We propose a new graph kernel for graph classification and comparison using Ollivier Ricci curvature. The Ricci curvature of an edge in a graph describes the connectivity in the local neighborhood. An edge in a densely connected neighborhood has positive curvature and an edge serving as a local bridge has negative curvature. We use the edge curvature distribution to form a graph kernel which is then used to compare and cluster graphs. The curvature kernel uses purely the graph topology and thereby works for settings when node attributes are not available.
Fast and Scalable Score-Based Kernel Calibration Tests
Gatsby Computational Neuroscience Unit（加布特计算神经科学单位）；University College London（伦敦大学学院）；Department of Information Technology（信息技术系）；Uppsala University（乌普萨拉大学）；Division of Statistics and Machine Learning（统计与机器学习 division）；Linköping University（林雪平大学）
Yale University（耶鲁大学）；Criteo AI Lab（Criteo人工智能实验室）；Google Research（谷歌研究院）；Facebook AI Research（脸书人工智能研究院）
A determinantal point process (DPP) on a collection of $M$ items is a model, parameterized by a symmetric kernel matrix, that assigns a probability to every subset of those items. Recent work shows that removing the kernel symmetry constraint, yielding nonsymmetric DPPs (NDPPs), can lead to significant predictive performance gains for machine learning applications. However, existing work leaves open the question of scalable NDPP sampling. There is only one known DPP sampling algorithm, based on Cholesky decomposition, that can directly apply to NDPPs as well. Unfortunately, its runtime is cubi…
We propose efficient random features for approximating a new and rich class of kernel functions that we refer to as Generalized Zonal Kernels (GZK). Our proposed GZK family, generalizes the zonal kernels (i.e., dot-product kernels on the unit sphere) by introducing radial factors in their Gegenbauer series expansion, and includes a wide range of ubiquitous kernel functions such as the entirety of dot-product kernels as well as the Gaussian and the recently introduced Neural Tangent kernels. Interestingly, by exploiting the reproducing property of the Gegenbauer polynomials, we can construct ef…
Scalable Kernel K-Means Clustering with Nystrom Approximation: Relative-Error Bounds
Stevens Institute of Technology（斯蒂文斯理工学院）；Rensselaer Polytechnic Institute（伦斯勒理工学院）；International Computer Science Institute（国际计算机科学研究所）；University of California at Berkeley（加州大学伯克利分校）
We develop an exact and scalable algorithm for one-dimensional Gaussian process regression with Matérn correlations whose smoothness parameter $ν$ is a half-integer. The proposed algorithm only requires $\mathcal{O}(ν^3 n)$ operations and $\mathcal{O}(νn)$ storage. This leads to a linear-cost solver since $ν$ is chosen to be fixed and usually very small in most applications. The proposed method can be applied to multi-dimensional problems if a full grid or a sparse grid design is used. The proposed method is based on a novel theory for Matérn correlation functions. We find that a suitable rear…
Scalable Linearized Laplace Approximation via Surrogate Neural Kernel
Machine Learning Group - Computer Science Department Escuela Politécnica Superior（计算机科学系机器学习小组）；Computer Science Department Escuela Politécnica Superior（计算机科学系）；Universidad Autónoma de Madrid（马德里自治大学）；Universidad Pontificia de Comillas（天主教comillas大学）；Aalborg University Copenhagen（哥本哈根奥胡斯大学）；Centro de Investigación Avanzada en Física Fundamental Universidad Autónoma de Madrid（马德里自治大学先进物理基础研究中心）
From Local Interactions to Global Operators: Scalable Gaussian Process Operator for Physical Systems
Department of Applied Mechanics（应用力学系）；Indian Institute of Technology Delhi（德里印度理工学院）；Yardi School of Artificial Intelligence (ScAI)（Yardi人工智能学院）；The Grainger College of Engineering University of Illinois Urbana-Champaign（伊利诺伊大学厄巴纳-香槟分校格里纳尔工程学院）
Yale University（耶鲁大学）；Criteo AI Lab（Criteo人工智能实验室）；Facebook AI Lab（Facebook人工智能实验室）
A determinantal point process (DPP) is an elegant model that assigns a probability to every subset of a collection of $n$ items. While conventionally a DPP is parameterized by a symmetric kernel matrix, removing this symmetry constraint, resulting in nonsymmetric DPPs (NDPPs), leads to significant improvements in modeling power and predictive performance. Recent work has studied an approximate Markov chain Monte Carlo (MCMC) sampling algorithm for NDPPs restricted to size-$k$ subsets (called $k$-NDPPs). However, the runtime of this approach is quadratic in $n$, making it infeasible for large-s…
Variable selection in Gaussian processes (GPs) is typically undertaken by thresholding the inverse lengthscales of automatic relevance determination kernels, but in high-dimensional datasets this approach can be unreliable. A more probabilistically principled alternative is to use spike and slab priors and infer a posterior probability of variable inclusion. However, existing implementations in GPs are very costly to run in both high-dimensional and large-$n$ datasets, or are only suitable for unsupervised settings with specific kernels. As such, we develop a fast and scalable variational infe…
University of Waterloo（滑铁卢大学）；Vector Institute for AI（Vector人工智能研究院）；Noah’s Ark Lab, Huawei Technologies（华为技术诺亚方舟实验室）
In typical scenarios where the Federated Learning (FL) framework applies, it is common for clients to have insufficient training data to produce an accurate model. Thus, models that provide not only point estimations, but also some notion of confidence are beneficial. Gaussian Process (GP) is a powerful Bayesian model that comes with naturally well-calibrated variance estimations. However, it is challenging to learn a stand-alone global GP since merging local kernels leads to privacy leakage. To preserve privacy, previous works that consider federated GPs avoid learning a global model by focus…
