Search Results for author: Terrence Alsup

Found 5 papers, 1 papers with code

Multifidelity Covariance Estimation via Regression on the Manifold of Symmetric Positive Definite Matrices

no code implementations23 Jul 2023 Aimee Maurais, Terrence Alsup, Benjamin Peherstorfer, Youssef Marzouk

We introduce a multifidelity estimator of covariance matrices formulated as the solution to a regression problem on the manifold of symmetric positive definite matrices.

Metric Learning regression

Multi-Fidelity Covariance Estimation in the Log-Euclidean Geometry

1 code implementation31 Jan 2023 Aimee Maurais, Terrence Alsup, Benjamin Peherstorfer, Youssef Marzouk

We introduce a multi-fidelity estimator of covariance matrices that employs the log-Euclidean geometry of the symmetric positive-definite manifold.

Metric Learning

Further analysis of multilevel Stein variational gradient descent with an application to the Bayesian inference of glacier ice models

no code implementations6 Dec 2022 Terrence Alsup, Tucker Hartland, Benjamin Peherstorfer, Noemi Petra

Multilevel Stein variational gradient descent is a method for particle-based variational inference that leverages hierarchies of surrogate target distributions with varying costs and fidelity to computationally speed up inference.

Bayesian Inference Variational Inference

Multilevel Stein variational gradient descent with applications to Bayesian inverse problems

no code implementations5 Apr 2021 Terrence Alsup, Luca Venturi, Benjamin Peherstorfer

The proposed multilevel Stein variational gradient descent moves most of the iterations to lower, cheaper levels with the aim of requiring only a few iterations on the higher, more expensive levels when compared to the traditional, single-level Stein variational gradient descent variant that uses the highest-level distribution only.

Context-aware surrogate modeling for balancing approximation and sampling costs in multi-fidelity importance sampling and Bayesian inverse problems

no code implementations22 Oct 2020 Terrence Alsup, Benjamin Peherstorfer

Thus, there is a trade-off between investing computational resources to improve the accuracy of surrogate models versus simply making more frequent recourse to expensive high-fidelity models; however, this trade-off is ignored by traditional modeling methods that construct surrogate models that are meant to replace high-fidelity models rather than being used together with high-fidelity models.

Cannot find the paper you are looking for? You can Submit a new open access paper.