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Balanced truncation is a well-established model order reduction method which has been applied to a variety of problems. Recently, a connection between linear Gaussian Bayesian inference problems and the system-theoretic concept of balanced…

Numerical Analysis · Mathematics 2024-01-04 Josie König , Melina A. Freitag

Vector autoregressive (VAR) models are widely used for causal discovery and forecasting in multivariate time series analysis. In the high-dimensional setting, which is increasingly common in fields such as neuroscience and econometrics,…

We consider reduced-rank modeling of the white noise covariance matrix in a large dimensional vector autoregressive (VAR) model. We first propose the reduced-rank covariance estimator under the setting where independent observations are…

Applications · Statistics 2014-12-09 Richard A. Davis , Pengfei Zang , Tian Zheng

We investigate an optimization problem governed by an elliptic partial differential equation with uncertain parameters. We introduce a robust optimization framework that accounts for uncertain model parameters. The resulting non-linear…

Optimization and Control · Mathematics 2019-09-24 Alessandro Alla , Michael Hinze , Philip Kolvenbach , Oliver Lass , Stefan Ulbrich

Dimension reduction is often needed in the area of data mining. The goal of these methods is to map the given high-dimensional data into a low-dimensional space preserving certain properties of the initial data. There are two kinds of…

Numerical Analysis · Mathematics 2015-03-23 Yanlai Chen

In this paper we present a reduced basis method which yields structure-preservation and a tight a posteriori error bound for the simulation of the damped wave equations on networks. The error bound is based on the exponential decay of the…

Numerical Analysis · Mathematics 2022-04-12 Nadine Stahl , Björn Liljegren-Sailer , Nicole Marheineke

The tuning parameter selection strategy for penalized estimation is crucial to identify a model that is both interpretable and predictive. However, popular strategies (e.g., minimizing average squared prediction error via cross-validation)…

Methodology · Statistics 2022-11-10 Julia Holter , Jonathan Stallrich

Parametric model order reduction by matrix interpolation allows for efficient prediction of the behavior of dynamic systems without requiring knowledge about the underlying parametric dependency. Within this approach, reduced models are…

Dynamical Systems · Mathematics 2025-06-03 Sebastian Resch-Schopper , Romain Rumpler , Gerhard Müller

In this paper a novel numerical approximation of parametric eigenvalue problems is presented. We motivate our study with the analysis of a POD reduced order model for a simple one dimensional example. In particular, we introduce a new…

Domain shift remains a key challenge in deploying machine learning models to the real world. Unsupervised domain adaptation (UDA) aims to address this by minimising domain discrepancy during training, but the discrepancy estimates suffer…

Machine Learning · Computer Science 2026-05-07 Andrea Napoli , Paul White

Bayesian inference for high-dimensional inverse problems is computationally costly and requires selecting a suitable prior distribution. Amortized variational inference addresses these challenges via a neural network that approximates the…

Machine Learning · Statistics 2023-01-19 Ali Siahkoohi , Gabrio Rizzuti , Rafael Orozco , Felix J. Herrmann

Variational data assimilation optimizes for an initial state of a dynamical system such that its evolution fits observational data. The physical model can subsequently be evolved into the future to make predictions. This principle is a…

Machine Learning · Computer Science 2021-05-21 Thomas Frerix , Dmitrii Kochkov , Jamie A. Smith , Daniel Cremers , Michael P. Brenner , Stephan Hoyer

Many applications including object reconstruction, robot guidance, and scene mapping require the registration of multiple views from a scene to generate a complete geometric and appearance model of it. In real situations, transformations…

Computer Vision and Pattern Recognition · Computer Science 2017-08-07 Marcelo Saval-Calvo , Jorge Azorin-Lopez , Andres Fuster-Guillo , Higinio Mora-Mora

In this work, our aim is to reconstruct the unknown initial value from terminal data. We develop a numerical framework on nonuniform time grids for fractional wave equations under the lower regularity assumptions. Then, we introduce a…

Numerical Analysis · Mathematics 2025-06-25 Dakang Cen , Zhiyuan Li , Wenlong Zhang

We present a comprehensive study of radial basis function (RBF) approximations for elliptic and obstacle-type boundary value problems under a variational formulation. Our focus is on practical accuracy, robustness and efficiency. To address…

Numerical Analysis · Mathematics 2026-04-23 Tan Phuong Dong Le , Giang Tran , Hans De Sterck

Four-dimensional weak-constraint variational data assimilation estimates a state given partial noisy observations and dynamical model by minimizing a cost function that takes into account both discrepancy between the state and observations…

Dynamical Systems · Mathematics 2023-04-13 Nazanin Abedini , Svetlana Dubinkina

This paper is a contribution in the context of variational data assimilation combined with statistical learning. The framework of data assimilation traditionally uses data collected at sensor locations in order to bring corrections to a…

Numerical Analysis · Mathematics 2023-05-09 Amina Benaceur , Barbara Verfürth

Partial-label learning is a popular weakly supervised learning setting that allows each training example to be annotated with a set of candidate labels. Previous studies on partial-label learning only focused on the classification setting…

Machine Learning · Computer Science 2023-06-16 Xin Cheng , Deng-Bao Wang , Lei Feng , Min-Ling Zhang , Bo An

Physics-governed models are increasingly paired with machine learning for accelerated predictions, yet most "physics--informed" formulations treat the governing equations as a penalty loss whose scale and meaning are set by heuristic…

Numerical Analysis · Mathematics 2026-04-14 Yuhe Wang , Min Wang

This paper is concerned with the recovery of (approximate) solutions to parabolic problems from incomplete and possibly inconsistent observational data, given on a time-space cylinder that is a strict subset of the computational domain…

Numerical Analysis · Mathematics 2021-07-13 Wolfgang Dahmen , Rob Stevenson , Jan Westerdiep