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We make a rigorous study of classical field equations on a 2-dimensional signature changing spacetime using the techniques of operator theory. Boundary conditions at the surface of signature change are determined by forming self-adjoint…

General Relativity and Quantum Cosmology · Physics 2008-11-26 L. J. Alty , C. J. Fewster

We prove strong convergence for a large class of finite element methods for the time-dependent Joule heating problem in three spatial dimensions with mixed boundary conditions on Lipschitz domains. We consider conforming subspaces for the…

Numerical Analysis · Mathematics 2018-01-31 Max Jensen , Axel Målqvist , Anna Persson

This paper introduces a novel computational framework for modeling and analyzing the spatiotemporal shape variability of tree-like 4D structures whose shapes deform and evolve over time. Tree-like 3D objects, such as botanical trees and…

Computational Geometry · Computer Science 2025-09-24 Tahmina Khanam , Hamid Laga , Mohammed Bennamoun , Guanjin Wang , Ferdous Sohel , Farid Boussaid , Guan Wang , Anuj Srivastava

In this article, we addressed the numerical solution of a non-linear evolutionary variational inequality, which is encountered in the investigation of quasi-static contact problems. Our study encompasses both the semi-discrete and…

Numerical Analysis · Mathematics 2024-01-05 Kamana Porwal , Tanvi Wadhawan

The numerical solution of time-dependent radiative transfer problems is challenging, both, due to the high dimension as well as the anisotropic structure of the underlying integro-partial differential equation. In this paper we propose a…

Numerical Analysis · Mathematics 2015-12-04 Herbert Egger , Matthias Schlottbom

We consider a finite element method for elliptic equation with heterogeneous and possibly high-contrast coefficients based on primal hybrid formulation. A space decomposition as in FETI and BDCC allows a sequential computations of the…

Numerical Analysis · Mathematics 2024-04-29 Alexandre L. Madureira , Marcus Sarkis

A continuum evolutionary model for micromagnetics is presented that, beside the standard magnetic balance laws, includes thermo-magnetic coupling. To allow conceptually efficient computer implementation, inspired by relaxation method of…

Analysis of PDEs · Mathematics 2013-02-06 Barbora Benešová , Martin Kružík , Tomáš Roubíček

The dynamic formulation of optimal transport has attracted growing interests in scientific computing and machine learning, and its computation requires to solve a PDE-constrained optimization problem. The classical Eulerian discretization…

Machine Learning · Computer Science 2022-05-17 Wei Wan , Yuejin Zhang , Chenglong Bao , Bin Dong , Zuoqiang Shi

We analyze space-time finite element methods for the numerical solution of distributed parabolic optimal control problems with energy regularization in the Bochner space $L^2(0,T;H^{-1}(\Omega))$. By duality, the related norm can be…

Numerical Analysis · Mathematics 2020-04-22 Ulrich Langer , Olaf Steinbach , Fredi Tröltzsch , Huidong Yang

We address the challenge of dimension reduction in the discrete-time optimal control problem which is solved repeatedly online within the framework of model predictive control. Our study demonstrates that a reduced-order approach, aimed at…

Systems and Control · Electrical Eng. & Systems 2024-04-19 Roland Schurig , Andreas Himmel , Rolf Findeisen

We develop a new optimisation technique that combines multiresolution subdivision surfaces for boundary description with immersed finite elements for the discretisation of the primal and adjoint problems of optimisation. Similar to wavelets…

Numerical Analysis · Mathematics 2016-01-20 Kosala Bandara , Thomas Rüberg , Fehmi Cirak

Recent advancements in image animation have utilized diffusion models to breathe life into static images. However, existing controllable frameworks typically rely on Lagrangian motion guidance, where optical flow is estimated relative to…

Computer Vision and Pattern Recognition · Computer Science 2026-05-13 Thong Nguyen , Khoi M. Le , Cong-Duy Nguyen , Luu Anh Tuan , See-Kiong Ng , Chunyan Miao

Image registration is a fundamental step in medical image analysis. Ideally, the transformation that registers one image to another should be a diffeomorphism that is both invertible and smooth. Traditional methods like geodesic shooting…

Computer Vision and Pattern Recognition · Computer Science 2019-07-02 Dongyang Kuang

We study optimal design problems involving variational inequalities with unilateral conditions in the domain and pointwise boundary observation. We use regularizing and penalization tehniques in the setting of the Hamiltonian approach to…

Optimization and Control · Mathematics 2025-12-30 Cornel Marius Murea , Dan Tiba

Image segmentation is an inherently ill-posed problem and thus requires regularization in order to limit the search space to reasonable solutions. A majority of segmentation methods integrates these regularization terms in one way or the…

Numerical Analysis · Mathematics 2018-10-31 Uri Nahum , Philippe C. Cattin

Deformable image registration is a fundamental task in medical image analysis and plays a crucial role in a wide range of clinical applications. Recently, deep learning-based approaches have been widely studied for deformable medical image…

Image and Video Processing · Electrical Eng. & Systems 2023-07-03 Jing Zou , Noémie Debroux , Lihao Liu , Jing Qin , Carola-Bibiane Schönlieb , Angelica I Aviles-Rivero

The present work aims at the application of finite element discretizations to a class of equilibrium problems involving moving constraints. Therefore, a Moreau--Yosida based regularization technique, controlled by a parameter, is discussed…

Numerical Analysis · Mathematics 2021-10-07 Steven-Marian Stengl

We address the problem to infer physical material parameters and boundary conditions from the observed motion of a homogeneous deformable object via the solution of an inverse problem. Parameters are estimated from potentially unreliable…

Graphics · Computer Science 2022-07-26 Sebastian Weiss , Robert Maier , Rüdiger Westermann , Daniel Cremers , Nils Thuerey

We consider the primal and dual forms of the optimality conditions for PDE-contrained optimization problems arising in Data-Driven Computational Mechanics when specialized to the reaction-diffusion context. Starting with the continuous…

Numerical Analysis · Mathematics 2025-12-24 Ramon Codina , Roberto Federico Ausas , Pedro Balbão Bazon , Cristian Guillermo Gebhardt

This paper presents a finite element method that preserves (at the degrees of freedom) the eigenvalue range of the solution of tensor-valued time-dependent convection--diffusion equations. Starting from a high-order spatial baseline…

Numerical Analysis · Mathematics 2026-01-09 Abdolreza Amiri , Gabriel R. Barrenechea , Tristan Pryer