English
Related papers

Related papers: A Novel Discrete Adjoint-based Level Set Topology …

200 papers

We propose a novel method, the adaptive local window, for improving level set segmentation technique. The window is estimated separately for each contour point, over iterations of the segmentation process, and for each individual object.…

Computer Vision and Pattern Recognition · Computer Science 2016-06-14 Assaf Hoogi , Christopher F. Beaulieu , Guilherme M. Cunha , Elhamy Heba , Claude B. Sirlin , Sandy Napel , Daniel L. Rubin

In this paper a class of higher order finite element methods for the discretization of surface Stokes equations is studied. These methods are based on an unfitted finite element approach in which standard Taylor-Hood spaces on an underlying…

Numerical Analysis · Mathematics 2019-09-19 Thomas Jankuhn , Arnold Reusken

This work presents an optimization framework for tailoring the nonlinear dynamic response of lightly damped mechanical systems using Spectral Submanifold (SSM) reduction. We derive the SSM-based backbone curve and its sensitivity with…

Optimization and Control · Mathematics 2025-12-23 Matteo Pozzi , Jacopo Marconi , Shobhit Jain , Mingwu Li , Francesco Braghin

We present an approach for forming sensitivity maps (or sensitivites) using ensembles. The method is an alternative to using an adjoint, which can be very challenging to formulate and also computationally expensive to solve. The main…

Computational Engineering, Finance, and Science · Computer Science 2018-09-21 C. E. Heaney , P. Salinas , F. Fang , C. C. Pain , I. M. Navon

Many applications in machine learning or signal processing involve nonsmooth optimization problems. This nonsmoothness brings a low-dimensional structure to the optimal solutions. In this paper, we propose a randomized proximal gradient…

Optimization and Control · Mathematics 2020-04-29 Dmitry Grishchenko , Franck Iutzeler , Jérôme Malick

A continuous system of moment equations is introduced that models the transverse dynamics of a beam of charged particles as it passes through an arbitrary lattice of quadrupoles and solenoids in the presence of self-fields. Then, figures of…

Accelerator Physics · Physics 2022-04-20 L. Dovlatyan , B. L. Beaudoin , S. Bernal , I. Haber , D. Sutter , T. M. Antonsen

Level set methods are widely used for image segmentation because of their capability to handle topological changes. In this paper, we propose a novel parametric level set method called Disjunctive Normal Level Set (DNLS), and apply it to…

Computer Vision and Pattern Recognition · Computer Science 2016-06-27 Fitsum Mesadi , Mujdat Cetin , Tolga Tasdizen

We present an adjoint-based optimization method to invert for stress and frictional parameters used in earthquake modeling. The forward problem is linear elastodynamics with nonlinear rate-and-state frictional faults. The misfit functional…

Numerical Analysis · Mathematics 2024-09-10 Vidar Stiernström , Martin Almquist , Eric M. Dunham

Estimation of the level set of a function (i.e., regions where the function exceeds some value) is an important problem with applications in digital elevation mapping, medical imaging, astronomy, etc. In many applications, the function of…

Applications · Statistics 2018-03-06 Kalyani Krishnamurthy , Waheed U. Bajwa , Rebecca Willett

The present work illustrates a difficulty with the level-set method to accurately capture the curvature of interfaces in regions that are of equal distance to two or more interfaces. Such regions are characterized by kinks in the level-set…

Fluid Dynamics · Physics 2014-09-24 Karl Yngve Lervåg , Åsmund Ervik

We present a distributed conjugate gradient method for distributed optimization problems, where each agent computes an optimal solution of the problem locally without any central computation or coordination, while communicating with its…

Optimization and Control · Mathematics 2024-02-27 Ola Shorinwa , Mac Schwager

In this paper, we propose an efficient and flexible algorithm to solve dynamic mean-field planning problems based on an accelerated proximal gradient method. Besides an easy-to-implement gradient descent step in this algorithm, a crucial…

Optimization and Control · Mathematics 2021-03-01 Jiajia Yu , Rongjie Lai , Wuchen Li , Stanley Osher

In this paper, we consider gradient-type methods for convex positively homogeneous optimization problems with relative accuracy. An analogue of the accelerated universal gradient-type method for positively homogeneous optimization problems…

Optimization and Control · Mathematics 2021-12-14 Fedor S. Stonyakin , Seydamet S. Ablaev , Inna V. Baran

This paper proposes a topology optimization method for non-thermal and thermal fluid problems using the Lattice Kinetic Scheme (LKS).LKS, which is derived from the Lattice Boltzmann Method (LBM), requires only macroscopic values, such as…

Numerical Analysis · Mathematics 2024-11-06 Yuta Tanabe , Kentaro Yaji , Kuniharu Ushijima

Many large-scale constrained optimization problems can be formulated as bilevel distributed optimization tasks over undirected networks, where agents collaborate to minimize a global cost function while adhering to constraints, relying only…

Optimization and Control · Mathematics 2025-11-25 Ajay Tak , Mayank Baranwal

This work aims to estimate time-resolved velocity field that is directly associated with pressure fluctuations in a subsonic round jet. To achieve this goal, synchronous measurements of the velocity field and in-flow pressure fluctuations…

Fluid Dynamics · Physics 2021-06-15 Songqi Li , Lawrence Ukeiley

We consider geometric multigrid methods for the solution of linear systems arising from isogeometric discretizations of elliptic partial differential equations. For classical finite elements, such methods are well known to be fast solvers…

Numerical Analysis · Mathematics 2017-05-16 Clemens Hofreither , Stefan Takacs , Walter Zulehner

This paper presents a parallel-in-time adjoint sensitivity analysis which combines a transient adjoint sensitivity analysis with the parareal approach in order to significantly speed up the simulation. The adjoint method is the method of…

Numerical Analysis · Mathematics 2023-07-04 Julian Sarpe , Andreas Klaedtke , Herbert De Gersem

We propose a new numerical scheme for approximating level-sets of Lipschitz multivariate functions which is robust to stochastic noise. The algorithm's main feature is an adaptive grid-based stochastic approximation strategy which…

Numerical Analysis · Mathematics 2025-09-19 Matteo Croci , Abdul-Lateef Haji-Ali , Ian C. J. Powell

This paper presents a spatial optimization methodology that extends the Spatial Packaging of Interconnected Systems with Physical Interaction (SPI2) framework to support arbitrary, non-convex design boundaries. We introduce a smooth,…

Computational Engineering, Finance, and Science · Computer Science 2026-05-19 S. Westerhof , T. Hofman