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Related papers: Adaptive Mesh Refinement for Characteristic Grids

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In this work, a simple and efficient dual iterative refinement (DIR) method is proposed for dense correspondence between two nearly isometric shapes. The key idea is to use dual information, such as spatial and spectral, or local and global…

Computer Vision and Pattern Recognition · Computer Science 2020-11-20 Rui Xiang , Rongjie Lai , Hongkai Zhao

Differentially private (DP) training protects individual examples by adding noise to gradients, but the injected noise interacts nontrivially with adaptive optimizers. Recent DP methods temporally filter privatized gradients to reduce…

Machine Learning · Computer Science 2026-05-06 Duc Dm , Thao Do , Minh Son Hoang , Anh Le Duc Tran , Daeyoung Kim , Huy Nguyen

Optimizing machine learning algorithms that are used to solve the objective function has been of great interest. Several approaches to optimize common algorithms, such as gradient descent and stochastic gradient descent, were explored. One…

Machine Learning · Computer Science 2022-10-06 Hilal AlQuabeh , Farha AlBreiki , Dilshod Azizov

We present the newly developed code, GAMER (GPU-accelerated Adaptive MEsh Refinement code), which has adopted a novel approach to improve the performance of adaptive mesh refinement (AMR) astrophysical simulations by a large factor with the…

Instrumentation and Methods for Astrophysics · Physics 2010-02-08 Hsi-Yu Schive , Yu-Chih Tsai , Tzihong Chiueh

Grids are a general representation for capturing regularly-spaced information, but since they are uniform in space, they cannot dynamically allocate resolution to regions with varying levels of detail. There has been some exploration of…

Graphics · Computer Science 2026-01-12 Julian Knodt , Seung-Hwan Baek

We present a novel algorithm, an adaptive-lag smoother, approximating efficiently, in an online fashion, sequences of expectations under the marginal smoothing distributions in general state-space models. The algorithm evolves recursively a…

Computation · Statistics 2019-10-23 Johan Alenlöv , Jimmy Olsson

Algebraic multigrid (AMG) is often an effective solver for symmetric positive definite (SPD) linear systems resulting from the discretization of general elliptic PDEs, or the spatial discretization of parabolic PDEs. However, convergence…

Numerical Analysis · Mathematics 2019-09-10 Thomas A. Manteuffel , Steffen Munzenmaier , John Ruge , Ben S. Southworth

We present a description of the adaptive mesh refinement (AMR) implementation of the PLUTO code for solving the equations of classical and special relativistic magnetohydrodynamics (MHD and RMHD). The current release exploits, in addition…

High Energy Astrophysical Phenomena · Physics 2015-05-30 A. Mignone , C. Zanni , P. Tzeferacos , B. van Straalen , P. Colella , G. Bodo

Method for a mosaic image representation (MIR) is proposed for a selective treatment of image fragments of different transition frequency. MIR method is based on piecewise-constant image approximation on a non-uniform orthogonal grid…

Data Analysis, Statistics and Probability · Physics 2011-03-14 Evgenia Gelman

Many modern computer vision and machine learning applications rely on solving difficult optimization problems that involve non-differentiable objective functions and constraints. The alternating direction method of multipliers (ADMM) is a…

Computer Vision and Pattern Recognition · Computer Science 2017-04-11 Zheng Xu , Mario A. T. Figueiredo , Xiaoming Yuan , Christoph Studer , Tom Goldstein

This paper describes an angular adaptivity algorithm for Boltzmann transport applications which for the first time shows evidence of $\mathcal{O}(n)$ scaling in both runtime and memory usage, where $n$ is the number of adapted angles. This…

Computational Physics · Physics 2020-01-29 S. Dargaville , A. G. Buchan , R. P. Smedley-Stevenson , P. N Smith , C. C. Pain

The paper aims to establish a fully discrete finite element (FE) scheme and provide cost-effective solutions for one-dimensional time-space Caputo-Riesz fractional diffusion equations on a bounded domain $\Omega$. Firstly, we construct a…

Numerical Analysis · Mathematics 2017-07-27 Xiaoqiang Yue , Weiping Bu , Shi Shu , Menghuan Liu , Shuai Wang

We present an adaptive algorithm for effectively solving rough differential equations (RDEs) using the log-ODE method. The algorithm is based on an error representation formula that accurately describes the contribution of local errors to…

Numerical Analysis · Mathematics 2023-07-25 Christian Bayer , Simon Breneis , Terry Lyons

In this work, we present a general framework for the design and analysis of two-level AMG methods. The approach is to find a basis for locally optimal or quasi-optimal coarse space, such as the space of constant vectors for standard…

Numerical Analysis · Mathematics 2017-05-23 Jinchao Xu , Hongxuan Zhang , Ludmil Zikatanov

We introduce \emph{Adaptive RAG Memory} (ARM), a retrieval-augmented generation (RAG) framework that replaces a static vector index with a \emph{dynamic} memory substrate governed by selective remembrance and decay. Frequently retrieved…

Information Retrieval · Computer Science 2026-01-07 Okan Bursa

Full interpretation of data from gravitational wave observations will require accurate numerical simulations of source systems, particularly binary black hole mergers. A leading approach to improving accuracy in numerical relativity…

General Relativity and Quantum Cosmology · Physics 2013-05-29 John G. Baker , James R. van Meter

We analyze the adaptive first order algorithm AMSGrad, for solving a constrained stochastic optimization problem with a weakly convex objective. We prove the $\mathcal{\tilde O}(t^{-1/4})$ rate of convergence for the norm of the gradient of…

Machine Learning · Statistics 2020-06-12 Ahmet Alacaoglu , Yura Malitsky , Volkan Cevher

Alternating direction method of multiplier (ADMM) is a powerful method to solve decentralized convex optimization problems. In distributed settings, each node performs computation with its local data and the local results are exchanged…

Machine Learning · Computer Science 2019-10-11 Xueru Zhang , Mohammad Mahdi Khalili , Mingyan Liu

As supercomputers advance towards exascale capabilities, computational intensity increases significantly, and the volume of data requiring storage and transmission experiences exponential growth. Adaptive Mesh Refinement (AMR) has emerged…

Distributed, Parallel, and Cluster Computing · Computer Science 2023-07-20 Daoce Wang , Jesus Pulido , Pascal Grosset , Jiannan Tian , Sian Jin , Houjun Tang , Jean Sexton , Sheng Di , Zarija Lukić , Kai Zhao , Bo Fang , Franck Cappello , James Ahrens , Dingwen Tao

We propose a data-driven and machine-learning-based approach to compute non-Galerkin coarse-grid operators in algebraic multigrid (AMG) methods, addressing the well-known issue of increasing operator complexity. Guided by the AMG theory on…

Numerical Analysis · Mathematics 2023-07-18 Ru Huang , Kai Chang , Huan He , Ruipeng Li , Yuanzhe Xi