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Related papers: Computational Relativistic Astrophysics With Adapt…

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We describe a photon-conserving radiative transfer algorithm, using a spatially-adaptive ray tracing scheme, and its parallel implementation into the adaptive mesh refinement (AMR) cosmological hydrodynamics code, Enzo. By coupling the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 John H. Wise , Tom Abel

The increasing demand for larger and higher fidelity simulations has made Adaptive Mesh Refinement (AMR) and unstructured mesh techniques essential to focus compute effort and memory cost on just the areas of interest in the simulation…

Graphics · Computer Science 2025-01-23 Xuan Huang , Will Usher , Valerio Pascucci

This work presents a methodology to predict a near-optimal spacing function, which defines the element sizes, suitable to perform steady RANS turbulent viscous flow simulations. The strategy aims at utilising existing high fidelity…

Computational Engineering, Finance, and Science · Computer Science 2024-06-25 Sergi Sanchez-Gamero , Oubay Hassan , Ruben Sevilla

There has been a lot of research interest in modified gravity theories which utilise the Vainshtein mechanism to recover standard general relativity in regions with high matter density, such as the Dvali-Gabadadze-Porrati and Galileon…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-24 Baojiu Li , Gong-Bo Zhao , Kazuya Koyama

Modelling the complex physics of the Interstellar Medium (ISM) in the context of large-scale numerical simulations is a challenging task. A number of methods have been proposed to embed a description of the ISM into different codes. We…

Instrumentation and Methods for Astrophysics · Physics 2011-03-03 T. Grassi , E. Merlin , L. Piovan , U. Buonomo , C. Chiosi

We have implemented non-ideal Magneto-Hydrodynamics (MHD) effects in the Adaptive Mesh Refinement (AMR) code RAMSES, namely ambipolar diffusion and Ohmic dissipation, as additional source terms in the ideal MHD equations. We describe in…

Solar and Stellar Astrophysics · Physics 2015-10-22 J. Masson , R. Teyssier , C. Mulet-Marquis , P. Hennebelle , G. Chabrier

We propose Adaptive Randomized Smoothing (ARS) to certify the predictions of our test-time adaptive models against adversarial examples. ARS extends the analysis of randomized smoothing using $f$-Differential Privacy to certify the adaptive…

Machine Learning · Computer Science 2025-07-11 Saiyue Lyu , Shadab Shaikh , Frederick Shpilevskiy , Evan Shelhamer , Mathias Lécuyer

We present a real-space adaptive-coordinate method, which combines the advantages of the finite-difference approach with the accuracy and flexibility of the adaptive coordinate method. The discretized Kohn-Sham equations are written in…

mtrl-th · Physics 2009-10-28 Francois Gygi , Giulia Galli

Yen et al. (2012) advanced a direct approach for the calculation of self-gravitational force to second order accuracy based on uniform grid discretization. This method improves the accuracy of N-body calculation by using exact integration…

Computational Physics · Physics 2020-01-15 Yao-Huan Tseng , Hsien Shang , Chien-Chang Yen

We present a modification to the Berger and Oliger adaptive mesh refinement algorithm designed to solve systems of coupled, non-linear, hyperbolic and elliptic partial differential equations. Such systems typically arise during constrained…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Frans Pretorius , Matthew W. Choptuik

We present the extension of an efficient and highly parallelisable framework for incompressible fluid flow simulations to viscoplastic fluids. The system is governed by incompressible conservation of mass, the Cauchy momentum equation and a…

Fluid Dynamics · Physics 2019-07-09 Knut Sverdrup , Nikolaos Nikiforakis , Ann Almgren

In this paper, we introduce Saliency-Based Adaptive Masking (SBAM), a novel and cost-effective approach that significantly enhances the pre-training performance of Masked Image Modeling (MIM) approaches by prioritizing token salience. Our…

Computer Vision and Pattern Recognition · Computer Science 2024-04-15 Hyesong Choi , Hyejin Park , Kwang Moo Yi , Sungmin Cha , Dongbo Min

Rapid development in numerical modelling of materials and the complexity of new models increases quickly together with their computational demands. Despite the growing performance of modern computers and clusters, calibration of such models…

Neural and Evolutionary Computing · Computer Science 2016-03-08 Tomáš Mareš , Eliška Janouchová , Anna Kučerová

In this paper, we discuss the convergence of an Algebraic MultiGrid (AMG) method for general symmetric positive-definite matrices. The method relies on an aggregation algorithm, named \emph{coarsening based on compatible weighted matching},…

Numerical Analysis · Mathematics 2023-07-18 Pasqua D'Ambra , Fabio Durastante , Salvatore Filippone , Ludmil Zikatanov

Given the importance of simulating hydromagnetic processes that impact star formation, we have earlier developed a 3D adaptive mesh approach that allows us to include hydromagnetic processes during the formation and evolution of cores,…

Astrophysics · Physics 2009-11-13 D. F. Duffin , R. E. Pudritz

Adaptive representations are increasingly indispensable for reducing the in-memory and on-disk footprints of large-scale data. Usual solutions are designed broadly along two themes: reducing data precision, e.g., through compression, or…

Graphics · Computer Science 2022-07-15 Harsh Bhatia , Duong Hoang , Nate Morrical , Valerio Pascucci , Peer-Timo Bremer , Peter Lindstrom

Given the compact binary evolution problem of numerical relativity, in the finite-difference, block-based, adaptive mesh refinement context, choices must be made on how evolved fields are to be discretized. In GR-Athena++, the space-time…

General Relativity and Quantum Cosmology · Physics 2024-06-14 Boris Daszuta , William Cook , Peter Hammond , Jacob Fields , Eduardo M. Gutiérrez , Sebastiano Bernuzzi , David Radice

Magnetic Resonance Imaging (MRI) is a kind of medical imaging technology used for diagnostic imaging of diseases, but its image quality may be suffered by the long acquisition time. The compressive sensing (CS) based strategy may decrease…

Optimization and Control · Mathematics 2021-11-25 Yanyun Ding , Peili Li , Yunhai Xiao , Haibin Zhang

Modern computing systems are capable of exascale calculations, which are revolutionizing the development and application of high-fidelity numerical models in computational science and engineering. While these systems continue to grow in…

Optimization and Control · Mathematics 2024-10-11 Graham Harper , Denis Ridzal , Tim Wildey

It can be computationally advantageous to perform computer simulations in a Lorentz boosted frame for a certain class of systems. However, even if the computer model relies on a covariant set of equations, it has been pointed out that…

Accelerator Physics · Physics 2009-10-01 J. -L. Vay , W. M. Fawley , C. G. Geddes , E. Cormier-Michel , D. P. Grote