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Modern automotive systems leverage deep neural networks (DNNs) for semantic segmentation and operate in two key application areas: (1) In-car, where the DNN solely operates in the vehicle without strict constraints on the data rate. (2)…

Machine Learning · Computer Science 2025-10-21 Danish Nazir , Gowtham Sai Inti , Timo Bartels , Jan Piewek , Thorsten Bagdonat , Tim Fingscheidt

We report on a new Monte Carlo method for simulating diffusive shock acceleration (DSA) of solar energetic particles at upstream and downstream regions of quasi-parallel collisionless shock waves under the influence of self-generated…

Space Physics · Physics 2014-08-14 Arto Sandroos , Gang Li , Lulu Zhao

The convergence of Boltzmann Fokker Planck solution can become arbitrarily slow with iterative procedures like source iteration. This paper derives and investigates a nonlinear diffusion acceleration scheme for the solution of the Boltzmann…

Numerical Analysis · Mathematics 2023-12-06 Japan K. Patel , Barry D. Ganapol , Martha M. Matuszak

We present a generalized, data-driven collisional operator for one-component plasmas, learned from molecular dynamics simulations, to extend the collisional kinetic model beyond the weakly coupled regime. The proposed operator features an…

Numerical Analysis · Mathematics 2025-10-20 Yue Zhao , Huan Lei

Video diffusion transformers have achieved remarkable progress in high-quality video generation, but remain computationally expensive due to the quadratic complexity of attention over high-dimensional video sequences. Recent acceleration…

Computer Vision and Pattern Recognition · Computer Science 2025-10-14 Wenhao Sun , Rong-Cheng Tu , Yifu Ding , Zhao Jin , Jingyi Liao , Shunyu Liu , Dacheng Tao

In this study, the Method of Characteristics (MOC) for Delayed Neutron Precursors (DNPs) is used to solve the precursors balance equation with turbulent diffusion. The diffusivity of DNPs, significantly higher than molecular diffusivity,…

Computational Physics · Physics 2024-11-07 Mathis Caprais , André Bergeron

In this work, we investigate the diffusive optical tomography (DOT) problem in the case that limited boundary measurements are available. Motivated by the direct sampling method (DSM), we develop a deep direct sampling method (DDSM) to…

Numerical Analysis · Mathematics 2021-05-10 Jiahua Jiang , Yi Li , Ruchi Guo

Finding the injection threshold for diffusive shock acceleration (DSA) of electrons in collisionless shocks has been a longstanding unsolved problem. Using first-principles kinetic simulations, we identify the conditions for electron…

High Energy Astrophysical Phenomena · Physics 2025-06-12 Siddhartha Gupta , Damiano Caprioli , Anatoly Spitkovsky

Machine learning methods, such as diffusion models, are widely explored as a promising way to accelerate high-fidelity fluid dynamics computation via a super-resolution process from faster-to-compute low-fidelity input. However, existing…

Computational Engineering, Finance, and Science · Computer Science 2025-12-24 Ruoyan Li , Zijie Huang , Haixin Wang , Guancheng Wan , Yizhou Sun , Wei Wang

Scaling video diffusion transformers (DiTs) is limited by their quadratic 3D attention, even though most of the attention mass concentrates on a small subset of positions. We turn this observation into VSA, a trainable, hardware-efficient…

Computer Vision and Pattern Recognition · Computer Science 2025-10-29 Peiyuan Zhang , Yongqi Chen , Haofeng Huang , Will Lin , Zhengzhong Liu , Ion Stoica , Eric Xing , Hao Zhang

Based on the Denoising Diffusion Probabilistic Model (DDPM), medical image segmentation can be described as a conditional image generation task, which allows to compute pixel-wise uncertainty maps of the segmentation and allows an implicit…

Image and Video Processing · Electrical Eng. & Systems 2022-11-01 Xutao Guo , Yanwu Yang , Chenfei Ye , Shang Lu , Yang Xiang , Ting Ma

The radiative transfer equation is a fundamental equation in transport theory and applications, which is a 5-dimensional PDE in the stationary one-velocity case, leading to great difficulties in numerical simulation. To tackle this…

Numerical Analysis · Mathematics 2022-01-05 Jianguo Huang , Yue Yu

Solving the radiation transport equation is a challenging task, due to the high dimensionality of the solution's phase space. The commonly used discrete ordinates (S$_N$) method suffers from ray effects which result from a break in…

Numerical Analysis · Mathematics 2019-02-20 Thomas Camminady , Martin Frank , Kerstin Küpper , Jonas Kusch

The analytical theory of diffusive cosmic ray acceleration at parallel stationary shock waves with magnetostatic turbulence is generalized to arbitrary shock speeds $V_s=\beta_1c$, including in particular relativistic speeds. This is…

High Energy Astrophysical Phenomena · Physics 2015-08-19 Reinhard Schlickeiser

We present novel algorithms for simulation optimization using random directions stochastic approximation (RDSA). These include first-order (gradient) as well as second-order (Newton) schemes. We incorporate both continuous-valued as well as…

Optimization and Control · Mathematics 2015-08-11 Prashanth L. A. , Shalabh Bhatnagar , Michael Fu , Steve Marcus

Rendering highly scattering participating media using brute force path tracing is a challenge. The diffusion approximation reduces the problem to solving a simple linear partial differential equation. Flux-limited diffusion introduces…

Graphics · Computer Science 2018-07-03 David Koerner , Jamie Portsmouth , Wenzel Jakob

Direction-of-arrival (DOA) estimation refers to the process of retrieving the direction information of several electromagnetic waves/sources from the outputs of a number of receiving antennas that form a sensor array. DOA estimation is a…

Information Theory · Computer Science 2017-01-10 Zai Yang , Jian Li , Petre Stoica , Lihua Xie

We reexamine nonlinear diffusive shock acceleration (DSA) at cosmological shocks in the large scale structure of the Universe, incorporating wave-particle interactions that are expected to operate in collisionless shocks. Adopting simple…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Hyesung Kang , Dongsu Ryu

We present results from a fully relativistic Monte Carlo simulation of diffusive shock acceleration (DSA) in unmodified shocks. The computer code uses a single algorithmic sequence to smoothly span the range from nonrelativistic speeds to…

Astrophysics · Physics 2009-11-10 Donald C. Ellison , Glen P. Double

The concept of Dielectric Laser Acceleration (DLA) provides highest gradients among non-plasma particle accelerators. However, stable beam transport and staging have not been shown experimentally yet. We present a scheme that confines the…

Accelerator Physics · Physics 2018-11-28 Uwe Niedermayer , Thilo Egenolf , Oliver Boine-Frankenheim , Peter Hommelhoff
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