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We find a class of exact solutions to the Lighthill Whitham Richards Payne (LWRP) traffic flow equations. Using two consecutive lagrangian transformations, a linearization is achieved. Next, depending on the initial density, we either apply…

Fluid Dynamics · Physics 2013-10-28 G. Rowlands , E. Infeld , A. A. Skorupski

A new Real Fluid Quasi-Conservative (RFQC) finite volume method is developed to address the numerical simulation of real fluids involving shock waves in transcritical and phase-change flows. To eliminate the spurious pressure oscillations…

Computational Physics · Physics 2026-02-16 Haotong Bai , Wenjia Xie , Yixin Yang , Ping Yi , Mingbo Sun

A new approach is presented for the calculation of p_n and pi_n which uses the Lambert W function. An approximation is first found and using a calculation technique it makes it possible to have an estimate of these two quantities more…

Number Theory · Mathematics 2020-06-04 Simon Plouffe

We derive formulas for the Coulomb matrix within the full-potential linearized augmented-plane-wave (FLAPW) method. The Coulomb matrix is a central ingredient in implementations of many-body perturbation theory, such as the Hartree-Fock and…

Materials Science · Physics 2010-03-01 Christoph Friedrich , Arno Schindlmayr , Stefan Bluegel

The superfluid fraction $f$ of a quantum fluid is defined in terms of the response of the system to a weak and constant drag. Notably, Leggett long ago derived two simple expressions providing a rigorous upper bound and a heuristic lower…

Quantum Gases · Physics 2025-01-16 Daniel Pérez-Cruz , Grigori E. Astrakharchik , Pietro Massignan

A normalizing flow is an invertible mapping between an arbitrary probability distribution and a standard normal distribution; it can be used for density estimation and statistical inference. Computing the flow follows the change of…

Machine Learning · Computer Science 2021-12-10 Derek Onken , Samy Wu Fung , Xingjian Li , Lars Ruthotto

By employing CFT techniques, we show how to compute in the context of \lambda-deformations of current algebras and coset CFTs the exact in the deformation parameters C-function for a wide class of integrable theories that interpolate…

High Energy Physics - Theory · Physics 2019-12-24 George Georgiou , Pantelis Panopoulos , Eftychia Sagkrioti , Konstantinos Sfetsos , Konstantinos Siampos

Time series imputation is important for numerous real-world applications. To overcome the limitations of diffusion model-based imputation methods, e.g., slow convergence in inference, we propose a novel method for time series imputation in…

Machine Learning · Computer Science 2025-05-08 Weizhu Qian , Dalin Zhang , Yan Zhao , Yunyao Cheng

We present an optical flow estimation approach that operates on the full four-dimensional cost volume. This direct approach shares the structural benefits of leading stereo matching pipelines, which are known to yield high accuracy. To this…

Computer Vision and Pattern Recognition · Computer Science 2017-04-26 Jia Xu , René Ranftl , Vladlen Koltun

Flow Matching has become a cornerstone of modern generative models like Stable Diffusion 3, largely due to the efficiency of its Rectified Flow (RF) variant. The success of RF hinges on iteratively learning straight trajectories, pushing…

Machine Learning · Computer Science 2026-05-19 Vansh Bansal , Saptarshi Roy , Purnamrita Sarkar , Alessandro Rinaldo

A potential motion of ideal incompressible fluid with a free surface and infinite depth is considered in two-dimensional geometry. A time-dependent conformal mapping of the lower complex half-plane of the auxiliary complex variable $w$ into…

Fluid Dynamics · Physics 2021-08-24 A. I. Dyachenko , S. A. Dyachenko , P. M. Lushnikov , V. E. Zakharov

The optimal power flow (OPF) problem minimizes power system operating cost subject to both engineering and network constraints. With the potential to find global solutions, significant research interest has focused on convex relaxations of…

Optimization and Control · Mathematics 2014-02-03 Daniel K. Molzahn , Ian A. Hiskens

Learning under a Wasserstein loss, a.k.a. Wasserstein loss minimization (WLM), is an emerging research topic for gaining insights from a large set of structured objects. Despite being conceptually simple, WLM problems are computationally…

Computation · Statistics 2017-06-07 Jianbo Ye , James Z. Wang , Jia Li

Generalized self-concordance is a key property present in the objective function of many important learning problems. We establish the convergence rate of a simple Frank-Wolfe variant that uses the open-loop step size strategy $\gamma_t =…

Optimization and Control · Mathematics 2024-04-09 Alejandro Carderera , Mathieu Besançon , Sebastian Pokutta

Robust estimation is essential in computer vision, robotics, and navigation, aiming to minimize the impact of outlier measurements for improved accuracy. We present a fast algorithm for Geman-McClure robust estimation, FracGM, leveraging…

Computer Vision and Pattern Recognition · Computer Science 2024-11-22 Bang-Shien Chen , Yu-Kai Lin , Jian-Yu Chen , Chih-Wei Huang , Jann-Long Chern , Ching-Cherng Sun

In this paper, we consider the numerical approximation of the quasi-static, linear Biot model in a 3D domain $\Omega$ when the right-hand side of the mass balance equation is concentrated on a 1D line source $\delta_{\Lambda}$. This model…

Numerical Analysis · Mathematics 2020-01-07 Nadia S. Taki , Ingeborg G. Gjerde

Chance constrained optimal power flow (OPF) has been recognized as a promising framework to manage the risk from variable renewable energy (VRE). In presence of VRE uncertainties, this paper discusses a distributionally robust chance…

Optimization and Control · Mathematics 2018-05-01 Chao Duan , Wanliang Fang , Lin Jiang , Li Yao , Jun Liu

AC optimal power flow (AC OPF) is a fundamental problem in power system operations. Accurately modeling the network physics via the AC power flow equations makes AC OPF a challenging nonconvex problem. To search for global optima, recent…

Optimization and Control · Mathematics 2024-04-09 Mohammad Rasoul Narimani , Daniel K. Molzahn , Katherine R. Davis , Mariesa L. Crow

Recent papers have shown that the Frank-Wolfe algorithm (FW) with open-loop step-sizes exhibits rates of convergence faster than the iconic $\mathcal{O}(t^{-1})$ rate. In particular, when the minimizer of a strongly convex function over a…

Optimization and Control · Mathematics 2025-01-22 Elias Wirth , Javier Pena , Sebastian Pokutta

This paper presents a parametric quadratic approximation of the AC optimal power flow (AC-OPF) problem for time-sensitive and market-based applications. The parametric approximation preserves the physics-based but simple representation…

Optimization and Control · Mathematics 2024-10-25 Gonzalo E. Constante-Flores , André H. Quisaguano , Antonio J. Conejo , Can Li