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The article discusses the gradient discretisation method (GDM) for distributed optimal control problems governed by diffusion equation with pure Neumann boundary condition. Using the GDM framework enables to develop an analysis that…

Numerical Analysis · Mathematics 2018-10-09 Jerome Droniou , Neela Nataraj , Devika Shylaja

A new time discretization scheme for the numerical simulation of two-phase flow governed by a thermodynamically consistent diffuse interface model is presented. The scheme is consistent in the sense that it allows for a discrete in time…

Analysis of PDEs · Mathematics 2014-02-27 Harald Garcke , Michael Hinze , Christian Kahle

We study a one dimensional model for two-phase flows in heterogeneous media, in which the capillary pressure functions can be discontinuous with respect to space. We first give a model, leading to a system of degenerated non-linear…

Analysis of PDEs · Mathematics 2009-09-08 Clément Cancès

In this work we are interested in dealing with single-phase flows in fractured porous media for underground processes. We focus our attention on domains where the presence of faults, with thickness several orders of magnitude smaller than…

Numerical Analysis · Mathematics 2019-08-01 Alessio Fumagalli , Isabelle Faille

We study optimization algorithms for the finite sum problems frequently arising in machine learning applications. First, we propose novel variants of stochastic gradient descent with a variance reduction property that enables linear…

Machine Learning · Computer Science 2017-07-06 Jakub Konečný

An industrial scheme, to simulate the two compressible phase flow in porous media, consists in a finite volume method together with a phase-by-phase upstream scheme. The implicit finite volume scheme satisfies industrial constraints of…

Numerical Analysis · Mathematics 2012-02-24 Bilal Saad , Mazen Saad

The Gross-Pitaevskii equation and its generalisations to dissipative and dipolar gases have been very useful in describing dynamics of cold atomic gases, as well as polaritons and other nonlinear systems. For some of these applications the…

Quantum Gases · Physics 2025-07-03 Ryan J. J. Connor , Callum W. Duncan , Andrew J. Daley

We develop an operator splitting method to simulate flows of isothermal compressible natural gas over transmission pipelines. The method solves a system of nonlinear hyperbolic partial differential equations (PDEs) of hydrodynamic type for…

Computational Physics · Physics 2022-06-03 Sergey A. Dyachenko , Anatoly Zlotnik , Alexander O. Korotkevich , Michael Chertkov

The need to smoothly cover a computational domain of interest generically requires the adoption of several grids. To solve the problem of interest under this grid-structure one must ensure the suitable transfer of information among the…

General Relativity and Quantum Cosmology · Physics 2009-11-11 Luis Lehner , Oscar Reula , Manuel Tiglio

As a common practice, the direction of natural gas flow in every pipeline is determined ex-ante for simplification purposes, and treated as a given parameter within the scheduling problem. However, in integrated gas and electric power…

Optimization and Control · Mathematics 2022-04-26 Junesoo Shin , Yannick Werner , Jalal Kazempour

In this paper we propose a Godunov-based discretization of a hyperbolic system of conservation laws with discontinuous flux, modeling vehicular flow on a network. Each equation describes the density evolution of vehicles having a common…

Numerical Analysis · Mathematics 2014-08-04 Gabriella Bretti , Maya Briani , Emiliano Cristiani

We provide a unifying framework for distributed convex optimization over time-varying networks, in the presence of constraints and uncertainty, features that are typically treated separately in the literature. We adopt a proximal…

Optimization and Control · Mathematics 2017-05-24 Kostas Margellos , Alessandro Falsone , Simone Garatti , Maria Prandini

We present an efficient finite difference method for the approximation of second derivatives, with respect to system parameters, of expectations for a class of discrete stochastic chemical reaction networks. The method uses a coupling of…

Quantitative Methods · Quantitative Biology 2012-10-16 Elizabeth Skubak Wolf , David F. Anderson

The gas-kinetic scheme (GKS) provides high computational efficiency and accuracy for continuum flow simulations but is unable to reliably capture rarefaction effects. In contrast, although the discrete velocity method (DVM) is better suited…

Fluid Dynamics · Physics 2026-05-08 Hangkong Wu , Yuze Zhu , Yajun Zhu , Kun Xu

We present a flexible discretization technique for computational models of thin tubular networks embedded in a bulk domain, for example a porous medium. These systems occur in the simulation of fluid flow in vascularized biological tissue,…

Computational Engineering, Finance, and Science · Computer Science 2022-02-01 Timo Koch

The solution of potential-driven steady-state flow in large networks is required in various engineering applications, such as transport of natural gas or water through pipeline networks. The resultant system of nonlinear equations depends…

Computational Physics · Physics 2026-03-20 Shriram Srinivasan , Kaarthik Sundar

We consider the finite difference discretization of isotropic elastic wave equations on nonuniform grids. The intended applications are seismic studies, where heterogeneity of the earth media can lead to severe oversampling for simulations…

Numerical Analysis · Mathematics 2022-02-15 Longfei Gao , David Keyes

The unified gas kinetic scheme (UGKS) is a direct modeling method based on the gas dynamical model on the mesh size and time step scales. With the implementation of particle transport and collision in a time-dependent flux function, the…

Computational Physics · Physics 2017-10-25 Yajun Zhu , Chengwen Zhong , Kun Xu

We discuss algorithms applicable to the numerical solution of second-order ordinary differential equations by finite-differences. We make particular reference to the solution of the dissipative particle dynamics fluid model, and present…

Soft Condensed Matter · Physics 2016-08-31 Keir E. Novik , Peter V. Coveney

We link regularity and smoothness analysis of multivariate vector subdivision schemes with network flow theory and with special linear optimization problems. This connection allows us to prove the existence of what we call optimal…

Numerical Analysis · Mathematics 2015-02-11 Maria Charina , Geir Dahl