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Nonlinear time fractional partial differential equations are widely used in modeling and simulations. In many applications, there are high contrast changes in media properties. For solving these problems, one often uses coarse spatial grid…

数值分析 · 数学 2022-07-13 Wenyuan Li , Anatoly Alikhanov , Yalchin Efendiev , Wing Tat Leung

In this paper we study elliptic partial differential equations with rapidly varying diffusion coefficient that can be represented as a perturbation of a reference coefficient. We develop a numerical method for efficiently solving multiple…

数值分析 · 数学 2020-12-21 Fredrik Hellman , Tim Keil , Axel Målqvist

We approximate a diffusion equation with highly oscillatory coefficients with a diffusion equation with constant coefficients. The approach is put in action in contexts where only partial information (namely the global energy stored in the…

最优化与控制 · 数学 2026-02-17 Claude Le Bris , Frédéric Legoll , Simon Ruget

A convergence result for a discontinuous Galerkin multiscale method for a second order elliptic problem is presented. We consider a heterogeneous and highly varying diffusion coefficient in $L^\infty(\Omega,\mathbb{R}^{d\times d}_{sym})$…

Heat diffusion processes have found wide applications in modelling dynamical systems over graphs. In this paper, we consider the recovery of a $k$-bandlimited graph signal that is an initial signal of a heat diffusion process from its…

信息论 · 计算机科学 2021-10-05 Longxiu Huang , Deanna Needell , Sui Tang

In this article we study inverse problems of recovering a space-time dependent source component from the lateral boundary observation in a subidffusion model. The mathematical model involves a Djrbashian-Caputo fractional derivative of…

数值分析 · 数学 2021-05-19 Bangti Jin , Yavar Kian , Zhi Zhou

In this study, we consider a class of non-autonomous time-fractional partial advection-diffusion-reaction (TF-ADR) equations with Caputo type fractional derivative. To obtain the numerical solution of the model problem, we apply the…

数值分析 · 数学 2023-08-08 Sandip Maji , Srinivasan Natesan

This paper introduces a stabilized finite element scheme for the Cahn--Hilliard cross-diffusion model, which is characterized by strongly coupled mobilities, nonlinear diffusion, and complex cross-diffusion terms. These features pose…

数值分析 · 数学 2025-05-08 Boyi Wang , Naresh Kumar , Jinyun Yuan

Practical diffusion sampling is a numerical approximation problem: under a fixed inference budget, one must simulate a reverse-time ODE or SDE using only a limited number of denoising steps, so discretization error is often the dominant…

机器学习 · 计算机科学 2026-05-12 Samuel Hurault , Thomas Moreau , Gabriel Peyré

This paper analyzes a time-stepping discontinuous Galerkin method for modified anomalous subdiffusion problems with two time fractional derivatives of orders $ \alpha $ and $ \beta $ ($ 0 < \alpha < \beta < 1 $). The stability of this…

数值分析 · 数学 2017-11-16 Binjie Li , Hao Luo , Xiaoping Xie

The problem of recovering coefficients in a diffusion equation is one of the basic inverse problems. Perhaps the most important term is the one that couples the length and time scales and is often referred to as {\it the\/} diffusion…

偏微分方程分析 · 数学 2021-01-19 Barbara Kaltenbacher , William Rundell

This study introduces the divergence-conforming discontinuous Galerkin finite element method (DGFEM) for numerically approximating optimal control problems with distributed constraints, specifically those governed by stationary generalized…

数值分析 · 数学 2025-04-23 Harpal Singh , Arbaz Khan

In computational system biology, the mesoscopic model of reaction-diffusion kinetics is described by a continuous time, discrete space Markov process. To simulate diffusion stochastically, the jump coefficients are obtained by a…

数值分析 · 数学 2018-02-19 Lina Meinecke , Stefan Engblom , Andreas Hellander , Per Lötstedt

We present an explicit method for simulating stochastic differential equations (SDEs) that have variable diffusion coefficients and satisfy the detailed balance condition with respect to a known equilibrium density. In Tupper and Yang…

数值分析 · 数学 2014-06-27 Paul Tupper , Xin Yang

This paper is dedicated to addressing the simultaneous inversion problem involving the initial value and space-dependent source term in a time-fractional diffusion-wave equation. Firstly, we establish the uniqueness of the inverse problem…

数值分析 · 数学 2025-02-25 Yun Zhang , Xiaoli Feng , Xiongbin Yan

This paper is devoted to the numerical analysis of a piecewise constant discontinuous Galerkin method for time fractional subdiffusion problems. The regularity of weak solution is firstly established by using variational approach and…

数值分析 · 数学 2022-02-22 Binjie Li , Hao Luo , Xiaoping Xie

We study Hibridizable Discontinuous Galerkin (HDG) discretizations for a class of non-linear interior elliptic boundary value problems posed in curved domains where both the source term and the diffusion coefficient are non-linear. We…

数值分析 · 数学 2021-12-30 Nestor Sánchez , Tonatiuh Sánchez-Vizuet , Manuel E. Solano

In this work, we theoretically and numerically discuss the time fractional subdiffusion-normal transport equation, which depicts a crossover from sub-diffusion (as $t\rightarrow 0$) to normal diffusion (as $t\rightarrow \infty$). Firstly,…

数值分析 · 数学 2023-09-20 Fugui Ma , Lijing Zhao , Weihua Deng , Yejuan Wang

We investigate a numerical behaviour of robust deterministic optimal control problem subject to a convection diffusion equation containing uncertain inputs. Stochastic Galerkin approach, turning the original optimization problem containing…

数值分析 · 数学 2023-03-01 Pelin Çiloğlu , Hamdullah Yücel

When applying the finite-differences method to numerically solve the one-dimensional diffusion equation, one must choose discretization steps $\Delta x$, $\Delta t$ in space and time, respectively. By applying large-deviation theory on the…

统计力学 · 物理学 2024-04-09 Naftali R. Smith