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We consider a two-dimensional model of double-diffusive convection and its time discretisation using a second-order scheme which treat the nonlinear term explicitly (backward differentiation formula with a one-leg method). Uniform bounds on…

Numerical Analysis · Mathematics 2014-02-28 Florentina Tone , Xiaoming Wang , Djoko Wirosoetisno

We propose an alternative method for one-dimensional continuum diffusion models with spatially variable (heterogeneous) diffusivity. Our method, which extends recent work on stochastic diffusion, assumes the constant-coefficient homogenized…

Computational Physics · Physics 2019-12-18 Elliot J. Carr

Dislocations are the main carriers of the permanent deformation of crystals. For simulations of engineering applications, continuum models where material microstructures are represented by continuous density distributions of dislocations…

Materials Science · Physics 2018-03-02 Xiaohua Niu , Yichao Zhu , Shuyang Dai , Yang Xiang

This paper aims to develop and analyze a numerical scheme for solving the backward problem of semilinear subdiffusion equations. We establish the existence, uniqueness, and conditional stability of the solution to the inverse problem by…

Numerical Analysis · Mathematics 2025-05-07 Xu Wu , Jiang Yang , Zhi Zhou

Structure-preserving particle methods have recently been proposed for a class of nonlinear continuity equations, including aggregation-diffusion equation in [J. Carrillo, K. Craig, F. Patacchini, Calc. Var., 58 (2019), pp. 53] and the…

Numerical Analysis · Mathematics 2025-06-19 Jingwei Hu , Samuel Q. Van Fleet , Andy T. S. Wan

The emergence of various notions of ``consistency'' in diffusion models has garnered considerable attention and helped achieve improved sample quality, likelihood estimation, and accelerated sampling. Although similar concepts have been…

Machine Learning · Computer Science 2023-08-02 Chieh-Hsin Lai , Yuhta Takida , Toshimitsu Uesaka , Naoki Murata , Yuki Mitsufuji , Stefano Ermon

We present a finite element scheme for fractional diffusion problems with varying diffusivity and fractional order. We consider a symmetric integral form of these nonlocal equations defined on general geometries and in arbitrary bounded…

Numerical Analysis · Mathematics 2023-06-28 Wenyu Lei , George Turkiyyah , Omar Knio

Stochastic diffusion equations are crucial for modeling a range of physical phenomena influenced by uncertainties. We introduce the generalized finite difference method for solving these equations. Then, we examine its consistency,…

Numerical Analysis · Mathematics 2024-11-22 Faezeh Nassajian Mojarrad

In this paper we study a system of advection-diffusion equations in a bulk domain coupled to an advection-diffusion equation on an embedded surface. Such systems of coupled partial differential equations arise in, for example, the modeling…

Numerical Analysis · Mathematics 2014-12-09 Sven Gross , Maxim A. Olshanskii , Arnold Reusken

Protein-stabilised emulsions can be seen as mixtures of unadsorbed proteins and of protein-stabilised droplets. To identify the contributions of these two components to the overall viscosity of sodium caseinate o/w emulsions, the…

Soft Condensed Matter · Physics 2019-01-30 Marion Roullet , Paul S. Clegg , William J. Frith

The paper studies a higher-order diffusion model of Maxwell-Stefan kind. The model is based upon higher-order moment equations of kinetic theory of mixtures, which include viscous dissipation in the model. Governing equations are analyzed…

Analysis of PDEs · Mathematics 2023-05-16 Bérénice Grec , Srboljub Simic

Based on the notion of a construction process consisting of the stepwise addition of particles to the pure fluid, a discrete model for the apparent viscosity as well as for the maximum packing fraction of polydisperse suspensions of…

Fluid Dynamics · Physics 2014-02-28 Aaron Dörr , Amsini Sadiki , Amirfarhang Mehdizadeh

We consider a finite element method which couples the continuous Galerkin method away from internal and boundary layers with a discontinuous Galerkin method in the vicinity of layers. We prove that this consistent method is stable in the…

Numerical Analysis · Mathematics 2012-11-06 Andrea Cangiani , John Chapman , Emmanuil Georgoulis , Max Jensen

We focus here on a class of fourth-order parabolic equations that can be written as a system of second-order equations by introducing an auxiliary variable. We design a novel second-order fully discrete mixed finite element method to…

Numerical Analysis · Mathematics 2020-08-28 Sana Keita , Abdelaziz Beljadid , Yves Bourgault

Diffusion models have emerged as a promising alternative to autoregressive models in modeling discrete categorical data. However, diffusion models that directly work on discrete data space fail to fully exploit the power of iterative…

Machine Learning · Computer Science 2025-10-24 Jaehyeong Jo , Sung Ju Hwang

We consider a discrete latent variable model for two-way data arrays, which allows one to simultaneously produce clusters along one of the data dimensions (e.g. exchangeable observational units or features) and contiguous groups, or…

In this paper, we introduce a data-driven modeling approach for dynamics problems with latent variables. The state-space of the proposed model includes artificial latent variables, in addition to observed variables that can be fitted to a…

Optimization and Control · Mathematics 2024-06-19 Yushuang Luo , Xiantao Li , Wenrui Hao

In this paper, we describe a stable finite element formulation for advection-diffusion-reaction problems that allows for robust automatic adaptive strategies to be easily implemented. We consider locally vanishing, heterogeneous, and…

Numerical Analysis · Mathematics 2021-09-01 Roberto J. Cier , Sergio Rojas , Victor M. Calo

It is well known that the classical energetically consistent micropolar model has limits in simulating the frequency band structure of packed granular materials (see Merkel et al., 2011). It is here shown that if a standard continualization…

Soft Condensed Matter · Physics 2021-04-27 Andrea Bacigalupo , Luigi Gambarotta

Flowing granular materials segregate due to differences in particle size (driven by percolation) and density (driven by buoyancy). Modelling the segregation of mixtures of large/heavy particles and small/light particles is challenging due…

Soft Condensed Matter · Physics 2021-05-18 Yifei Duan , Paul B. Umbanhowar , Julio M. Ottino , Richard M. Lueptow