English
Related papers

Related papers: Diffusion model and analysis of diffusion process …

200 papers

Expanding medium is very common in many different fields, such as biology and cosmology. It brings a nonnegligible influence on particle's diffusion, which is quite different from the effect of an external force field. The dynamic mechanism…

Statistical Mechanics · Physics 2023-02-22 Xudong Wang , Yao Chen

We describe the mathematical theory of diffusion and heat transport with a view to including some of the main directions of recent research. The linear heat equation is the basic mathematical model that has been thoroughly studied in the…

Analysis of PDEs · Mathematics 2017-06-27 Juan Luis Vázquez

We present the idea of intertwining of two diffusions by Feynman-Kac operators. We present some variations and implications of the method and give examples of its applications. Among others, it turns out to be a very useful tool for finding…

Probability · Mathematics 2014-10-21 Maciej Wiśniewolski , Jacek Jakubowski

We analyze a pair of diffusion equations which are derived in the infinite system--size limit from a microscopic, individual--based, stochastic model. Deviations from the conventional Fickian picture are found which ultimately relate to the…

Statistical Mechanics · Physics 2015-05-18 Duccio Fanelli , Alan J. McKane

The interdiffusion of a solvent into a polymer melt has been studied using large scale molecular dynamics and Monte Carlo simulation techniques. The solvent concentration profile and weight gain by the polymer have been measured as a…

Soft Condensed Matter · Physics 2009-11-10 Mesfin Tsige , Gary S. Grest

We discuss the diffusion phenomenon in the parabolic and hyperbolic regimes. New effects related to the finite velocity of the diffusion process are predicted, that can partially explain the strange behavior associated to adsorption…

Mathematical Physics · Physics 2014-02-13 A. Sapora , M. Codegone , G. Barbero

Estimating parameters of a diffusion process given continuous-time observations of the process via maximum likelihood approaches or, online, via stochastic gradient descent or Kalman filter formulations constitutes a well-established…

Methodology · Statistics 2025-03-17 Jan Albrecht , Sebastian Reich

We present several results on smoothness in $L_{p}$ sense of filtering densities under the Lipschitz continuity assumption on the coefficients of a partially observable diffusion processes. We obtain them by rewriting in divergence form…

Probability · Mathematics 2009-08-14 N. V. Krylov

We expand on a previous study of fronts in finite particle number reaction-diffusion systems in the presence of a reaction rate gradient in the direction of the front motion. We study the system via reaction-diffusion equations, using the…

Statistical Mechanics · Physics 2009-11-11 Elisheva Cohen , David A. Kessler , Herbert Levine

A new scaling law model for propagation of optical beams through atmospheric turbulence is presented and compared to a common scalar stochastic waveoptics technique. This methodology tracks the evolution of the important beam wavefront and…

Optics · Physics 2021-05-05 Sophia Potoczak Bragdon , Daniel Cargill , Jacob Grosek

The diffusion of small solvent molecules in glassy polymers may take on a variety of different forms. Fickian, anomalous, Case II, and super Case II diffusion have all been observed, and theoretical models exist that describe each specific…

Soft Condensed Matter · Physics 2017-07-27 Jiayuan Miao , Mesfin Tsige , Philip L. Taylor

We present a position Langevin equation for overdamped particle motion on rough two-dimensional surfaces. A Brownian Dynamics algorithm is suggested to evolve this equation numerically, allowing for the prediction of effective (projected)…

Soft Condensed Matter · Physics 2009-11-13 Ali Naji , Frank L. H. Brown

Diffusion models, a family of generative models based on deep learning, have become increasingly prominent in cutting-edge machine learning research. With a distinguished performance in generating samples that resemble the observed data,…

Machine Learning · Computer Science 2023-05-02 Lequan Lin , Zhengkun Li , Ruikun Li , Xuliang Li , Junbin Gao

The problem of the molecular diffusion in a biphasic fluid mixture is studied here from the two complementary points of view of Continuum Mechanics - in a somewhat different manner from Truesdell in "Mechanical basis of diffusion" (J. Chem.…

Classical Physics · Physics 2009-05-12 Thierry Désoyer

We propose an approach to approximate the boundary crossing probabilities for general one-dimensional diffusion processes, and derive the convergence rate for this approximation scheme. There results are based on the explicit expression of…

Probability · Mathematics 2015-10-28 Jinghai Shao , Liqun Wang

This work is an extended version of the paper arXiv:0803.2669v1[math-ph], in which the main results were announced. We consider certain classical diffusion process for a wave function on the phase space. It is shown that at the time of…

Mathematical Physics · Physics 2008-12-31 E. M. Beniaminov

We introduce a novel particle-based algorithm for end-to-end training of latent diffusion models. We reformulate the training task as minimizing a free energy functional and obtain a gradient flow that does so. By approximating the latter…

Machine Learning · Statistics 2026-03-31 Tim Y. J. Wang , Juan Kuntz , O. Deniz Akyildiz

Diffusion in inhomogeneous materials can be described by both the Fick and Fokker--Planck diffusion equations. Here, we study a mixed Fick and Fokker-Planck diffusion problem with coefficients rapidly oscillating both in space and time. We…

Analysis of PDEs · Mathematics 2020-03-17 Micol Amar , Daniele Andreucci , Emilio N. M. Cirillo

We study the diffusion phenomena on the negatively curved surface made up of congruent heptagons. Unlike the usual two-dimensional plane, this structure makes the boundary increase exponentially with the distance from the center, and hence…

Statistical Mechanics · Physics 2008-07-15 Seung Ki Baek , Su Do Yi , Beom Jun Kim

The mesosocpic concept is applied to the theory of mixtures. The aim is to investigate the diffusion phenomenon from a mesoscopic point of view. The domain of the field quantities is extended by the set of mesoscopic variables, here the…

Statistical Mechanics · Physics 2007-05-23 A. Palumbo , C. Papenfuss , P. Rogolino