中文
相关论文

相关论文: Stopped diffusion processes: boundary corrections …

200 篇论文

For a Keller-Segel model for chemotaxis in two spatial dimensions we consider a modification of a positivity preserving fully discrete scheme using a local extremum diminishing flux limiter. We discretize space using piecewise linear finite…

数值分析 · 数学 2026-02-20 Panagiotis Chatzipantelidis , Christos Pervolianakis

Diffusion models have emerged as state-of-the-art generative models for image generation. However, sampling from diffusion models is usually time-consuming due to the inherent autoregressive nature of their sampling process. In this work,…

机器学习 · 计算机科学 2024-05-28 Zhiwei Tang , Jiasheng Tang , Hao Luo , Fan Wang , Tsung-Hui Chang

In this article we consider the estimation of static parameters for partially observed diffusion processes with discrete-time observations over a fixed time interval. In particular, when one only has access to time-discretized solutions of…

统计方法学 · 统计学 2025-09-26 Miguel Alvarez , Ajay Jasra

This paper solves a Bayes sequential impulse control problem for a diffusion, whose drift has an unobservable parameter with a change point. The partially-observed problem is reformulated into one with full observations, via a change of…

最优化与控制 · 数学 2014-08-19 Lokman A. Abbas-Turki , Ioannis Karatzas , Qinghua Li

In this paper, we discuss the steady and time-dependent nonlinear convection-diffusion (advection-diffusion) equations with the Dirichlet boundary condition. For the steady nonlinear equation, we use an iteration method to reformulate the…

数值分析 · 数学 2025-07-28 Qiwei Feng , Catalin Trenchea

Diffusion models, which convert noise into new data instances by learning to reverse a diffusion process, have become a cornerstone in contemporary generative modeling. In this work, we develop non-asymptotic convergence theory for a…

机器学习 · 计算机科学 2024-08-06 Gen Li , Yuting Wei , Yuejie Chi , Yuxin Chen

The one-dimensional triplet contact process with diffusion (TCPD) model has been studied using fast multispin GPU Monte Carlo simulations. In particular, the particle density \rho and the density of pairs of neighboring particles \rho_p…

统计力学 · 物理学 2015-06-15 Raoul D. Schram , Gerard T. Barkema

Transition path theory (TPT) for diffusion processes is a framework for analysing the transitions of multiscale ergodic diffusion processes between disjoint metastable subsets of state space. Most methods for applying TPT involve the…

数值分析 · 数学 2021-03-31 Nada Cvetković , Tim Conrad , Han Cheng Lie

By means of a unifying measure-theoretic approach, we establish lower bounds on the Hausdorff dimension of the space-time set which can support anomalous dissipation for weak solutions of fluid equations, both in the presence or absence of…

偏微分方程分析 · 数学 2024-07-29 Luigi De Rosa , Theodore D. Drivas , Marco Inversi

This paper is concerned with $3$-D stochastic Euler-Poisson equations with insulating boundary conditions forced by the Wiener process. We first establish the global existence and uniqueness of the solution to the system, then we prove that…

偏微分方程分析 · 数学 2025-02-18 Yachun Li , Ming Mei , Lizhen Zhang

Diffusion models perform remarkably well on high-dimensional data such as images, often using only a modest number of reverse-time steps. Despite this practical success, existing convergence theory does not fully explain why such samplers…

机器学习 · 计算机科学 2026-05-11 Ahmad Aghapour , Erhan Bayraktar

Diffusion models, emerging as powerful deep generative tools, excel in various applications. They operate through a two-steps process: introducing noise into training samples and then employing a model to convert random noise into new…

计算机视觉与模式识别 · 计算机科学 2026-02-13 Huijie Zhang , Yifu Lu , Ismail Alkhouri , Saiprasad Ravishankar , Dogyoon Song , Qing Qu

We derive expressions for the first three moments of the decision time (DT) distribution produced via first threshold crossings by sample paths of a drift-diffusion equation. The "pure" and "extended" diffusion processes are widely used to…

神经元与认知 · 定量生物学 2016-01-26 Vaibhav Srivastava , Philip Holmes , Patrick Simen

We prove an averaging principle which asserts convergence of diffusion processes on domains separated by semi-permeable membranes, when diffusion coefficients tend to infinity while the flux through the membranes remains constant. In the…

泛函分析 · 数学 2019-08-08 Adam Bobrowski , Bogdan Kazmierczak , Markus Kunze

A finite difference method is constructed to solve singularly perturbed convection-diffusion problems posed on smooth domains. Constraints are imposed on the data so that only regular exponential boundary layers appear in the solution. A…

数值分析 · 数学 2021-12-23 Alan F. Hegarty , Eugene O'Riordan

We present an improved method for computing incompressible viscous flow around suspended rigid particles using a fixed and uniform computational grid. The main idea is to incorporate Peskin's regularized delta function approach [Acta…

流体动力学 · 物理学 2018-09-24 Markus Uhlmann

In the present work, the Eulerian Large Eddy Simulation of dilute disperse phase flows is investigated. By highlighting the main advantages and drawbacks of the available approaches in the literature, a choice is made in terms of modelling:…

数值分析 · 数学 2015-08-21 Christophe Chalons , Marc Massot , Aymeric Vié

Using a continuum bead-spring Monte Carlo model, we study the anomalous diffusion dynamics of a self-avoiding tethered membrane by means of extensive computer simulations. We focus on the subdiffusive stochastic motion of the membrane's…

软凝聚态物质 · 物理学 2008-05-14 Hristina Popova , Andrey Milchev

Motivated by the normal form of a fast-slow ordinary differential equation exhibiting a pitchfork singularity we consider the discrete-time dynamical system that is obtained by an application of the explicit Euler method. Tracking…

动力系统 · 数学 2019-11-22 Luca Arcidiacono , Maximilian Engel , Christian Kuehn

The document describes a numerical algorithm to simulate plasmas and fluids in the 3 dimensional space by the Euler method, in which the spatial meshes are fixed to the space. The plasmas and fluids move through the spacial Euler mesh…

等离子体物理 · 物理学 2020-04-09 Hiroki Nakamura , Shigeo Kawata , Ken Uchibori , Takahiro Karino