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In this paper we present a rigorous cost and error analysis of a multilevel estimator based on randomly shifted Quasi-Monte Carlo (QMC) lattice rules for lognormal diffusion problems. These problems are motivated by uncertainty…

Fast and accurate predictions of uncertainties in the computed dose are crucial for the determination of robust treatment plans in radiation therapy. This requires the solution of particle transport problems with uncertain parameters or…

医学物理 · 物理学 2022-11-09 Pia Stammer , Lucas Burigo , Oliver Jäkel , Martin Frank , Niklas Wahl

Geophysical methods provide a cost-effective way to characterize the subsurface for hydrogeological projects, but they rely on solving an inverse problem. Traditionally, deterministic approaches are used, which face challenges due to…

地球物理 · 物理学 2025-12-05 Arsalan Ahmed , Thomas Hermans , David Dudal , Wouter Deleersnyder

We present novel Monte Carlo (MC) and multilevel Monte Carlo (MLMC) methods to determine the unbiased covariance of random variables using h-statistics. The advantage of this procedure lies in the unbiased construction of the estimator's…

统计理论 · 数学 2024-05-09 Sharana Kumar Shivanand

A common way to simulate the transport and spread of pollutants in the atmosphere is via stochastic Lagrangian dispersion models. Mathematically, these models describe turbulent transport processes with stochastic differential equations…

In this study, we develop a probabilistic approach to map the parametric uncertainty to the output state uncertainty in first-order hyperbolic conservation laws. We analyze this problem for nonlinear immiscible two-phase transport in…

计算物理 · 物理学 2021-05-11 Farzaneh Rajabi , Hamdi A. Tchelepi

Accurate modeling of contamination in subsurface flow and water aquifers is crucial for agriculture and environmental protection. Here, we demonstrate a parallel method to quantify the propagation of the uncertainty in the dispersal of…

Uncertainty quantification approaches have been more critical in large language models (LLMs), particularly high-risk applications requiring reliable outputs. However, traditional methods for uncertainty quantification, such as…

人工智能 · 计算机科学 2024-07-01 Ferhat Ozgur Catak , Murat Kuzlu

We propose a multilevel Markov chain Monte Carlo (MCMC) method for the Bayesian inference of random field parameters in PDEs using high-resolution data. Compared to existing multilevel MCMC methods, we additionally consider level-dependent…

数值分析 · 数学 2025-08-19 Pieter Vanmechelen , Geert Lombaert , Giovanni Samaey

Through the Bayesian lens of data assimilation, uncertainty on model parameters is traditionally quantified through the posterior covariance matrix. However, in modern settings involving high-dimensional and computationally expensive…

统计计算 · 统计学 2023-11-16 Michael Stanley , Mikael Kuusela , Brendan Byrne , Junjie Liu

Computing risk measures of a financial portfolio comprising thousands of derivatives is a challenging problem because (a) it involves a nested expectation requiring multiple evaluations of the loss of the financial portfolio for different…

数理金融 · 定量金融 2023-01-10 Michael B. Giles , Abdul-Lateef Haji-Ali

We present a new antithetic multilevel Monte Carlo (MLMC) method for the estimation of expectations with respect to laws of diffusion processes that can be elliptic or hypo-elliptic. In particular, we consider the case where one has to…

数值分析 · 数学 2025-04-29 Yuga Iguchi , Ajay Jasra , Mohamed Maama , Alexandros Beskos

We present an analysis of multilevel Monte Carlo techniques for the forward problem of uncertainty quantification for the radiative transport equation, when the coefficients ({\em cross-sections}) are heterogenous random fields. To do this,…

数值分析 · 数学 2020-01-15 Ivan G. Graham , Matthew J. Parkinson , Robert Scheichl

In this article, we study the application of Multi-Level Monte Carlo (MLMC) approaches to numerical random homogenization. Our objective is to compute the expectation of some functionals of the homogenized coefficients, or of the…

数值分析 · 数学 2013-01-15 Yalchin Efendiev , Cornelia Kronsbein , Frederic Legoll

The Markov chain Monte Carlo (MCMC) method is used to evaluate the imaginary-time path integral of a quantum oscillator with a potential that includes both a quadratic term and a quartic term whose coupling is varied by several orders of…

计算物理 · 物理学 2020-08-27 Shikhar Mittal , Marise J. E. Westbroek , Peter R. King , Dimitri D. Vvedensky

Uncertainty analysis in the outcomes of model predictions is a key element in decision-based material design to establish confidence in the models and evaluate the fidelity of models. Uncertainty Propagation (UP) is a technique to determine…

机器学习 · 计算机科学 2023-02-13 Danial Khatamsaz , Vahid Attari , Raymundo Arroyave , Douglas L. Allaire

Multilevel Monte Carlo (MLMC) is a recently proposed variation of Monte Carlo (MC) simulation that achieves variance reduction by simulating the governing equations on a series of spatial (or temporal) grids with increasing resolution.…

统计计算 · 统计学 2017-04-26 Hillary Fairbanks , Alireza Doostan , Christian Ketelsen , Gianluca Iaccarino

We establish a notion of random entropy solution for degenerate fractional conservation laws incorporating randomness in the initial data, convective flux and diffusive flux. In order to quantify the solution uncertainty, we design a…

数值分析 · 数学 2020-10-02 Ujjwal Koley , Deep Ray , Tanmay Sarkar

Markov chain Monte Carlo (MCMC) is an established approach for uncertainty quantification and propagation in scientific applications. A key challenge in applying MCMC to scientific domains is computation: the target density of interest is…

机器学习 · 统计学 2022-10-05 Diana Cai , Ryan P. Adams

In this paper we introduce and discuss numerical schemes for the approximation of kinetic equations for flocking behavior with phase transitions that incorporate uncertain quantities. This class of schemes here considered make use of a…

数值分析 · 数学 2019-10-31 Jose Antonio Carrillo , Mattia Zanella