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Efficiently performing predictive studies of irradiated particle-laden turbulent flows has the potential of providing significant contributions towards better understanding and optimizing, for example, concentrated solar power systems. As…

Computational Physics · Physics 2018-08-20 Hillary R. Fairbanks , Lluis Jofre , Gianluca Geraci , Gianluca Iaccarino , Alireza Doostan

In this paper, we study the problem of uncertainty estimation and calibration for LLMs. We begin by formulating the uncertainty estimation problem, a relevant yet underexplored area in existing literature. We then propose a supervised…

Machine Learning · Computer Science 2024-10-24 Linyu Liu , Yu Pan , Xiaocheng Li , Guanting Chen

Nested Monte Carlo is widely used for risk estimation, but its efficiency is limited by the discontinuity of the indicator function and high computational cost. This paper proposes a nested Multilevel Monte Carlo (MLMC) method combined with…

Numerical Analysis · Mathematics 2026-04-06 Yu Xu , Xiaoqun Wang

Uncertainty quantification (UQ) in Large Language Models (LLMs) is essential for their safe and reliable deployment, particularly in critical applications where incorrect outputs can have serious consequences. Current UQ methods typically…

Computation and Language · Computer Science 2025-04-10 Nicola Cecere , Andrea Bacciu , Ignacio Fernández Tobías , Amin Mantrach

A ubiquitous challenge in design space exploration or uncertainty quantification of complex engineering problems is the minimization of computational cost. A useful tool to ease the burden of solving such systems is model reduction. This…

Numerical Analysis · Mathematics 2021-04-16 Felix Newberry , Jerrad Hampton , Kenneth Jansen , Alireza Doostan

We design and implement a novel algorithm for computing a multilevel Monte Carlo (MLMC) estimator of the cumulative distribution function of a quantity of interest in problems with random input parameters or initial conditions. Our approach…

Numerical Analysis · Mathematics 2020-08-26 Søren Taverniers , Daniel M. Tartakovsky

Monte Carlo simulation is often used for the reliability assessment of power systems, but it converges slowly when the system is complex. Multilevel Monte Carlo (MLMC) can be applied to speed up computation without compromises on model…

Computation · Statistics 2022-07-12 Ensieh Sharifnia , Simon Tindemans

We propose a variance reduction framework for variational inference using the Multilevel Monte Carlo (MLMC) method. Our framework is built on reparameterized gradient estimators and "recycles" parameters obtained from past update history in…

Machine Learning · Statistics 2021-12-03 Masahiro Fujisawa , Issei Sato

We consider the computational efficiency of Monte Carlo (MC) and Multilevel Monte Carlo (MLMC) methods applied to partial differential equations with random coefficients. These arise, for example, in groundwater flow modelling, where a…

Numerical Analysis · Mathematics 2024-12-12 Anastasia Istratuca , Aretha Teckentrup

Laplace Neural Operators (LNOs) have recently emerged as a promising approach in scientific machine learning due to the ability to learn nonlinear maps between functional spaces. However, this framework often requires substantial amounts of…

Machine Learning · Computer Science 2025-02-04 Haoyang Zheng , Guang Lin

Deep neural networks have shown great success in prediction quality while reliable and robust uncertainty estimation remains a challenge. Predictive uncertainty supplements model predictions and enables improved functionality of downstream…

Machine Learning · Computer Science 2021-12-02 Johanna Rock , Tiago Azevedo , René de Jong , Daniel Ruiz-Muñoz , Partha Maji

Parameters in climate models are usually calibrated manually, exploiting only small subsets of the available data. This precludes both optimal calibration and quantification of uncertainties. Traditional Bayesian calibration methods that…

Statistics Theory · Mathematics 2021-10-04 Oliver R. A. Dunbar , Alfredo Garbuno-Inigo , Tapio Schneider , Andrew M. Stuart

Monte Carlo methods to evaluate and maximize the likelihood function enable the construction of confidence intervals and hypothesis tests, facilitating scientific investigation using models for which the likelihood function is intractable.…

Methodology · Statistics 2017-02-13 Edward L. Ionides , Carles Breto , Joonha Park , Richard A. Smith , Aaron A. King

Metamodels, or the regression analysis of Monte Carlo simulation results, provide a powerful tool to summarize simulation findings. However, an underutilized approach is the multilevel metamodel (MLMM) that accounts for the dependent data…

Methodology · Statistics 2025-11-21 Joshua Gilbert , Luke Miratrix

Cardiovascular simulations are increasingly used for non-invasive diagnosis of cardiovascular disease, to guide treatment decisions, and in the design of medical devices. Quantitative assessment of the variability of simulation outputs due…

Medical Physics · Physics 2020-02-24 Jongmin Seo , Daniele E. Schiavazzi , Andrew M. Kahn , Alison L. Marsden

Explicit quantification of uncertainty in engineering simulations is being increasingly used to inform robust and reliable design practices. In the aerospace industry, computationally-feasible analyses for design optimization purposes often…

Fluid Dynamics · Physics 2019-11-13 Jayant Mukhopadhaya , Brian T. Whitehead , John F. Quindlen , Juan J. Alonso

Deep learning (DL)-based methods have achieved state-of-the-art performance for many medical image segmentation tasks. Nevertheless, recent studies show that deep neural networks (DNNs) can be miscalibrated and overconfident, leading to…

Image and Video Processing · Electrical Eng. & Systems 2024-06-28 Yidong Zhao , Joao Tourais , Iain Pierce , Christian Nitsche , Thomas A. Treibel , Sebastian Weingärtner , Artur M. Schweidtmann , Qian Tao

In this paper the application of the multi-level Monte Carlo (MLMC) method on numerical simulations of turbulent flows with uncertain parameters is investigated. Several strategies for setting up the MLMC method are presented, and the…

Computation · Statistics 2016-08-22 Qingsha Chen , Ju Ming

The use of deep learning for medical imaging has seen tremendous growth in the research community. One reason for the slow uptake of these systems in the clinical setting is that they are complex, opaque and tend to fail silently. Outside…

Computer Vision and Pattern Recognition · Computer Science 2018-07-03 Terrance DeVries , Graham W. Taylor

Uncertainty Quantification through Markov Chain Monte Carlo (MCMC) can be prohibitively expensive for target probability densities with expensive likelihood functions, for instance when the evaluation it involves solving a Partial…

Computation · Statistics 2020-12-11 Mikkel B. Lykkegaard , Grigorios Mingas , Robert Scheichl , Colin Fox , Tim J. Dodwell