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An error control technique aimed to assess the quality of smoothed finite element approximations is presented in this paper. Finite element techniques based on strain smoothing appeared in 2007 were shown to provide significant advantages…

Part I of this work [2] developed the exact diffusion algorithm to remove the bias that is characteristic of distributed solutions for deterministic optimization problems. The algorithm was shown to be applicable to a larger set of…

Optimization and Control · Mathematics 2017-12-27 Kun Yuan , Bicheng Ying , Xiaochuan Zhao , Ali H. Sayed

In this paper, robust nonparametric estimators, instead of local linear estimators, are adapted for infinitesimal coefficients associated with integrated jump-diffusion models to avoid the impact of outliers on accuracy. Furthermore,…

Statistics Theory · Mathematics 2018-06-26 Yuping Song , Hanchao Wang

We introduce and explain key relations between a posteriori error estimates and subspace correction methods viewed as preconditioners for problems in infinite dimensional Hilbert spaces. We set the stage using the Finite Element Exterior…

Numerical Analysis · Mathematics 2025-04-16 Yuwen Li , Ludmil T. Zikatanov

This paper considers the finite element solution of the boundary value problem of Poisson's equation and proposes a guaranteed em a posteriori local error estimation based on the hypercircle method. Compared to the existing literature on…

Numerical Analysis · Mathematics 2021-12-17 Taiga Nakano , Xuefeng Liu

Score-based diffusion models achieve state-of-the-art performance for inverse problems, but their practical deployment is hindered by long inference times and cumbersome hyperparameter tuning. While pretrained diffusion models can be reused…

Computer Vision and Pattern Recognition · Computer Science 2026-05-13 Julio Oscanoa , Irmak Sivgin , Cagan Alkan , Daniel Ennis , John Pauly , Mert Pilanci , Shreyas Vasanawala

We consider so-called Herrmann and Hydrostatic mixed formulations of classical linear elasticity and analyse the error associated with locally stabilised $P_1-P_0$ finite element approximation. First, we prove a stability estimate for the…

Numerical Analysis · Mathematics 2018-01-15 Arbaz Khan , Catherine E. Powell , David J. Silvester

The Reduced Basis (RB) method is a well established method for the model order reduction of problems formulated as parametrized partial differential equations. One crucial requirement for the application of RB schemes is the availability of…

Numerical Analysis · Mathematics 2016-11-25 Andreas Buhr , Christian Engwer , Mario Ohlberger , Stephan Rave

In this paper, we propose a novel adaptive finite element method for an elliptic equation with line Dirac delta functions as a source term. We first study the well-posedness and global regularity of the solution in the whole domain. Instead…

Numerical Analysis · Mathematics 2022-07-12 Huihui Cao , Hengguang Li , Nianyu Yi , Peimeng Yin

In this work, a complete error analysis is presented for fully discrete solutions of the subdiffusion equation with a time-dependent diffusion coefficient, obtained by the Galerkin finite element method with conforming piecewise linear…

Numerical Analysis · Mathematics 2018-09-24 Bangti Jin , Buyang Li , Zhi Zhou

Diffusion models have been firmly established as principled zero-shot solvers for linear and nonlinear inverse problems, owing to their powerful image prior and iterative sampling algorithm. These approaches often rely on Tweedie's formula,…

Machine Learning · Computer Science 2026-04-29 Jonathan Patsenker , Henry Li , Myeongseob Ko , Ruoxi Jia , Yuval Kluger

Imputation methods play a critical role in enhancing the quality of practical time-series data, which often suffer from pervasive missing values. Recently, diffusion-based generative imputation methods have demonstrated remarkable success…

Machine Learning · Computer Science 2025-10-03 Zeqi Ye , Minshuo Chen

In this paper, we introduce a simple local flux recovery for $\mathcal{Q}_k$ finite element of a scalar coefficient diffusion equation on quadtree meshes, with no restriction on the irregularities of hanging nodes. The construction requires…

Numerical Analysis · Mathematics 2021-07-14 Shuhao Cao

Goal oriented error estimation and adaptive procedures are essential for the accurate and efficient evaluation of numerical simulations that involve complex domains. By locally improving the approximation quality we can solve expensive…

Neural posterior estimation (NPE), a simulation-based computational approach for Bayesian inference, has shown great success in approximating complex posterior distributions. Existing NPE methods typically rely on normalizing flows, which…

Machine Learning · Statistics 2025-03-14 Tianyu Chen , Vansh Bansal , James G. Scott

We propose a guaranteed and fully computable upper bound on the energy norm of the error in low-rank Tensor Train (TT) approximate solutions of (possibly) high dimensional reaction-diffusion problems. The error bound is obtained from…

Numerical Analysis · Mathematics 2020-04-03 Sergey Dolgov , Tomáš Vejchodský

In this work, we investigate the recovery of a parameter in a diffusion process given by the order of derivation in time for a class of diffusion type equations, including both classical and time-fractional diffusion equations, from the…

Analysis of PDEs · Mathematics 2021-11-04 Bangti Jin , Yavar Kian

Using diffusion models to solve inverse problems is a growing field of research. Current methods assume the degradation to be known and provide impressive results in terms of restoration quality and diversity. In this work, we leverage the…

Computer Vision and Pattern Recognition · Computer Science 2025-06-02 Charles Laroche , Andrés Almansa , Eva Coupete

In this work we investigate an inverse problem of recovering point sources and their time-dependent strengths from {a posteriori} partial internal measurements in a subdiffusion model which involves a Caputo fractional derivative in time…

Analysis of PDEs · Mathematics 2024-12-12 Kuang Huang , Bangti Jin , Yavar Kian , Georges Sadaka , Zhi Zhou

Sampling from the posterior is a key technical problem in Bayesian statistics. Rigorous guarantees are difficult to obtain for Markov Chain Monte Carlo algorithms of common use. In this paper, we study an alternative class of algorithms…

Statistics Theory · Mathematics 2024-08-26 Andrea Montanari , Yuchen Wu