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In the paper, we discuss the reconstruction of scalar parameters in a linear diffusion equation with fractional in time differential operators and with additional nonlocal (convolution) terms, which incorporate memory effects in models.…

Analysis of PDEs · Mathematics 2026-03-30 Sergii V. Siryk , Lidiia Tereshchenko , Nataliya Vasylyeva

The forward problems of pattern formation have been greatly empowered by extensive theoretical studies and simulations, however, the inverse problem is less well understood. It remains unclear how accurately one can use images of pattern…

Computational Physics · Physics 2021-04-07 Hongbo Zhao , Richard D. Braatz , Martin Z. Bazant

Poisson distributed measurements in inverse problems often stem from Poisson point processes that are observed through discretized or finite-resolution detectors, one of the most prominent examples being positron emission tomography (PET).…

Statistics Theory · Mathematics 2024-07-25 Marco Mauritz , Benedikt Wirth

Reconstructing PDE-governed fields from sparse and irregular measurements is challenging due to their ill-posed nature. Deterministic surrogates are trained on dense fields that struggle with limited measurements and uncertainty…

Machine Learning · Computer Science 2026-05-18 Hao Zhou , Rui Zhang , Han Wan , Hao Sun

Physics-Informed Neural Networks (PINN) are a machine learning tool that can be used to solve direct and inverse problems related to models described by Partial Differential Equations. This paper proposes an adaptive inverse PINN applied to…

Numerical Analysis · Mathematics 2024-11-28 Marco Berardi , Fabio Difonzo , Matteo Icardi

For parameter identification problems the Fr\'echet-derivative of the parameter-to-state map is of particular interest. In many applications, e.g. in seismic tomography, the unknown quantity is modeled as a coefficient in a linear…

Analysis of PDEs · Mathematics 2019-01-30 Thies Gerken , Simon Grützner

The reconstruction of unsteady flow fields from limited measurements is a challenging and crucial task for many engineering applications. Machine learning models are gaining popularity for solving this problem due to their ability to learn…

Fluid Dynamics · Physics 2026-01-09 Marc Amorós-Trepat , Luis Medrano-Navarro , Qiang Liu , Luca Guastoni , Nils Thuerey

Positron Emission Tomography (PET) is a functional imaging modality that enables the visualization of biochemical and physiological processes across various tissues. Recently, deep learning (DL)-based methods have demonstrated significant…

Image and Video Processing · Electrical Eng. & Systems 2026-01-16 Yiran Sun , Osama Mawlawi

This paper studies the problem of parameter estimation in resonant, acoustic fluid-structure interaction problems over a wide frequency range. Problems with multiple resonances are known to be subjected to local minima, which represents a…

Computational Physics · Physics 2019-03-06 Peter Göransson , Jacques Cuenca , Timo Lähivaara

These lecture notes summarize various summer schools that I have given on the topic of solving inverse problems (state and parameter estimation) by combining optimally measurement observations and parametrized PDE models. After defining a…

Numerical Analysis · Mathematics 2022-03-16 Olga Mula

We introduce and analyze a method of learning-informed parameter identification for partial differential equations (PDEs) in an all-at-once framework. The underlying PDE model is formulated in a rather general setting with three unknowns:…

Optimization and Control · Mathematics 2023-08-25 Christian Aarset , Martin Holler , Tram Thi Ngoc Nguyen

In this work, we derive particle schemes, based on micro-macro decomposition, for linear kinetic equations in the diffusion limit. Due to the particle approximation of the micro part, a splitting between the transport and the collision part…

Numerical Analysis · Mathematics 2017-01-19 Anaïs Crestetto , Nicolas Crouseilles , Mohammed Lemou

In this paper, we present a practical algorithm based on sparsity regularization to effectively solve nonlinear dynamic inverse problems that are encountered in subsurface model calibration. We use an iteratively reweighted algorithm that…

Numerical Analysis · Computer Science 2009-11-13 Lianlin Li , B. Jafarpour

This paper considers the problem of parameter identification for a multirobot system. We wish to understand when is it feasible for an adversarial observer to reverse-engineer the parameters of tasks being performed by a team of robots by…

Optimization and Control · Mathematics 2020-09-30 Jaskaran Singh Grover , Changliu Liu , Katia Sycara

This paper deals with the problem of on-line identification of the parameters of a realistic dynamical model of a photovoltaic array connected to a power system through a power converter. It has been shown in the literature that, when…

Systems and Control · Electrical Eng. & Systems 2022-09-16 Alexey Bobtsov , Fernando Mancilla-David , Stanislav Aranovskiy , Romeo Ortega

The transport and localization of RNA molecules, crucial for cellular function and development, involve a combination of diffusion and active transport mechanisms. Here, we are motivated by understanding the dynamics of RNA in Xenopus…

Analysis of PDEs · Mathematics 2025-10-21 Qinyu Xu

Reconstructing flow fields from sparse measurements is a fundamental problem in fluid mechanics with broad implications for modeling, control, and design. In this work, we propose a novel operator learning framework that leverages the…

Computational Engineering, Finance, and Science · Computer Science 2026-05-25 Qian Zhang , George Em Karniadakis

Parametric imaging is a compartmental approach that processes nuclear imaging data to estimate the spatial distribution of the kinetic parameters governing tracer flow. The present paper proposes a novel and efficient computational method…

Numerical Analysis · Mathematics 2018-08-21 Mara Scussolini , Sara Garbarino , Gianmario Sambuceti , Giacomo Caviglia , Michele Piana

We propose a simple, interpretable framework for solving a wide range of image reconstruction problems such as denoising and deconvolution. Given a corrupted input image, the model synthesizes a spatially varying linear filter which, when…

Image and Video Processing · Electrical Eng. & Systems 2018-11-29 Shu Kong , Charless Fowlkes

In this paper, we develop a unified approach to study partial identification of a finite-dimensional parameter defined by a general moment model with incomplete data. We establish a novel characterization of the identified set for the true…

Econometrics · Economics 2025-10-03 Yanqin Fan , Hyeonseok Park , Brendan Pass , Xuetao Shi