English
Related papers

Related papers: Reconstruction of Transient Anisotropic Diffusion …

200 papers

The subdiffusion model that involves a Caputo fractional derivative in time is widely used to describe anomalously slow diffusion processes. In this work we aim at recovering the locations of small conductivity inclusions in the model from…

Numerical Analysis · Mathematics 2025-05-29 Jiho Hong , Bangti Jin , Zhizhang Wu

Adjoint-based design optimizations are usually computationally expensive and those costs scale with resolution. To address this, researchers have proposed machine learning approaches for inverse design that can predict higher-resolution…

Machine Learning · Computer Science 2024-08-19 Milad Habibi , Mark Fuge

Four-dimensional computed tomography (4DCT) is essential for medical imaging applications like radiotherapy, which demand precise respiratory motion representation. Traditional methods for reconstructing 4DCT data suffer from artifacts and…

Medical Physics · Physics 2025-07-21 Antoine De Paepe , Alexandre Bousse , Clémentine Phung-Ngoc , Dimitris Visvikis

We study nonparametric Bayesian models for reversible multi-dimensional diffusions with periodic drift. For continuous observation paths, reversibility is exploited to prove a general posterior contraction rate theorem for the drift…

Statistics Theory · Mathematics 2024-08-02 Matteo Giordano , Kolyan Ray

The paper considers an inverse problem of reconstructing the spatially distributed complex dielectric permittivity function using backscattered data of the electric field in the frequency domain. We develop iterative algorithm for…

Medical Physics · Physics 2024-10-29 Larisa Beilina , Anders Eriksson , Noora Neittaanmäki

Denoising Diffusion Probabilistic Models (DDPM) are powerful state-of-the-art methods used to generate synthetic data from high-dimensional data distributions and are widely used for image, audio, and video generation as well as many more…

Machine Learning · Statistics 2025-04-25 Iskander Azangulov , George Deligiannidis , Judith Rousseau

Diffusion problems with anisotropic features arise in the various areas of science and engineering fields. As a Lagrangian mesh-less method, SPH has a special advantage in addressing the diffusion problems due to the the benefit of dealing…

Computational Engineering, Finance, and Science · Computer Science 2024-10-14 Xiaojing Tang , Oskar Haidn , Xiangyu Hu

We propose a new approach for the accurate reconstruction of cosmic microwave background distributions from observations containing in addition to the primary fluctuations the radiation from unresolved extragalactic point sources and pixel…

Astrophysics · Physics 2007-05-23 A. T. Bajkova

This work investigates both direct and inverse problems of the variable-exponent sub-diffusion model, which attracts increasing attentions in both practical applications and theoretical aspects. Based on the perturbation method, which…

Numerical Analysis · Mathematics 2025-01-31 Zhiyuan Li , Chunlong Sun , Xiangcheng Zheng

Real-world data often has a long-tailed distribution, where the scarcity of tail samples significantly limits the model's generalization ability. Denoising Diffusion Probabilistic Models (DDPM) are generative models based on stochastic…

Computer Vision and Pattern Recognition · Computer Science 2024-09-24 Jingyu Kong , Yuan Guo , Yu Wang , Yuping Duan

Denoising diffusion probabilistic models (DDPMs) (Ho et al. 2020) have shown impressive results on image and waveform generation in continuous state spaces. Here, we introduce Discrete Denoising Diffusion Probabilistic Models (D3PMs),…

Machine Learning · Computer Science 2023-02-23 Jacob Austin , Daniel D. Johnson , Jonathan Ho , Daniel Tarlow , Rianne van den Berg

Diffusion models have emerged as the new state-of-the-art generative model with high quality samples, with intriguing properties such as mode coverage and high flexibility. They have also been shown to be effective inverse problem solvers,…

Computer Vision and Pattern Recognition · Computer Science 2025-10-06 Hyungjin Chung , Dohoon Ryu , Michael T. McCann , Marc L. Klasky , Jong Chul Ye

Uncertainty quantification is critical in scientific inverse problems to distinguish identifiable parameters from those that remain ambiguous given available measurements. The Conditional Diffusion Model-based Inverse Problem Solver (CDI)…

Machine Learning · Computer Science 2026-01-27 Dmitrii Torbunov , Yihui Ren , Lijun Wu , Yimei Zhu

We propose an advanced Chebyshev expansion method for the numerical calculation of linear response functions at finite temperature. Its high stability and the small required resources allow for a comprehensive study of the optical…

Disordered Systems and Neural Networks · Physics 2016-08-31 Alexander Weisse

The concept of diffusion in collisionless space plasmas like those near the magnetopause and in the geomagnetic tail is reexamined from a fundamental statistical point of view making use of the division of particle orbits into waiting…

Space Physics · Physics 2014-06-25 R. A. Treumann , W. Baumjohann

We present the first framework to solve linear inverse problems leveraging pre-trained latent diffusion models. Previously proposed algorithms (such as DPS and DDRM) only apply to pixel-space diffusion models. We theoretically analyze our…

Machine Learning · Computer Science 2023-07-04 Litu Rout , Negin Raoof , Giannis Daras , Constantine Caramanis , Alexandros G. Dimakis , Sanjay Shakkottai

The classical Ka\v{c}anov scheme for the solution of nonlinear variational problems can be interpreted as a fixed point iteration method that updates a given approximation by solving a linear problem in each step. Based on this observation,…

Numerical Analysis · Mathematics 2021-11-30 Pascal Heid , Thomas P. Wihler

Diffusion probabilistic models (DPMs) have become a popular approach to conditional generation, due to their promising results and support for cross-modal synthesis. A key desideratum in conditional synthesis is to achieve high…

Computer Vision and Pattern Recognition · Computer Science 2023-02-17 Ye Zhu , Yu Wu , Kyle Olszewski , Jian Ren , Sergey Tulyakov , Yan Yan

We revisit the inverse source problem in a two dimensional absorbing and scattering medium and present a non-iterative reconstruction method using measurements of the radiating flux at the boundary. The attenuation and scattering…

Analysis of PDEs · Mathematics 2020-01-29 Hiroshi Fujiwara , Kamran Sadiq , Alexandru Tamasan

The nanostructure inverse problem is an attractive problem that helps researchers to understand the relationship between the properties and the structure of nanomaterials. This study focuses on the problem of recovering the model system of…

Machine Learning · Computer Science 2026-03-10 Jiarui Cao , Zhiyang Zhang , Heming Wang , Jun Xu , Ling Lan , Simon J. L. Billinge , Ran Gu