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In this article, we address the challenge of solving the ill-posed reconstruction problem in computed tomography using a translation invariant diagonal frame decomposition (TI-DFD). First, we review the concept of a TI-DFD for general…

Numerical Analysis · Mathematics 2023-08-08 Simon Göppel , Markus Haltmeier , Jürgen Frikel

Although diffusion models can generate remarkably high-quality samples, they are intrinsically bottlenecked by their expensive iterative sampling procedure. Consistency models (CMs) have recently emerged as a promising diffusion model…

The Radon transform Rf of functions f on SO(3) has recently been applied extensively in texture analysis, i.e. the analysis of preferred crystallographic orientation. In practice one has to determine the orientation probability density…

Functional Analysis · Mathematics 2014-03-07 Swanhild Bernstein , Svend Ebert , Isaac Z. Pesenson

We establish two new direct product theorems for the randomized query complexity of Boolean functions. The first shows that computing $n$ copies of a function $f$, even with a small success probability of $\gamma^n$, requires $\Theta(n)$…

Computational Complexity · Computer Science 2025-12-10 Shalev Ben-David , Eric Blais

In this paper, we present the Directly Denoising Diffusion Model (DDDM): a simple and generic approach for generating realistic images with few-step sampling, while multistep sampling is still preserved for better performance. DDDMs require…

Computer Vision and Pattern Recognition · Computer Science 2024-06-03 Dan Zhang , Jingjing Wang , Feng Luo

Sub-sampling is applied to simulated $T_1$-$D$ NMR signals and its influence on inversion performance is evaluated. For this different levels of sub-sampling were employed ranging from the fully sampled signal down to only less than two…

Chemical Physics · Physics 2024-01-02 Julian B. B. Beckmann , Mick D. Mantle , Andrew J. Sederman , Lynn F. Gladden

Score Distillation Sampling (SDS) is a recent but already widely popular method that relies on an image diffusion model to control optimization problems using text prompts. In this paper, we conduct an in-depth analysis of the SDS loss…

Computer Vision and Pattern Recognition · Computer Science 2024-07-08 Thiemo Alldieck , Nikos Kolotouros , Cristian Sminchisescu

An exact arithmetic, memory efficient direct solution method for finite element method (FEM) computations is outlined. Unlike conventional black-box or low-rank direct solvers that are opaque to the underlying physical problem, the proposed…

Computational Engineering, Finance, and Science · Computer Science 2020-02-13 Javad Moshfegh , Marinos N. Vouvakis

A systematic digital-discrete method for obtaining continuous functions with smoothness to a certain order (C^(n)) from sample data is designed. This method is based on gradually varied functions and the classical finite difference method.…

Numerical Analysis · Mathematics 2010-10-19 Li Chen

Synthetic Minority Over-sampling Technique (SMOTE) is the most popular over-sampling method. However, its random nature makes the synthesized data and even imbalanced classification results unstable. It means that in case of running SMOTE n…

Machine Learning · Computer Science 2020-03-24 Hadi Mansourifar , Weidong Shi

Two algorithms are introduced for the computation of discrete integral transforms with a multiscale approach operating in discrete three-dimensional (3D) volumes while considering its real-time implementation. The first algorithm, referred…

We compare the Radon transform in its standard and symplectic formulations and argue that the inversion of the latter can be performed more efficiently.

Quantum Physics · Physics 2010-11-29 Paolo Facchi , Marilena Ligabò , Saverio Pascazio

Denoising Diffusion Probabilistic Models (DDPMs) have gained great attention in adversarial purification. Current diffusion-based works focus on designing effective condition-guided mechanisms while ignoring a fundamental problem, i.e., the…

Computer Vision and Pattern Recognition · Computer Science 2024-12-02 Jiancheng Zhang , Peiran Dong , Yongyong Chen , Yin-Ping Zhao , Song Guo

We introduce a new overlapping Domain Decomposition Method (DDM) to solve the fully nonlinear Monge-Amp\`ere equation. While DDMs have been extensively studied for linear problems, their application to fully nonlinear partial differential…

Numerical Analysis · Mathematics 2023-06-05 Yassine Boubendir , Jake Brusca , Brittany Froese Hamfeldt , Tadanaga Takahashi

We propose a sampling scheme on the sphere and develop a corresponding spherical harmonic transform (SHT) for the accurate reconstruction of the diffusion signal in diffusion magnetic resonance imaging (dMRI). By exploiting the antipodal…

Medical Physics · Physics 2015-02-26 Alice P. Bates , Zubair Khalid , Rodney A. Kennedy

The Derivative Source Method (DSM) takes derivatives of a particle transport equation with respect to selected parameters and solves them via the standard Monte Carlo random walk simulation along with the original transport problem. The…

Computational Physics · Physics 2025-01-14 Ilham Variansyah , Ryan G. McClarren , Todd S. Palmer

RGB-D salient object detection (SOD) demonstrates its superiority on detecting in complex environments due to the additional depth information introduced in the data. Inevitably, an independent stream is introduced to extract features from…

Computer Vision and Pattern Recognition · Computer Science 2022-06-03 Guangyu Ren , Yinxiao Yu , Hengyan Liu , Tania Stathaki

In this paper we discuss a deterministic form of ensemble Kalman inversion as a regularization method for linear inverse problems. By interpreting ensemble Kalman inversion as a low-rank approximation of Tikhonov regularization, we are able…

Numerical Analysis · Mathematics 2023-10-31 Fabian Parzer , Otmar Scherzer

Diffuse optical tomography (DOT) is an imaging modality which uses near-infrared light. Although iterative numerical schemes are commonly used for its inverse problem, correct solutions are not obtained unless good initial guesses are…

Numerical Analysis · Mathematics 2021-06-07 Yu Jiang , Manabu Machida , Norikazu Todoroki

Recent diffusion probabilistic models (DPM) in the field of pansharpening have been gradually gaining attention and have achieved state-of-the-art (SOTA) performance. In this paper, we identify shortcomings in directly applying DPMs to the…

Computer Vision and Pattern Recognition · Computer Science 2024-04-18 Zihan Cao , Xiao Wu , Liang-Jian Deng