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The sparse-views x-ray computed tomography (CT) is essential for medical diagnosis and industrial nondestructive testing. However, in particular, the reconstructed image usually suffers from complex artifacts and noise, when the sampling is…

Medical Physics · Physics 2019-10-08 Genwei Ma , Yining Zhu , Xing Zhao

In this paper, we study the convergence of Alternating Projection (AP) algorithm for the matrix completion and compressed sensing problems. We also present computational evidence for the excellent performance of the algorithm. Also, in the…

Optimization and Control · Mathematics 2017-11-08 Ming Jun Lai , Abraham Varghese

Proton computed tomography (pCT) aims to facilitate precise dose planning for hadron therapy, a promising and effective method for cancer treatment. Hadron therapy utilizes protons and heavy ions to deliver well focused doses of radiation,…

Ultrawideband radar is an attractive technology for a variety of applications including security systems. As such, it is essential to develop low-cost systems that produce clear target images. Electromagnetic inverse scattering with…

Signal Processing · Electrical Eng. & Systems 2021-10-14 Takuya Sakamoto

We propose a novel algorithm for image reconstruction in radio interferometry. The ill-posed inverse problem associated with the incomplete Fourier sampling identified by the visibility measurements is regularized by the assumption of…

Instrumentation and Methods for Astrophysics · Physics 2012-10-12 R. E. Carrillo , J. D. McEwen , Y. Wiaux

The Method of Alternating Projections (MAP), a classical algorithm for solving feasibility prob- lems, has recently been intensely studied for nonconvex sets. However, intrinsically available are only local convergence results: convergence…

Optimization and Control · Mathematics 2013-05-21 Heinz H. Bauschke , Hung M. Phan , Xianfu Wang

We develop and analyze a variant of the SARAH algorithm, which does not require computation of the exact gradient. Thus this new method can be applied to general expectation minimization problems rather than only finite sum problems. While…

Optimization and Control · Mathematics 2020-08-28 Lam M. Nguyen , Katya Scheinberg , Martin Takáč

In this paper, as opposed to the random phase masks, the structured illuminations with a pixel-dependent deterministic phase shift are considered to derandomize the model setup. The RAAR algorithm is modified to adapt to two or more…

Numerical Analysis · Mathematics 2017-02-01 Ji Li , Tie Zhou

We summarize recent results and ongoing activities in mathematical algorithms and computer science methods related to proton computed tomography (pCT) and intensity-modulated particle therapy (IMPT) treatment planning. Proton therapy…

Medical Physics · Physics 2021-08-24 Yair Censor , Keith E. Schubert , Reinhard W. Schulte

We present a new iterative rotation inversion technique based on the Simultaneous Algebraic Reconstruction Technique developed for image reconstruction. We describe in detail our algorithmic implementation and compare it to the classical…

Solar and Stellar Astrophysics · Physics 2024-06-17 Sylvain G. Korzennik , Antonio Eff-Darwich

English: This paper concerns the image reconstruction from a few projections in Computed Tomography (CT). The main objective of this paper is to show that the problem is so ill posed that no classical method, such as analytical methods…

Data Analysis, Statistics and Probability · Physics 2007-05-23 Ali Mohammad-Djafari

In this paper we analyse convergence of projected fixed-point iteration on a Riemannian manifold of matrices with fixed rank. As a retraction method we use `projector splitting scheme'. We prove that the projector splitting scheme converges…

Numerical Analysis · Mathematics 2016-04-08 Denis Kolesnikov , Ivan Oseledets

The development of fast and accurate image reconstruction algorithms is a central aspect of computed tomography. In this paper, we investigate this issue for the sparse data problem in photoacoustic tomography (PAT). We develop a direct and…

Computer Vision and Pattern Recognition · Computer Science 2018-08-31 Stephan Antholzer , Markus Haltmeier , Johannes Schwab

Motivated by the remarkable success of Bayesian additive regression trees (BART) in regression modelling, we propose a novel nonparametric Bayesian method, termed Functional BART (FBART), tailored specifically for function-on-scalar…

Methodology · Statistics 2025-06-03 Jiahao Cao , Shiyuan He , Bohai Zhang

Existing approaches to image reconstruction in photoacoustic computed tomography (PACT) with acoustically heterogeneous media are limited to weakly varying media, are computationally burdensome, and/or cannot effectively mitigate the…

Medical Physics · Physics 2013-03-25 Chao Huang , Kun Wang , Liming Nie , Lihong V. Wang , Mark A. Anastasio

This paper proposes a randomized optimization framework for constrained signal reconstruction, where the word "constrained" implies that data-fidelity is imposed as a hard constraint instead of adding a data-fidelity term to an objective…

Optimization and Control · Mathematics 2024-06-28 Shunsuke Ono

In this paper, we propose a systematic approach for extending first-order optimization algorithms, originally designed for unconstrained strongly convex problems, to handle closed and convex set constraints. We show that the resulting…

Optimization and Control · Mathematics 2026-01-05 Mengmou Li , Ioannis Lestas , Masaaki Nagahara

We introduce a quadratically convergent semismooth Newton method for nonlinear semidefinite programming that eliminates the need for the generalized Jacobian regularity, a common yet stringent requirement in existing approaches. Our…

Optimization and Control · Mathematics 2026-01-14 Fuxiaoyue Feng , Chao Ding , Xudong Li

In many applications, a large number of features are collected with the goal to identify a few important ones. Sometimes, these features lie in a metric space with a known distance matrix, which partially reflects their co-importance…

Methodology · Statistics 2021-09-28 Xuechan Li , Anthony Sung , Jichun Xie

We investigate the inverse source problem for the wave equation, arising in photo- and thermoacoustic tomography. There exist quite a few theoretically exact inversion formulas explicitly expressing solution of this problem in terms of the…

Analysis of PDEs · Mathematics 2018-08-01 Ngoc Do , Leonid Kunyansky