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Computed tomography (CT) involves a patient's exposure to ionizing radiation. To reduce the radiation dose, we can either lower the X-ray photon count or down-sample projection views. However, either of the ways often compromises image…

Image and Video Processing · Electrical Eng. & Systems 2023-10-12 Wenjun Xia , Yongyi Shi , Chuang Niu , Wenxiang Cong , Ge Wang

This paper deals with the classic radiotherapy dose fractionation problem for cancer tumors concerning the following goals: a) To maximize the effect of radiation on the tumor, restricting the effect produced to the organs at risk (healing…

Optimization and Control · Mathematics 2021-02-17 Luis Alberto Fernández , Lucía Fernández

In this paper, the tools provided by the theory of Optimal Experimental Design are applied to a nonlinear calibration model. This is motivated by the need of estimating radiation doses using radiochromic films for radiotherapy purposes. The…

Applications · Statistics 2020-05-20 Jesús López-Fidalgo , Mariano Amo-Salas

Inverse design problems are common in engineering and materials science. The forward direction, i.e., computing output quantities from design parameters, typically requires running a numerical simulation, such as a FEM, as an intermediate…

Machine Learning · Computer Science 2026-02-18 Jens U. Kreber , Christian Weißenfels , Joerg Stueckler

X-ray microtomography at synchrotron sources is fundamentally limited by the high radiation dose applied to the samples, which restricts investigations to non-native tissue states and thereby compromises the biological relevance of the…

Iterative methods for tomographic image reconstruction have great potential for enabling high quality imaging from low-dose projection data. The computational burden of iterative reconstruction algorithms, however, has been an impediment in…

Image and Video Processing · Electrical Eng. & Systems 2019-07-25 Kai Zhang , Alireza Entezari

In this first paper of a two-paper series, we present a method for optimizing the dynamic delivery of fluence maps in radiation therapy. For a given fluence map and a given delivery time, the optimization of the leaf trajectories of a…

Medical Physics · Physics 2016-08-10 David Craft , Marleen Balvert

Many high-dimensional optimisation problems exhibit rich geometric structures in their set of minimisers, often forming smooth manifolds due to over-parametrisation or symmetries. When this structure is known, at least locally, it can be…

Optimization and Control · Mathematics 2025-10-27 Evan Markou , Thalaiyasingam Ajanthan , Stephen Gould

We present a method for handling dose constraints as part of a convex programming framework for inverse treatment planning. Our method uniformly handles mean dose, maximum dose, minimum dose, and dose-volume (i.e., percentile) constraints…

Medical Physics · Physics 2019-03-05 Anqi Fu , Baris Ungun , Lei Xing , Stephen Boyd

Spatial light modulation is important for many scientific and industrial applications. The spatial light modulator and optical data projector both rely on precisely configurable optical elements to shape a light beam. Here we explore an…

Image and Video Processing · Electrical Eng. & Systems 2022-10-05 David Ceddia , Andrew M. Kingston , Daniele Pelliccia , Alexander Rack , David M. Paganin

In high-performance computing (HPC) environments, particularly in synchrotron radiation facilities, vast amounts of X-ray images are generated. Processing large-scale X-ray Computed Tomography (X-CT) datasets presents significant…

Image and Video Processing · Electrical Eng. & Systems 2026-02-19 Amarjit Singh , Kento Sato , Kohei Yoshida , Kentaro Uesugi , Yasumasa Joti , Takaki Hatsui , Andrès Rubio Proaño

Computed tomography (CT) has been developed as a non-destructive technique for observing minute internal images of samples. It has been difficult to obtain photo-realistic (clean or clear) CT images due to various unwanted artifacts…

Quantum Physics · Physics 2023-09-12 Kyungtaek Jun

Effective sparse representation of X-Ray medical images within the context of data reduction is considered. The proposed framework is shown to render an enormous reduction in the cardinality of the data set required to represent this class…

Computer Vision and Pattern Recognition · Computer Science 2016-11-15 Laura Rebollo-Neira

Deep neural networks have received considerable attention in clinical imaging, particularly with respect to the reduction of radiation risk. Lowering the radiation dose by reducing the photon flux inevitably results in the degradation of…

Image and Video Processing · Electrical Eng. & Systems 2021-09-14 Khalid L. Alsamadony , Ertugrul U. Yildirim , Guenther Glatz , Umair bin Waheed , Sherif M. Hanafy

This contribution describes the implementation of a data--driven shape optimization pipeline in a naval architecture application. We adopt reduced order models (ROMs) in order to improve the efficiency of the overall optimization, keeping a…

Numerical Analysis · Mathematics 2024-01-22 Nicola Demo , Giulio Ortali , Gianluca Gustin , Gianluigi Rozza , Gianpiero Lavini

While machine learning models are typically trained to solve prediction problems, we might often want to use them for optimization problems. For example, given a dataset of proteins and their corresponding fluorescence levels, we might want…

Machine Learning · Computer Science 2024-10-18 Jakub Grudzien Kuba , Masatoshi Uehara , Pieter Abbeel , Sergey Levine

In a previous paper, we reviewed theoretically some of the available processing schemes for X-ray wavefront sensing based on random modulation. We here show experimental applications of the technique for characterising both refractive and…

Instrumentation and Detectors · Physics 2020-02-24 Sebastien Berujon , Ruxandra Cojocaru , Pierre Piault , Rafael Celestre , Thomas Roth , Raymond Barrett , Eric Ziegler

Diffusion models are proficient at generating high-quality images. They are however effective only when operating at the resolution used during training. Inference at a scaled resolution leads to repetitive patterns and structural…

Computer Vision and Pattern Recognition · Computer Science 2024-11-28 Haosen Yang , Adrian Bulat , Isma Hadji , Hai X. Pham , Xiatian Zhu , Georgios Tzimiropoulos , Brais Martinez

In two-phase image segmentation, convex relaxation has allowed global minimisers to be computed for a variety of data fitting terms. Many efficient approaches exist to compute a solution quickly. However, we consider whether the nature of…

Numerical Analysis · Mathematics 2018-08-01 Jack Spencer