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相关论文: Experimental design for MRI by greedy policy searc…

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Accelerated MRI shortens acquisition time by subsampling in the measurement $\kappa$-space. Recovering a high-fidelity anatomical image from subsampled measurements requires close cooperation between two components: (1) a sampler that…

图像与视频处理 · 电气工程与系统科学 2022-07-28 Tianwei Yin , Zihui Wu , He Sun , Adrian V. Dalca , Yisong Yue , Katherine L. Bouman

This work applies Bayesian experimental design to selecting optimal projection geometries in (discretized) parallel beam X-ray tomography assuming the prior and the additive noise are Gaussian. The introduced greedy exhaustive optimization…

数值分析 · 数学 2021-08-11 Martin Burger , Andreas Hauptmann , Tapio Helin , Nuutti Hyvönen , Juha-Pekka Puska

Undersampling is a common method in Magnetic Resonance Imaging (MRI) to subsample the number of data points in k-space, reducing acquisition times at the cost of decreased image quality. A popular approach is to employ undersampling…

图像与视频处理 · 电气工程与系统科学 2023-08-23 Tobias Weber , Michael Ingrisch , Bernd Bischl , David Rügamer

Many problems in signal processing and machine learning can be formalized as weak submodular optimization tasks. For such problems, a simple greedy algorithm (\textsc{Greedy}) is guaranteed to find a solution achieving the objective with a…

离散数学 · 计算机科学 2021-11-24 Abolfazl Hashemi , Haris Vikalo , Gustavo de Veciana

Magnetic Resonance Imaging (MRI) has long been considered to be among "the gold standards" of diagnostic medical imaging. The long acquisition times, however, render MRI prone to motion artifacts, let alone their adverse contribution to the…

图像与视频处理 · 电气工程与系统科学 2021-04-14 Tomer Weiss , Ortal Senouf , Sanketh Vedula , Oleg Michailovich , Michael Zibulevsky , Alex Bronstein

It is known that greedy methods perform well for maximizing monotone submodular functions. At the same time, such methods perform poorly in the face of non-monotonicity. In this paper, we show - arguably, surprisingly - that invoking the…

机器学习 · 计算机科学 2017-04-07 Moran Feldman , Christopher Harshaw , Amin Karbasi

The structure of Magnetic Resonance Images (MRI) and especially their compressibility in an appropriate representation basis enables the application of the compressive sensing theory, which guarantees exact image recovery from incomplete…

统计理论 · 数学 2013-07-26 Nicolas Chauffert , Philippe Ciuciu , Pierre Weiss

Magnetic Resonance Imaging (MRI) has become an important technique in the clinic for the visualization, detection, and diagnosis of various diseases. However, one bottleneck limitation of MRI is the relatively slow data acquisition process.…

图像与视频处理 · 电气工程与系统科学 2022-11-28 Xue Liu , Juan Zou , Xiawu Zheng , Cheng Li , Hairong Zheng , Shanshan Wang

We investigate the performance of a deterministic GREEDY algorithm for the problem of maximizing functions under a partition matroid constraint. We consider non-monotone submodular functions and monotone subadditive functions. Even though…

离散数学 · 计算机科学 2019-02-22 Tobias Friedrich , Andreas Göbel , Frank Neumann , Francesco Quinzan , Ralf Rothenberger

Magnetic resonance imaging (MRI) is the cornerstone technique for diagnostic medicine, biology, and neuroscience. This imaging method is highly innovative, noninvasive and its impact continues to grow. It can be used for measuring changes…

There is growing interest in learning Fourier domain sampling strategies (particularly for magnetic resonance imaging, MRI) using optimization approaches. For non-Cartesian sampling patterns, the system models typically involve non-uniform…

图像与视频处理 · 电气工程与系统科学 2023-02-07 Guanhua Wang , Jeffrey A. Fessler

We present a mathematical framework and computational methods to optimally design a finite number of sequential experiments. We formulate this sequential optimal experimental design (sOED) problem as a finite-horizon partially observable…

机器学习 · 计算机科学 2024-03-28 Wanggang Shen , Xun Huan

Motivated by recent work on stochastic gradient descent methods, we develop two stochastic variants of greedy algorithms for possibly non-convex optimization problems with sparsity constraints. We prove linear convergence in expectation to…

数值分析 · 数学 2014-07-02 Nam Nguyen , Deanna Needell , Tina Woolf

Previous studies on event-related functional magnetic resonance imaging experimental designs are primarily based on linear models, in which a known shape of the hemodynamic response function (HRF) is assumed. However, the HRF shape is…

应用统计 · 统计学 2014-01-09 Ming-Hung Kao , Dibyen Majumdar , Abhyuday Mandal , John Stufken

Magnetic resonance imaging (MRI) is a powerful medical imaging modality, but long acquisition times limit throughput, patient comfort, and clinical accessibility. Diffusion-based generative models serve as strong image priors for reducing…

机器学习 · 计算机科学 2026-02-13 Sriram Ravula , Brett Levac , Yamin Arefeen , Ajil Jalal , Alexandros G. Dimakis , Jonathan I. Tamir

Randomized experiments are considered the gold standard for estimating causal effects. However, out of the set of possible randomized assignments, some may be likely to produce poor effect estimates and misleading conclusions. Restricted…

统计方法学 · 统计学 2025-08-28 Maggie Wang , René F. Kizilcec , Michael Baiocchi

We consider the exploration problem: an agent equipped with a depth sensor must map out a previously unknown environment using as few sensor measurements as possible. We propose an approach based on supervised learning of a greedy…

机器学习 · 计算机科学 2022-03-29 Louis Ly , Yen-Hsi Richard Tsai

Recent advances in deep learning methods have come to define the state-of-the-art for many medical imaging applications, surpassing even human judgment in several tasks. Those models, however, when trained to reduce the empirical risk on a…

计算机视觉与模式识别 · 计算机科学 2019-01-14 Christian S. Perone , Pedro Ballester , Rodrigo C. Barros , Julien Cohen-Adad

Sparsity learning with known grouping structure has received considerable attention due to wide modern applications in high-dimensional data analysis. Although advantages of using group information have been well-studied by shrinkage-based…

机器学习 · 统计学 2018-09-28 Wei Qian , Wending Li , Yasuhiro Sogawa , Ryohei Fujimaki , Xitong Yang , Ji Liu

This article studies the benefits of using spatially randomized experimental designs which partition the experimental area into distinct, non-overlapping units with treatments assigned randomly. Such designs offer improved policy evaluation…

统计理论 · 数学 2025-11-18 Ying Yang , Chengchun Shi , Fang Yao , Shouyang Wang , Hongtu Zhu