English
Related papers

Related papers: Fast gain calibration in radio astronomy using alt…

200 papers

We present two efficient numerical methods for susceptibility artifact correction applicable in Echo Planar Imaging (EPI), an ultra fast Magnetic Resonance Imaging (MRI) technique widely used in clinical applications. Both methods address a…

Optimization and Control · Mathematics 2016-11-23 Jan Macdonald , Lars Ruthotto

The problem of directivity enhancement, leading to the increase in the directivity gain over a certain desired angle of arrival/departure (AoA/AoD), is considered in this work. A new formulation of the volumetric array directivity problem…

Systems and Control · Electrical Eng. & Systems 2023-01-10 Bruno Felipe Costa , Taufik Abrão

This work proposes a novel motion guided method for target-less self-calibration of a LiDAR and camera and use the re-projection of LiDAR points onto the image reference frame for real-time depth upsampling. The calibration parameters are…

Computer Vision and Pattern Recognition · Computer Science 2020-07-06 Juan Castorena , Gint Puskorius , Gaurav Pandey

We consider the noisy matrix sensing problem in the over-parameterization setting, where the estimated rank $r$ is larger than the true rank $r_\star$ of the target matrix $X_\star$. Specifically, our main objective is to recover a matrix $…

Machine Learning · Computer Science 2025-06-03 Zhiyu Liu , Zhi Han , Yandong Tang , Shaojie Tang , Yao Wang

The Alternating Direction Method of Multipliers (ADMM) is widely used for linearly constrained convex problems. It is proven to have an $o(1/\sqrt{K})$ nonergodic convergence rate and a faster $O(1/K)$ ergodic rate after ergodic averaging,…

Numerical Analysis · Mathematics 2018-12-13 Huan Li , Zhouchen Lin

This paper introduces two new algorithms to accurately estimate the process noise covariance of a discrete-time Kalman filter online for robust orbit determination in the presence of dynamics model uncertainties. Common orbit determination…

Signal Processing · Electrical Eng. & Systems 2021-05-17 Nathan Stacey , Simone D'Amico

The alternating direction method of multipliers (ADMM) were extensively investigated in the past decades for solving separable convex optimization problems. Fewer researchers focused on exploring its convergence properties for the nonconvex…

Numerical Analysis · Mathematics 2019-07-02 Jianchao Bai , Junli Liang , Ke Guo , Yang Jing

Our aim is to assess the benefits and limitations of using the redundant visibility information in regular phased array systems for improving the calibration. Regular arrays offer the possibility to use redundant visibility information to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Parisa Noorishad , Stefan J. Wijnholds , Arnold van Ardenne , Thijs van der Hulst

In this paper, we propose an adaptive proximal inexact gradient (APIG) framework for solving a class of nonsmooth composite optimization problems involving function and gradient errors. Unlike existing inexact proximal gradient methods, the…

Information Theory · Computer Science 2025-04-03 Xilai Fan , Bo Jiang , Ya-Feng Liu

Adaptive gradient methods, such as AdaGrad, are among the most successful optimization algorithms for neural network training. While these methods are known to achieve better dimensional dependence than stochastic gradient descent (SGD) for…

Optimization and Control · Mathematics 2025-06-09 Ruichen Jiang , Devyani Maladkar , Aryan Mokhtari

In this paper, a fast algorithm for the Direction Of Arrival (DOA) estimation of radiating sources, based on partial covariance matrix and without eigende- composition of incoming signals is extended to two dimensional problem of joint…

Information Theory · Computer Science 2015-03-18 Y. Khmou , S. Safi

We propose a variant of alternating direction method of multiplier (ADMM) to solve constrained trajectory optimization problems. Our ADMM framework breaks a joint optimization into small sub-problems, leading to a low iteration cost and…

Robotics · Computer Science 2023-02-28 Ruiqi Ni , Zherong Pan , Xifeng Gao

Adaptive optics (AO) have been used to correct wavefronts to achieve diffraction limited point spread functions in a broad range of optical applications, prominently ground-based astronomical telescopes operating in near infra-red. While…

Instrumentation and Methods for Astrophysics · Physics 2018-10-03 Alexandre J. T. S. Mello , Antonin H. Bouchez , Andrew Szentgyorgyi , Marcos A. van Dam , Henrique Lupinari

In radio astronomy obtaining a high dynamic range in synthesis imaging of wide fields requires a correction for time and direction-dependent effects. Applying direction-dependent correction can be done by either partitioning the image in…

Instrumentation and Methods for Astrophysics · Physics 2019-09-17 Sebastiaan van der Tol , Bram Veenboer , André R. Offringa

In this paper, we propose and analyze an inexact version of the symmetric proximal alternating direction method of multipliers (ADMM) for solving linearly constrained optimization problems. Basically, the method allows its first subproblem…

Optimization and Control · Mathematics 2020-06-05 Vando A. Adona , Max L. N. Gonçalves

We provide a new proof of the linear convergence of the alternating direction method of multipliers (ADMM) when one of the objective terms is strongly convex. Our proof is based on a framework for analyzing optimization algorithms…

Optimization and Control · Mathematics 2015-05-20 Robert Nishihara , Laurent Lessard , Benjamin Recht , Andrew Packard , Michael I. Jordan

The discrete-dipole approximation (DDA) is a flexible technique for computing scattering and absorption by targets of arbitrary geometry. In this paper we perform systematic study of various non-stationary iterative (conjugate gradient)…

Atmospheric and Oceanic Physics · Physics 2007-05-23 Piotr J. Flatau

Radio astronomy is entering a new era with new and future radio observatories such as the Low Frequency Array and the Square Kilometer Array. We describe in detail an automated flagging pipeline and evaluate its performance. With only a…

Instrumentation and Methods for Astrophysics · Physics 2010-07-16 A. R. Offringa , A. G. de Bruyn , S. Zaroubi , M. Biehl

The angular differential imaging (ADI) is used to improve contrast in high resolution astronomical imaging. An example is the direct imaging of exoplanet in camera fed by Extreme Adaptive Optics. The subtraction of the main dazzling object…

Instrumentation and Methods for Astrophysics · Physics 2018-07-04 Carmelo Arcidiacono , Valeria Simoncini

The alternating direction method of multipliers within a shape optimization framework is developed for solving geometric inverse problems, focusing on a cavity identification problem from the perspective of non-destructive testing and…

Optimization and Control · Mathematics 2024-02-07 Julius Fergy Tiongson Rabago , Aissam Hadri , Lekbir Afraites , Ahmed S. Hendy , Mahmoud A. Zaky