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We reformulate the gain correction problem of the radio interferometry as an optimization problem with regularization, which is solved efficiently with an iterative algorithm. Combining this new method with our previously proposed imaging…

Instrumentation and Methods for Astrophysics · Physics 2024-12-05 Shiro Ikeda , Takeshi Nakazato , Takashi Tsukagoshi , Tsutomu T. Takeuchi , Masayuki Yamaguchi

Spike and slab priors play a key role in inducing sparsity for sparse signal recovery. The use of such priors results in hard non-convex and mixed integer programming problems. Most of the existing algorithms to solve the optimization…

Methodology · Statistics 2019-04-02 Fekadu L. Bayisa , Zhiyong Zhou , Ottmar Cronie , Jun Yu

The Square Kilometre Array (SKA) will operate one of the world's largest continuous scientific data systems, sustaining petascale imaging under strict power envelopes. Current radio-interferometric pipelines typically achieve only 4-14% of…

Using inverse planning tools to create radiotherapy treatment plans is an iterative process, where clinical trade-offs are explored by changing the relative importance of different objectives and rerunning the optimizer until a desirable…

Flux calibration of spectra in reverberation mapping (RM) is most often performed by assuming the flux constancy of some specified narrow emission lines, which stem from an extended region that is sometimes partially spatially resolved, in…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Yan-Rong Li , Jian-Min Wang , Chen Hu , Pu Du , Jin-Ming Bai

The new generation of radio synthesis arrays, such as LOFAR and SKA, have been designed to surpass existing arrays in terms of sensitivity, angular resolution and frequency coverage. This evolution has led to the development of advanced…

Instrumentation and Methods for Astrophysics · Physics 2013-07-19 Sanaz Kazemi , Sarod Yatawatta , Saleem Zaroubi

In this paper, we propose a novel distributed alternating direction method of multipliers (ADMM) algorithm with synergetic communication and computation, called SCCD-ADMM, to reduce the total communication and computation cost of the…

Signal Processing · Electrical Eng. & Systems 2020-09-30 Zhuojun Tian , Zhaoyang Zhang , Jue Wang , Xiaoming Chen , Wei Wang , Huaiyu Dai

Calibrating telescope data is one of the most important issues an observer faces. In this chapter we describe a number of the methods which are commonly used to calibrate radio telescope data in the centimeter wavelength regime. This…

Astrophysics · Physics 2007-05-23 K. O'Neil

In this paper, multi-stream transmission in interference networks aided by multiple amplify-and-forward (AF) relays in the presence of direct links is considered. The objective is to minimize the sum power of transmitters and relays by…

Signal Processing · Electrical Eng. & Systems 2018-12-31 Cenk M. Yetis , Ronald Y. Chang

Solar radio emission, especially at metre-wavelengths, is well known to vary over small spectral ($\lesssim$100\,kHz) and temporal ($<1$\,s) spans. It is comparatively recently, with the advent of a new generation of instruments, that it…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Surajit Mondal , Atul Mohan , Divya Oberoi , John S. Morgan , Leonid Benkevitch , Colin J. Lonsdale , Meagan Crowley , Iver H. Cairns

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

In distributed optimization and federated learning, asynchronous alternating direction method of multipliers (ADMM) serves as an attractive option for large-scale optimization, data privacy, straggler nodes and variety of objective…

Machine Learning · Computer Science 2025-08-19 Sagar Shrestha

This manual is intended to help ALMA and other interferometer users improve images by recognising limitations and how to overcome them and deciding when and how to use self-calibration. The images provided by the ALMA Science Archive are…

Instrumentation and Methods for Astrophysics · Physics 2022-07-13 A. M. S. Richards , E. Moravec , S. Etoka , E. B. Fomalont , A. F. Pérez-Sánchez , M. C. Toribio , R. A. Laing

In this lecture, we describe a number of advanced gain calibration techniques. In particular, self-calibration is an important tool in interferometric imaging at all wavelengths. It allows the observer to determine and remove residual phase…

Instrumentation and Methods for Astrophysics · Physics 2018-05-15 Crystal L. Brogan , Todd R. Hunter , Ed B. Fomalont

Semidefinite programming (SDP) is a fundamental convex optimization problem with wide-ranging applications. However, solving large-scale instances remains computationally challenging due to the high cost of solving linear systems and…

Optimization and Control · Mathematics 2025-12-22 Hantao Nie , Dong An , Zaiwen Wen

Next generation radio telescopes, like the Square Kilometre Array, will acquire an unprecedented amount of data for radio astronomy. The development of fast, parallelisable or distributed algorithms for handling such large-scale data sets…

Instrumentation and Methods for Astrophysics · Physics 2016-10-28 Alexandru Onose , Rafael E. Carrillo , Jason D. McEwen , Yves Wiaux

Radio-astronomy is about to embark on a new way of doing science. The revolution that is about to take place is not due to the enormous sensitivity of the Square Kilometre Array, which is still a decade away, but due to its pathfinders,…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 Ray P. Norris

In this paper, we propose a new stochastic alternating direction method of multipliers (ADMM) algorithm, which incrementally approximates the full gradient in the linearized ADMM formulation. Besides having a low per-iteration complexity as…

Machine Learning · Computer Science 2013-08-19 Leon Wenliang Zhong , James T. Kwok

In this paper, we review the parallel and distributed optimization algorithms based on alternating direction method of multipliers (ADMM) for solving "big data" optimization problem in smart grid communication networks. We first introduce…

Systems and Control · Computer Science 2015-03-03 Lanchao Liu , Zhu Han

The arrival of the Square Kilometer Array (SKA) will revitalise all aspects of Very Long Baseline Interferometry (VLBI) astronomy at the lower frequencies. In the last decade there have been huge strides towards routinely achieving high…

Instrumentation and Methods for Astrophysics · Physics 2017-02-15 Maria J. Rioja , Richard Dodson , Gabor Orosz , Hiroshi Imai , Sandor Frey