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Full polarimetric radio interferometric calibration is performed by estimating 2 by 2 Jones matrices representing instrumental and propagation effects. The solutions obtained in this way differ from the true solutions by a 2 by 2 unitary…

Instrumentation and Methods for Astrophysics · Physics 2013-07-19 Sarod Yatawatta

High precison calibration is essential for a new generation of radio interferometers looking for Epoch of Reionization and Baryon Acoustic Oscillation signatures in neutral hydrogen. These arrays have so far been calibrated by redundant…

Instrumentation and Methods for Astrophysics · Physics 2017-01-10 J. L. Sievers

The knowledge of receiver beam shapes is essential for accurate radio interferometric imaging. Traditionally, this information is obtained by holographic techniques or by numerical simulation. However, such methods are not feasible for an…

Instrumentation and Methods for Astrophysics · Physics 2013-07-19 Sarod Yatawatta

Context. The QUBIC collaboration is building a bolometric interferometer dedicated to the detection of B-mode polarization fluctuations in the Cosmic Microwave Background. Aims. We introduce a self-calibration procedure related to those…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 M. -A. Bigot-Sazy , R. Charlassier , J. -Ch. Hamilton , J. Kaplan , G. Zahariade

Model calibration is essential for ensuring that the predictions of deep neural networks accurately reflect true probabilities in real-world classification tasks. However, deep networks often produce over-confident or under-confident…

Machine Learning · Computer Science 2025-04-01 Jinxu Lin , Linwei Tao , Minjing Dong , Chang Xu

It is not uncommon that real-world data are distributed with a long tail. For such data, the learning of deep neural networks becomes challenging because it is hard to classify tail classes correctly. In the literature, several existing…

Computer Vision and Pattern Recognition · Computer Science 2024-07-19 Mengke Li , Yiu-ming Cheung , Yang Lu , Zhikai Hu , Weichao Lan , Hui Huang

Cameras and LiDAR are essential sensors for autonomous vehicles. Camera-LiDAR data fusion compensate for deficiencies of stand-alone sensors but relies on precise extrinsic calibration. Many learning-based calibration methods predict…

Computer Vision and Pattern Recognition · Computer Science 2025-07-08 Ni Ou , Zhuo Chen , Xinru Zhang , Junzheng Wang

Having an accurate calibration method is crucial for any scientific research done by a radio telescope. The next generation radio telescopes such as the Square Kilometre Array (SKA) will have a large number of receivers which will produce…

Instrumentation and Methods for Astrophysics · Physics 2018-04-03 Ahmad Mouri Sardarabadi , Alle-Jan van der Veen , Léon V. E. Koopmans

Existing deep learning methods have made significant progress in gait representation learning. Quantization can facilitate the application of gait models as a model-agnostic general compression technique. Typically, appearance-based models…

Computer Vision and Pattern Recognition · Computer Science 2026-03-24 S. Tian , H. Gao , G. Hong , S. Wang , J. Wang , X. Yu , S. Zhang

Context. Modern radio astronomical arrays have (or will have) more than one order of magnitude more receivers than classical synthesis arrays, such as the VLA and the WSRT. This makes gain calibration a computationally demanding task.…

Instrumentation and Methods for Astrophysics · Physics 2014-10-09 Stefano Salvini , Stefan J. Wijnholds

A machine learning model is calibrated if its predicted probability for an outcome matches the observed frequency for that outcome conditional on the model prediction. This property has become increasingly important as the impact of machine…

Machine Learning · Computer Science 2025-02-25 Muthu Chidambaram , Rong Ge

Our ability to calibrate current kilometer-scale interferometers can potentially confound the inference of astrophysical signals. Current calibration uncertainties are well described by a Gaussian process. I exploit this description to…

Instrumentation and Methods for Astrophysics · Physics 2022-04-27 Reed Essick

For personalized ranking models, the well-calibrated probability of an item being preferred by a user has great practical value. While existing work shows promising results in image classification, probability calibration has not been much…

Information Retrieval · Computer Science 2022-04-27 Wonbin Kweon , SeongKu Kang , Hwanjo Yu

The sparse layouts of radio interferometers result in an incomplete sampling of the sky in Fourier space which leads to artifacts in the reconstructed images. Cleaning these systematic effects is essential for the scientific use of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-27 Kevin Schmidt , Felix Geyer , Stefan Fröse , Paul-Simon Blomenkamp , Marcus Brüggen , Francesco de Gasperin , Dominik Elsässer , Wolfgang Rhode

Deep neural networks may perform poorly when training datasets are heavily class-imbalanced. Recently, two-stage methods decouple representation learning and classifier learning to improve performance. But there is still the vital issue of…

Computer Vision and Pattern Recognition · Computer Science 2021-04-02 Zhisheng Zhong , Jiequan Cui , Shu Liu , Jiaya Jia

Direction dependent calibration of widefield radio interferometers estimates the systematic errors along multiple directions in the sky. This is necessary because with most systematic errors that are caused by effects such as the ionosphere…

Instrumentation and Methods for Astrophysics · Physics 2021-12-22 Sarod Yatawatta

In this paper, the problem of distributed optimization is studied via a network of agents. Each agent only has access to a noisy gradient of its own objective function, and can communicate with its neighbors via a network. To handle this…

Optimization and Control · Mathematics 2025-06-19 Yuchen Yang , Kaihong Lu , Long Wang

Class probabilities predicted by most multiclass classifiers are uncalibrated, often tending towards over-confidence. With neural networks, calibration can be improved by temperature scaling, a method to learn a single corrective…

Machine Learning · Computer Science 2019-10-29 Meelis Kull , Miquel Perello-Nieto , Markus Kängsepp , Telmo Silva Filho , Hao Song , Peter Flach

In this paper, we introduce a distributed algorithm that optimizes the Gaussian signal covariance matrices of multi-antenna users transmitting to a common multi-antenna receiver under imperfect and possibly delayed channel state…

Information Theory · Computer Science 2015-02-06 Panayotis Mertikopoulos , Aris L. Moustakas

Consider the problem of finding the best matching in a weighted graph where we only have access to predictions of the actual stochastic weights, based on an underlying context. If the predictor is the Bayes optimal one, then computing the…

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