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This research presents a machine-learning approach for tumor detection in medical images using convolutional neural networks (CNNs). The study focuses on preprocessing techniques to enhance image features relevant to tumor detection,…

Image and Video Processing · Electrical Eng. & Systems 2024-03-01 Ha Anh Vu

Future high redshift 21-cm experiments will suffer from a high degree of contamination, due both to astrophysical foregrounds and to non-astrophysical and instrumental effects. In order to reliably extract the cosmological signal from the…

The non-Gaussian nature of the epoch of reionization (EoR) 21-cm signal has a significant impact on the error variance of its power spectrum $P({\bf \textit{k}})$. We have used a large ensemble of semi-numerical simulations and an…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-26 Rajesh Mondal , Somnath Bharadwaj , Suman Majumdar

Convolutional Neural Networks (CNNs) work very well for supervised learning problems when the training dataset is representative of the variations expected to be encountered at test time. In medical image segmentation, this premise is…

Image and Video Processing · Electrical Eng. & Systems 2021-01-26 Neerav Karani , Ertunc Erdil , Krishna Chaitanya , Ender Konukoglu

We explore the possibility of constraining model parameters of the Epoch of Reionization (EoR) from 21cm brightness temperature maps, using a combination of morphological descriptors constructed from the eigenvalues of the Contour Minkowski…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-19 Akanksha Kapahtia , Pravabati Chingangbam , Raghunath Ghara , Stephen Appleby , Tirthankar Roy Choudhury

Convolutional Neural Networks have become the norm in image classification. Nevertheless, their difficulty to maintain high accuracy across datasets has become apparent in the past few years. In order to utilize such models in real-world…

Computer Vision and Pattern Recognition · Computer Science 2022-07-28 Aristotelis Ballas , Christos Diou

Convolutional Neural Network (CNN) have been widely used in image classification. Over the years, they have also benefited from various enhancements and they are now considered as state of the art techniques for image like data. However,…

Computer Vision and Pattern Recognition · Computer Science 2022-06-06 Thomas Gonzalez , Antoine Blais , Nicolas Couëllan , Christian Ruiz

We measure several properties of the reionization process and the corresponding low-frequency 21-cm signal associated with the neutral hydrogen distribution, using a large volume, high resolution simulation of cosmic reionization. The…

Due to memory constraints on current hardware, most convolution neural networks (CNN) are trained on sub-megapixel images. For example, most popular datasets in computer vision contain images much less than a megapixel in size (0.09MP for…

Computer Vision and Pattern Recognition · Computer Science 2020-10-23 Hans Pinckaers , Bram van Ginneken , Geert Litjens

The Epoch of Reionization (EoR) remains a poorly understood cosmic era for the most part. Yet, efforts are still going on to probe and understand this epoch. We present a review of the latest developments in the techniques (especially…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-26 Chandra Shekhar Murmu , Raghunath Ghara , Suman Majumdar , Kanan K. Datta

Unaccounted for systematics from foregrounds and instruments can severely limit the sensitivity of current experiments from detecting redshifted 21~cm signals from the Epoch of Reionization (EoR). Upcoming experiments are faced with a…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-06 Nithyanandan Thyagarajan , Aaron Parsons , David DeBoer , Judd Bowman , Aaron Ewall-Wice , Abraham Neben , Nipanjana Patra

We report the development of deep learning coherent electron diffractive imaging at sub-angstrom resolution using convolutional neural networks (CNNs) trained with only simulated data. We experimentally demonstrate this method by applying…

Materials Science · Physics 2022-04-19 Dillan J. Chang , Colum M. O'Leary , Cong Su , Salman Kahn , Alex Zettl , Jim Ciston , Peter Ercius , Jianwei Miao

One of the most promising probes to constrain the reionization history of the universe is the power spectrum of neutral hydrogen 21 cm emission fluctuations. The corresponding analyses require computationally efficient modelling of…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-21 Barun Maity , Tirthankar Roy Choudhury

The reionization process is expected to be prolonged by the small-scale absorbers (SSAs) of ionizing photons, which have been seen as Lyman-limit systems in quasar absorption line observations. We use a set of semi-numerical simulations to…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-09 Peng-Ju Wu , Yidong Xu , Xin Zhang , Xuelei Chen

We review the observable consequences of the epoch of reionization (EoR) on the cosmic microwave background (CMB), and the resulting constraints on the EoR. We discuss how Thomson scattering with the free electrons produced during EoR…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-27 Christian L. Reichardt

Convolutional Neural Networks (CNNs) achieve state-of-the-art performance in many computer vision tasks. However, this achievement is preceded by extreme manual annotation in order to perform either training from scratch or fine-tuning for…

Computer Vision and Pattern Recognition · Computer Science 2016-09-08 Filip Radenović , Giorgos Tolias , Ondřej Chum

This paper presents a data processing algorithm with machine learning for polarization extraction and event selection applied to photoelectron track images taken with X-ray polarimeters. The method uses a convolutional neural network (CNN)…

Instrumentation and Methods for Astrophysics · Physics 2019-09-04 Takao Kitaguchi , Kevin Black , Teruaki Enoto , Asami Hayato , Joanne E. Hill , Wataru B. Iwakiri , Philip Kaaret , Tsunefumi Mizuno , Toru Tamagawa

We investigate systematic effects in direction dependent gain calibration in the context of the Low-Frequency Array (LOFAR) 21-cm Epoch of Reionization (EoR) experiment. The LOFAR EoR Key Science Project aims to detect the 21-cm signal of…

Convolutional neural networks (CNNs), inspired by biological visual cortex systems, are a powerful category of artificial neural networks that can extract the hierarchical features of raw data to greatly reduce the network parametric…

Emerging Technologies · Computer Science 2021-05-14 Mengxi Tan , Xingyuan Xu , David J. Moss
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