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We use XMM-Newton blank-sky and closed-cover background data to explore the background subtraction methods for large extended sources filling the EPIC field of view, such as nearby galaxy clusters, for which local background estimation is…

Astrophysics · Physics 2009-11-11 J. Nevalainen , M. Markevitch , D. Lumb

Cellular manufacturing (CM) is an approach that includes both flexibility of job shops and high production rate of flow lines. Although CM provides many benefits in reducing throughput times, setup times, work-in-process inventories but the…

Adaptation and Self-Organizing Systems · Physics 2012-01-27 Manojit Chattopadhyay , Pranab K. Dan , Sitanath Majumdar

Self-Organizing Map algorithms have been used for almost 40 years across various application domains such as biology, geology, healthcare, industry and humanities as an interpretable tool to explore, cluster and visualize high-dimensional…

Neural and Evolutionary Computing · Computer Science 2020-11-12 Florent Forest , Mustapha Lebbah , Hanane Azzag , Jérôme Lacaille

The ESA's X-ray Multi-Mirror Mission (XMM-Newton) created a new, high quality version of the XMM-Newton serendipitous source catalogue, 4XMM-DR9, which provides a wealth of information for observed sources. The 4XMM-DR9 catalogue is…

Instrumentation and Methods for Astrophysics · Physics 2021-04-28 Yanxia Zhang , Yongheng Zhao , Xue-Bing Wu

We attack the problem of learning concepts automatically from noisy web image search results. Going beyond low level attributes, such as colour and texture, we explore weakly-labelled datasets for the learning of higher level concepts, such…

Computer Vision and Pattern Recognition · Computer Science 2013-12-17 Eren Golge , Pinar Duygulu

Extensive astronomical surveys, like those conducted with the {\em Chandra} X-ray Observatory, detect hundreds of thousands of unidentified cosmic sources. Machine learning (ML) methods offer an efficient, probabilistic approach to classify…

Instrumentation and Methods for Astrophysics · Physics 2026-01-09 Shivam Kumaran , Samir Mandal , Sudip Bhattacharyya

We propose to use Self-Organizing Maps (SOM) to map the impact of physical models onto observables. Using this approach, we are be able to determine how theories relate to each other given their signatures. In cosmology this will be…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-13 Agnès Ferté , Shoubaneh Hemmati , Daniel Masters , Brigitte Montminy , Peter L. Taylor , Eric Huff , Jason Rhodes

XMM-Newton has produced an extensive X-ray source catalogue in which the standard pipeline determines the variability of sufficiently bright sources through chi-square and fractional variability tests. Faint sources, however, are not…

High Energy Astrophysical Phenomena · Physics 2020-08-26 Inés Pastor-Marazuela , Natalie A. Webb , Damien T. Wojtowicz , Joeri van Leeuwen

Procedures based on current methods to detect sources in X-ray images are applied to simulated XMM images. All significant instrumental effects are taken into account, and two kinds of sources are considered -- unresolved sources…

Astrophysics · Physics 2009-11-06 I. Valtchanov , M. Pierre , R. Gastaud

This paper proposes schemes for automated and weighted Self-Organizing Time Maps (SOTMs). The SOTM provides means for a visual approach to evolutionary clustering, which aims at producing a sequence of clustering solutions. This task we…

Neural and Evolutionary Computing · Computer Science 2013-11-25 Peter Sarlin

We explore the application of XMM-Newton Optical Monitor (XMM-OM) ultraviolet (UV) data to study galaxy evolution. Our sample is constructed as the intersection of all Abell clusters with z < 0.05 and having archival XMM-OM data in either…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Neal A. Miller , Richard O'Steen , Steffi Yen , K. D. Kuntz , Derek Hammer

Results of neural network learning are always subject to some variability, due to the sensitivity to initial conditions, to convergence to local minima, and, sometimes more dramatically, to sampling variability. This paper presents a set of…

Statistics Theory · Mathematics 2007-06-13 Eric De Bodt , Marie Cottrell , Michel Verleysen

One of the goals of machine learning is to eliminate tedious and arduous repetitive work. The manual and semi-automatic classification of millions of hours of solar wind data from multiple missions can be replaced by automatic algorithms…

Space Physics · Physics 2020-08-20 Jorge Amaya , Romain Dupuis , Maria Elena Innocenti , Giovanni Lapenta

This paper adopts and adapts Kohonen's standard Self-Organizing Map (SOM) for exploratory temporal structure analysis. The Self-Organizing Time Map (SOTM) implements SOM-type learning to one-dimensional arrays for individual time units,…

Machine Learning · Computer Science 2014-05-06 Peter Sarlin

Motif discovery is a fundamental step in data mining tasks for time-series data such as clustering, classification and anomaly detection. Even though many papers have addressed the problem of how to find motifs in time-series by proposing…

Machine Learning · Computer Science 2020-04-20 Maria Inês Silva , Roberto Henriques

We present preliminary results from our on-going study: Comparing and optimizing source detection procedures for XMM images. By constructing realistic spatial and spectral source distributions and ``observing'' these through the XMM Science…

Astrophysics · Physics 2007-05-23 Jesper Rasmussen , Kristian Pedersen , Martin Gotz

Machine-part cell formation is used in cellular manufacturing in order to process a large variety, quality, lower work in process levels, reducing manufacturing lead-time and customer response time while retaining flexibility for new…

Artificial Intelligence · Computer Science 2011-05-09 Manojit Chattopadhyay , Surajit Chattopadhyay , Pranab K. Dan

[ABRIDGED] The XMM Cluster Survey (XCS) is predicted to detect thousands of clusters observed serendipitously in XMM-Newton pointings. We investigate automating optical follow-up of cluster candidates using the SDSS public archive,…

Nowadays, with the advance of technology, there is an increasing amount of unstructured data being generated every day. However, it is a painful job to label and organize it. Labeling is an expensive, time-consuming, and difficult task. It…

Machine Learning · Computer Science 2020-06-25 Pedro H. M. Braga , Heitor R. Medeiros , Hansenclever F. Bassani

Texture is one of the most important properties of visual surface that helps in discriminating one object from another or an object from background. The self-organizing map (SOM) is an excellent tool in exploratory phase of data mining. It…

Computer Vision and Pattern Recognition · Computer Science 2014-08-20 Marghny H. Mohamed , Mohammed M. Abdelsamea