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The characterization and analysis of microstructure is the foundation of microstructural science, connecting the materials structure to its composition, process history, and properties. Microstructural quantification traditionally involves…

Computer Vision and Pattern Recognition · Computer Science 2020-10-28 Elizabeth A. Holm , Ryan Cohn , Nan Gao , Andrew R. Kitahara , Thomas P. Matson , Bo Lei , Srujana Rao Yarasi

Conventionally, CMD analyses of nearby star clusters are based on observations in 2 passbands. They are plagued by considerable degeneracies between age, metallicity, distance (and extinction) that can largely be resolved by including…

The aim of this paper is to give a short review on cluster dynamics modeling in the field of atoms and point defects clustering in materials. It is shown that this method, due to its low computer cost, can handle long term evolution that…

Materials Science · Physics 2007-09-13 Alain Barbu , Emmanuel Clouet

Clusters of galaxies, being the largest collapsed structures in the universe, offer valuable insights into the nature of cosmic evolution. Precise calibration of the mass of clusters can be obtained by extracting their gravitational lensing…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-05 Sayan Saha , Louis Legrand , Julien Carron

The presence of differential reddening in the direction of Galactic globular clusters (GCs) has proven to be a serious limitation in the traditional colour-magnitude diagram (CMD) analysis. Here, we estimate local reddening variations in…

Astrophysics of Galaxies · Physics 2023-04-19 M. V. Legnardi , A. P. Milone , G. Cordoni , E. P. Lagioia , E. Dondoglio , A. F. Marino , S. Jang , A. Mohandasan , T. Ziliotto

Outside galaxy clusters the competition between the inwards gravitational attraction and the outwards expansion of the Universe leads to a special radius of velocity cancellation, which is called the turn-around radius. Measurements of the…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-02 Steen H. Hansen , Farbod Hassani , Lucas Lombriser , Martin Kunz

We present a machine-learning approach for estimating galaxy cluster masses from Chandra mock images. We utilize a Convolutional Neural Network (CNN), a deep machine learning tool commonly used in image recognition tasks. The CNN is trained…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-20 M. Ntampaka , J. ZuHone , D. Eisenstein , D. Nagai , A. Vikhlinin , L. Hernquist , F. Marinacci , D. Nelson , R. Pakmor , A. Pillepich , P. Torrey , M. Vogelsberger

Aims. We explore machine learning techniques to forecast star formation rate, stellar mass, and metallicity across galaxies with redshifts ranging from 0.01 to 0.3. Methods. Leveraging CatBoost and deep learning architectures, we utilize…

Astrophysics of Galaxies · Physics 2024-05-27 F. Z. Zeraatgari , F. Hafezianzadeh , Y. -X. Zhang , A. Mosallanezhad , J. -Y. Zhang

We have implemented a Monte Carlo algorithm to model and predict the response of various kinds of CCDs to X-ray photons and minimally-ionizing particles and have applied this model to the CCDs in the Chandra X-ray Observatory's Advanced CCD…

Astrophysics · Physics 2015-06-24 L. K. Townsley , P. S. Broos , G. Chartas , E. Moskalenko , J. A. Nousek , G. G. Pavlov

In machine learning, observation features are measured in a metric space to obtain their distance function for optimization. Given similar features that are statistically sufficient as a population, a statistical distance between two…

Machine Learning · Statistics 2020-06-23 Xin Lu

Globular clusters (GCs) have been at the heart of many longstanding questions in many sub-fields of astronomy and, as such, systematic identification of GCs in external galaxies has immense impacts. In this study, we take advantage of M87's…

Recent developed deep unsupervised methods allow us to jointly learn representation and cluster unlabelled data. These deep clustering methods mainly focus on the correlation among samples, e.g., selecting high precision pairs to gradually…

Computer Vision and Pattern Recognition · Computer Science 2019-08-13 Jianlong Wu , Keyu Long , Fei Wang , Chen Qian , Cheng Li , Zhouchen Lin , Hongbin Zha

The availability of a robust and efficient routine for calculating light curves of a finite source magnified due to bending its light by the gravitational field of an intervening binary lens is essential for determining the characteristics…

Astrophysics · Physics 2008-11-26 M. Dominik

Unsupervised classification called clustering is a process of organizing objects into groups whose members are similar in some way. Clustering of uncertain data objects is a challenge in spatial data bases. In this paper we use Probability…

Databases · Computer Science 2013-12-10 Ramachandra Rao Kurada

The circum-galactic medium (CGM) can feasibly be mapped by multiwavelength surveys covering broad swaths of the sky. With multiple large datasets becoming available in the near future, we develop a likelihood-free Deep Learning technique…

The analyses relying on 3D point clouds are an utterly complex task, often involving million of points, but also requiring computationally efficient algorithms because of many real-time applications; e.g. autonomous vehicle. However, point…

Computer Vision and Pattern Recognition · Computer Science 2019-06-11 Can Chen , Luca Zanotti Fragonara , Antonios Tsourdos

Upcoming deep imaging surveys such as the Vera C. Rubin Observatory Legacy Survey of Space and Time will be confronted with challenges that come with increased depth. One of the leading systematic errors in deep surveys is the blending of…

Cosmology and Nongalactic Astrophysics · Physics 2022-12-27 Erfan Nourbakhsh , J. Anthony Tyson , Samuel J. Schmidt , The LSST Dark Energy Science Collaboration

The clustered planarity problem (c-planarity) asks whether a hierarchically clustered graph admits a planar drawing such that the clusters can be nicely represented by regions. We introduce the cd-tree data structure and give a new…

Data Structures and Algorithms · Computer Science 2015-06-19 Thomas Bläsius , Ignaz Rutter

(abridged) Mass loss is a key parameter in the evolution of massive stars, with discrepancies between theory and observations and with unknown importance of the episodic mass loss. To address this we need increased numbers of classified…

Solar and Stellar Astrophysics · Physics 2022-10-19 Grigoris Maravelias , Alceste Z. Bonanos , Frank Tramper , Stephan de Wit , Ming Yang , Paolo Bonfini

The spatial morphological study of studied clusters is carried out through the identified probable members within them. The field stars decontamination is performed by the statistical cleaning approach (depends on the magnitude and colour…

Astrophysics of Galaxies · Physics 2017-12-05 Gireesh C. Joshi