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We describe a new tool developed for solar flare forecasting on the base of some sunspot group properties. Assuming that the flare frequency follows the Poisson statistics, this tool uses a database containing the morphological…

Solar and Stellar Astrophysics · Physics 2019-05-16 M. Falco , P. Costa , P. Romano

Selecting subsets of features that differentiate between two conditions is a key task in a broad range of scientific domains. In many applications, the features of interest form clusters with similar effects on the data at hand. To recover…

Machine Learning · Computer Science 2022-11-11 Ram Dyuthi Sristi , Gal Mishne , Ariel Jaffe

Sunspot numbers are important tracers of historical solar activity. They are important in the prediction of oncoming solar maximum, in the design of lifetimes of space assets, and in assessing the extent of solar-radiation impact on the…

Solar and Stellar Astrophysics · Physics 2016-02-26 K. S. Balasubramaniam , T. W. Henry

To deepen the analysis of the photometric properties of the umbra of a sunspot, we study proper motions of small features such as umbral dots (UDs) inside a single sunspot observed by the Solar Optical Telescope of Hinode close to the disk…

Solar and Stellar Astrophysics · Physics 2018-07-17 Hadis Goodarzi , Serge Koutchmy , Ali Adjabshirizadeh

An open question in deep clustering is how to understand what in the image is creating the cluster assignments. This visual understanding is essential to be able to trust the results of an inherently complex algorithm like deep learning,…

Computer Vision and Pattern Recognition · Computer Science 2020-10-13 Sarah Ryan , Nichole Carlson , Harris Butler , Tasha Fingerlin , Lisa Maier , Fuyong Xing

Image super-resolution has been an important subject in image processing and recognition. Here, we present an attention-aided convolutional neural network (CNN) for solar image super-resolution. Our method, named SolarCNN, aims to enhance…

Solar and Stellar Astrophysics · Physics 2024-03-28 Chunhui Xu , Jason T. L. Wang , Haimin Wang , Haodi Jiang , Qin Li , Yasser Abduallah , Yan Xu

We explore the use of strong lensing by galaxy clusters to constrain the dark energy equation of state and its possible time variation. The cores of massive clusters often contain several multiply imaged systems of background galaxies at…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Anson D'Aloisio , Priyamvada Natarajan

Solar flares, especially C, M, and X class, pose significant risks to satellite operations, communication systems, and power grids. We present a novel approach for predicting extreme solar flares using HMI intensitygrams and magnetograms.…

Solar and Stellar Astrophysics · Physics 2026-01-09 Juyoung Yun , Jungmin Shin

Dimensionality reduction methods such as t-SNE and UMAP are popular methods for visualizing data with a potential (latent) clustered structure. They are known to group data points at the same time as they embed them, resulting in…

Machine Learning · Computer Science 2025-09-04 Elizabeth Coda , Ery Arias-Castro , Gal Mishne

In this paper, we introduce a novel methodology for leveraging shape-based characteristics of magnetograms of active region (AR) patches and provide a novel capability for predicting solar flares covering the entirety of the solar disk (AR…

Computer Vision and Pattern Recognition · Computer Science 2024-06-18 Chetraj Pandey , Temitope Adeyeha , Jinsu Hong , Rafal A. Angryk , Berkay Aydin

The presence of fine structures in the sunspot vector magnetic fields has been confirmed from Hinode as well as other earlier observations. We studied 43 sunspots based on the data sets taken from ASP/DLSP, Hinode (SOT/SP) and SVM (USO). In…

Solar and Stellar Astrophysics · Physics 2015-05-13 Sanjiv Kumar Tiwari , P. Venkatakrishnan , K. Sankarasubramanian

The propagation of solar waves through the sunspot of AR 9787 is observed using temporal cross-correlations of SOHO/MDI Dopplergrams. We then use three-dimensional MHD numerical simulations to compute the propagation of wave packets through…

Astrophysics · Physics 2009-11-13 R. Cameron , L. Gizon , T. L. Duvall

Interacting particles on graphs are routinely used to study magnetic behaviour in physics, disease spread in epidemiology, and opinion dynamics in social sciences. The literature on mean-field approximations of such systems for large graphs…

Physics and Society · Physics 2022-07-15 Kai Cui , Wasiur R. KhudaBukhsh , Heinz Koeppl

The magnetic and velocity fields in sunspots are highly structured on small spatial scales which are encoded in the Stokes profiles. Our aim is to identify Stokes profiles in a sunspot which exhibit spectral characteristics that deviate…

Solar and Stellar Astrophysics · Physics 2024-01-09 Rohan Eugene Louis , Shibu K. Mathew , A. Raja Bayanna

Recently, two methods have shown outstanding performance for clustering images and jointly learning the feature representation. The first, called Information Maximiz-ing Self-Augmented Training (IMSAT), maximizes the mutual information…

Computer Vision and Pattern Recognition · Computer Science 2019-12-12 Jizong Peng , Christian Desrosiers , Marco Pedersoli

Current modularity-based community detection algorithms attempt to find cluster memberships that maximize modularity within a fixed graph topology. Diverging from this conventional approach, our work introduces a novel strategy that employs…

Data Analysis, Statistics and Probability · Physics 2024-02-27 Yongyu Wang , Shiqi Hao , Xiaoyang Wang , Xiaotian Zhuang

We investigate the inclusion of clustering maps in a weak lensing Minkowski functional (MF) analysis of DES-like and LSST-like simulations to constrain cosmological parameters. The standard 3x2pt approach to lensing and clustering data uses…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-25 Nisha Grewal , Joe Zuntz , Tilman Tröster , Alexandra Amon

The decay of sunspot groups is a relatively unknown field since most studies have focused mainly on the decay of sunspots or sunspot groups, but only on small samples. As an extension of the recent work of \citet{2020ApJ...892..107M} which…

Solar and Stellar Astrophysics · Physics 2021-02-24 Judit Muraközy

Time-distance helioseismic measurements in surface- and deep-focus geometries for wave-paths that distinguish surface magnetic contributions from those due to deeper perturbations beneath a large sunspot are presented and analysed. Travel…

Astrophysics · Physics 2008-02-21 S. P. Rajaguru

Correlative microscopy aims at combining two or more modalities to gain more information than the one provided by one modality on the same biological structure. Registration is needed at different steps of correlative microscopies…

Computer Vision and Pattern Recognition · Computer Science 2020-12-02 Stephan Kunne , Guillaume Potier , Jean Mérot , Perrine Paul-Gilloteaux