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The inversion of ring fit parameters to obtain subsurface flow maps in ring-diagram analysis for 8 years of SDO observations is computationally expensive, requiring ~3200 CPU hours. In this paper we apply machine learning techniques to the…

Solar and Stellar Astrophysics · Physics 2019-02-06 Rasha Alshehhi , Chris S. Hanson , Laurent Gizon , Shravan Hanasoge

We have computed seismic images of magnetic activity on the far surface of the Sun by using a seismic-holography technique. As in previous works, the method is based on the comparison of waves going in and out of a particular point in the…

Solar and Stellar Astrophysics · Physics 2010-03-05 F. Perez Hernandez , I. Gonzalez Hernandez

Estimates of the photospheric magnetic, electric and plasma velocity fields are essential for studying the dynamics of the solar atmosphere, for example through the derivative quantities of Poynting and relative helicity flux and by using…

Solar and Stellar Astrophysics · Physics 2017-12-18 E. Lumme , J. Pomoell , E. K. J. Kilpua

We compare measurements of horizontal flows on the surface of the Sun using helioseismic time--distance inversions and coherent structure tracking of solar granules. Tracking provides 2D horizontal flows on the solar surface, whereas the…

Solar and Stellar Astrophysics · Physics 2015-06-15 M. Svanda , Th. Roudier , M. Rieutord , R. Burston , L. Gizon

A number of basic image processing tasks, such as any geometric transformation require interpolation at subpixel image values. In this work we utilize the multidimensional coordinate Hermite spline interpolation defined on non-equal spaced,…

Computer Vision and Pattern Recognition · Computer Science 2024-03-21 Konstantinos K. Delibasis , Iro Oikonomou , Aristides I. Kechriniotis , Georgios N. Tsigaridas

Understanding convection is important in stellar physics, for example as an input in stellar evolution models. Helioseismic estimates of convective flow amplitudes in deeper regions of the solar interior disagree by orders of magnitude…

Solar and Stellar Astrophysics · Physics 2021-05-12 Vincent G. A. Böning , Aaron C. Birch , Laurent Gizon , Thomas L. Duvall

We study the sensitivity of wave travel times to steady and spatially homogeneous horizontal flows added to a realistic simulation of the solar convection performed by Robert F. Stein, Ake Nordlund, Dali Georgobiani, and David Benson. Three…

Solar and Stellar Astrophysics · Physics 2015-05-13 S. Couvidat , A. C. Birch

We present an efficient method for two dimensional inversions for the solar rotation rate using the Subtractive Optimally Localized Averages (SOLA) method and a modification of the R1 X R1 technique proposed by Sekii (1993). The SOLA method…

Astrophysics · Physics 2015-06-24 F. P. Pijpers , M. J. Thompson

We developed a method to automatically detect and trace solar filaments in H\alpha\ full-disk images. The program is able not only to recognize filaments and determine their properties, such as the position, the area, the spine, and other…

Solar and Stellar Astrophysics · Physics 2015-06-15 Qi Hao , Cheng Fang , P. F. Chen

Quantum computing can empower machine learning models by enabling kernel machines to leverage quantum kernels for representing similarity measures between data. Quantum kernels are able to capture relationships in the data that are not…

Solutions of partial differential equations can often be written as surface integrals having a kernel related to a singular fundamental solution. Special methods are needed to evaluate the integral accurately at points on or near the…

Numerical Analysis · Mathematics 2025-10-16 J. Thomas Beale , Svetlana Tlupova

We perform helioseismic holography on realistic solar convection simulations and compare the observed travel-time perturbations with the expected travel times from the horizontal flows in the simulations computed from forward models under…

Astrophysics · Physics 2016-03-28 D. C. Braun , A. C. Birch , D. Benson , R. F. Stein , Å. Nordlund

Complex models are often used to understand interactions and drivers of human-induced and/or natural phenomena. It is worth identifying the input variables that drive the model output(s) in a given domain and/or govern specific model…

Methodology · Statistics 2023-11-07 Matieyendou Lamboni

We describe a new algorithm for reconstruction of Differential Emission Measures (DEMs) in the solar corona. Although a number of such algorithms currently exist, they can have difficulty converging for some cases, and can be complex, slow,…

Solar and Stellar Astrophysics · Physics 2020-12-11 Joseph Plowman , Amir Caspi

Graph-based methods pervade the inference toolkits of numerous disciplines including sociology, biology, neuroscience, physics, chemistry, and engineering. A challenging problem encountered in this context pertains to determining the…

Machine Learning · Computer Science 2018-09-25 Daniel Romero , Vassilis N. Ioannidis , Georgios B. Giannakis

Kernels are often developed and used as implicit mapping functions that show impressive predictive power due to their high-dimensional feature space representations. In this study, we gradually construct a series of simple feature maps that…

Machine Learning · Computer Science 2020-07-20 Gurhan Ceylan , S. Ilker Birbil

In this article, we consider flat and curved Riemannian symmetric spaces in the complex case and we study their basic integral kernels, in potential and spherical analysis: heat, Newton, Poisson kernels and spherical functions, i.e. the…

Probability · Mathematics 2020-12-22 P. Graczyk , P. Sawyer

The solar-cyle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic…

Solar and Stellar Astrophysics · Physics 2016-12-07 R. Howe , S. Basu , G. R. Davies , W. H. Ball , W. J. Chaplin , Y. Elsworth , R. Komm

We introduce a highly-parallelizable architecture for estimating parameters of compact binary coalescence using gravitational-wave data and waveform models. Using a spherical harmonic mode decomposition, the waveform is expressed as a sum…

General Relativity and Quantum Cosmology · Physics 2015-08-06 C. Pankow , P. Brady , E. Ochsner , R. O'Shaughnessy

The great success of Helioseismology resides in the remarkable progress achieved in the understanding of the structure and dynamics of the solar interior. This success mainly relies on the ability to conceive, implement, and operate…

Solar and Stellar Astrophysics · Physics 2018-02-05 P. L. Palle , T. Appourchaux , J. Christensen-Dalsgaard , R. A. Garcia