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Dealing with land cover classification of the new image sources has also turned to be a complex problem requiring large amount of memory and processing time. In order to cope with these problems, statistical learning has greatly helped in…

Locating where transient signals travel between a source and receiver requires a final step that is needed after using a theory of diffraction such as the integral theorem of Helmholtz and Kirchhoff. Introduced here, the final step accounts…

Classical Physics · Physics 2014-11-18 John L. Spiesberger

In this work, we introduce a spatio-temporal kernel for Gaussian process (GP) regression-based sound field estimation. Notably, GPs have the attractive property that the sound field is a linear function of the measurements, allowing the…

Audio and Speech Processing · Electrical Eng. & Systems 2024-07-08 David Sundström , Shoichi Koyama , Andreas Jakobsson

In this paper we present new results of spectraphotometrical investigations of the flaring kernels sizes and their intensities measured simultaneously in various parts of the H-alpha line profile. Our investigations were based on the very…

Astrophysics · Physics 2015-05-13 K. Radziszewski , P. Rudawy

Radio remote sensing of the heliosphere using spacecraft radio signals has been used to study the near-sun plasma in and out of the ecliptic, close to the sun, and on spatial and temporal scales not accessible with other techniques. Studies…

Musical source separation methods exploit source-specific spectral characteristics to facilitate the decomposition process. Kernel Additive Modelling (KAM) models a source applying robust statistics to time-frequency bins as specified by a…

Sound · Computer Science 2017-11-01 Delia Fano Yela , Sebastian Ewert , Derry FitzGerald , Mark Sandler

Electromagnetic wave scattering off density inhomogeneities in the solar corona is an important process which determines both the apparent source size and the time profile of radio bursts observed at 1 AU. Here we model the scattering…

Solar and Stellar Astrophysics · Physics 2019-03-05 N. H. Bian , A. G. Emslie , E. P. Kontar

Wave propagation through sunspots involves conversion between waves of acoustic and magnetic character. In addition, the thermal structure of sunspots is very different than that of the quiet Sun. As a consequence, the interpretation of…

Solar and Stellar Astrophysics · Physics 2016-10-05 T. Felipe , D. C. Braun , A. D. Crouch , A. C. Birch

A crucial feature not widely accounted for in local helioseismology is that surface magnetic regions actually open a window from the interior into the solar atmosphere, and that the seismic waves leak through this window, reflect high in…

Solar and Stellar Astrophysics · Physics 2015-06-24 H. Moradi , P. S. Cally , D. Przybylski , S. Shelyag

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

The use of covariance kernels is ubiquitous in the field of spatial statistics. Kernels allow data to be mapped into high-dimensional feature spaces and can thus extend simple linear additive methods to nonlinear methods with higher order…

Machine Learning · Statistics 2017-11-16 Jean-Francois Ton , Seth Flaxman , Dino Sejdinovic , Samir Bhatt

Seismic traveltime tomography using transmission data is widely used to image the Earth's interior from global to local scales. In seismic imaging, it is used to obtain velocity models for subsequent depth-migration or full-waveform…

Computational Physics · Physics 2021-04-06 Umair bin Waheed , Tariq Alkhalifah , Ehsan Haghighat , Chao Song , Jean Virieux

Using spectral-element and adjoint methods, we investigate body waves interacting with the Earth's most dramatic interface, the core-mantle boundary (CMB). Intermediate-to-high frequency seismograms are computed incorporating topography…

Geophysics · Physics 2022-10-26 Maria Koroni , Anselme Borgeaud , Andreas Fichtner , Frédéric Deschamps

This article presents a quantum computing approach to designing of similarity measures and kernels for classification of stochastic symbolic time series. In the area of machine learning, kernels are important components of various…

Quantum Physics · Physics 2025-06-10 Vanio Markov , Vladimir Rastunkov , Daniel Fry

A new time--distance far-side imaging technique was recently developed by utilizing multiple multi-skip acoustic waves. The measurement procedure is applied to 11 years of Doppler observations from the Solar Dynamics Observatory /…

Solar and Stellar Astrophysics · Physics 2022-01-05 Junwei Zhao , Grace Y. Jing , Ruizhu Chen

A kernel-based framework for spatio-temporal data analysis is introduced that applies in situations when the underlying system dynamics are governed by a dynamic equation. The key ingredient is a representer theorem that involves…

Statistics Theory · Mathematics 2020-11-16 Oleg Szehr , Dario Azzimonti , Laura Azzimonti

We present a new method for helioseismic diagnostics of the three-dimensional structure of sound speed, magnetic fields and flow velocities in the convection zone by inversion of acoustic travel-time data. The data are measurements of the…

Solar and Stellar Astrophysics · Physics 2018-06-11 A. G. Kosovichev , T. L. Duvall

We apply time-distance helioseismology, local correlation tracking and Fourier spatial-temporal filtering methods to realistic supergranule scale simulations of solar convection and compare the results with high-resolution observations from…

Numerical models of solar flares typically focus on the behaviour of directly-heated flare models, adopting magnetic field- aligned, plane-parallel methodologies. With high spatial- and spectral-resolution ground-based optical observations…

Solar and Stellar Astrophysics · Physics 2022-09-21 Christopher M. J. Osborne , Lyndsay Fletcher

In this paper, we aim to perform sensitivity analysis of set-valued models and, in particular, to quantify the impact of uncertain inputs on feasible sets, which are key elements in solving a robust optimization problem under constraints.…