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Seismic full waveform inversion (FWI) is a powerful technique to generate high resolution images of the Earth's interior. However, significant uncertainty exists in all FWI solutions due to imperfect acquisition geometries, inherent noise…

Geophysics · Physics 2026-03-13 Xuebin Zhao , Andrew Curtis

We study the generalized Forchheimer flows of slightly compressible fluids in heterogeneous porous media. The media's porosity and coefficients of the Forchheimer equation are functions of the spatial variables. The partial differential…

Analysis of PDEs · Mathematics 2016-03-23 Emine Celik , Luan Hoang

Normal and anomalous diffusion are ubiquitous in many complex systems [1] . Here, we define a time and space generalized diffusion equation (GDE), which uses fractional-time derivatives and transformed d-path Laplacian operators on…

Physics and Society · Physics 2022-02-02 Fernando Diaz-Diaz , Ernesto Estrada

Recent works have shown that high probability metrics with stochastic gradient descent (SGD) exhibit informativeness and in some cases advantage over the commonly adopted mean-square error-based ones. In this work we provide a formal…

Machine Learning · Computer Science 2022-11-03 Dragana Bajovic , Dusan Jakovetic , Soummya Kar

Ray tracing 3D Gaussian particles enables realistic effects such as depth of field, refractions, and flexible camera modeling for novel-view synthesis. However, existing methods trace Gaussians through proxy geometry, which requires…

Computer Vision and Pattern Recognition · Computer Science 2025-12-05 Changhe Liu , Ehsan Javanmardi , Naren Bao , Alex Orsholits , Manabu Tsukada

Transmission spectroscopy, which consists of measuring the wavelength-dependent absorption of starlight by a planet's atmosphere during a transit, is a powerful probe of atmospheric composition. However, the expected signal is typically…

Earth and Planetary Astrophysics · Physics 2015-05-30 N. P. Gibson , S. Aigrain , S. Roberts , T. M. Evans , M. Osborne , F. Pont

This contribution is the chapter 2 of the book "geodetic time series analysis" (10.1007/978-3-030-21718-1). The book is dedicated to the art of fitting a trajectory model to those geodetic time series in order to extract accurate…

Other Statistics · Statistics 2019-08-30 Machiel S. Bos , Jean-Philippe Montillet , Simon D. P. Williams , Rui M. S. Fernandes

Over-water communication has been an important research field of wireless communications and radar. Since there are so many parameters in this environment that are changing continuously in the spatial and temporal domains such as weather…

Signal Processing · Electrical Eng. & Systems 2018-12-27 Ahmed Abdelmoaty

The incomplete sampling of data in complex polarization measurements from radio telescopes negatively affects both the rotation measure (RM) transfer function and the Faraday depth spectra derived from these data. Such gaps in polarization…

Instrumentation and Methods for Astrophysics · Physics 2021-02-24 S. W. Ndiritu , A. M. M. Scaife , D. L. Tabb , M. Carcamo , J. Hanson

It is seen how to write the standard\^E form of the four partial differential equations in four unknowns of anisotropic thermoelasticity as a single equation in one variable, in terms of isothermal and isentropic wave operators. This…

Classical Physics · Physics 2020-05-11 N. H. Scott

This article develops an approximate proximal approach for the generalized method of lines. The present results are extensions and applications of previous ones which have been published since 2011, in books and articles such as [3,4,5,6].…

General Mathematics · Mathematics 2022-06-01 Fabio Silva Botelho

Ray tracing is a widely used technique for modeling optical systems, involving sequential surface-by-surface computations, which can be computationally intensive. We propose Ray2Ray, a novel method that leverages implicit neural…

Machine Learning · Computer Science 2025-07-29 Shiva Sinaei , Chuanjun Zheng , Kaan Akşit , Daisuke Iwai

This paper develops one of the methods for study of nonlinear Partial Differential equations. We generalize Sato equation and represent the algorithm for construction of some classes of nonlinear Partial Differential Equations (PDE)…

Exactly Solvable and Integrable Systems · Physics 2007-05-23 A. I. Zenchuk

Whenever oceanic currents flow over rough topography, there is an associated stress that acts to modify the flow. In the deep ocean, this stress is predominantly a form drag due to pressure differentials across topography, caused by the…

Atmospheric and Oceanic Physics · Physics 2026-02-13 Daniel R. Johnston , Callum J. Shakespeare , Navid C. Constantinou

Exact expressions for all the steady-state fields (E, H, D, B) in uniaxial linear media composed of an arbitrary number of layers having arbitrary thicknesses subjected to normal incidence are derived. Generic boundary condition relations…

Materials Science · Physics 2007-05-23 Pieder Beeli

Radio propagation modeling is essential in telecommunication research, as radio channels result from complex interactions with environmental objects. Recently, Machine Learning has been attracting attention as a potential alternative to…

The equations of motion in a macroscopically inhomogeneous porous medium saturated by a fluid are derived. As a first verification of the validity of these equations, a two-layer rigid frame porous system considered as one single porous…

Radiative transfer is a key bottleneck in computational astrophysics: it is nonlocal, stiff, and tightly coupled to hydrodynamics. We introduce Ray-trax, a GPU-oriented, fully differentiable 3D ray tracer written in JAX that solves the…

Instrumentation and Methods for Astrophysics · Physics 2025-11-13 Lorenzo Branca , Rune Rost , Tobias Buck

Geometric perturbation theory is universal. A typical example is provided by the 3D wave equation, widely used in acoustics. We face vibrating eardrums as a binaural auditory input stemming from an external sound source. In the setup of…

Mathematical Physics · Physics 2020-03-18 David T. Heider , J. Leo van Hemmen

Bayesian learning using Gaussian processes provides a foundational framework for making decisions in a manner that balances what is known with what could be learned by gathering data. In this dissertation, we develop techniques for…

Machine Learning · Statistics 2022-04-29 Alexander Terenin