Tootfinder

A (digital?) makeover of a vintage map with elevation data.
Based on the 1894 Rand McNally Map of #Africa
(source unknown)
#Geography #Topography

Harnessing Data and Physics for Deep Learning Phase Recovery
Kaiqiang Wang, Edmund Y. Lam
https://arxiv.org/abs/2404.01360 https://ar…

Harnessing Data and Physics for Deep Learning Phase Recovery
Phase recovery, calculating the phase of a light wave from its intensity measurements, is essential for various applications, such as coherent diffraction imaging, adaptive optics, and biomedical imaging. It enables the reconstruction of an object's refractive index distribution or topography as well as the correction of imaging system aberrations. In recent years, deep learning has been proven to be highly effective in addressing phase recovery problems. Two main deep learning phase recovery s…

Harnessing Data and Physics for Deep Learning Phase Recovery
Kaiqiang Wang, Edmund Y. Lam
https://arxiv.org/abs/2404.01360 https://ar…

Harnessing Data and Physics for Deep Learning Phase Recovery
Phase recovery, calculating the phase of a light wave from its intensity measurements, is essential for various applications, such as coherent diffraction imaging, adaptive optics, and biomedical imaging. It enables the reconstruction of an object's refractive index distribution or topography as well as the correction of imaging system aberrations. In recent years, deep learning has been proven to be highly effective in addressing phase recovery problems. Two main deep learning phase recovery s…

Two-dimensional turbulence above topography: condensation transition and selection of minimum enstrophy solutions
Basile Gallet
https://arxiv.org/abs/2404.06475

Two-dimensional turbulence above topography: condensation transition and selection of minimum enstrophy solutions
We consider two-dimensional flows above topography, revisiting the selective decay (or minimum-enstrophy) hypothesis of Bretherton and Haidvogel. We derive a `condensed branch' of solutions to the variational problem where a domain-scale condensate coexists with a flow at the (smaller) scale of the topography. The condensate arises through a supercritical bifurcation as the conserved energy of the initial condition exceeds a threshold value, a prediction that we quantitatively validate using Di…

Sibiu/Hermannstadt seems more pleasant than Braşov/Kronstadt. Mainly because the old city is closer to the station and there aren’t any six-lane bulevarduls inbetween. The surroundings are less hilly than in Braşov but the old city itself is centred on a hill and has interesting topography.

Stochastic Geometry Models for Texture Synthesis of Machined Metallic Surfaces: Sandblasting and Milling
Natascha Jeziorski, Claudia Redenbach
https://arxiv.org/abs/2403.13439

Stochastic Geometry Models for Texture Synthesis of Machined Metallic Surfaces: Sandblasting and Milling
Training defect detection algorithms for visual surface inspection systems requires a large and representative set of training data. Often there is not enough real data available which additionally cannot cover the variety of possible defects. Synthetic data generated by a synthetic visual surface inspection environment can overcome this problem. Therefore, a digital twin of the object is needed, whose micro-scale surface topography is modeled by texture synthesis models. We develop stochastic …

Internal-wave convection and shear near the top of a deep equatorial seamount
Hans van Haren
https://arxiv.org/abs/2402.11264 https://

Internal-wave convection and shear near the top of a deep equatorial seamount
The near-equatorial ocean experiences particular dynamics because the Coriolis force is weak. One modelled effect of these dynamics is strong reduction of turbulent mixing in the ocean interior. Unknowns are effects on internal wave breaking and associated turbulent mixing above steeply sloping topography. In this paper, high-resolution temperature observations are analyzed from sensors that were moored near the top of a deep Ceara Basin seamount for one week. A vertical string held sensors bet…

This https://arxiv.org/abs/2403.12444 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_nli…

Weakly nonlinear analysis of Turing pattern dynamics on curved surfaces
Pattern dynamics on curved surfaces are ubiquitous. Although the effect of surface topography on pattern dynamics has gained much interest, there is a limited understanding of the roles of surface geometry and topology in pattern dynamics. Recently, we reported that a static pattern on a flat plane can become a propagating pattern on a curved surface [Nishide and Ishihara, Phys. Rev. Lett. 2022]. By examining reaction-diffusion equations on axisymmetric surfaces, certain conditions for the onse…

This https://arxiv.org/abs/2403.09888 has been replaced.
initial toot: https://mastoxiv.page/@arXiv_…

Rapid hydrofracture of icy moon shells: insights from glaciology
Europa's surface features many regions of complex topography termed 'chaos terrains'. One set of hypotheses for chaos terrain formation require upward migration of liquid water from perched water bodies formed by convection and tidal heating within the icy shell. However, consideration of the behaviour of terrestrial ice sheets suggests the rapid downwards, not upwards, movement of water from perched water bodies, initiated through hydrofracture and without a propagation limit provided there is…

On the stability of fully nonlinear hydraulic-fall solutions to the forced water-wave problem
Jack S. Keeler, Mark G. Blyth
https://arxiv.org/abs/2403.06933

On the stability of fully nonlinear hydraulic-fall solutions to the forced water-wave problem
Two-dimensional free-surface flow over localised topography is examined with the emphasis on the stability of hydraulic-fall solutions. A Gaussian topography profile is assumed with a positive or negative amplitude modelling a bump or a dip, respectively. Steady hydraulic-fall solutions to the full incompressible, irrotational Euler equations are computed, and their linear and nonlinear stability is analysed by computing eigenspectra of the pertinent linearised operator and by solving an initia…

Real-time portable muography with Hankuk Atmospheric-muon Wide Landscaping : HAWL
J. Seo, N. Carlin, D. F. F. S. Cavalcante, J. S. Chung, L. E. Franca, C. Ha, J. Kim, J. Y. Kim, H. Kimku, B. C. Koh, Y. J. Lee, B. B. Manzato, S. W. Oh, R. L. C. Pitta, S. J. Won
https://arxiv.org/abs/2403.02638 https://arxiv.org/pdf/2403.02638
arXiv:2403.02638v1 Announce Type: new
Abstract: Cosmic ray muons prove valuable across various fields, from particle physics experiments to non-invasive tomography, thanks to their high flux and exceptional penetrating capability. Utilizing a scintillator detector, one can effectively study the topography of mountains situated above tunnels and underground spaces. The Hankuk Atmospheric-muon Wide Landscaping (HAWL) project successfully charts the mountainous region of eastern Korea by measuring cosmic ray muons with a detector in motion. The real-time muon flux measurement shows a tunnel length accuracy of 6.5 %, with a detectable overburden range spanning from 8 to 400 meter-water-equivalent depth. This is the first real-time portable muon tomography.

Internal-wave convection and shear near the top of a deep equatorial seamount
Hans van Haren
https://arxiv.org/abs/2402.11264 https://

Internal-wave convection and shear near the top of a deep equatorial seamount
The near-equatorial ocean experiences particular dynamics because the Coriolis force is weak. One modelled effect of these dynamics is strong reduction of turbulent mixing in the ocean interior. Unknowns are effects on internal wave breaking and associated turbulent mixing above steeply sloping topography. In this paper, high-resolution temperature observations are analyzed from sensors that were moored near the top of a deep Ceara Basin seamount for one week. A vertical string held sensors bet…

Bathymetry reconstruction from experimental data using PDE-constrained optimisation
Judith Angel, J\"orn Behrens, Sebastian G\"otschel, Marten Hollm, Daniel Ruprecht, Robert Seifried
https://arxiv.org/abs/2404.05556

Bathymetry reconstruction from experimental data using PDE-constrained optimisation
Knowledge of the bottom topography, also called bathymetry, of rivers, seas or the ocean is important for many areas of maritime science and civil engineering. While direct measurements are possible, they are time consuming and expensive. Therefore, many approaches have been proposed how to infer the bathymetry from measurements of surface waves. Mathematically, this is an inverse problem where an unknown system state needs to be reconstructed from observations with a suitable model for the flo…

Inter-individual and inter-site neural code conversion and image reconstruction without shared stimuli
Haibao Wang, Jun Kai Ho, Fan L. Cheng, Shuntaro C. Aoki, Yusuke Muraki, Misato Tanaka, Yukiyasu Kamitani
https://arxiv.org/abs/2403.11517

Inter-individual and inter-site neural code conversion and image reconstruction without shared stimuli
The human brain demonstrates substantial inter-individual variability in fine-grained functional topography, posing challenges in identifying common neural representations across individuals. Functional alignment has the potential to harmonize these individual differences. However, it typically requires an identical set of stimuli presented to different individuals, which is often unavailable. To address this, we propose a content loss-based neural code converter, designed to convert brain acti…

Assimilation of SWOT Altimetry and Sentinel-1 Flood Extent Observations for Flood Reanalysis -- A Proof-of-Concept
Thanh Huy Nguyen, Sophie Ricci, Andrea Piacentini, Charlotte Emery, Raquel Rodriguez Suquet, Santiago Pe\~na Luque
https://arxiv.org/abs/2403.14394

Assimilation of SWOT Altimetry and Sentinel-1 Flood Extent Observations for Flood Reanalysis -- A Proof-of-Concept
In spite of astonishing advances and developments in remote sensing technologies, meeting the spatio-temporal requirements for flood hydrodynamic modeling remains a great challenge for Earth Observation. The assimilation of multi-source remote sensing data in 2D hydrodynamic models participates to overcome such a challenge. The recently launched Surface Water and Ocean Topography (SWOT) wide-swath altimetry satellite provides a global coverage of water surface elevation at a high resolution. SW…

Abyssal Slope CUrrents
Esther Cap\'o, James C. McWilliams, Jonathan Gula, M. Jeroen Molemaker, Pierre Damien, Ren\'e Schubert
https://arxiv.org/abs/2402.11152

Abyssal Slope CUrrents
Realistic computational simulations in different oceanic basins reveal prevalent prograde mean flows (i.e. in the direction of topographic Rossby wave propagation along isobaths; a.k.a. topostrophy) on topographic slopes in the deep ocean, consistent with the barotropic theory of eddy-driven mean flows. Attention is focused on the Western Mediterranean Sea with strong currents and steep topography. These prograde mean currents induce an opposing bottom drag stress and thus a turbulent boundary-…

Bathymetry reconstruction from experimental data using PDE-constrained optimisation
Judith Angel, J\"orn Behrens, Sebastian G\"otschel, Marten Hollm, Daniel Ruprecht, Robert Seifried
https://arxiv.org/abs/2404.05556

Bathymetry reconstruction from experimental data using PDE-constrained optimisation
Knowledge of the bottom topography, also called bathymetry, of rivers, seas or the ocean is important for many areas of maritime science and civil engineering. While direct measurements are possible, they are time consuming and expensive. Therefore, many approaches have been proposed how to infer the bathymetry from measurements of surface waves. Mathematically, this is an inverse problem where an unknown system state needs to be reconstructed from observations with a suitable model for the flo…

Weakly nonlinear analysis of Turing pattern dynamics on curved surfaces
Ryosuke Nishide, Shuji Ishihara
https://arxiv.org/abs/2403.12444 https://

Weakly nonlinear analysis of Turing pattern dynamics on curved surfaces
Pattern dynamics on curved surfaces are ubiquitous. Although the effect of surface topography on pattern dynamics has gained much interest, there is a limited understanding of the roles of surface geometry and topology in pattern dynamics. Recently, we reported that a static pattern on a flat plane can become a propagating pattern on a curved surface [Nishide and Ishihara, Phys. Rev. Lett. 2022]. By examining reaction-diffusion equations on axisymmetric surfaces, certain conditions for the onse…

Rapid hydrofracture of icy moon shells: insights from glaciology
Robert Law
https://arxiv.org/abs/2403.09888 https://arxiv.org/pdf/24…

Rapid hydrofracture of icy moon shells: insights from glaciology
Europa's surface features many regions of complex topography termed 'chaos terrains'. One set of hypotheses for chaos terrain formation require upward migration of liquid water from perched water bodies formed by convection and tidal heating within the icy shell. However, consideration of the behaviour of terrestrial ice sheets suggests the rapid downwards, not upwards, movement of water from perched water bodies, initiated through hydrofracture and without a propagation limit provided there is…