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The homotopy theory of topological defects in ordered media fails to completely characterize systems with broken translational symmetry. We argue that the problem can be understood in terms of the lack of rotational Goldstone modes in such…

Soft Condensed Matter · Physics 2009-09-14 Bryan Gin-ge Chen , Gareth P. Alexander , Randall D. Kamien

Variable curvature mirrors of large amplitude are designed by using finite element analysis. The specific case studied reaches at least a 800 {\mu}m sag with an optical quality better than {\lambda}/5 over a 120 mm clear aperture. We…

Instrumentation and Methods for Astrophysics · Physics 2014-11-19 Emmanuel Hugot , Marc Ferrari , Gerard R. Lemaitre , Fabrice Madec , Sebastien Vives , Elodie Chardin , David Le Mignant , Jean Gabriel Cuby

We present a promising approach to the extremely fast sensing and correction of small wavefront errors in adaptive optics systems. As our algorithm's computational complexity is roughly proportional to the number of actuators, it is…

Instrumentation and Methods for Astrophysics · Physics 2016-11-26 Christoph U. Keller , Visa Korkiakoski , Niek Doelman , Rufus Fraanje , Raluca Andrei , Michel Verhaegen

Context. For accurately measuring intensities and determining magnetic field strengths of small-scale solar (magnetic) structure, knowledge of and compensation for the point spread function is crucial. For images recorded with the Swedish…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 G. B. Scharmer , M. G. Löfdahl , T. I. M. van Werkhoven , J. de la Cruz Rodriguez

High-resolution ground-based solar imaging relies heavily on multi-object multi-frame blind deconvolution to correct for atmospheric turbulence. However, the traditional joint maximum likelihood estimation methods in which object and the…

Instrumentation and Methods for Astrophysics · Physics 2026-05-13 A. Asensio Ramos

If the optical system of a telescope is perturbed from rotational symmetry, the Zernike wavefront aberration coefficients describing that system can be expressed as a function of position in the focal plane using spin-weighted Zernike…

Instrumentation and Methods for Astrophysics · Physics 2018-02-19 Stephen M. Kent

The optics of a number of future X-ray telescopes will have very long focal lengths (10 - 20 m), and will consist of a number of nested/stacked thin, grazing-incidence mirrors. The optical quality characterization of a real mirror can be…

Instrumentation and Methods for Astrophysics · Physics 2015-09-09 D. Spiga , S. Basso , M. Bavdaz , V. Burwitz , M. Civitani , O. Citterio , M. Ghigo , G. Hartner , B. Menz , G. Pareschi , L. Proserpio , B. Salmaso , G. Tagliaferri , E. Wille

We design a new absolute optical instrument by composing Luneburg lens and Lissajous lens, and analyze its imaging mechanism from the perspective of simple harmonic oscillations. The imaging positions are determined by the periods of…

Polarimetric imaging aims to recover polarimetric parameters, including Total Intensity (TI), Degree of Polarization (DoP), and Angle of Polarization (AoP), from captured polarized measurements. In real-world scenarios, these measurements…

Image and Video Processing · Electrical Eng. & Systems 2026-03-09 Chu Zhou , Yufei Han , Junda Liao , Linrui Dai , Wangze Xu , Art Subpa-Asa , Heng Guo , Boxin Shi , Imari Sato

Tool wear monitoring is crucial for quality control and cost reduction in manufacturing processes, of which drilling applications are one example. In this paper, we present a U-Net based semantic image segmentation pipeline, deployed on…

Computer Vision and Pattern Recognition · Computer Science 2024-02-12 Elke Schlager , Andreas Windisch , Lukas Hanna , Thomas Klünsner , Elias Jan Hagendorfer , Tamara Teppernegg

We characterize the mechanical quality factor of micro-oscillators covered by a highly reflective coating. We test an approach to the reduction of mechanical losses, that consists in limiting the size of the coated area to reduce the strain…

Optics · Physics 2012-08-27 E. Serra , F. S. Cataliotti , F. Marin , F. Marino , A. Pontin , G. A. Prodi , M. Bonaldi

Metasurfaces have attracted extensive interests due to their ability to locally manipulate optical parameters of light and easy integration to complex optical systems. Particularly, metasurfaces can provide a novel platform for splitting…

The availability and performance of laser-based adaptive optics (AO) systems are strongly dependent on the power and quality of the laser beam before being projected to the sky. Frequent and time-consuming alignment procedures are usually…

Instrumentation and Methods for Astrophysics · Physics 2014-05-23 Clémentine Béchet , Andrés Guesalaga , Benoit Neichel , Vincent Fesquet , Héctor González-Núñez , Sebastián Zúñiga , Pedro Escarate , Dani Guzman

A fruitful approach for solving signal deconvolution problems consists of resorting to a frame-based convex variational formulation. In this context, parallel proximal algorithms and related alternating direction methods of multipliers have…

Other Computer Science · Computer Science 2015-05-28 Nelly Pustelnik , Jean-Christophe Pesquet , Caroline Chaux

Many modern statistical estimation problems are defined by three major components: a statistical model that postulates the dependence of an output variable on the input features; a loss function measuring the error between the observed…

Optimization and Control · Mathematics 2018-10-09 Ying Cui , Jong-Shi Pang , Bodhisattva Sen

Attention mechanisms have revolutionized several domains of artificial intelligence, such as natural language processing and computer vision, by enabling models to selectively focus on relevant parts of the input data. While recent work has…

Machine Learning · Computer Science 2026-02-03 Addison Kristanto Julistiono , Davoud Ataee Tarzanagh , Navid Azizan

Multifractal analysis has revealed regularities in many self-seeding phenomena, yet its use in modern deep learning remains limited. Existing end-to-end multifractal methods rely on heavy pooling or strong feature-space decimation, which…

Computer Vision and Pattern Recognition · Computer Science 2025-12-03 Miguel L. Martins , Miguel T. Coimbra , Francesco Renna

Deformable convolution, originally proposed for the adaptation to geometric variations of objects, has recently shown compelling performance in aligning multiple frames and is increasingly adopted for video super-resolution. Despite its…

Computer Vision and Pattern Recognition · Computer Science 2020-09-16 Kelvin C. K. Chan , Xintao Wang , Ke Yu , Chao Dong , Chen Change Loy

A splitting of modes in a circular graded-index optical fiber is demonstrated by solving the full Maxwell equations using the perturbation analysis. It is shown that the degeneracy of vortex Laguerre-Gauss modes with distinct orbital…

Optics · Physics 2016-04-13 Nikolai I. Petrov

We propose and implement an aberration correction method for the creation of extended arrays of spots well beyond the isoplanatic region of any optical system. The method relies on an extensive calibration of aberrations in terms of Zernike…

Optics · Physics 2025-12-19 Yohann Machu , Gautier Creutzer , Clément Sayrin , Michel Brune