English
Related papers

Related papers: Computing aberration coefficients for plane-symmet…

200 papers

We give an algorithm for constructing the algebraic hull of a given matrix Lie algebra in characteristic zero. It is based on an algorithm for finding integral linear dependencies of the roots of a polynomial, that is probably of…

Rings and Algebras · Mathematics 2007-05-23 Claus Fieker , Willem de Graaf

For more than twenty years, Ray Tracing methods have continued to improve on both accuracy and computational time aspects. However, most state-of-the-art image-based ray tracers still rely on a description of the environment that only…

Signal Processing · Electrical Eng. & Systems 2024-01-23 Jérome Eertmans , Claude Oestges , Laurent Jacques

Consider a reflected diffusion on the positive half-line. We approximate it by solutions of stochastic differential equations using the penalty method: We emulate the "hard barrier" of reflection by a "soft barrier" of a large drift…

Probability · Mathematics 2016-10-17 Cameron Bruggeman , Andrey Sarantsev

In this work, we present a detailed procedure of computer implementation of the laws of refraction and reflection on an arbitrary surface with rotational symmetry with respect to the propagation axis. The goal is to facilitate the…

Optics · Physics 2025-01-07 J. E. Gómez-Correa , A. L. Padilla-Ortiz , S. Chávez-Cerda

We present the results obtained with an end-to-end simulator of an Extreme Adaptive Optics (XAO) system control loop. It is used to predict its on-sky performances and to optimise the AO loop algorithms. It was first used to validate a…

Instrumentation and Methods for Astrophysics · Physics 2023-01-10 Anthony Berdeu , Michel Tallon , Éric Thiébaut , Mary Angelie Alagao , Sitthichat Sukpholtham , Maud Langlois , Adithep Kawinkij , Puttiwat Kongkaew

The concept of Automorphic Lie Algebras arises in the context of reduction groups introduced in the early 1980s in the field of integrable systems. Automorphic Lie Algebras are obtained by imposing a discrete group symmetry on a current…

Exactly Solvable and Integrable Systems · Physics 2015-06-23 Vincent Knibbeler , Sara Lombardo , Jan A Sanders

We study theoretically and experimentally coherent imaging of surface plasmon polaritons using either leakage radiation microscopy through a thin metal film or interference microscopy through a thick metal film. Using a rigorous modal…

We consider algebraic iterative reconstruction methods with applications in image reconstruction. In particular, we are concerned with methods based on an unmatched projector/backprojector pair; i.e., the backprojector is not the exact…

Numerical Analysis · Mathematics 2019-02-14 Yiqiu Dong , Per Christian Hansen , Michiel E. Hochstenbach , Nicolai Andre Brogaard Riis

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

Existing works on motion deblurring either ignore the effects of depth-dependent blur or work with the assumption of a multi-layered scene wherein each layer is modeled in the form of fronto-parallel plane. In this work, we consider the…

Computer Vision and Pattern Recognition · Computer Science 2022-02-08 Kuldeep Purohit , Subeesh Vasu , M. Purnachandra Rao , A. N. Rajagopalan

We extend a result proved in \cite{Col} for mirror symmetries of planar systems to measure-preserving non-linear reversibilities of $n$-dimensional systems, dropping the analyticity and nondegeneracy conditions.

Dynamical Systems · Mathematics 2015-10-07 Marco Sabatini

The theory of Lie point symmetries is applied to study the generalized Zakharov system with two unknown parameters. The system reduces into a three-dimensional real value functions system, where we find that admits five Lie point…

Exactly Solvable and Integrable Systems · Physics 2020-06-23 K. Krishnakumar , A. Durga Devi , A. Paliathanasis

We study Lie-Hamilton systems on the plane, i.e. systems of first-order differential equations describing the integral curves of a $t$-dependent vector field taking values in a finite-dimensional real Lie algebra of planar Hamiltonian…

Mathematical Physics · Physics 2015-02-18 A. Ballesteros , A. Blasco , F. J. Herranz , J. de Lucas , C. Sardón

This paper addresses the problem of determining the symmetries of a plane or space curve defined by a rational parametrization. We provide effective methods to compute the involution and rotation symmetries for the planar case. As for space…

Algebraic Geometry · Mathematics 2014-05-13 J. G. Alcázar , C. Hermoso , G. Muntingh

Mechanically reconfigurable reflectors can modify their geometries to realize large angle beam scanning. This paper studies a method for reconfiguring a reflector geometry from a standard parabolic shape to offset parabolic shapes with…

Materials Science · Physics 2021-11-02 Bin Xu , Houfei Fang , Shuidong Jiang , Yangqing Hou , Lan Lan

Multiple lidars are prevalently used on mobile vehicles for rendering a broad view to enhance the performance of localization and perception systems. However, precise calibration of multiple lidars is challenging since the feature…

Computer Vision and Pattern Recognition · Computer Science 2019-04-30 Jianhao Jiao , Qinghai Liao , Yilong Zhu , Tianyu Liu , Yang Yu , Rui Fan , Lujia Wang , Ming Liu

The optical aberrations of a system can be described in terms of the wave aberrations, defined as the departure from the ideal spherical wavefront; or the ray aberrations, which are in turn the deviations from the paraxial ray intersection…

Optics · Physics 2016-01-20 John Restrepo , Pawel J. Stoerck , Ivo Ihrke

Accurately measuring the geometry and spatially-varying reflectance of real-world objects is a complex task due to their intricate shapes formed by concave features, hollow engravings and diverse surfaces, resulting in inter-reflection and…

Computer Vision and Pattern Recognition · Computer Science 2024-12-16 Jing Yang , Pratusha Bhuvana Prasad , Qing Zhang , Yajie Zhao

The paper presents the geometry of Lie algebroids and its applications to optimal control. The first part deals with the theory of Lie algebroids, connections on Lie algebroids and dynamical systems defined on Lie algebroids (mainly…

Differential Geometry · Mathematics 2013-02-26 Liviu Popescu

Beamforming in ultrasound imaging has significant impact on the quality of the final image, controlling its resolution and contrast. Despite its low spatial resolution and contrast, delay-and-sum is still extensively used nowadays in…

Computer Vision and Pattern Recognition · Computer Science 2016-05-20 Teodora Szasz , Adrian Basarab , Denis Kouamé