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Related papers: Enhanced Approximate Cloaking by SH and FSH Lining

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We design sources for the two-dimensional Helmholtz equation that can cloak an object by cancelling out the incident field in a region, without the sources completely surrounding the object to hide. As in previous work for real positive…

Analysis of PDEs · Mathematics 2022-03-07 Maxence Cassier , Trent DeGiovanni , Sébastien Guenneau , Fernando Guevara Vasquez

This article analyzes an explicit temporal splitting numerical scheme for the stochastic Allen-Cahn equation driven by additive noise, in a bounded spatial domain with smooth boundary in dimension $d\le 3$. The splitting strategy is…

Probability · Mathematics 2018-04-03 Charles-Edouard Bréhier , Jianbo Cui , Jialin Hong

We study approximate cloaking using transformation optics for electromagnetic waves in the time domain. Our approach is based on estimates of the degree of visibility in the frequency domain for all frequencies in which the frequency…

Analysis of PDEs · Mathematics 2019-01-15 Hoai-Minh Nguyen , Loc Tran

We give an $\alpha(1+\epsilon)$-approximation algorithm for solving covering LPs, assuming the presence of a $(1/\alpha)$-approximation algorithm for a certain optimization problem. Our algorithm is based on a simple modification of the…

Data Structures and Algorithms · Computer Science 2020-12-18 Eklavya Sharma

We make precise some results on the cloaking of displacement fields in linear elasticity. In the spirit of transformation media theory, the transformed governing equations in Cosserat and Willis frameworks are shown to be equivalent to…

Analysis of PDEs · Mathematics 2019-04-08 Richard Craster , Andre Diatta , Sebastien Guenneau , Harsha Hutridurga

Using a sum rule, we derive new bounds on Herglotz functions that generalize those given in (Gustafson and Sj\"oberg 2010) and (Bernland, Luger and Gustafson 2011). These bounds apply to a wide class of linear passive systems such as…

Mathematical Physics · Physics 2017-08-02 Maxence Cassier , Graeme W. Milton

Recently, Petrik et al. demonstrated that L1Regularized Approximate Linear Programming (RALP) could produce value functions and policies which compared favorably to established linear value function approximation techniques like LSPI.…

Machine Learning · Computer Science 2012-10-19 Gavin Taylor , Ron Parr

We present an $\ell^2_2+\ell_1$-regularized discrete least squares approximation over general regions under assumptions of hyperinterpolation, named hybrid hyperinterpolation. Hybrid hyperinterpolation, using a soft thresholding operator…

Numerical Analysis · Mathematics 2024-07-08 Congpei An , Jiashu Ran , Alvise Sommariva

Near neighbor problems are fundamental in algorithms for high-dimensional Euclidean spaces. While classical approaches suffer from the curse of dimensionality, locality sensitive hashing (LSH) can effectively solve a-approximate r-near…

Data Structures and Algorithms · Computer Science 2016-12-15 Wenlong Mou , Liwei Wang

We propose a scheme of acoustic spherical cloaking by means of background irrotational flow in compressible fluid. The background flow forms a virtual curved spacetime and guides the sound waves bypass the cloaked objects. To satisfy the…

Classical Physics · Physics 2016-08-24 Ruo-Yang Zhang , Qing Zhao , Mo-Lin Ge

Inspired by regularization techniques in statistics and machine learning, we study complementary composite minimization in the stochastic setting. This problem corresponds to the minimization of the sum of a (weakly) smooth function endowed…

Machine Learning · Computer Science 2024-01-24 Alexandre d'Aspremont , Cristóbal Guzmán , Clément Lezane

A method for improving the accuracy of hydrodynamical codes that use a moving Voronoi mesh is described. Our scheme is based on a new regularization scheme that constrains the mesh to be centroidal to high precision while still allowing the…

Instrumentation and Methods for Astrophysics · Physics 2015-03-30 Philip Mocz , Mark Vogelsberger , Rudiger Pakmor , Shy Genel , Volker Springel , Lars Hernquist

We present a boundary integral formulation of the Helmholtz equation with visco-thermal boundary conditions, in two dimensions. Such boundary conditions allow for the accurate simulation of viscous and thermal losses in the vicinity of the…

Numerical Analysis · Mathematics 2026-01-27 Jacob Linden , Travis Askham , Jeremy Hoskins

Cloaking techniques conceal objects by controlling the flow of electromagnetic waves to minimize scattering. Herein, the effectiveness of homogenized anisotropic materials in non-resonant dielectric multilayer cloaking is studied. Because…

Optics · Physics 2014-01-07 Akihiro Takezawa , Mitsuru Kitamura

The ODE method has been a workhorse for algorithm design and analysis since the introduction of the stochastic approximation. It is now understood that convergence theory amounts to establishing robustness of Euler approximations for ODEs,…

Optimization and Control · Mathematics 2020-10-02 Shuhang Chen , Adithya Devraj , Andrey Bernstein , Sean Meyn

Conformal invisibility devices are only supposed to work within the validity range of geometrical optics. Here we show by numerical simulations and analytical arguments that for certain quantized frequencies they are nearly perfect even in…

Optics · Physics 2015-05-27 Huanyang Chen , Ulf Leonhardt , Tomas Tyc

An acoustic cloak envelopes an object so that sound incident from all directions passes through and around the cloak as though the object were not present. A theory of acoustic cloaking is developed using the transformation or…

Materials Science · Physics 2008-07-13 Andrew N. Norris

We revisit the proximity effect produced by QSOs at redshifts 2.1-3.3 applying the FLO approach (Saitta et al. 2008) to a sample of ~6300 Ly-alpha lines fitted in 21 high resolution, high signal-to-noise spectra. This new technique allows…

Astrophysics · Physics 2015-05-13 V. D'Odorico , M. Bruscoli , F. Saitta , F. Fontanot , M. Viel , S. Cristiani , P. Monaco

We seek the response, in particular the spectral absorptance, of a rigidly-backed periodically-(in one horizontal~~ direction) ~inhomogeneous ~layer ~composed ~of ~alternating rigid and macroscopically-homogeneous porous portions, submitted…

Applied Physics · Physics 2018-10-05 Armand Wirgin

We design a device that generates fields canceling out a known probing field inside a region to be cloaked while generating very small fields far away from the device. The fields we consider satisfy the Laplace equation, but the approach…

Mathematical Physics · Physics 2015-06-03 Fernando Guevara Vasquez , Graeme W. Milton , Daniel Onofrei