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Related papers: Multiscale Optimal Filtering on the Sphere

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In this paper, we propose a meshfree approximation method for the implicit filter developed in [2], which is a novel numerical algorithm for nonlinear filtering problems. The implicit filter approximates conditional distributions in the…

Numerical Analysis · Mathematics 2015-08-05 Feng Bao , Yanzhao Cao , Clayton Webster , Guannan Zhang

This paper is concerned with density estimation of directional data on the sphere. We introduce a procedure based on thresholding on a new type of spherical wavelets called {\it needlets}. We establish a minimax result and prove its…

Statistics Theory · Mathematics 2010-04-30 P. Baldi , G. Kerkyacharian , D. Marinucci , D. Picard

In order to produce high dynamic range images in radio interferometry, bright extended sources need to be removed with minimal error. However, this is not a trivial task because the Fourier plane is sampled only at a finite number of…

Instrumentation and Methods for Astrophysics · Physics 2011-01-17 Sarod Yatawatta

Lowpass envelope approximation of smooth continuous-variable signals are introduced in this work. Envelope approximations are necessary when a given signal has to be approximated always to a larger value (such as in TV white space…

Information Theory · Computer Science 2017-06-06 Animesh Kumar

Scale-discretised wavelets yield a directional wavelet framework on the sphere where a signal can be probed not only in scale and position but also in orientation. Furthermore, a signal can be synthesised from its wavelet coefficients…

Information Theory · Computer Science 2017-08-17 Jason D. McEwen , Claudio Durastanti , Yves Wiaux

Optimum Bayes estimator for General Gaussian Distributed (GGD) data in wavelet is provided. The GGD distribution describes a wide class of signals including natural images. A wavelet thresholding method for image denoising is proposed.…

Methodology · Statistics 2012-07-27 Masoud Hashemi , Soosan Beheshti

This letter presents a novel \textit{quantum algorithm} for signal denoising, which performs a thresholding in the frequency domain through amplitude amplification and using an adaptive threshold determined by local mean values. The…

Quantum Physics · Physics 2023-12-27 Sayantan Dutta , Adrian Basarab , Denis Kouamé , Bertrand Georgeot

We address the problem of estimating the spherical-harmonic power spectrum of a statistically isotropic scalar signal from noise-contaminated data on a region of the unit sphere. Three different methods of spectral estimation are…

Astrophysics · Physics 2009-11-13 F. A. Dahlen , Frederik J Simons

We consider channels affected by intersymbol interference with reduced-complexity, mutual information optimized, channel-shortening detection. For such settings, we optimize the transmit filter, taking into consideration the reduced…

Information Theory · Computer Science 2013-10-24 Andrea Modenini , Fredrik Rusek , Giulio Colavolpe

We consider a separation problem where the observation consists of the sum of a high amplitude smooth signal and a low amplitude transient signal. We propose a method for decomposition that relies on solving instances of a `constrained…

Signal Processing · Electrical Eng. & Systems 2020-07-15 Ilker Bayram

We propose a new monotonically convergent algorithm which can enforce spectral constraints on the control field (and extends to arbitrary filters). The procedure differs from standard algorithms in that at each iteration the control field…

Quantum Physics · Physics 2015-05-13 M. Lapert , R. Tehini , G. Turinici , D. Sugny

Propulsion at microscopic scales is often achieved through propagating traveling waves along hair-like organelles called flagella. Taylor's two-dimensional swimming sheet model is frequently used to provide insight into problems of…

Fluid Dynamics · Physics 2014-06-05 Thomas D. Montenegro-Johnson , Eric Lauga

We describe a novel method for removing noise (in wavelet domain) of unknown variance from microarrays. The method is based on a smoothing of the coefficients of the highest subbands. Specifically, we decompose the noisy microarray into…

Signal Processing · Electrical Eng. & Systems 2018-08-01 Mario Mastriani , Alberto. E. Giraldez

We develop techniques to solve ill-posed inverse problems on the sphere by sparse regularisation, exploiting sparsity in both axisymmetric and directional scale-discretised wavelet space. Denoising, inpainting, and deconvolution problems,…

Information Theory · Computer Science 2017-08-17 Christopher G. R. Wallis , Yves Wiaux , Jason D. McEwen

We study shortest-path routing in large weighted, undirected graphs, where expanding search frontiers raise time and memory costs for exact solvers. We propose \emph{SPHERE}, a query-aware partitioning heuristic that adaptively splits the…

Distributed, Parallel, and Cluster Computing · Computer Science 2026-03-16 Robert Fabian Lindermann , Paul-Niklas Ken Kandora , Simon Caspar Zeller , Adrian Asmund Fessler , Steffen Rebennack

Sphere decoding (SD) of polar codes is an efficient method to achieve the error performance of maximum likelihood (ML) decoding. But the complexity of the conventional sphere decoder is still high, where the candidates in a target sphere…

Information Theory · Computer Science 2013-08-14 Kai Niu , Kai Chen , Jiaru Lin

Filter synthesis is an inverse problem that is traditionally approached rationally by considering spatially disjoint resonators, approximating them as lumped elements, and engineering the coupling of selected pairs. This approach strongly…

Applied Physics · Physics 2024-07-09 Fabian T. Faul , Laurent Cronier , Ali Alhulaymi , A. Douglas Stone , Philipp del Hougne

Future cosmological surveys will provide 3D large scale structure maps with large sky coverage, for which a 3D Spherical Fourier-Bessel (SFB) analysis in spherical coordinates is natural. Wavelets are particularly well-suited to the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 F. Lanusse , A. Rassat , J. -L. Starck

Graph sampling addresses the problem of selecting a node subset in a graph to collect samples, so that a K-bandlimited signal can be reconstructed in high fidelity. Assuming an independent and identically distributed (i.i.d.) noise model,…

Signal Processing · Electrical Eng. & Systems 2019-10-23 Fen Wang , Gene Cheung , Yongchao Wang

We present an edge preserving and denoising filter for enhancing the features in images, which contain an ROI having a narrow spatial extent. Typical examples include angiograms, or ROI spatially distributed in multiple locations and…

Computer Vision and Pattern Recognition · Computer Science 2013-03-12 Joseph Suresh Paul , Joshin John Mathew , Souparnika Kandoth Naroth , Chandrasekar Kesavadas