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Related papers: Extracting the Spectrum by Spatial Filtering

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It is demonstrated that non-constant kernel solution, that can fit the spatial variations of the kernel can be obtained with minimum computing time. The CPU cost required with this new extension of the image subtraction method is almost the…

Astrophysics · Physics 2007-05-23 C. Alard

We present a framework for the optimal filtering of spherical signals contaminated by realizations of an additive, zero-mean, uncorrelated and anisotropic noise process on the sphere. Filtering is performed in the wavelet domain given by…

Signal Processing · Electrical Eng. & Systems 2021-02-09 Adeem Aslam , Zubair Khalid , Jason D. McEwen

Here, we investigate the physical mechanisms that may enable squeezing a complex electromagnetic field distribution through a narrow and/or partially obstructed region with little amplitude and phase distortions. Following our recent works,…

Materials Science · Physics 2015-06-03 Mario G. Silveirinha , Nader Engheta

Sampling from unnormalized densities is analogous to the generative modeling problem, but the target distribution is defined by a known energy function instead of data samples. Because evaluating the energy function is often costly, a…

Machine Learning · Computer Science 2026-05-06 Aaron Havens , Brian Karrer , Neta Shaul

In this paper, a new algorithm for extracting features from sequences of multidimensional observations is presented. The independently developed Dynamic Mode Decomposition and Matrix Pencil methods provide a least-squares model-based…

Numerical Analysis · Mathematics 2018-04-20 Leonid Pogorelyuk , Clarence W. Rowley

Sterile filters incorporating endotoxin adsorption function emerged recently to pretreat dialysate liquids fed to a hemodialysis filtration process. Their application significantly enhances the survival rate during dialysis treatment as…

Instrumentation and Detectors · Physics 2018-03-22 Martin Wiese , Chris Malkomes , Bernd Krause , Matthias Wessling

We introduce SurfFlow, an open-source high-throughput workflow package designed for automated first-principles calculations of surface energies in arbitrary crystals. Our package offers a comprehensive solution capable of handling…

Materials Science · Physics 2023-11-07 Firat Yalcin , Michael Wolloch

One of the major challenges of employing a dual-frequency phase-shifting algorithm for phase retrieval is its sensitivity to noise. Yun et. al [H Yun, B Li, S Zhang. 2017] proposed a dual-frequency method based on the Fourier transform…

Instrumentation and Detectors · Physics 2018-05-23 Minmin Wang , Canlin Zhou , Shuchun Si , Zhenkun Lei , Xiaolei Li , Hui Li , YanJie Li

Methods for reconstructing the spectral density of a vibrational environment from experimental data can yield key insights into the impact of the environment on molecular function. Although such experimental methods exist, they generally…

Chemical Physics · Physics 2025-09-11 Roosmarijn de Wit , Jonathan Keeling , Brendon W. Lovett , Alex W. Chin

The scattering of electromagnetic pulses is described using a non-singular boundary integral method to solve directly for the field components in the frequency domain, and Fourier transform is then used to obtain the complete space-time…

Optics · Physics 2023-07-19 Evert Klaseboer , Qiang Sun , Derek Y. C. Chan

Below the scale of supergranules we find that cellular flows are present in the solar photosphere at two distinct size scales, approximately 2 Mm and 4 Mm, with distinct characteristic times. Simultaneously present in the flow is a…

Astrophysics · Physics 2015-06-24 J. K. Lawrence , A. C. Cadavid , A. Ruzmaikin

Spatial resolution of most imaging devices is fundamentally restricted by diffraction. This limitation is manifested in the loss of high spatial frequency information contained in evanescent waves. As a result, conventional far-field optics…

Optics · Physics 2010-03-16 Leonid Alekseyev , Evgenii Narimanov , Jacob Khurgin

The unfolding of a gamma ray spectrum experience many difficulties due to noise in the recorded data, that is based mainly on the change of photon energy due to scattering mechanisms (either in the detector or the medium), the accumulation…

Mathematical Physics · Physics 2009-05-04 D. S. Vlachos , O. T. Kosmas

The space-filter approach has proved a fundamental tool in studying turbulence in neutral fluids, providing the ability to analyze scale-to-scale energy transfer in configuration space. It is well known that turbulence in plasma presents…

Plasma Physics · Physics 2020-08-26 S. S. Cerri , E. Camporeale

We consider bifurcation of solutions from a given trivial branch for a class of strongly indefinite elliptic systems via the spectral flow. Our main results establish bifurcation invariants that can be obtained from the coefficients of the…

Analysis of PDEs · Mathematics 2015-12-15 Nils Waterstraat

This is the first article in a series of three dealing with the exploitation of speckle for imaging purposes. Speckle is the complex interference wave-field produced by a random distribution of un-resolved scatterers. In this paper, we show…

Applied Physics · Physics 2026-02-06 Elsa Giraudat , Flavien Bureau , William Lambert , Mathias Fink , Alexandre Aubry

Dual comb spectroscopy allows for high-resolution spectra to be measured over broad bandwidths, but an essential requirement for coherent integration is the availability of a phase reference. Usually, this means that the combs' phase and…

Optics · Physics 2016-06-01 David Burghoff , Yang Yang , Qing Hu

We present a new method for the generation of atmospheric turbulence phase screens based on the frequency shift property of the Fourier transform. This method produces low spatial frequency distortions without additional computation time…

Optics · Physics 2020-01-08 Daniel A. Paulson , Chensheng Wu , Christopher C. Davis

Kernel estimation techniques, such as mean shift, suffer from one major drawback: the kernel bandwidth selection. The bandwidth can be fixed for all the data set or can vary at each points. Automatic bandwidth selection becomes a real…

Computer Vision and Pattern Recognition · Computer Science 2011-11-10 Aurelie Bugeau , Patrick Pérez

Hyperspectral data consists of large number of features which require sophisticated analysis to be extracted. A popular approach to reduce computational cost, facilitate information representation and accelerate knowledge discovery is to…

Machine Learning · Computer Science 2015-09-29 Phool Preet , Sanjit Singh Batra , Jayadeva