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In this paper we propose a scalable version of a state-of-the-art deterministic time-invariant feature extraction approach based on consecutive changes of basis and nonlinearities, namely, the scattering network. The first focus of the…

Machine Learning · Statistics 2017-07-20 Randall Balestriero , Herve Glotin

We introduce a semiclassical quantization method which is based on a stroboscopic description of the classical and the quantum flows. We show that this approach emerges naturally when one is interested in extracting the energy spectrum…

Chaotic Dynamics · Physics 2007-05-23 Bruno Eckhardt , Uzy Smilansky

In order to reconstruct the initial conditions of the universe it is important to devise a method that can efficiently constrain the shape of the power spectrum of primordial matter density fluctuations in a model-independent way from data.…

Astrophysics · Physics 2009-11-10 Pia Mukherjee , Yun Wang

Spectral methods have emerged as a simple yet surprisingly effective approach for extracting information from massive, noisy and incomplete data. In a nutshell, spectral methods refer to a collection of algorithms built upon the eigenvalues…

Machine Learning · Statistics 2021-10-26 Yuxin Chen , Yuejie Chi , Jianqing Fan , Cong Ma

We describe a method for deriving the position and flux of point and compact sources observed by a scanning survey mission. Results from data simulated to test our method are presented, which demonstrate that at least a 10-fold improvement…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 F. van Leeuwen , A. N. Morgan , D. L. Harrison

Upper-ocean flows are a multi-scale jigsaw puzzle of turbulence and waves. Characterizing these flows is essential for understanding their role in redistributing heat, carbon, and nutrients, yet power spectral analysis cannot always…

Atmospheric and Oceanic Physics · Physics 2025-05-05 J. W. Skinner , A. Lawrence , J. Callies

We show that dispersive propagation of light followed by phase detection has properties that can be exploited for extracting features from the waveforms. This discovery is spearheading development of a new class of physics-inspired…

Computer Vision and Pattern Recognition · Computer Science 2017-06-27 Bahram Jalali , Madhuri Suthar , Mohamad Asghari , Ata Mahjoubfar

Slow resonant extraction from synchrotrons via radio-frequency knock-out is a well-established technique to deliver charged particle beams for various applications. In this contribution, we present explicit analytical expressions for…

Accelerator Physics · Physics 2025-11-12 P. A. Arrutia Sota , E. C. Cortes Garcia , V. A. Sansipersico

The electric field within the streamer channel is a critical parameter in the calculation model for the nonlinear breakdown voltage of SF6, motivating the research presented in this paper. By using a 2D fluid model, we investigate the…

Plasma Physics · Physics 2024-10-01 Zihao Feng , Xinxin Wang , Xiaobing Zou , Haiyun Luo , Yangyang Fu

We introduce a modified algorithm to perform nonlinear filtering of a time series by locally linear phase space projections. Unlike previous implementations, the algorithm can be used not only for a posteriori processing but includes the…

chao-dyn · Physics 2015-06-24 Thomas Schreiber , Marcus Richter

A method for spatial deconvolution of spectra is presented. It follows the same fundamental principles as the ``MCS image deconvolution algorithm'' (Magain, Courbin, Sohy, 1998) and uses information contained in the spectrum of a reference…

Astrophysics · Physics 2009-10-31 F. Courbin , P. Magain , M. Kirkove , S. Sohy

We analyze signal recovery when samples are taken concomitantly from a signal and its Fourier transform. This two-sided sampling framework extends classical one-sided reconstruction and is particularly useful when measurements in either…

Signal Processing · Electrical Eng. & Systems 2026-03-18 Mert Kayaalp , Oleg Szehr

We describe the relationship between different forms of linearized expressions for the spatial distribution of intensity of X-ray projection images obtained in the Fresnel region. We prove that under the natural validity conditions some of…

Medical Physics · Physics 2015-03-25 T. E. Gureyev , Ya. I. Nesterets

This paper is concerned with a direct sampling method for imaging the support of a frequency-dependent source term embedded in a homogeneous and isotropic medium. The source term is given by the Fourier transform of a time-dependent source…

Numerical Analysis · Mathematics 2022-12-12 Hongxia Guo , Guanghui Hu , Mengjie Zhao

We present a particle filter construction for a system that exhibits time-scale separation. The separation of time-scales allows two simplifications that we exploit: i) The use of the averaging principle for the dimensional reduction of the…

Numerical Analysis · Mathematics 2008-06-05 Dror Givon , Panagiotis Stinis , Jonathan Weare

Our current understanding of the structure and dynamics of aqueous interfaces at the molecular level has grown substantially in the last few decades due to the continuous development of surface-specific spectroscopies, such as vibrational…

Chemical Physics · Physics 2023-09-27 Yair Litman , Jinggang Lan , Yuki Nagata , David M. Wilkins

We present a spectrally accurate fast algorithm for evaluating the solution to the scalar wave equation in free space driven by a large collection of point sources in a bounded domain. With $M$ sources temporally discretized by $N_t$ time…

Numerical Analysis · Mathematics 2025-11-27 Nour G. Al Hassanieh , Alex H. Barnett , Leslie Greengard

Pulsar dynamic spectra exhibit high visibility fringes arising from interference between scattered radio waves. These fringes may be random or highly ordered patterns, depending on the nature of the scattering or refraction. Here we…

Astrophysics · Physics 2009-11-10 Mark Walker , Dan Stinebring

Spectra of the cellular photospheric flows are determined from full-disk Doppler velocity observations acquired by the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO) spacecraft. Three different…

Solar and Stellar Astrophysics · Physics 2015-10-01 David H. Hathaway , Thibaud Teil , Aimee A. Norton , Irina Kitiashvili

Even though the analysis of unsteady 2D flow fields is challenging, fluid mechanics experts generally have an intuition on where in the simulation domain specific features are expected. Using this intuition, showing similar regions enables…

Human-Computer Interaction · Computer Science 2023-08-10 Baldwin Nsonga , Gerik Scheuermann