English
Related papers

Related papers: Time-Frequency Analysis of Fourier Integral Operat…

200 papers

Neural Operators (NOs) are a leading method for surrogate modeling of partial differential equations. Unlike traditional neural networks, which approximate individual functions, NOs learn the mappings between function spaces. While NOs have…

Astrophysics of Galaxies · Physics 2025-08-01 Keith Poletti , Stella S. R. Offner , Rachel A. Ward

We consider a class of Fourier integral operators, globally defined on $\mathbb{R}^{d}$, with symbols and phases satisfying product type estimates (the so-called $SG$ or scattering classes). We prove a sharp continuity result for such…

Functional Analysis · Mathematics 2015-02-19 Elena Cordero , Fabio Nicola , Luigi Rodino

Grafakos and Sansing \cite{GS} have shown how to obtain directionally sensitive time-frequency decompositions in $L^2(\mr^n)$ based on Gabor systems in $\ltr;$ the key tool is the "ridge idea," which lifts a function of one variable to a…

Functional Analysis · Mathematics 2014-02-18 Ole Christensen , Brigitte Forster , Peter Massopust

In this article we prove a sharp decay estimate for certain multilinear oscillatory integral operators of a form inspired by the general framework of Christ, Li, Tao, and Thiele [6]. A key purpose of this work is to determine when such…

Classical Analysis and ODEs · Mathematics 2019-12-19 Philip T. Gressman , Ellen Urheim

This paper introduces Gabor scattering, a feature extractor based on Gabor frames and Mallat's scattering transform. By using a simple signal model for audio signals specific properties of Gabor scattering are studied. It is shown that for…

Sound · Computer Science 2019-10-02 Roswitha Bammer , Monika Dörfler , Pavol Harar

Diffusive representations of fractional differential and integral operators can provide a convenient means to construct efficient numerical algorithms for their approximate evaluation. In the current literature, many different variants of…

Numerical Analysis · Mathematics 2024-07-15 Kai Diethelm

Recently, implicit neural representations (INR) have made significant strides in various vision-related domains, providing a novel solution for Multispectral and Hyperspectral Image Fusion (MHIF) tasks. However, INR is prone to losing…

Computer Vision and Pattern Recognition · Computer Science 2024-04-24 Yu-Jie Liang , Zihan Cao , Liang-Jian Deng , Xiao Wu

Efficient estimators of Fourier-space statistics for large number of objects rely on Fast Fourier Transforms (FFTs), which are affected by aliasing from unresolved small scale modes due to the finite FFT grid. Aliasing takes the form of a…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-09 Emiliano Sefusatti , Martin Crocce , Roman Scoccimarro , Hugh Couchman

When the order of an integrator is a complex number, the integrator is called a complex fractional order integrator (CFOI). The impulse response invariant discretization (IRID) method is proposed to approximately discretize the CFOI. The…

Systems and Control · Electrical Eng. & Systems 2019-11-19 Zhenlong Wu , YangQuan Chen , Donghai Li

This paper is devoted to studying the boundedness of multilinear operartors and their commutators on generalized weighted Morrey spaces, which includes multilinear fractional maximal operator and multilinear fractional integral operator.…

Classical Analysis and ODEs · Mathematics 2023-06-27 Xi Cen , Qianjun He , Xiang Li , Dunyan Yan

Based on a unique waveform with strong exponential localization property, an exact mathematical method for solving problems in signal analysis in time-frequency domain is presented. An analogue of the Gabor frame exposes the non-commutative…

Mathematical Physics · Physics 2012-06-12 Aramazd H. Muzhikyan , Gagik T. Avanesyan

Efficient and accurate detection of subtle motion generated from small objects in noisy environments, as needed for vital sign monitoring, is challenging, but can be substantially improved with magnification. We developed a complex Gabor…

Signal Processing · Electrical Eng. & Systems 2022-12-12 Md Farhan Tasnim Oshim , Toral Surti , Stephanie Carreiro , Deepak Ganesan , Suren Jayasuriya , Tauhidur Rahman

In this article, we study the properties of the nonlinear Fourier spectrum in order to gain better control of the temporal support of the signals synthesized using the inverse nonlinear Fourier transform (NFT). In particular, we provide…

Computational Physics · Physics 2018-09-17 Vishal Vaibhav

A technique is described that is used to improve the detection of radio-frequency interference in astronomical radio observatories. It is applied on a two-dimensional interference mask after regular detection in the time-frequency domain…

Instrumentation and Methods for Astrophysics · Physics 2012-03-01 A. R. Offringa , J. J. van de Gronde , J. B. T. M. Roerdink

Classical and recent results on uncertainty principles for functions on finite Abelian groups relate the cardinality of the support of a function to the cardinality of the support of its Fourier transforms. We use these results and their…

Classical Analysis and ODEs · Mathematics 2007-05-23 Felix Krahmer , Goetz E. Pfander , Peter Rashkov

Existing video recognition algorithms always conduct different training pipelines for inputs with different frame numbers, which requires repetitive training operations and multiplying storage costs. If we evaluate the model using other…

Computer Vision and Pattern Recognition · Computer Science 2023-03-28 Yitian Zhang , Yue Bai , Chang Liu , Huan Wang , Sheng Li , Yun Fu

In this article, we propose an index modulation system suitable for optical communications, based on jointly driving the time and frequency of the signal: an index-time frequency hopping (I-TFH) system. We analyze its performance from the…

Signal Processing · Electrical Eng. & Systems 2020-02-27 Francisco J. Escribano , Alexandre Wagemakers , Georges Kaddoum , Joao V. C. Evangelista

Interferometers play an increasingly important role for spatially resolved observations. If employed at full potential, interferometry can probe an enormous dynamic range in spatial scale. Interpretation of the observed visibilities…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 C. Brinch , C. P. Dullemond

We consider the decomposition of bounded linear operators on Hilbert spaces in terms of functions forming frames. Similar to the singular-value decomposition, the resulting frame decompositions encode information on the structure and…

Numerical Analysis · Mathematics 2021-05-26 Simon Hubmer , Ronny Ramlau

Multiple Operator Integrals (MOIs) have played a foundational role in operator theory and functional calculus, particularly for analyzing Hermitian matrices via spectral decomposition. Conventional MOIs rely on the assumption of…

Functional Analysis · Mathematics 2025-06-26 Shih-Yu Chang
‹ Prev 1 8 9 10 Next ›