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Related papers: Linear and synchrosqueezed time-frequency represen…

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Synchrosqueezed transforms are non-linear processes for a sharpened time-frequency representation of wave-like components. They are efficient tools for identifying and analyzing wave-like components from their superposition. This paper is…

Statistics Theory · Mathematics 2016-08-10 Haizhao Yang

The reconstruction of images from their corresponding noisy Radon transform is a typical example of an ill-posed linear inverse problem as arising in the application of computerized tomography (CT). As the (naive) solution does not depend…

Energy conversion in a physical system requires time-translation invariance breaking according to Noether's theorem. Closely associated with this symmetry-conservation relation, the frequencies of electromagnetic waves are found to be…

Time-frequency representations such as the spectrogram are commonly used to analyze signals having a time-varying distribution of spectral energy, but the spectrogram is constrained by an unfortunate tradeoff between resolution in time and…

Sound · Computer Science 2009-03-19 Kelly R. Fitz , Sean A. Fulop

Some questions of application of trigonometric splines in problems of spectral analysis are considered. The known effects of overlay in the frequency and time domains are discussed; deployment effects in these areas are firstly considered.…

Numerical Analysis · Mathematics 2019-10-03 V. P. Denysiuk

This letter is the first part of a three-part tutorial on orthogonal time frequency space (OTFS) modulation, which is a promising candidate waveform for future wireless networks. This letter introduces and compares two popular…

Information Theory · Computer Science 2022-09-13 Zhiqiang Wei , Shuangyang Li , Weijie Yuan , Robert Schober , Giuseppe Caire

The duality of space and time in Maxwell's equations has prompted interest in time boundaries and the accompanying temporal analog of spatial reflection and refraction. However, achieving observable time boundary effects at optical…

Optics · Physics 2023-03-27 Olivia Y. Long , Kai Wang , Avik Dutt , Shanhui Fan

Time-frequency (TF) representations of time series are intrinsically subject to the boundary effects. As a result, the structures of signals that are highlighted by the representations are garbled when approaching the boundaries of the TF…

Signal Processing · Electrical Eng. & Systems 2021-02-24 Adrien Meynard , Hau-Tieng Wu

It is the purpose of the paper to describe the virtues of time-frequency methods for signal processing applications, having astronomical time series in mind. Different methods are considered and their potential usefulness respectively…

Astrophysics · Physics 2009-11-07 R. Vio , W. Wamsteker

This paper provides an analysis of the linearized inverse problem in multifrequency electrical impedance tomography. We consider an isotropic conductivity distribution with a finite number of unknown inclusions with different frequency…

Numerical Analysis · Mathematics 2016-10-06 Giovanni S. Alberti , Habib Ammari , Bangti Jin , Jin-Keun Seo , Wenlong Zhang

Magnetic resonance imaging (MRI) plays a vital role in clinical diagnostics, yet it remains hindered by long acquisition times and motion artifacts. Multi-contrast MRI reconstruction has emerged as a promising direction by leveraging…

Computer Vision and Pattern Recognition · Computer Science 2026-01-15 Xinming Fang , Chaoyan Huang , Juncheng Li , Jun Wang , Jun Shi , Guixu Zhang

The analysis of the time-frequency content of a signal is a classical problem in signal processing, with a broad number of applications in real life. Many different approaches have been developed over the decades, which provide alternative…

Numerical Analysis · Mathematics 2022-06-02 Antonio Cicone , Wing Suet Li , Haomin Zhou

An accurate treatment of electronic spectra in large systems with a technique such as time dependent density functional theory (TDDFT) is computationally challenging. Due to the Nyquist sampling theorem, direct real time simulations must be…

Materials Science · Physics 2024-01-17 Matthias Kick , Ezra Alexander , Anton Beiersdorfer , Troy Van Voorhis

Magnetic resonance fingerprinting (MRF) is able to estimate multiple quantitative tissue parameters from a relatively short acquisition. The main characteristic of an MRF sequence is the simultaneous application of (a) transient states…

Medical Physics · Physics 2019-02-26 Christiaan C. Stolk , Alessandro Sbrizzi

We propose neural network layers that explicitly combine frequency and image feature representations and show that they can be used as a versatile building block for reconstruction from frequency space data. Our work is motivated by the…

Computer Vision and Pattern Recognition · Computer Science 2023-06-29 Nalini M. Singh , Juan Eugenio Iglesias , Elfar Adalsteinsson , Adrian V. Dalca , Polina Golland

Temporal modeling is crucial for video super-resolution. Most of the video super-resolution methods adopt the optical flow or deformable convolution for explicitly motion compensation. However, such temporal modeling techniques increase the…

Computer Vision and Pattern Recognition · Computer Science 2022-04-15 Takashi Isobe , Xu Jia , Xin Tao , Changlin Li , Ruihuang Li , Yongjie Shi , Jing Mu , Huchuan Lu , Yu-Wing Tai

The synchrosqueezing method aims at decomposing 1D functions as superpositions of a small number of "Intrinsic Modes", supposed to be well separated both in time and frequency. Based on the unidimensional wavelet transform and its…

Numerical Analysis · Mathematics 2012-11-22 Marianne Clausel , Thomas Oberlin , Valérie Perrier

This study concerns the efficiency of time-spectral methods for numerical solution of differential equations. It is found that the time-spectral method GWRM demonstrates insensitivity to stiffness and chaoticity due to the implicit nature…

Numerical Analysis · Mathematics 2024-06-05 Jan Scheffel

We propose a bootstrapping framework to quantify uncertainty in time-frequency representations (TFRs) generated by the short-time Fourier transform (STFT) and the STFT-based synchrosqueezing transform (SST) for oscillatory signals with…

Methodology · Statistics 2026-01-28 Hau-Tieng Wu , Zhou Zhou

Line spectral estimation is the problem of recovering the frequencies and amplitudes of a mixture of a few sinusoids from equispaced samples. However, in a variety of signal processing problems arising in imaging, radar, and localization we…

Information Theory · Computer Science 2016-09-28 Reinhard Heckel , Mahdi Soltanolkotabi