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In this paper, we propose a new regression-based algorithm to compute Graph Fourier Transform (GFT). Our algorithm allows different regularizations to be included when computing the GFT analysis components, so that the resulting components…

Signal Processing · Electrical Eng. & Systems 2018-11-22 Seyed Hamid Safavi , Manas Khatua , Ngai-Man Cheung , Farah Torkamani-Azar

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

The sparse representation of signals defined on Euclidean domains has been successfully applied in signal processing. Bringing the power of sparse representations to non-regular domains is still a challenge, but promising approaches have…

Computational Geometry · Computer Science 2020-11-26 Lizeth J. Fuentes Perez , Luciano A. Romero Calla , Anselmo A. Montenegro , Claudio Mura , Renato Pajarola

Finding a sparse representation of a possibly noisy signal can be modeled as a variational minimization with l_q-sparsity constraints for q less than one. Especially for real-time, on-line, or iterative applications, in which problems of…

Numerical Analysis · Mathematics 2017-09-04 Martin Ehler

In this paper, we develop a linearized fractional Crank-Nicolson-Galerkin FEM for Kirchhoff type quasilinear time-fractional integro-differential equation $\left(\mathcal{D}^{\alpha}\right)$. In general, the solutions to the time-fractional…

Numerical Analysis · Mathematics 2022-08-24 Lalit Kumar

A traditional assumption underlying most data converters is that the signal should be sampled at a rate exceeding twice the highest frequency. This statement is based on a worst-case scenario in which the signal occupies the entire…

Information Theory · Computer Science 2015-05-13 Yonina C. Eldar

The data analysis of space-based gravitational wave detectors like Taiji faces significant challenges from non-stationary noise, which compromises the efficacy of traditional frequency-domain analysis. This work proposes a unified framework…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Minghui Du , Ziren Luo , Peng Xu

The Dirac-{\delta} distribution may be realized through sequences of convlutions, the latter being also regarded as approximation to the identity. The present study proposes the so called pre-orthogonal adaptive Fourier decomposition…

Classical Analysis and ODEs · Mathematics 2020-08-04 Wei Qu , Tao Qian , Guan-Tie Deng

This paper introduces a sampling frequency offset (SFO) estimation method based on the Farrow structure, which is typically utilized for the SFO compensation and thereby enables a reduction of the implementation complexity of the SFO…

Signal Processing · Electrical Eng. & Systems 2025-09-19 Deijany Rodriguez Linares , Oksana Moryakova , Håkan Johansson

A class of random non-stationary signals termed timbre x dynamics is introduced and studied. These signals are obtained by non-linear transformations of sta-tionary random gaussian signals, in such a way that the transformation can be…

Information Theory · Computer Science 2015-10-29 H Omer , B Torrésani

We extend our recently developed sparse-stochastic fragmented exchange formalism for ground-state hybrid DFT (ngH-DFT) to calculate absorption spectra within linear-response time-dependent Generalized Kohn-Sham DFT (LR-GKS-TDDFT), for…

Chemical Physics · Physics 2025-03-11 Mykola Sereda , Tucker Allen , Nadine C. Bradbury , Khaled Z. Ibrahim , Daniel Neuhauser

Temporal disaggregation is a method commonly used in official statistics to enable high-frequency estimates of key economic indicators, such as GDP. Traditionally, such methods have relied on only a couple of high-frequency indicator series…

Econometrics · Economics 2022-10-19 Luke Mosley , Idris Eckley , Alex Gibberd

Some elements of the theory and algorithmics corresponding to the computation of semilinear sparse models for discrete-time signals are presented. In this study, we will focus on approximately eventually periodic discrete-time signals, that…

Optimization and Control · Mathematics 2021-10-22 Fredy Vides

This paper analyzes a space-time finite element method for fractional wave problems. The method uses a Petrov-Galerkin type time-stepping scheme to discretize the time fractional derivative of order $ \gamma $ ($1<\gamma<2$). We establish…

Numerical Analysis · Mathematics 2018-03-12 Binjie Li , Hao Luo , Xiaoping Xie

Estimation of a sparse spectral precision matrix, the inverse of a spectral density matrix, is a canonical problem in frequency-domain analysis of high-dimensional time series (HDTS), with applications in neurosciences and environmental…

Methodology · Statistics 2025-11-11 Navonil Deb , Amy Kuceyeski , Sumanta Basu

In this paper, we study the problem of a batch of linearly correlated image alignment, where the observed images are deformed by some unknown domain transformations, and corrupted by additive Gaussian noise and sparse noise simultaneously.…

Computer Vision and Pattern Recognition · Computer Science 2022-12-14 Sijia Xia , Duo Qiu , Xiongjun Zhang

We describe a family of iterative algorithms that involve the repeated execution of discrete and inverse discrete Fourier transforms. One interesting member of this family is motivated by the discrete Fourier transform uncertainty principle…

Signal Processing · Electrical Eng. & Systems 2026-05-19 H. Robert Frost

The dynamic mode decomposition (DMD) is a data-driven approach that extracts the dominant features from spatiotemporal data. In this work, we introduce sparse-mode DMD, a new variant of the optimized DMD framework that specifically…

Machine Learning · Statistics 2025-07-29 Sara M. Ichinaga , Steven L. Brunton , Aleksandr Y. Aravkin , J. Nathan Kutz

In this article, we are concerned with the analysis on the numerical reconstruction of the spatial component in the source term of a time-fractional diffusion equation. This ill-posed problem is solved through a stabilized nonlinear…

Numerical Analysis · Mathematics 2020-05-06 Daijun Jiang , Yikan Liu , Dongling Wang

We consider the problem of sparse normal means estimation in a distributed setting with communication constraints. We assume there are $M$ machines, each holding $d$-dimensional observations of a $K$-sparse vector $\mu$ corrupted by…

Machine Learning · Statistics 2022-02-15 Chen Amiraz , Robert Krauthgamer , Boaz Nadler