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Transformer models have shown great potential in computer vision, following their success in language tasks. Swin Transformer is one of them that outperforms convolution-based architectures in terms of accuracy, while improving efficiency…

Computer Vision and Pattern Recognition · Computer Science 2023-06-27 Jinkyu Koo , John Yang , Le An , Gwenaelle Cunha Sergio , Su Inn Park

In this paper, we revisit the use of spectrograms in neural networks, by making the window length a continuous parameter optimizable by gradient descent instead of an empirically tuned integer-valued hyperparameter. The contribution is…

Machine Learning · Computer Science 2022-08-26 Maxime Leiber , Axel Barrau , Yosra Marnissi , Dany Abboud

We revisit the classical problem of Fourier-sparse signal reconstruction -- a variant of the \emph{Set Query} problem -- which asks to efficiently reconstruct (a subset of) a $d$-dimensional Fourier-sparse signal ($\|\hat{x}(t)\|_0 \leq…

Data Structures and Algorithms · Computer Science 2023-11-21 Yeqi Gao , Zhao Song , Baocheng Sun , Omri Weinstein , Ruizhe Zhang

Background: Windowed Fourier decompositions (WFD) are widely used in measuring stationary and non-stationary spectral phenomena and in describing pairwise relationships among multiple signals. Although a variety of WFDs see frequent…

Quantitative Methods · Quantitative Biology 2019-01-30 Christopher K. Kovach , Phillip E. Gander

We consider the problem of building numerically stable algorithms for computing Discrete Fourier Transform (DFT) of $N$- length signals with known frequency support of size $k$. A typical algorithm, in this case, would involve solving…

Signal Processing · Electrical Eng. & Systems 2024-12-03 Charantej Reddy Pochimireddy , Aditya Siripuram , Brad Osgood

A novel addition to the family of integral transforms, the quadratic phase Fourier transform (QPFT) embodies a variety of signal processing tools, including the Fourier transform (FT), fractional Fourier transform (FRFT), linear canonical…

Functional Analysis · Mathematics 2024-02-20 Aamir Hamid Dar

This paper introduces a novel time-frequency distribution, referred to as the Two-Dimensional Non-Separable Quadratic Phase Wigner Distribution (2D-NSQPWD), formulated within the framework of the Two-Dimensional Non-Separable Quadratic…

Signal Processing · Electrical Eng. & Systems 2025-09-25 Mukul Chauhan , Waseem Z. Lone , Amit K. Verma

This paper considers the non-Hermitian Zakharov-Shabat (ZS) scattering problem which forms the basis for defining the SU$(2)$-nonlinear Fourier transform (NFT). The theoretical underpinnings of this generalization of the conventional…

Numerical Analysis · Mathematics 2018-07-24 Vishal Vaibhav

Object orientation provides a flexible framework for the implementation of the convolution of arbitrary distributions of real-valued random variables. We discuss an algorithm which is based on the discrete Fourier transformation (DFT) and…

Computation · Statistics 2014-08-07 Peter Ruckdeschel , Matthias Kohl

There are various approaches to exploiting "hidden structure" in instances of hard combinatorial problems to allow faster algorithms than for general unstructured or random instances. For SAT and its counting version #SAT, hidden structure…

Data Structures and Algorithms · Computer Science 2012-04-30 Serge Gaspers , Stefan Szeider

Fourier and related transforms is a family of algorithms widely employed in diverse areas of computational science, notoriously difficult to scale on high-performance parallel computers with large number of processing elements (cores). This…

Distributed, Parallel, and Cluster Computing · Computer Science 2019-05-09 Dmitry Pekurovsky

In the sliding window model, we are required to maintain the target statistics over the most recent $n$ elements of a data stream, which is captured by a window of size $n$ sliding over the data stream. Exact computation usually requires…

Data Structures and Algorithms · Computer Science 2026-04-28 Ryo Suzuki , Yutaro Yamaguchi

In this paper we propose a new wavelet transform applicable to functions defined on graphs, high dimensional data and networks. The proposed method generalizes the Haar-like transform proposed in [1], and it is defined via a hierarchical…

Computer Vision and Pattern Recognition · Computer Science 2015-05-20 Idan Ram , Michael Elad , Israel Cohen

We present an efficient, fast and robust Nonlinear Fourier Transform (NFT) algorithm to detect eigenvalues of the discrete spectrum. It outperforms other known NFT algorithms as it detects the eigenvalues from the continuous spectrum, the…

Information Theory · Computer Science 2018-12-10 Vahid Aref , Son T. Le , Henning Buelow

The standard particle-in-cell algorithm suffers from grid heating. There exists a gridless alternative which bypasses the deposition step and calculates each Fourier mode of the charge density directly from the particle positions. We show…

Plasma Physics · Physics 2019-09-04 Matthew S. Mitchell , Matthew T. Miecnikowski , Gregory Beylkin , Scott E. Parker

This paper introduces the theory and hardware implementation of two new algorithms for computing a single component of the discrete Fourier transform. In terms of multiplicative complexity, both algorithms are more efficient, in general,…

Discrete Mathematics · Computer Science 2018-01-24 G. Jerônimo da Silva , R. M. Campello de Souza , H. M. de Oliveira

We propose RSFT, which is an extension of the one dimensional Sparse Fourier Transform algorithm to higher dimensions in a way that it can be applied to real, noisy data. The RSFT allows for off-grid frequencies. Furthermore, by…

Systems and Control · Computer Science 2016-10-05 Shaogang Wang , Vishal M. Patel , Athina Petropulu

Standard negative log-likelihood (NLL) for Supervised Fine-Tuning (SFT) applies uniform token-level weighting. This rigidity creates a two-fold failure mode: (i) overemphasizing low-probability targets can amplify gradients on noisy…

Computation and Language · Computer Science 2026-02-13 Zecheng Wang , Deyuan Liu , Chunshan Li , Yupeng Zhang , Zhengyun Zhao , Dianhui Chu , Bingning Wang , Dianbo Sui

Given an $n$-length input signal $\mbf{x}$, it is well known that its Discrete Fourier Transform (DFT), $\mbf{X}$, can be computed in $O(n \log n)$ complexity using a Fast Fourier Transform (FFT). If the spectrum $\mbf{X}$ is exactly…

Data Structures and Algorithms · Computer Science 2015-01-27 Sameer Pawar , Kannan Ramchandran

Modern compression systems use linear transformations in their encoding and decoding processes, with transforms providing compact signal representations. While multiple data-dependent transforms for image/video coding can adapt to diverse…

Image and Video Processing · Electrical Eng. & Systems 2024-11-26 Alessandro Gnutti , Fabrizio Guerrini , Riccardo Leonardi , Antonio Ortega