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The short-time Fourier transform (STFT) is widely used for analyzing non-stationary signals. However, its performance is highly sensitive to its parameters, and manual or heuristic tuning often yields suboptimal results. To overcome this…

Sound · Computer Science 2025-06-27 Maxime Leiber , Yosra Marnissi , Axel Barrau , Sylvain Meignen , Laurent Massoulié

Many vision-related tasks benefit from reasoning over multiple modalities to leverage complementary views of data in an attempt to learn robust embedding spaces. Most deep learning-based methods rely on a late fusion technique whereby…

Computer Vision and Pattern Recognition · Computer Science 2020-03-04 Austin Reiter , Menglin Jia , Pu Yang , Ser-Nam Lim

Generalized analytic signal associated with the linear canonical transform (LCT) was proposed recently by Fu and Li ["Generalized Analytic Signal Associated With Linear Canonical Transform," Opt. Commun., vol. 281, pp. 1468-1472, 2008].…

Information Theory · Computer Science 2017-09-21 Soo-Chang Pei , Shih-Gu Huang

Modified Hamiltonians are used in the field of geometric numerical integration to show that symplectic schemes for Hamiltonian systems are accurate over long times. For nonlinear systems the series defining the modified Hamiltonian usually…

Numerical Analysis · Mathematics 2018-11-14 Shami A Alsallami , Jitse Niesen , Frank W Nijhoff

We study the problem of efficiently computing the derivative of the fixed-point of a parametric nondifferentiable contraction map. This problem has wide applications in machine learning, including hyperparameter optimization, meta-learning…

Machine Learning · Statistics 2024-06-05 Riccardo Grazzi , Massimiliano Pontil , Saverio Salzo

We present Integer Linear Programming (ILP) Modulo Theories (IMT). An IMT instance is an Integer Linear Programming instance, where some symbols have interpretations in background theories. In previous work, the IMT approach has been…

Logic in Computer Science · Computer Science 2013-04-09 Panagiotis Manolios , Vasilis Papavasileiou

We study the convergence of the new family of mimetic finite difference schemes for linear diffusion problems recently proposed in [38]. In contrast to the conventional approach, the diffusion coefficient enters both the primary mimetic…

Numerical Analysis · Mathematics 2016-12-07 G. Manzini , K. Lipnikov , J. D. Moulton , M. Shashkov

Narrowing and unification are very useful tools for symbolic analysis of rewrite theories, and thus for any model that can be specified in that way. A very clear example of their application is the field of formal cryptographic protocol…

Symbolic Computation · Computer Science 2023-07-14 Raúl López-Rueda , Santiago Escobar , Julia Sapiña

By viewing the nonuniform discrete Fourier transform (NUDFT) as a perturbed version of a uniform discrete Fourier transform, we propose a fast, stable, and simple algorithm for computing the NUDFT that costs $\mathcal{O}(N\log…

Numerical Analysis · Mathematics 2017-01-18 Diego Ruiz-Antolin , Alex Townsend

Approximate unlearning has gained popularity as an approach to efficiently update an LLM so that it behaves (roughly) as if it was not trained on a subset of data to begin with. However, existing methods are brittle in practice and can…

Machine Learning · Computer Science 2025-04-08 Kevin Kuo , Amrith Setlur , Kartik Srinivas , Aditi Raghunathan , Virginia Smith

M. Kruskal showed that each continuous-time nearly-periodic dynamical system admits a formal $U(1)$ symmetry, generated by the so-called roto-rate. When the nearly-periodic system is also Hamiltonian, Noether's theorem implies the existence…

Dynamical Systems · Mathematics 2021-12-17 J. W. Burby , E. Hirvijoki , M. Leok

We contend that what are called Linear Canonical Transforms (LCTs) should be seen as a part of the theory of unitary irreducible representations of the '2+1' Lorentz group. The integral kernel representation found by Collins, Moshinsky and…

Mathematical Physics · Physics 2012-06-07 Kurt Bernardo Wolf

The approximate discrete Radon transform (ADRT) is a hierarchical multiscale approximation of the Radon transform. In this paper, we factor the ADRT into a product of linear transforms that resemble convolutions and derive an explicit…

Numerical Analysis · Mathematics 2026-01-08 Weilin Li , Karl Otness , Kui Ren , Donsub Rim

Transformation optics offers an unconventional approach to the control of electromagnetic fields. A transformation optical structure is designed by first applying a form-invariant coordinate transform to Maxwell's equations, in which part…

The advances in geometric approaches to optical devices due to transformation optics has led to the development of cloaks, concentrators, and other devices. It has also been shown that transformation optics can be used to gravitational…

Other Condensed Matter · Physics 2017-03-13 Sophia R. Sklan , Baowen Li

We consider discrete-time (DT) systems S in which a DT input is first tranformed to a continuous-time (CT) format by phase-amplitude modulation, then modified by a non-linear CT dynamical transformation F, and finally converted back to DT…

Systems and Control · Computer Science 2014-11-06 Omer Tanovic , Alexandre Megretski , Yan Li , Vladimir M. Stojanovic , Mitra Osqui

This article presents an identification methodology to capture general relationships, with application to piecewise nonlinear approximations of model predictive control for constrained (non)linear systems. The mathematical formulation…

Optimization and Control · Mathematics 2017-01-06 Van-Vuong Trinh , Mazen Alamir , Patrick Bonnay

In this paper we present a novel algorithm for onboard radial distortion correction for unmanned aerial vehicles (UAVs) equipped with an inertial measurement unit (IMU), that runs in real-time. This approach makes calibration procedures…

Computer Vision and Pattern Recognition · Computer Science 2021-03-18 Marcus Valtonen Örnhag , Patrik Persson , Mårten Wadenbäck , Kalle Åström , Anders Heyden

In this paper we propose a multigrid optimization algorithm (MG/OPT) for the numerical solution of a class of quasilinear variational inequalities of the second kind. This approach is enabled by the fact that the solution of the variational…

Numerical Analysis · Mathematics 2022-05-24 Sergio González-Andrade , Sofía López

Neural machine translation (NMT) often makes mistakes in translating low-frequency content words that are essential to understanding the meaning of the sentence. We propose a method to alleviate this problem by augmenting NMT systems with…

Computation and Language · Computer Science 2016-10-06 Philip Arthur , Graham Neubig , Satoshi Nakamura