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In recent years, manifold learning has become increasingly popular as a tool for performing non-linear dimensionality reduction. This has led to the development of numerous algorithms of varying degrees of complexity that aim to recover man…

Machine Learning · Statistics 2013-06-03 Dominique Perraul-Joncas , Marina Meila

A variational formulation of accelerated optimization on normed spaces was recently introduced by considering a specific family of time-dependent Bregman Lagrangian and Hamiltonian systems whose corresponding trajectories converge to the…

Optimization and Control · Mathematics 2022-01-11 Valentin Duruisseaux , Melvin Leok

Diverse applications in photonics and microwave engineering require a means of measurement of the instantaneous frequency of a signal. A photonic implementation typically applies an interferometer equipped with three or more output ports to…

Radio maps provide radio frequency metrics, such as the received signal strength, at every location of a geographic area. These maps, which are estimated using a set of measurements collected at multiple positions, find a wide range of…

Information Theory · Computer Science 2024-03-26 Daniel Romero , Tien Ngoc Ha , Raju Shrestha , Massimo Franceschetti

Adaptive radar waveform design grounded in information-theoretic principles is critical for advancing cognitive radar performance in complex environments. This paper investigates the optimization of phase-coded waveforms under constant…

Signal Processing · Electrical Eng. & Systems 2025-05-01 Ruofeng Yu , Caiguang Zhang , Chenyang Luo , Mengdi Bai , Shangqu Yan , Wei Yang , Yaowen Fu

Efficient beam alignment is a crucial component in millimeter wave systems with analog beamforming, especially in fast-changing vehicular settings. This paper proposes a position-aided approach where the vehicle's position (e.g., available…

Information Theory · Computer Science 2017-09-19 Vutha Va , Junil Choi , Takayuki Shimizu , Gaurav Bansal , Robert W. Heath

Algorithms for mutual interference mitigation and object parameter estimation are a key enabler for automotive applications of frequency-modulated continuous wave (FMCW) radar. In this paper, we introduce a signal separation method to…

Signal Processing · Electrical Eng. & Systems 2024-10-03 Mate Toth , Erik Leitinger , Klaus Witrisal

Quantum parameter estimation offers solid conceptual grounds for the design of sensors enjoying quantum advantage. This is realised not only by means of hardware supporting and exploiting quantum properties, but data analysis has its impact…

In this paper we implement experimentally the spatial shape modelling of nondiffracting optical beams via computer generated holograms. The results reported here are the experimental confirmation of the so called Frozen Wave method,…

The amplification obtained using weak values is quantified through a detailed investigation of the signal to noise ratio for an optical beam deflection measurement. We show that for a given deflection, input power and beam radius, the use…

Quantum Physics · Physics 2009-10-14 David J. Starling , P. Ben Dixon , Andrew N. Jordan , John C. Howell

Growing interest in 21 cm tomography has led to the design and construction of broadband radio interferometers with low noise, moderate angular resolution, high spectral resolution, and wide fields of view. With characteristics somewhat…

Instrumentation and Methods for Astrophysics · Physics 2010-10-25 Adrian Liu , Max Tegmark , Scott Morrison , Andrew Lutomirski , Matias Zaldarriaga

Millimeter-wave (mmWave) communication systems rely on narrow beams for achieving sufficient receive signal power. Adjusting these beams is typically associated with large training overhead, which becomes particularly critical for…

Signal Processing · Electrical Eng. & Systems 2022-09-09 João Morais , Arash Behboodi , Hamed Pezeshki , Ahmed Alkhateeb

Wide-field images made by radio interferometers are invariably affected by direction-dependent systematic effects such as the ionosphere or the beam pattern. Calibration along a set of discrete directions in the sky is the default technique…

Instrumentation and Methods for Astrophysics · Physics 2026-02-06 Sebastiaan van der Tol , Sarod Yatawatta , Bram Veenboer , David Rafferty

We describe and demonstrate a technique for correcting direction dependent artifacts due to asymmetries in antenna patterns and differences among antennas used in radio interoferometric imaging. The technique can correct images in all…

Instrumentation and Methods for Astrophysics · Physics 2021-10-13 W. D. Cotton , T. Mauch

This paper develops a unifying framework for signal reconstruction from interferometric measurements that is broadly applicable to various applications of interferometry. In this framework, the problem of signal reconstruction in…

Information Theory · Computer Science 2017-07-03 Davood Mardani , George K. Atia , Ayman F. Abouraddy

Many astronomical questions require deep, wide-field observations at low radio frequencies. Phased arrays like LOFAR and SKA-low are designed for this, but have inherently unstable element gains, leading to time, frequency and…

Instrumentation and Methods for Astrophysics · Physics 2025-08-28 S. A. Brackenhoff , A. R. Offringa , M. Mevius , L. V. E. Koopmans , J. K. Chege , E. Ceccotti , C. Höfer , L. Gao , S. Ghosh , F. G. Mertens , S. Munshi

In long-baseline interferometry, bandwidth smearing of an extended source occurs at finite bandwidth when its different components produce interference packets that only partially overlap. In this case, traditional model fitting or image…

Instrumentation and Methods for Astrophysics · Physics 2013-08-07 Régis Lachaume , Jean-Philippe Berger

Fitting an unknown number of hyperplanes to data is a fundamental yet challenging problem in machine learning, characterized by its non-convexity, non-differentiability, and unknown model order. Existing approaches often struggle with local…

Machine Learning · Computer Science 2026-05-28 Zhiqin Cheng , Yu Zhan , Mingjin Zhang , Lingbo Liu , Liang Lin

We extend the classical primal-dual interior point method from the Euclidean setting to the Riemannian one. Our method, named the Riemannian interior point method, is for solving Riemannian constrained optimization problems. We establish…

Optimization and Control · Mathematics 2024-03-06 Zhijian Lai , Akiko Yoshise

Interferometry with quantum light is known to provide enhanced precision for estimating a single phase. However, depending on the parameters involved, the quantum limit for the simultaneous estimation of multiple parameters may not…

Quantum Physics · Physics 2014-03-07 Philip J. D. Crowley , Animesh Datta , Marco Barbieri , Ian A. Walmsley
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