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An efficient despeckling method using a quantum-inspired adaptive threshold function is presented for reducing noise of ultrasound images. In the first step, the ultrasound image is decorrelated by an spectrum equalization procedure due to…

Computer Vision and Pattern Recognition · Computer Science 2018-07-10 Hamid Reza Shahdoosti

We seek to improve estimates of the power spectrum covariance matrix from a limited number of simulations by employing a novel statistical technique known as shrinkage estimation. The shrinkage technique optimally combines an empirical…

Astrophysics · Physics 2009-11-13 Adrian C. Pope , István Szapudi

Hyperspectral imaging is an important tool having been applied in various fields, but still limited in observation of dynamic scenes. In this paper, we propose a snapshot hyperspectral imaging technique which exploits both spectral and…

Instrumentation and Detectors · Physics 2018-12-26 Chao Deng , Xuemei Hu , Jinli Suo , Yuanlong Zhang , Zhili Zhang , Qionghai Dai

Low-count positron emission tomography (PET) reconstruction is a challenging inverse problem due to severe degradations arising from Poisson noise, photon scarcity, and attenuation correction errors. Existing deep learning methods typically…

Image and Video Processing · Electrical Eng. & Systems 2026-04-09 Zheng Zhang , Hao Tang , Yingying Hu , Zhanli Hu , Jing Qin

We present a new deterministic algorithm for the sparse Fourier transform problem, in which we seek to identify k << N significant Fourier coefficients from a signal of bandwidth N. Previous deterministic algorithms exhibit quadratic…

Numerical Analysis · Mathematics 2012-07-27 David Lawlor , Yang Wang , Andrew Christlieb

In data assimilation, an ensemble provides a way to propagate the probability density of a system described by a nonlinear prediction model. Although a large ensemble size is required for statistical accuracy, the ensemble size is typically…

Numerical Analysis · Mathematics 2024-11-12 Bosu Choi , Yoonsang Lee

We provide a new robust convergence analysis of the well-known power method for computing the dominant singular vectors of a matrix that we call the noisy power method. Our result characterizes the convergence behavior of the algorithm when…

Data Structures and Algorithms · Computer Science 2015-02-05 Moritz Hardt , Eric Price

Verification of a quantum advantage in the presence of noise is a key open problem in the study of near-term quantum devices. In this work, we show how to assess the quality of photonic interference in a linear optical quantum device (boson…

Quantum Physics · Physics 2021-03-03 Jelmer J. Renema , Hui Wang , Jian Qin , Xiang You , Chaoyang Lu , Jianwei Pan

We present the one-dimensional Lyman-$\alpha$ forest power spectrum measurement derived from the data release 1 (DR1) of the Dark Energy Spectroscopic Instrument (DESI). The measurement of the Lyman-$\alpha$ forest power spectrum along the…

Photon-number squeezing and correlations enable measurement of absorption with an accuracy exceeding that of the shot-noise limit. However, sub-shot noise imaging and sensing based on these methods require high detection efficiency, which…

Quantum Physics · Physics 2019-03-06 E. Knyazev , F. Ya. Khalili , M. V. Chekhova

We present a fast method for estimating the cosmic microwave background polarization power spectra using unbiased estimates of heuristically-weighted correlation functions. This extends the O(N_pix^(3/2)) method of Szapudi et al. (2001) to…

Astrophysics · Physics 2009-11-07 Gayoung Chon , Anthony Challinor , Simon Prunet , Eric Hivon , Istvan Szapudi

It is commonplace in cosmology to analyze fields projected onto the celestial sphere, and in particular density fields that are defined by a set of points e.g. galaxies. When performing an harmonic-space analysis of such data (e.g. an…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-02 Antón Baleato Lizancos , Martin White

Previous work on calculating energy spectra from Compton scattering events has either neglected considering the pulsed structure of the incident laser beam, or has calculated these effects in an approximate way subject to criticism. In this…

With the steadily improving sensitivity afforded by current and future galaxy surveys, a robust extraction of two-point correlation function measurements may become increasingly hampered by the presence of astrophysical foregrounds or…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Franz Elsner , Boris Leistedt , Hiranya V. Peiris

This work addresses a central challenge in the numerical analysis of the cutoff spatially homogeneous Boltzmann equation: the development of rigorously justified, accurate numerical schemes. We present (i) a novel Fourier spectral method…

Numerical Analysis · Mathematics 2026-03-30 Yanzhi Gui , Ling-Bing He , Liu Liu

We propose to use Gaussian process regression to accurately estimate the diffusion MRI signal at arbitrary locations in q-space. By estimating the signal on a grid, we can do synthetic diffusion spectrum imaging: reconstructing the ensemble…

Applications · Statistics 2020-01-03 Jens Sjölund , Anders Eklund , Evren Özarslan , Hans Knutsson

In this paper, a novel and robust algorithm is proposed for adaptive beamforming based on the idea of reconstructing the autocorrelation sequence (ACS) of a random process from a set of measured data. This is obtained from the first column…

Information Theory · Computer Science 2021-06-25 Saeed Mohammadzadeh , Vitor H. Nascimento , Rodrigo C. de Lamare , Osman Kukrer

We show that in presence of a local and uncorrelated dephasing noise, quantum advantage can be obtained in the Fisher information-based lower bound of the minimum uncertainty in estimating parameters of the system Hamiltonian. The quantum…

Quantum Physics · Physics 2024-05-27 Aparajita Bhattacharyya , Ahana Ghoshal , Ujjwal Sen

This paper focuses on the quantum amplitude estimation algorithm, which is a core subroutine in quantum computation for various applications. The conventional approach for amplitude estimation is to use the phase estimation algorithm, which…

Quantum Physics · Physics 2020-01-28 Yohichi Suzuki , Shumpei Uno , Rudy Raymond , Tomoki Tanaka , Tamiya Onodera , Naoki Yamamoto

We report a direct demonstration of quantum-enhanced sensing in the Fourier domain by comparing single- and two-photon interference in a fiber-based interferometer under strictly identical noise conditions. The simultaneous acquisition of…

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