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We present an efficient and automatic approach for accurate reconstruction of instances of big 3D objects from multiple, unorganized and unstructured point clouds, in presence of dynamic clutter and occlusions. In contrast to conventional…

Computer Vision and Pattern Recognition · Computer Science 2017-08-18 Tolga Birdal , Slobodan Ilic

We investigate the inverse source problem for the wave equation, arising in photo- and thermoacoustic tomography. There exist quite a few theoretically exact inversion formulas explicitly expressing solution of this problem in terms of the…

Analysis of PDEs · Mathematics 2018-08-01 Ngoc Do , Leonid Kunyansky

This paper considers a noisy data structure recovery problem. The goal is to investigate the following question: Given a noisy observation of a permuted data set, according to which permutation was the original data sorted? The focus is on…

Information Theory · Computer Science 2020-11-24 Minoh Jeong , Alex Dytso , Martina Cardone , H. Vincent Poor

Over the next decade, cosmological measurements of the large-scale structure of the Universe will be sensitive to the combined effects of dynamical dark energy and massive neutrinos. The matter power spectrum is a key repository of this…

Cosmology and Nongalactic Astrophysics · Physics 2014-05-21 Amol Upadhye , Rahul Biswas , Adrian Pope , Katrin Heitmann , Salman Habib , Hal Finkel , Nicholas Frontiere

We present a simple and efficient Bayesian recursive algorithm for the data-pattern scheme for quantum state reconstruction, which is applicable to situations where measurement settings can be controllably varied efficiently. The algorithm…

Analysing next-generation cosmological data requires balancing accurate modeling of non-linear gravitational structure formation and computational demands. We propose a solution by introducing a machine learning-based field-level emulator,…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-12 Ludvig Doeser , Drew Jamieson , Stephen Stopyra , Guilhem Lavaux , Florent Leclercq , Jens Jasche

Diffusion autoencoders (DAEs) are typically formulated as a noise prediction model and trained with a linear-$\beta$ noise schedule that spends much of its sampling steps at high noise levels. Because high noise levels are associated with…

Computer Vision and Pattern Recognition · Computer Science 2025-05-01 Pramook Khungurn , Sukit Seripanitkarn , Phonphrm Thawatdamrongkit , Supasorn Suwajanakorn

We apply the nonlinear reconstruction method to simulated halo fields. For halo number density $2.77\times 10^{-2}$ $(h^{-1} {\rm Mpc})^{-3}$ at $z=0$, corresponding to the SDSS main sample density, we find the scale where the noise…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-02 Yu Yu , Hong-Ming Zhu , Ue-Li Pen

In the cosmic microwave background or galaxy density maps, missing fluctuations in masked regions can be reconstructed from fluctuations in the surrounding unmasked regions if the original fluctuations are sufficiently smooth. One…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-09 Atsushi J. Nishizawa , Kaiki Taro Inoue

Signal recovery from nonlinear measurements involves solving an iterative optimization problem. In this paper, we present a framework to optimize the sensing parameters to improve the quality of the signal recovered by the given iterative…

Image and Video Processing · Electrical Eng. & Systems 2020-06-09 Zikui Cai , Rakib Hyder , M. Salman Asif

Low redshift measurements of Baryon Acoustic Oscillations (BAO) test the late time evolution of the Universe and are a vital probe of Dark Energy. Over the past decade both the 6-degree Field Galaxy Survey (6dFGS) and Sloan Digital Sky…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-12 Paul Carter , Florian Beutler , Will J. Percival , Chris Blake , Jun Koda , Ashley J. Ross

The sparse layouts of radio interferometers result in an incomplete sampling of the sky in Fourier space which leads to artifacts in the reconstructed images. Cleaning these systematic effects is essential for the scientific use of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-27 Kevin Schmidt , Felix Geyer , Stefan Fröse , Paul-Simon Blomenkamp , Marcus Brüggen , Francesco de Gasperin , Dominik Elsässer , Wolfgang Rhode

Precision measurements of the large scale structure of the Universe require large numbers of high fidelity mock catalogs to accurately assess, and account for, the presence of systematic effects. We introduce and test a scheme for…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-01 Tomomi Sunayama , Nikhil Padmanabhan , Katrin Heitmann , Salman Habib , Esteban Rangel

In this paper, we propose an original manner to employ a tangential cover algorithm - minDSS - in order to geometrically reconstruct noisy digital contours. To do so, we exploit the representation of graphical objects by maximal primitives…

Computer Vision and Pattern Recognition · Computer Science 2021-11-11 Antoine Vacavant , Bertrand Kerautret , Fabien Feschet

We consider the problem of finding a sparse solution for an underdetermined linear system of equations when the known parameters on both sides of the system are subject to perturbation. This problem is particularly relevant to…

Systems and Control · Computer Science 2016-06-16 Reza Arablouei

The baryon acoustic oscillation (BAO) method for constraining the expansion history is adversely affected by non-linear structure formation, which washes out the correlation function peak created at decoupling. To increase the constraining…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Yookyung Noh , Martin White , Nikhil Padmanabhan

The subject of this paper is beam deconvolution in small angular scale CMB experiments. The beam effect is reversed using the Jacobi iterative method, which was designed to solved systems of algebraic linear equations. The beam is a non…

Astrophysics · Physics 2009-11-07 Carlo Burigana , Diego Saez

Image-generative artificial intelligence (AI) has garnered significant attention in recent years. In particular, the diffusion model, a core component of generative AI, produces high-quality images with rich diversity. In this study, we…

Computer Vision and Pattern Recognition · Computer Science 2024-09-13 Sho Ozaki , Shizuo Kaji , Toshikazu Imae , Kanabu Nawa , Hideomi Yamashita , Keiichi Nakagawa

An efficient computational approach for optimal reconstruction of binary-type images suitable for models in various applications including biomedical imaging is developed and validated. The methodology includes derivative-free optimization…

Optimization and Control · Mathematics 2022-09-27 Paul R. Arbic , Vladislav Bukshtynov

We present a new method for modeling inhomogeneous cosmic reionization on large scales. Utilizing high-resolution radiation-hydrodynamic simulations with 2048^3 dark matter particles, 2048^3 gas cells, and 17 billion adaptive rays in a L =…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Nick Battaglia , Hy Trac , Renyue Cen , Abraham Loeb