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We present a simple, efficient and robust approach to improve cosmological redshift measurements. The method is based on the presence of a reference sample for which a precise redshift number distribution (dN/dz) can be obtained for…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-13 Nicolas Tejos , Aldo Rodriguez-Puebla , Joel R. Primack

We present a modified model order reduction (MOR) technique for the FFT-based simulation of composite microstructures. It utilizes the earlier introduced MOR technique (Kochmann et al. [2019]), which is based on solving the…

Computational Engineering, Finance, and Science · Computer Science 2021-03-19 Christian Gierden , Johanna Waimann , Bob Svendsen , Stefanie Reese

In reconstruction analysis of galaxy redshift surveys, one works backwards from the observed galaxy distribution to the primordial density field in the same region, then evolves the primordial fluctuations forward in time with an N-body…

Astrophysics · Physics 2016-08-30 Vijay K. Narayanan , David H. Weinberg

The tilt, rotation, or offset of each CCD with respect to the focal plane, as well as the distortion of the focal plane itself, cause shape distortions to the observed objects, an effect typically known as field distortion (FD). We point…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Jun Zhang , Fuyu Dong , Hekun Li , Xiangchong Li , Yingke Li , Dezi Liu , Wentao Luo , Liping Fu , Guoliang Li , Zuhui Fan

Multi-channel short-time Fourier transform (STFT) domain-based processing of reverberant microphone signals commonly relies on power-spectral-density (PSD) estimates of early source images, where early refers to reflections contained within…

Audio and Speech Processing · Electrical Eng. & Systems 2022-11-21 T. Dietzen , S. Doclo , M. Moonen , T. van Waterschoot

Data dimensionality reduction in radio interferometry can provide savings of computational resources for image reconstruction through reduced memory footprints and lighter computations per iteration, which is important for the scalability…

Instrumentation and Methods for Astrophysics · Physics 2017-05-03 S. Vijay Kartik , Rafael E. Carrillo , Jean-Philippe Thiran , Yves Wiaux

This paper presents a dense depth estimation approach from light-field (LF) images that is able to compensate for strong rolling shutter (RS) effects. Our method estimates RS compensated views and dense RS compensated disparity maps. We…

Computer Vision and Pattern Recognition · Computer Science 2024-12-05 Hermes McGriff , Renato Martins , Nicolas Andreff , Cedric Demonceaux

Accurate estimation of photometric redshifts (photo-$z$) is crucial in studies of both galaxy evolution and cosmology using current and future large sky surveys. In this study, we employ Random Forest (RF), a machine learning algorithm, to…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-27 Junhao Lu , Zhijian Luo , Zhu Chen , Liping Fu , Wei Du , Yan Gong , Yicheng Li , Xian-Min Meng , Zhirui Tang , Shaohua Zhang , Chenggang Shu , Xingchen Zhou , Zuhui Fan

The reconstruction fidelity of computational optical imaging is fundamentally constrained by the model-reality gap, i.e., the inevitable discrepancy between idealized forward models and the physical imaging process. Conventional paradigms…

Optics · Physics 2026-05-22 Sui-peng Wang , Si-yi Xie , Chang-tao Cai , Zhun Wei , Rui Chen

We present a structure finding algorithm designed to identify galaxy groups in photometric redshift data sets: the probability friends-of-friends (pFoF) algorithm. This algorithm is derived by combining the friends-of-friends algorithm in…

Astrophysics · Physics 2009-11-13 I-hui Li , Howard K. C. Yee

Remote Sensing Image Super-Resolution (RSISR) reconstructs high-resolution (HR) remote sensing images from low-resolution inputs to support fine-grained ground object interpretation. Existing methods face three key challenges: (1)…

Computer Vision and Pattern Recognition · Computer Science 2025-04-18 Yide Liu , Haijiang Sun , Xiaowen Zhang , Qiaoyuan Liu , Zhouchang Chen , Chongzhuo Xiao

Simulations involving free surfaces and fluid interfaces are important in many areas of engineering. There is, however, still a need for improved simulation methods. Recently, a new efficient geometric VOF method called isoAdvector for…

Fluid Dynamics · Physics 2019-01-23 Henning Scheufler , Johan Roenby

Online reconstruction based on RGB-D sequences has thus far been restrained to relatively slow camera motions (<1m/s). Under very fast camera motion (e.g., 3m/s), the reconstruction can easily crumble even for the state-of-the-art methods.…

Computer Vision and Pattern Recognition · Computer Science 2021-05-13 Jiazhao Zhang , Chenyang Zhu , Lintao Zheng , Kai Xu

We present an efficient preconditioning technique for accelerating the fixed point iteration in real-space Kohn-Sham density functional theory (DFT) calculations. The preconditioner uses a low rank approximation of the dielectric matrix…

Materials Science · Physics 2023-03-29 Sambit Das , Vikram Gavini

The stochastic density functional theory (DFT) [Phys. Rev. Lett. 111, 106402 (2013)] is a valuable linear scaling approach to Kohn-Sham DFT that does not rely on the sparsity of the density matrix. Linear (and often sub-linear) scaling is…

Chemical Physics · Physics 2019-02-20 Ming Chen , Roi Baer , Daniel Neuhauser , Eran Rabani

Nonlinearities in the gravitational evolution, galaxy bias, and redshift-space distortion drive the observed galaxy density fields away from the initial near-Gaussian states. Exploiting such a non-Gaussian galaxy density field requires…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-04 Joseph Tomlinson , Donghui Jeong , Juhan Kim

The ill-posed problem of phase retrieval in optics, using one or more intensity measurements, has a multitude of applications using electromagnetic or matter waves. Many phase retrieval algorithms are computed on pixel arrays using discrete…

Image and Video Processing · Electrical Eng. & Systems 2022-09-21 J. A. Pollock , K. S. Morgan , L. C. P. Croton , M. K. Croughan , G. Ruben , N. Yagi , H. Sekiguchi , M. J. Kitchen

Sparse-view computed tomography (CT) is a practical solution to reduce radiation dose, but the resulting ill-posed inverse problem poses significant challenges for accurate image reconstruction. Although deep learning and diffusion-based…

Image and Video Processing · Electrical Eng. & Systems 2025-06-10 Changsheng Fang , Yongtong Liu , Bahareh Morovati , Shuo Han , Yu Shi , Li Zhou , Shuyi Fan , Hengyong Yu

Feature Transformation (FT) crafts new features from original ones via mathematical operations to enhance dataset expressiveness for downstream models. However, existing FT methods exhibit critical limitations: discrete search struggles…

Machine Learning · Computer Science 2025-05-22 Nanxu Gong , Zijun Li , Sixun Dong , Haoyue Bai , Wangyang Ying , Xinyuan Wang , Yanjie Fu

The use of Fourier methods in wave-front reconstruction can significantly reduce the computation time for large telescopes with a high number of degrees of freedom. However, Fourier algorithms for discrete data require a rectangular data…

Instrumentation and Methods for Astrophysics · Physics 2017-06-07 Charlotte Z. Bond , Carlos M. Correia , Jean-François Sauvage , Benoit Neichel , Thierry Fusco