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Many modern astronomical instruments rely on the optimal coupling of starlight into single-mode fibers (SMFs). For ground-based telescopes, this coupling is limited by atmospheric turbulence. We propose an integrated wavefront corrector…

Instrumentation and Methods for Astrophysics · Physics 2024-08-23 Dhwanil Patel , Momen Diab , Ross Cheriton , Jacob Taylor , Libertad Rojas , Suresh Sivanandam

We introduce a novel deep reinforcement learning (DRL) approach to jointly optimize transmit beamforming and reconfigurable intelligent surface (RIS) phase shifts in a multiuser multiple input single output (MU-MISO) system to maximize the…

Networking and Internet Architecture · Computer Science 2023-03-30 Baturay Saglam , Doga Gurgunoglu , Suleyman S. Kozat

The accumulation of aberrations along the optical path in a telescope produces distortions and speckles in the resulting images, limiting the performance of cameras at high angular resolution. It is important to achieve the highest possible…

Instrumentation and Methods for Astrophysics · Physics 2021-03-17 Benjamin J. S. Pope , Laurent Pueyo , Yinzi Xin , Peter G. Tuthill

X-ray emission spectroscopy is emerging as an important complement to x-ray absorption fine structure spectroscopy, providing a characterization of the occupied electronic density of states local to the species of interest. Here, we present…

Neural Radiance Fields (NeRFs) have shown great potential in novel view synthesis. However, they struggle to render sharp images when the data used for training is affected by motion blur. On the other hand, event cameras excel in dynamic…

Computer Vision and Pattern Recognition · Computer Science 2024-06-04 Marco Cannici , Davide Scaramuzza

Most single image super-resolution (SR) methods are developed on synthetic low-resolution (LR) and high-resolution (HR) image pairs, which are simulated by a predetermined degradation operation, e.g., bicubic downsampling. However, these…

Image and Video Processing · Electrical Eng. & Systems 2021-10-22 Rui Ma , Johnathan Czernik , Xian Du

Synthetic aperture radar (SAR) can measure the phase with antenna and microwave, which cannot be directly extended to visible light imaging due to phase lost. In this letter, we reported an active remote sensing with visible light via…

Optics · Physics 2022-04-26 Meng Xiang , An Pan , Yiyi Zhao , Xuewu Fan , Hui Zhao , Chuang Li , Baoli Yao

In this paper we analyze the image formation problem for undulator radiation through an optical system, accounting for the influence of the electron beam emittance. On the one hand, image formation with Synchrotron Radiation is governed by…

Accelerator Physics · Physics 2009-09-29 Gianluca Geloni , Evgeni Saldin , Evgeni Schneidmiller , Mikhail Yurkov

Large language models (LLMs) exhibit persistent miscalibration, especially after instruction tuning and preference alignment. Modified training objectives can improve calibration, but retraining is expensive. Inference-time steering offers…

Machine Learning · Computer Science 2026-02-06 Miranda Muqing Miao , Young-Min Cho , Lyle Ungar

Recently, Neural Radiance Fields (NeRF) have emerged as a potent method for synthesizing novel views from a dense set of images. Despite its impressive performance, NeRF is plagued by its necessity for numerous calibrated views and its…

Computer Vision and Pattern Recognition · Computer Science 2023-03-13 Jiayang Bai , Letian Huang , Wen Gong , Jie Guo , Yanwen Guo

In this work, we devote ourselves to the challenging task of Unsupervised Multi-view Representation Learning (UMRL), which requires learning a unified feature representation from multiple views in an unsupervised manner. Existing UMRL…

Machine Learning · Computer Science 2023-03-09 Yiyang Zhou , Qinghai Zheng , Shunshun Bai , Jihua Zhu

Refraction-enhanced x-ray radiography (REXR) is used to infer shock-wave positions of more than one shock wave, launched by a multiple-picket pulse in a planar plastic foil. This includes locating shock waves before the shocks merge, during…

Optical images of transparent three-dimensional objects can be different from a replica of the object's cross section in the image plane due to refraction at the surface or in the body of the object. Simulations of the object's image are…

We have developed a simulation-based method of spectral analysis for pile-up affected data of X-ray CCDs without any loss of photon statistics. As effects of the photon pile-up appear as complicated nonlinear detector responses, we employ a…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Tsubasa Tamba , Hirokazu Odaka , Aya Bamba , Hiroshi Murakami , Koji Mori , Kiyoshi Hayashida , Yukikatsu Terada , Tsunefumi Mizuno , Masayoshi Nobukawa

In a scanning transmission electron microscope (STEM), producing a high-resolution image generally requires an electron beam focused to the smallest point possible. However, the magnetic lenses used to focus the beam are unavoidably…

This paper develops a novel framework for phase retrieval, a problem which arises in X-ray crystallography, diffraction imaging, astronomical imaging and many other applications. Our approach combines multiple structured illuminations…

Information Theory · Computer Science 2011-09-21 Emmanuel J. Candes , Yonina Eldar , Thomas Strohmer , Vlad Voroninski

Efficient multilayer optics for radiation in the water window range are difficult to manufacture due to extremely small layer thicknesses and severe intermixing of elements between the layers. Therefore, adequate analytics and short…

Photopolymerization enables the production of micro-optical elements, such as diffractive optical elements or GRIN optics. This process utilizes targeted spatial modulation of the refractive index, which is achieved through additive…

Optics · Physics 2026-03-16 Andreas Heinrich , Manuel Rank

Representational similarity analysis (RSA) is a multivariate technique to investigate cortical representations of objects or constructs. While avoiding ill-posed matrix inversions that plague multivariate approaches in the presence of many…

Methodology · Statistics 2021-12-03 Roberto Viviani

Generative models have made significant progress in synthesizing visual content, including images, videos, and 3D/4D structures. However, they are typically trained with surrogate objectives such as likelihood or reconstruction loss, which…

Computer Vision and Pattern Recognition · Computer Science 2026-01-21 Yuanzhi Liang , Yijie Fang , Ke Hao , Rui Li , Ziqi Ni , Ruijie Su , Chi Zhang