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Causal representation learning (CRL) offers the promise of uncovering the underlying causal model by which observed data was generated, but the practical applicability of existing methods remains limited by the strong assumptions required…

Machine Learning · Computer Science 2026-01-30 Yuhang Liu , Zhen Zhang , Dong Gong , Erdun Gao , Biwei Huang , Mingming Gong , Anton van den Hengel , Kun Zhang , Javen Qinfeng Shi

Coherent Synchrotron Radiation can severely limit the performance of accelerators designed for high brightness and short bunch length. Examples include light sources based on ERLs or FELs, and bunch compressors for linear colliders. In…

Accelerator Physics · Physics 2015-05-13 David Sagan , Georg Hoffstaetter , Christopher Mayes , Udom Sae-Ueng

Coherent transition radiation (CTR) from relativistic electron beam interaction with an overdense plasma foil is investigated by making use of two-dimensional particle-in-cell simulations. Well-defined single electron beam either of uniform…

Plasma Physics · Physics 2019-02-14 W. J. Ding , F. Y. Li , S. M. Weng , P. Bai , Z. M. Sheng

Neural Radiance Fields (NeRF) has achieved unprecedented view synthesis quality using coordinate-based neural scene representations. However, NeRF's view dependency can only handle simple reflections like highlights but cannot deal with…

Computer Vision and Pattern Recognition · Computer Science 2022-04-07 Yuan-Chen Guo , Di Kang , Linchao Bao , Yu He , Song-Hai Zhang

Correcting the optical aberrations and the manufacturing deviations of cameras is a challenging task. Due to the limitation on volume and the demand for mass production, existing mobile terminals cannot rectify optical degradation. In this…

Computer Vision and Pattern Recognition · Computer Science 2023-05-11 Shiqi Chen , Ting Lin , Huajun Feng , Zhihai Xu , Qi Li , Yueting Chen

Diffractive/refractive optics, such as Phase Fresnel Lenses (PFL's), offer the potential to achieve excellent imaging performance in the x-ray and gamma-ray photon regimes. In principle, the angular resolution obtained with these devices…

Inhomogeneities in the refractive index of a biological sample can introduce phase aberrationsin microscopy systems, severely impairing the quality of images. Adaptive optics can be employed to correct for phase aberrations and improve…

This paper presents the first-principle design approach for X-ray active optics, using the simulation-modulation cycle in place of the measurement-modulation feedback loops used in traditional active optics. Hence, the new active optics…

Optics · Physics 2024-01-09 Dezhi Diao , Han Dong , Fugui Yang , Ming Li , Weifan Sheng , Xiaowei Zhang

Direct-conversion radio (DCR) receivers can offer highly integrated low-cost hardware solutions for spectrum sensing in cognitive radio systems. However, DCR receivers are susceptible to radio frequency (RF) impairments, such as in-phase…

Information Theory · Computer Science 2015-10-23 Alexandros-Apostolos A. Boulogeorgos , Nestor D. Chatzidiamantis , George K. Karagiannidis

Neural Radiance Fields (NeRFs) typically struggle to reconstruct and render highly specular objects, whose appearance varies quickly with changes in viewpoint. Recent works have improved NeRF's ability to render detailed specular appearance…

Computer Vision and Pattern Recognition · Computer Science 2024-05-24 Dor Verbin , Pratul P. Srinivasan , Peter Hedman , Ben Mildenhall , Benjamin Attal , Richard Szeliski , Jonathan T. Barron

Convolutional Neural Networks (CNNs) perform very well in image classification and object detection in recent years, but even the most advanced models have limited rotation invariance. Known solutions include the enhancement of training…

Computer Vision and Pattern Recognition · Computer Science 2022-02-28 Zongbo Hao , Tao Zhang , Mingwang Chen , Kaixu Zhou

Remote focusing (RF) is a technique that greatly extends the aberration-free axial scan range of an optical microscope. To maximise the diffraction limited depth range in an RF system, the magnification of the relay lenses should be such…

Optics · Physics 2021-01-05 Sharika Mohanan , Alexander D. Corbett

Optical aberrations of optical systems cause significant degradation of imaging quality. Aberration correction by sophisticated lens designs and special glass materials generally incurs high cost of manufacturing and the increase in the…

Computer Vision and Pattern Recognition · Computer Science 2023-04-13 Shuang Cui , Bingnan Wang , Quan Zheng

In a previous paper, we reviewed theoretically some of the available processing schemes for X-ray wavefront sensing based on random modulation. We here show experimental applications of the technique for characterising both refractive and…

Instrumentation and Detectors · Physics 2020-02-24 Sebastien Berujon , Ruxandra Cojocaru , Pierre Piault , Rafael Celestre , Thomas Roth , Raymond Barrett , Eric Ziegler

Aligning a lens system relative to an imager is a critical challenge in camera manufacturing. While optimal alignment can be mathematically computed under ideal conditions, real-world deviations caused by manufacturing tolerances often…

Robotics · Computer Science 2025-10-06 Matthias Burkhardt , Tobias Schmähling , Pascal Stegmann , Michael Layh , Tobias Windisch

The use of coherent x-ray beams has been greatly developing for the past decades. They are now used by a wide scientific community to study biological materials, phase transitions in crystalline materials, soft matter, magnetism, strained…

Materials Science · Physics 2010-09-01 V. L. R. Jacques , S. Ravy , D. Le Bolloc'h , E. Pinsolle , M. Sauvage-Simkin , F. Livet

Vision-based reinforcement learning (RL) is a promising approach to solve control tasks involving images as the main observation. State-of-the-art RL algorithms still struggle in terms of sample efficiency, especially when using image…

Machine Learning · Computer Science 2021-10-05 Elie Aljalbout , Maximilian Ulmer , Rudolph Triebel

The capability of the adaptive optics to correct for the segmentation error is analyzed in terms of the residual wavefront RMS and the power spectral density of the phase. The analytical model and the end-to-end simulation give…

Astrophysics · Physics 2009-11-11 Natalia Yaitskova , Christophe Verinaud

Accurately predicting the consequences of agents' actions is a key prerequisite for planning in robotic control. Model-based reinforcement learning (MBRL) is one paradigm which relies on the iterative learning and prediction of state-action…

Machine Learning · Computer Science 2022-03-21 Nathan Lambert , Kristofer Pister , Roberto Calandra

The output of image the segmentation process is usually not very clear due to low quality features of Satellite images. The purpose of this study is to find a suitable Conditional Random Field (CRF) to achieve better clarity in a segmented…

Computer Vision and Pattern Recognition · Computer Science 2026-05-21 Aashish Dhawan , Pankaj Bodani , Vishal Garg