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Spatiotemporal modulation offers a variety of opportunities for light manipulations. In this paper, we propose a way towards arbitrary transformation for pulses sequentially propagating within one waveguide in space via temporal waveguide…

Optics · Physics 2023-11-15 Zhaohui Dong , Xianfeng Chen , Luqi Yuan

Wave-front sensing from focal plane multiple images is a promising technique for high-contrast imaging systems. However, the wave-front error of an optics system can be properly reconstructed only when it is very small. This paper presents…

Instrumentation and Methods for Astrophysics · Physics 2015-05-19 Jiangpei Dou , Deqing Ren , Yongtian Zhu

A qualitative comparison of total variation like penalties (total variation, Huber variant of total variation, total generalized variation, ...) is made in the context of global seismic tomography. Both penalized and constrained…

Geophysics · Physics 2012-04-09 Ignace Loris , Caroline Verhoeven

The advent of advanced crystallographic techniques has shifted structural biology from static, single-conformer models toward probing protein dynamics. Extracting cooperative motions from temporally and spatially averaged electron density…

Quantitative Methods · Quantitative Biology 2025-09-08 Avinash Mandaiya , Veit Elser

Free space propagation and conventional optical systems such as lenses and mirrors all perform spatial unitary transforms. However, the subset of transforms available through these conventional systems is limited in scope. We present here a…

The multiple scattering of coherent light is a problem of both fundamental and applied importance. In optics, phase conjugation allows spatial focussing and imaging through a multiply scattering medium; however, temporal control is…

Recently, adversarial imitation learning has shown a scalable reward acquisition method for inverse reinforcement learning (IRL) problems. However, estimated reward signals often become uncertain and fail to train a reliable statistical…

Machine Learning · Computer Science 2023-01-06 Dong-Sig Han , Hyunseo Kim , Hyundo Lee , Je-Hwan Ryu , Byoung-Tak Zhang

We study an inverse initial source problem that models Photoacoustic tomography measurements with array detectors, and introduce a method that can be viewed as a modification of the so called back and forth nudging method. We show that the…

Analysis of PDEs · Mathematics 2016-11-23 Olga Chervova , Lauri Oksanen

In this paper, we consider the problem of controlling a dynamical system such that its trajectories satisfy a temporal logic property in a given amount of time. We focus on multi-affine systems and specifications given as syntactically…

Systems and Control · Computer Science 2012-03-27 Ebru Aydin Gol , Calin Belta

We introduce bounded generation as a generalized task to control video generation to synthesize arbitrary camera and subject motion based only on a given start and end frame. Our objective is to fully leverage the inherent generalization…

Computer Vision and Pattern Recognition · Computer Science 2024-03-22 Haiwen Feng , Zheng Ding , Zhihao Xia , Simon Niklaus , Victoria Abrevaya , Michael J. Black , Xuaner Zhang

In this article, we consider the inverse source problem arising in photoacoustic tomography in elastic media. We show that the time reversal method, proposed by Tittelfitz [Inverse Problems 28.5 (2012): 055004], converges with the sharp…

Analysis of PDEs · Mathematics 2017-07-20 Vitaly Katsnelson , Linh V. Nguyen

This paper presents a single-step tunable group delay phaser for spectrum sniffing. This device may be seen as a "time filter", where frequencies are suppressed by time separation rather than by spectral attenuation. Compared to its…

Optics · Physics 2015-01-26 Tongfeng Guo , Qingfeng Zhang , Yifan Chen , Rui Wang , Christophe Caloz

Iterative projection algorithms for phase retrieval are tested on two simple toy models. The result provides useful insights in the behavior of these algorithms.

Optics · Physics 2007-05-23 S. Marchesini

An iterative method is derived for image reconstruction. Among other attributes, this method allows constraints unrelated to the radiation measurements to be incorporated into the reconstructed image. A comparison is made with the widely…

Computational Physics · Physics 2011-01-06 Clinton DeW. Van Siclen

Adaptive (or deformable) mirrors are widely used as wavefront correctors in adaptive optics systems. The optical calibration of an adaptive mirror is a fundamental step during its life-cycle: the process is in facts required to compute a…

Instrumentation and Methods for Astrophysics · Physics 2022-10-11 Runa Briguglio , Marco Xompero , Armando Riccardi

Human intelligence exhibits compositional generalization (i.e., the capacity to understand and produce unseen combinations of seen components), but current neural seq2seq models lack such ability. In this paper, we revisit iterative…

Computation and Language · Computer Science 2020-12-09 Yinuo Guo , Hualei Zhu , Zeqi Lin , Bei Chen , Jian-Guang Lou , Dongmei Zhang

We consider a class of systems with time-varying parameters, which are written as linear regressions with bounded disturbances. The task is to estimate such parameters under the condition that the regressor is finitely exciting (FE).…

Systems and Control · Electrical Eng. & Systems 2021-11-24 Anton Glushchenko , Konstantin Lastochkin

Iterative regularization exploits the implicit bias of an optimization algorithm to regularize ill-posed problems. Constructing algorithms with such built-in regularization mechanisms is a classic challenge in inverse problems but also in…

Optimization and Control · Mathematics 2022-02-02 Cesare Molinari , Mathurin Massias , Lorenzo Rosasco , Silvia Villa

We introduce a unified framework for iterative reasoning that leverages non-Euclidean geometry via Bregman divergences, higher-order operator averaging, and adaptive feedback mechanisms. Our analysis establishes that, under mild smoothness…

Machine Learning · Computer Science 2025-02-07 Jacob Fein-Ashley

We consider a mathematical model of thermoacoustic tomography and other multi-wave imaging techniques with variable sound speed and attenuation. We find that a Neumann series reconstruction algorithm, previously studied under the assumption…

Analysis of PDEs · Mathematics 2012-12-21 Andrew Homan