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An alternative approach to ultrasound computed tomography (USCT) for medical imaging is proposed, with the intent to (i) shorten acquisition time for devices with a large number of emitters, (ii) eliminate the calibration step, and (iii)…

Medical Physics · Physics 2022-01-25 Ines Elisa Ulrich , Christian Boehm , Andrea Zunino , Cyrill Bösch , Andreas Fichtner

This paper is concerned with a direct sampling method for imaging the support of a frequency-dependent source term embedded in a homogeneous and isotropic medium. The source term is given by the Fourier transform of a time-dependent source…

Numerical Analysis · Mathematics 2022-12-12 Hongxia Guo , Guanghui Hu , Mengjie Zhao

Presented is a novel way to combine snapshot compressive imaging and lateral shearing interferometry in order to capture the spatio-spectral phase of an ultrashort laser pulse in a single shot. A deep unrolling algorithm is utilised for the…

The contemporary superconductive electronics is widely using planar circuits with micrometer-scale elements for a variety of applications. With the rise of complexity of a circuit and increased number of its components, a simple impedance…

Applied Physics · Physics 2019-07-24 A. Karpov , A. P. Zhuravel , A. S. Averkin , V. I. Chichkov , A. V. Ustinov

Sampling theory in fractional Fourier Transform (FrFT) domain has been studied extensively in the last decades. This interest stems from the ability of the FrFT to generalize the traditional Fourier Transform, broadening the traditional…

Information Theory · Computer Science 2024-04-30 Václav Pavlíček , Ayush Bhandari

Thomson scattering spectra measure the response of plasma particles to incident radiation. In warm dense matter, which is opaque to visible light, x-ray Thomson scattering (XRTS) enables a detailed probe of the electron distribution and has…

Plasma Physics · Physics 2024-08-29 Thomas W. Hentschel , Alina Kononov , Andrew D. Baczewski , Stephanie B. Hansen

The importance of ultrasound is well established in the imaging of human tissue. In order to enhance image quality by exploiting nonlinear effects, recently techniques such as harmonic imaging and nonlinearity parameter tomography have been…

Analysis of PDEs · Mathematics 2025-02-13 Barbara Kaltenbacher

Measuring the dynamics and mechanical properties of muscles and joints is important to understand the (patho)physiology of muscles. However, acquiring dynamic time-resolved MRI data is challenging. We have previously developed…

This paper presents a detailed evaluation of the envelope-tracking adaptive integral method (ET-AIM), an FFT-accelerated algorithm for analyzing electromagnetic scattering. ET-AIM is used to solve progressively more complex benchmark…

Computational Physics · Physics 2014-09-01 Guneet Kaur , Ali E. Yilmaz

This paper considers the problem of sampling and reconstruction of a continuous-time sparse signal without assuming the knowledge of the sampling instants or the sampling rate. This topic has its roots in the problem of recovering multiple…

Information Theory · Computer Science 2017-01-31 Ayush Bhandari , Aurelien Bourquard , Ramesh Raskar

A core challenge for signal data recovery is to model the distribution of signal matrix (SM) data based on measured low-quality data in biomedical engineering of magnetic particle imaging (MPI). For acquiring the high-resolution…

Signal Processing · Electrical Eng. & Systems 2025-01-09 Liwen Zhang , Zhaoji Miao , Fan Yang , Gen Shi , Jie He , Yu An , Hui Hui , Jie Tian

The phase-locking of transverse higher-order resonator modes results in a beam with rapidly oscillating spatial intensity profile. To complete the description of such transverse mode-locked (TML) beams, their spatiotemporal phase dynamics…

Optics · Physics 2024-12-13 Jan Wichmann , Michael Zwilich , Carsten Fallnich

Measurement of the optical transmission matrix (TM) of an opaque material is an advanced form of space-variant aberration correction. Beyond imaging, TM-based methods are emerging in a range of fields including optical communications,…

Real-time magnetic resonance imaging (MRI) methods generally shorten the measuring time by acquiring less data than needed according to the sampling theorem. In order to obtain a proper image from such undersampled data, the reconstruction…

Numerical Analysis · Mathematics 2013-12-05 Housen Li , Markus Haltmeier , Shuo Zhang , Jens Frahm , Axel Munk

Scattering of nonstationary electromagnetic fields from axially symmetrical bodies is numerically investigated. Simulations are performed using the time- and frequency-domain approaches. Computational results obtained for a finite perfectly…

Mathematical Physics · Physics 2007-05-23 I. G. Efimova

We present a fast and accurate analytical method for fluorescence lifetime imaging microscopy (FLIM) using the extreme learning machine (ELM). We used extensive metrics to evaluate ELM and existing algorithms. First, we compared these…

Biological Physics · Physics 2022-03-28 Zhenya Zang , Dong Xiao , Quan Wang , Zinuo Li , Wujun Xie , Yu Chen , David Day Uei Li

This study examines the feasibility of the full-field ultrasonic characterization of fractures in rock. To this end, a slab-like specimen of granite is subjected to in-plane, O(10$^4$Hz) excitation while monitoring the induced 2D wavefield…

Geophysics · Physics 2017-11-21 Fatemeh Pourahmadian , Bojan B. Guzina

As time can be introduced as an additional degree of freedom, temporal metamaterials nowadays open up new avenues for wave control and manipulation. Among these advancements, temporal metamaterial-based antireflection coatings have recently…

Optics · Physics 2025-11-19 Haonan Hou , Kai Peng , Yangkai Wang , Jiarui Wang , Xudong Zhang , Ren Wang , Hao Hu , Jiang Xiong

A time domain system of equations is proposed to model elastic wave propagation in an unbounded two-dimensional anisotropic solid using perfectly matched layer (PML). Starting from a system of first-order frequency domain stress-velocity…

Computational Physics · Physics 2013-12-16 Hisham Assi , Richard S. C. Cobbold

We are concerned with time-dependent inverse source problems in elastodynamics. The source term is supposed to be the product of a spatial function and a temporal function with compact support. We present frequency-domain and time-domain…

Analysis of PDEs · Mathematics 2018-04-04 Gang Bao , Guanghui Hu , Yavar Kian , Tao Yin