scholarly journals Full recovery of ultrafast waveforms lost under noise

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Benjamin Crockett ◽  
Luis Romero Cortés ◽  
Saikrishna Reddy Konatham ◽  
José Azaña
Keyword(s):  
Frequency Spectrum ◽  
Radio Astronomy ◽  
Full Recovery ◽  
Signal Frequency ◽  
Signal Denoising ◽  
Single Shot ◽  
Unknown Parameters ◽  
Significant Challenge ◽  
Band Noise ◽  
Order Of Magnitude

AbstractThe ability to detect ultrafast waveforms arising from randomly occurring events is essential to such diverse fields as bioimaging, spectroscopy, radio-astronomy, sensing and telecommunications. However, noise remains a significant challenge to recover the information carried by such waveforms, which are often too weak for detection. The key issue is that most of the undesired noise is contained within the broad frequency band of the ultrafast waveform, such that it cannot be alleviated through conventional methods. In spite of intensive research efforts, no technique can retrieve the complete description of a noise-dominated ultrafast waveform of unknown parameters. Here, we propose a signal denoising concept involving passive enhancement of the coherent content of the signal frequency spectrum, which enables the full recovery of arbitrary ultrafast waveforms buried under noise, in a real-time and single-shot fashion. We experimentally demonstrate the retrieval of picosecond-resolution waveforms that are over an order of magnitude weaker than the in-band noise. By granting access to previously undetectable information, this concept shows promise for advancing various fields dealing with weak or noise-dominated broadband waveforms.

Partial discharge signal denoising method based on frequency spectrum clustering and local mean decomposition

2020 ◽  
Vol 14 (10) ◽  
pp. 853-861
Author(s):  
Shanjun Li ◽  
Sashuang Sun ◽  
Qin Shu ◽  
Minwei Chen ◽  
Dakun Zhang ◽  
...  
Keyword(s):  
Frequency Spectrum ◽  
Partial Discharge ◽  
Signal Denoising ◽  
Denoising Method ◽  
Local Mean Decomposition ◽  
Local Mean

scholarly journals Efficient gradient-based parameter estimation for dynamic models using qualitative data

2021 ◽  
Author(s):  
Leonard Schmiester ◽  
Daniel Weindl ◽  
Jan Hasenauer
Keyword(s):  
Parameter Estimation ◽  
Qualitative Data ◽  
Dynamic Models ◽  
Unknown Parameters ◽  
Differential Equation Models ◽  
Gradient Calculation ◽  
Order Of Magnitude ◽  
Gradient Based ◽  
Objective Function Values

AbstractMotivationUnknown parameters of dynamical models are commonly estimated from experimental data. However, while various efficient optimization and uncertainty analysis methods have been proposed for quantitative data, methods for qualitative data are rare and suffer from bad scaling and convergence.ResultsHere, we propose an efficient and reliable framework for estimating the parameters of ordinary differential equation models from qualitative data. In this framework, we derive a semi-analytical algorithm for gradient calculation of the optimal scaling method developed for qualitative data. This enables the use of efficient gradient-based optimization algorithms. We demonstrate that the use of gradient information improves performance of optimization and uncertainty quantification on several application examples. On average, we achieve a speedup of more than one order of magnitude compared to gradient-free optimization. Additionally, in some examples, the gradient-based approach yields substantially improved objective function values and quality of the fits. Accordingly, the proposed framework substantially improves the parameterization of models from qualitative data.AvailabilityThe proposed approach is implemented in the open-source Python Parameter EStimation TOolbox (pyPESTO). All application examples and code to reproduce this study are available at https://doi.org/10.5281/zenodo.4507613.

Abstract 15240: Evaluation of the Performance and Safety of Wideband Cardiac MRI in Patients With a Cardiac Implantable Electronic Device (CIED)

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sarah M Schwartz ◽  
Ashitha Pathrose ◽  
Ali Serhal ◽  
Ryan Avery ◽  
Ann Ragin ◽  
...  
Keyword(s):  
Image Quality ◽  
Electronic Device ◽  
Pulse Sequences ◽  
Free Breathing ◽  
Whole Body ◽  
Breath Hold ◽  
Single Shot ◽  
Before And After ◽  
Order Of Magnitude ◽  
Chest X Ray

Introduction: Wideband late gadolinium enhancement (LGE) CMR is capable of suppressing image artifacts induced by cardiac implanted electronic devices (CIEDs). We implemented our own wideband segmented (seg) breath-hold and wideband single-shot (SS) free-breathing LGE pulse sequences and used them clinically since 2016. The purpose of this study was to evaluate image quality and CMR safety of wideband LGE compared to standard LGE. Methods: We retrospectively identified 54 consecutive patients (mean age: 61±15 years; 31% females) with CIED (33 t-ICD, 4 s-ICD, 15 pacemaker, 1 CRT-D, 1 CRT-P) who underwent CMR at 1.5T (Avanto, Siemens). Standard seg, wideband seg, and wideband SS LGE used standard imaging parameters. 16 myocardial segments were scored for scar/myocardial conspicuity and presence of any visual artifact on a 5-point Likert scale (1:worst; 3:acceptable; 5:best). Distance between center of the heart and CIED (CXR D) was measured on chest X-ray. Whole-body specific absorption rate (SAR) was read from DICOM metadata. Device changes were calculated from pre- and post- device interrogation measurements. Results: Both wideband seg and SS LGE consistently produced better image quality than standard LGE (Figure 1A). Median conspicuity and artifact scores were significantly better for wideband seg (F=20.6, p<0.001) and wideband SS (F=24.2, p<0.001) LGE compared to standard LGE. There was a trend in conspicuity and artifact scores with CIED distance for standard LGE (rho=0.476, p=0.02), but not wideband LGE scans (Figure 1B, 1C). Whole-body SAR averaged for both wideband scans (0.15±0.04 W/kg) was one order of magnitude below the 2.0 W/kg FDA limit. Device parameters (sensing, impedance, threshold, battery level) did not differ before and after CMR including wideband LGE. Conclusions: Both wideband seg and SS LGE scans produced improved image quality compared to standard LGE while maintaining CMR safety. *The first two authors (SS and AP) contributed equally

scholarly journals Atom interferometry with thousand-fold increase in dynamic range

2020 ◽  
Vol 6 (45) ◽  
pp. eabd0650
Author(s):  
Dimitry Yankelev ◽  
Chen Avinadav ◽  
Nir Davidson ◽  
Ofer Firstenberg
Keyword(s):  
Dynamic Range ◽  
Fold Increase ◽  
Atom Interferometry ◽  
Single Shot ◽  
Inertial Forces ◽  
Simultaneous Operation ◽  
Interferometric Sensors ◽  
Maximal Sensitivity ◽  
Order Of Magnitude ◽  
Atom Interferometers

The periodicity inherent to any interferometric signal entails a fundamental trade-off between sensitivity and dynamic range of interferometry-based sensors. Here, we develop a methodology for substantially extending the dynamic range of such sensors without compromising their sensitivity, stability, and bandwidth. The scheme is based on simultaneous operation of two nearly identical interferometers, providing a moiré-like period much larger than 2π and benefiting from close-to-maximal sensitivity and from suppression of common-mode noise. The methodology is highly suited to atom interferometers, which offer record sensitivities in measuring gravito-inertial forces but suffer from limited dynamic range. We experimentally demonstrate an atom interferometer with a dynamic-range enhancement of more than an order of magnitude in a single shot and more than three orders of magnitude within a few shots for both static and dynamic signals. This approach can considerably improve the operation of interferometric sensors in challenging, uncertain, or rapidly varying conditions.

scholarly journals Micromachining of Invar Foils with GHz, MHz and kHz Femtosecond Burst Modes

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 733 ◽  
Author(s):  
Simas Butkus ◽  
Vytautas Jukna ◽  
Domas Paipulas ◽  
Martynas Barkauskas ◽  
Valdas Sirutkaitis
Keyword(s):  
Repetition Rate ◽  
Laser System ◽  
Single Shot ◽  
Burst Mode ◽  
Average Laser Power ◽  
Order Of Magnitude ◽  
Multiple Pulses ◽  
Constant Duration ◽  
Percussion Drilling

In this work, a burst mode laser is used for micromachining of 20 µm–250 µm thick Invar (Fe64/Ni36) foils. Holes were drilled by firing multiple pulses transversely onto the sample without moving the beam (percussion drilling). The utilized laser system generates a burst of a controllable number of pulses (at 1030 nm) with tunable pulse-to-pulse time spacing ranging from 200 ps to 16 ns. The sub-pulses within the burst have equal amplitudes and a constant duration of 300 fs that do not change regardless of the spacing in time between them. In such a way, the laser generates GHz to MHz repetition rate pulse bursts with a burst repetition rate ranging from 100 kHz to a single shot. Drilling of the material is compared with the non-burst mode of kHz repetition rate. In addition, we analyze the drilling speed and the resulting dependence of the quality of the holes on the number of pulses per burst as well as the average laser power to find the optimal micromachining parameters for percussion drilling. We demonstrate that the micromachining throughput can be of an order of magnitude higher when using the burst mode as compared to the best results of the conventional kHz case; however, excess thermal damage was also evident in some cases.

Investigation of Complex Signal and its Bilateral Frequency Spectrum

2010 ◽  
Vol 455 ◽  
pp. 194-199
Author(s):  
K. Wang ◽  
Hong Ren Zhang
Keyword(s):  
Frequency Spectrum ◽  
Spectrum Analysis ◽  
Signal Analysis ◽  
Complex Function ◽  
Engineering Application ◽  
Signal Frequency ◽  
Complex Signal ◽  
Mechanism Synthesis ◽  
Accuracy Theory ◽  
Expanded Form

Aim at complex function Fourier transform, the complex index expanded form have been discussed in this paper. The paper indicates that the periodical complex function can be used to describe the motion trace of a point in complex plane. Then the engineering application of complex signal frequency spectrum analysis has been discussed in this paper. This technique has been applied to the fields of mechanical engineering and some innovative achievements have been obtained, such as the establishment of new rotation accuracy theory, the suggestion of spectrum analysis for mechanism synthesis and the invention of polar locus generator. This paper also points out some misunderstandings that due to oversight of complex signal in the academia of signal analysis.

Cause Analysis and Diagnosis of Unbalanced Vibration of Rotor

2013 ◽  
Vol 765-767 ◽  
pp. 2180-2184
Author(s):  
Hong Wei Chen ◽  
Rong Jie Wang
Keyword(s):  
Frequency Spectrum ◽  
Radial Direction ◽  
Vibration Signal ◽  
Signal Frequency ◽  
Cause Analysis ◽  
Material Defects ◽  
Unbalanced Rotor ◽  
Frequency Components ◽  
Diagnosis Method ◽  
Spectrum Characteristics

The paper starts from from the rotor unbalance fault, and analyze the reasons of unbalanced rotor are improper design, material defects, process and assemble error, process problem; Summarizes the frequency spectrum characteristics of rotor unbalance, its features, frequency components of speed have protruding peak on spectrum diagram of detection in radial direction;Puts forward the diagnosis methods of Unbalanced vibration, the first step is to analyze vibration signal frequency components, then analyze its characteristics of vibration in the direction of the change of amplitude and phase. Proved by examples, this paper summarizes the rotor unbalance analysis and diagnosis method is simple and practical, and has reference significance for other vibration problem.

scholarly journals Photometry of K2 Campaign 9 bulge data

2019 ◽  
Vol 627 ◽  
pp. A54 ◽  
Author(s):  
R. Poleski ◽  
M. Penny ◽  
B. S. Gaudi ◽  
A. Udalski ◽  
C. Ranc ◽  
...  
Keyword(s):  
Response Function ◽  
New Method ◽  
Galactic Bulge ◽  
Eclipsing Binary ◽  
Significant Challenge ◽  
Long Period ◽  
Order Of Magnitude ◽  
Stellar Density ◽  
Very High

In its Campaign 9, K2 observed dense regions toward the Galactic bulge in order to constrain the microlensing parallaxes and probe for free-floating planets. Photometric reduction of the K2 bulge data poses a significant challenge due to a combination of the very high stellar density, large pixels of the Kepler camera, and the pointing drift of the spacecraft. Here we present a new method to extract K2 photometry in dense stellar regions. We extended the Causal Pixel Model developed for less-crowded fields, first by using the pixel response function together with accurate astrometric grids, second by combining signals from a few pixels, and third by simultaneously fitting for an astrophysical model. We tested the method on two microlensing events and a long-period eclipsing binary. The extracted K2 photometry is an order of magnitude more precise than the photometry from other method.

scholarly journals Rapid and site-specific deep phosphoproteome profiling by data-independent acquisition (DIA) without the need for spectral libraries

2019 ◽  
Author(s):  
Dorte B. Bekker-Jensen ◽  
Oliver M. Bernhardt ◽  
Alexander Hogrebe ◽  
Ana Martinez del Val ◽  
Lynn Verbeke ◽  
...  
Keyword(s):  
Kinase Inhibitors ◽  
Dynamic Range ◽  
Phosphorylation Site ◽  
Software Tool ◽  
Single Shot ◽  
Data Independent Acquisition ◽  
Order Of Magnitude ◽  
Site Localization ◽  
Using Data ◽  
Spectral Libraries

ABSTRACTQuantitative phosphoproteomics has in recent years revolutionized understanding of cell signaling, but it remains a challenge to scale the technology for high-throughput analyses. Here we present a rapid and reproducible phosphoproteomics approach to systematically analyze hundreds of samples by fast liquid chromatography tandem mass spectrometry using data independent acquisition (DIA). To overcome the inherent issue of positional phosphopeptide isomers in DIA-based phosphoproteomics, we developed and employed an accurate site localization scoring algorithm, which is incorporated into the Spectronaut software tool. Using a library of synthetic phosphopeptides spiked-in to a yeast phosphoproteome in different ratios we show that it is on par with the top site localization score for data-dependent acquisition (DDA) based phosphoproteomics. Single-shot DIA-based phosphoproteomics achieved an order of magnitude broader dynamic range, higher reproducibility of identification and improved sensitivity and accuracy of quantification compared to state-of-the-art DDA-based phosphoproteomics. Importantly, direct DIA without the need of spectral libraries performed almost on par with analyses using specific project-specific libraries. Moreover, we implemented and benchmarked an algorithm for globally determining phosphorylation site stoichiometry in DIA. Finally, we demonstrate the scalability of the DIA approach by systematically analyzing the effects of thirty different kinase inhibitors in context of epidermal growth factor (EGF) signaling showing that a large proportion of EGF-dependent phospho-regulation is mediated by a specific set of protein kinases.

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