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作者： Dau, Hoang Duursma, Iwan M. Kiah, Han Mao Milenkovic, Olgica University of Illinois at Urbana-Champaign UrbanaIL61801 United States Department of Electrical and Computer Systems Engineering Monash University MelbourneVIC3800 Australia Department of Mathematics University of Illinois at Urbana-Champaign UrbanaIL61801 United States Coordinated Science Laboratory University of Illinois at Urbana-Champaign UrbanaIL61801 United States Division of Mathematical Sciences School of Physical and Mathematical Sciences Nanyang Technological University Singapore637371 Singapore

Despite their exceptional error-correcting properties, Reed-Solomon (RS) codes have been overlooked in distributed storage applications due to the common belief that they have poor repair bandwidth. A naive repair approach would require for the whole file to be reconstructed in order to recover a single erased codeword symbol. In a recent work, Guruswami and Wootters (STOC'16) proposed a single erasure repair method for RS codes that achieves the optimal repair bandwidth amongst all linear encoding schemes. Their key idea is to recover the erased symbol by collecting a sufficiently large number of its traces, each of which can be constructed from a number of traces of other symbols. We extend the trace collection technique to cope with two and three erasures. © 2018 IEEE.

关键词： Bandwidth

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DeepNIS: Deep neural network for nonlinear electromagnetic inverse scattering

arXiv

引用

arXiv 2018年

作者： Li, Lianlin Wang, Long Gang Teixeira, Fernando L. Liu, Che Nehorai, Arye Cui, Tie Jun School of Electronics Engineering and Computer Sciences Peking University Beijing100871 China ElectroScience Laboratory Ohio State University ColumbusOH43212 United States State Key Laboratory of Millimeter Waves Southeast University Nanjing210096 China Department of Electrical & Systems Engineering Washington University in St. Louis Washington63130 United States

Nonlinear electromagnetic (EM) inverse scattering is a quantitative and super-resolution imaging technique, in which more realistic interactions between the internal structure of scene and EM wavefield are taken into account in the imaging procedure, in contrast to conventional tomography. However, it poses important challenges arising from its intrinsic strong nonlinearity, ill-posedness, and expensive computation costs. To tackle these difficulties, we, for the first time to our best knowledge, exploit a connection between the deep neural network (DNN) architecture and the iterative method of nonlinear EM inverse scattering. This enables the development of a novel DNN-based methodology for nonlinear EM inverse problems (termed here DeepNIS). The proposed DeepNIS consists of a cascade of multi-layer complex-valued residual convolutional neural network (CNN) modules. We numerically and experimentally demonstrate that the DeepNIS outperforms remarkably conventional nonlinear inverse scattering methods in terms of both the image quality and computational time. We show that DeepNIS can learn a general model approximating the underlying EM inverse scattering system. It is expected that the DeepNIS will serve as powerful tool in treating highly nonlinear EM inverse scattering problems over different frequency bands, involving large-scale and high-contrast objects, which are extremely hard and impractical to solve using conventional inverse scattering methods. Copyright © 2018, The Authors. All rights reserved.

关键词： Deep neural networks

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Search for axion-like dark matter using solid-state nuclear magnetic resonance

arXiv

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arXiv 2021年

作者： Aybas, Deniz Adam, Janos Blumenthal, Emmy Gramolin, Alexander V. Johnson, Dorian Kleyheeg, Annalies Afach, Samer Blanchard, John W. Centers, Gary P. Garcon, Antoine Engler, Martin Figueroa, Nataniel L. Sendra, Marina Gil Wickenbrock, Arne Lawson, Matthew Wang, Tao Wu, Teng Luo, Haosu Mani, Hamdi Mauskopf, Philip Graham, Peter W. Rajendran, Surjeet Jackson Kimball, Derek F. Budker, Dmitry Sushkov, Alexander O. Department of Physics Boston University BostonMA02215 United States Department of Electrical and Computer Engineering Boston University BostonMA02215 United States Helmholtz-Institut GSI Helmholtzzentrum für Schwerionenforschung Mainz55128 Germany Johannes Gutenberg-Universität Mainz Mainz55128 Germany The Oskar Klein Centre for Cosmoparticle Physics Department of Physics Stockholm University AlbaNova Stockholm10691 Sweden Nordita KTH Royal Institute of Technology Stockholm University Roslagstullsbacken 23 Stockholm10691 Sweden Department of Physics Princeton University PrincetonNJ08544 United States State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronics Center for Quantum Information Technology Peking University Beijing100871 China Shanghai Institute of Ceramics Chinese Academy of Sciences China School of Earth and Space Exploration Arizona State University TempeAZ85287 United States Stanford Institute for Theoretical Physics Stanford University StanfordCA94305 United States Department of Physics & Astronomy The Johns Hopkins University BaltimoreMD21218 United States Department of Physics California State University East Bay HaywardCA94542-3084 United States Department of Physics University of California BerkeleyCA94720-7300 United States Photonics Center Boston University BostonMA02215 United States

We report the results of an experimental search for ultralight axion-like dark matter in the mass range 162 neV to 166 neV. The detection scheme of our Cosmic Axion Spin Precession Experiment (CASPEr) is based on a precision measurement of 207Pb solid-state nuclear magnetic resonance in a polarized ferroelectric crystal. Axion-like dark matter can exert an oscillating torque on 207Pb nuclear spins via the electric-dipole moment coupling gd, or via the gradient coupling gaNN. We calibrated the detector and characterized the excitation spectrum and relaxation parameters of the nuclear spin ensemble with pulsed magnetic resonance measurements in a 4.4 T magnetic field. We swept the magnetic field near this value and searched for axion-like dark matter with Compton frequency within a 1 MHz band centered at 39.65 MHz. Our measurements place the upper bounds |gd| −4 GeV−2 and |gaNN| −1 GeV−1 (95% confidence level) in this frequency range. The constraint on gd corresponds to an upper bound of 1.0 × 10−21 e · cm on the amplitude of oscillations of the neutron electric dipole moment, and 4.3×10−6 on the amplitude of oscillations of CP-violating θ parameter of quantum chromodynamics. Our results demonstrate the feasibility of using solid-state nuclear magnetic resonance to search for axion-like dark matter in the nanoelectronvolt mass range. Copyright © 2021, The Authors. All rights reserved.

关键词： Quantum theory

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Robust ADRC for Nonlinear Time-varying System with Uncertainties 6

Robust ADRC for Nonlinear Time-varying System with Uncertain...

引用

2017 IEEE 6th Data Driven Control and Learning systems Conference (DDCLS’17)

作者： Xiangyang Li Wei Ai Zhiqiang Gao Senping Tian Key Laboratory of Autonomous Systems and Networked Control Ministry of Education School of Automation Science and Engineering South China University of Technology IEEE Center for Advanced Control Technologies Department of Electrical and Computer EngineeringCleveland State University

ISBN: (纸本)9781509054626

Active disturbance rejection control(ADRC) exemplifies the spirit of the data-driven control(DDC) design strategy and shows much promise in obtaining consistent applications in industrial control systems with uncertainties, without the premise that the detailed mathematical model of the controlled system is given. Instead, it is shown that the information needed for the control system to work at high level of effectiveness can be extracted from the input-output data by the use of the extended state observer(ESO). On the other hand, it is shown in this paper that the robustness of ADRC depends on the effectiveness of ESO. Furthermore, taking advantage of the rich body of knowledge in the existing field of robust control, the estimation error in ESO is analysed and, for the purpose of improved robustness, a unique nonlinear component is added to the conventional ADRC law. The modified ADRC which is a kind of robust ADRC law is validated in simulation for a nonlinear time-varying system with parametric and functional uncertainties. It is shown that the proposed robust ADRC law provides more effective tracking performance than the conventional ADRC when the bandwidth of ESO is not wide enough.

关键词： Active Disturbance Rejection Control(ADRC) Robust Control Extended State Observer(ESO) Nonlinear Time-varying System

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A dynamic adaptive algorithm for statistical up-scaling based short-term wind power prediction of regions

A dynamic adaptive algorithm for statistical up-scaling base...

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2017 China International electrical and Energy Conference, CIEEC 2017

作者： Peng, Xiaosheng Chen, Yuzhu Che, Jianfeng Wang, Bo School of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan China State Key Laboratory of Operation and Control of Renewable Energy and Storage Systems China Electric Power Research Institute Beijing China

ISBN: (纸本)9781509062751

Wind power Prediction (WPP) of regions is beneficial for the department of power grid dispatching to evaluate the wind power output characteristics from a global perspective and to formulate a scientific and reasonable scheduling scheme for power grid. The statistical up-scaling based WPP of regions is one of the most popular methods, which has been widely applied by the industrial companies. The selection of reference wind farms is one of the key factors of the statistical up-scaling method based WPP of regions. However, most of the methods for the selection of reference wind farms are not flexible, which restrict the improvement of the WPP accuracy, as the weather of wind farm sub-regions are always changeable. To overcome the challenge, a dynamic adaptive algorithm based WPP of regions is presented in the paper, in terms of the dynamic selection of reference wind farms, the dynamic selection of the WPP methods based on the classification of the weather types of the wind farms and the dynamic selection of the up-scaling method. The results show that the proposed method is with higher accuracy than the traditional statistical up-scaling based WPP of regions and is applicable for industrial WPP of regional wind farms. © 2017 IEEE.

关键词： Wind farm

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引用

IEEE International Conference on Recent Trends in Electronics, Information & Communication Technology (RTEICT)

作者： P.P Gokul B K Akhil Kumar K. M Shiva Maryland Power Electronics Laboratory Electrical and Computer Engineering Department Institute for Systems Research University of Maryland College Park MD USA

Identifying paraphrase in Malayalam language is difficult task because it is a highly agglutinative language and the linguistic structure in Malayalam language is complex compared to other languages. Here we use individual words synonyms to find the similarity between two sentences. In this paper, cosine similarity method is used to find the paraphrases in Malayalam language. In this paper we present the observations on sentence similarity between two Malayalam sentences using cosine similarity method, we used test data of 900 and 1400 sentence pairs of FIRE 2016 Malayalam corpus that used in two iterations to present and obtained an accuracy of 0.8 and 0.59.

关键词： Tagging Semantics Conferences Market research Communications technology Training

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Coupled Electro-Thermal Transient Analysis of Superconducting DC Transmission systems Using FDTD and VEM Modeling

引用

IEEE Transactions on Applied Superconductivity 2017年第8期27卷

作者： Doukas, Dimitrios I. Chrysochos, Andreas I. Papadopoulos, Theofilos A. Labridis, Dimitris P. Harnefors, Lennart Velotto, Giovanni School of Electrical and Computer Engineering Aristotle University of Thessaloniki Thessaloniki54124 Greece Power Systems Laboratory Department of Electrical and Computer Engineering Democritus University of Thrace Xanthi67100 Greece ABB Corporate Research Västerås72178 Sweden

In this paper, detailed mathematical formulation of a coupled electro-thermal model for transient studies of high-temperature superconducting (HTS) transmission systems is presented. Regarding the thermal modeling, the volume-element method is used in order heat transfer equations on a two-dimensional axisymmetric cable model to be solved and temperature distribution over space and time to be determined. For the modeling of the electric part, a constant-parameter finite-difference time-domain method is utilized to calculate voltages and currents over space and time as well. The analysis is conducted on a bipolar cable suggested by the Electric power Research Institute for long-distance HTS dc transmission to highlight the electric and thermal domain interaction under transient conditions. Different test cases are conducted to evaluate the electric and thermal transient performance of the examined HTS cable. © 2002-2011 IEEE.

关键词： Finite difference time domain method

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On the Performance of X-Duplex Relaying

On the Performance of X-Duplex Relaying

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作者： Li, Shuai Zhou, Mingxin Wu, Jianjun Song, Lingyang Li, Yonghui Li, Hongbin State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Peking University Beijing100871 China School of Electrical and Information Engineering University of Sydney CamperdownNSW2006 Australia

In this paper, we study an X-duplex relay system with one source, one amplify-and-forward relay, and one destination, where the relay is equipped with a shared antenna and two radio frequency (RF) chains used for transmission or reception. X-duplex relay can adaptively configure the connection between its RF chains and antenna to operate in either half-duplex (HD) or full-duplex (FD) mode, according to the instantaneous channel conditions. We first derive the distribution of the signal to interference plus noise ratio, based on which we then analyze the outage probability, average symbol error rate (SER), and average sum rate. We also investigate the X-duplex relay with power allocation and derive the lower bound and upper bound of the corresponding outage probability. Both analytical and simulated results show that the X-duplex relay achieves a better performance over pure FD and HD schemes in terms of SER, outage probability and average sum rate, and the performance floor caused by the residual self interference can be eliminated using flexible RF chain configurations. © 2017 IEEE.

关键词： Antennas

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Analysis of the possibility of levitation of ferromagnetic bodies in a static magnetic field

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IOP Conference Series: Materials Science and engineering 2019年第1期680卷

作者： M A Vernezi K I Goryanina O I Katin D Yu Donskoy A D Lukyanov A N Tooraj Laboratory of local automation and embedded systems Don State Technical University Gagarin Square 1 Rostov-on-Don 344000 Russia Federation Instrumentation Lab School of electrical and computer engineering University of Tehran Tehran Iran

The hypothesis of the existence of three-dimensional regions near the sources of the magnetic field, in which it is possible to obtain a stable position of the magnetic object in a stationary field. The hypothesis is based on the existence of two types of points: points with zero field level and points with local extremum of this field. The obtained distributions of magnetic forces act stabilizing on the object under study, in particular, create the effect of levitation of ferromagnetic bodies in the gravitational field of the Earth. Examples of configurations of the field sources that generate many such points. systems of current windings providing creation of one-and two-dimensional configurations of areas near sources within which magnetic levitation is possible are analyzed.

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Single-Shot Multi-Stage Damage and Ablation of Silicon by Femtosecond Mid-infrared Laser Pulses

arXiv

引用

arXiv 2019年

作者： Werner, Kevin Gruzdev, Vitaly Talisa, Noah Kafka, Kyle Austin, Drake Liebig, Carl M. Chowdhury, Enam Ohio State University Department of Physics ColumbusOH43224 United States BAE Systems 130 Daniel Webster Hwy. MER15-1813 MerrimackNH03054 United States University of New Mexico Department of Physics and Astronomy AlbuquerqueNM87131 United States University of Rochester Laboratory for Laser Energetics RochesterNY14623 United States Air Force Research Laboratory Materials and Manufacturing Directorate Wright-Patterson Air Force Base OH45433 United States Ohio State University Department of Material Science and Engineering ColumbusOH43224 United States Ohio State University Department of Electrical and Computer Engineering ColumbusOH43224 United States

Although ultrafast laser materials processing has advanced at a breakneck pace over the last two decades, most applications have been developed with laser pulses at near-IR or visible wavelengths. Recent progress in mid-infrared (MIR) femtosecond laser source development may create novel capabilities for material processing. This is because, at high intensities required for such processing, wavelength tuning to longer wavelengths opens the pathway to a special regime of laser-solid interactions. Under these conditions, due to the λ2 scaling, the ponderomotive energy of laser-driven electrons may significantly exceed photon energy, band gap and electron affinity and can dominantly drive absorption, resulting in a paradigm shift in the traditional concepts of ultrafast laser-solid interactions. Irreversible high-intensity ultrafast MIR laser-solid interactions are of primary interest in this connection, but they have not been systematically studied so far. To address this fundamental gap, we performed a detailed experimental investigation of high-intensity ultrafast modifications of silicon by single femtosecond MIR pulses (λ= 2.7 – 4.2 μm). Ultrafast melting, interaction with silicon-oxide surface layer, and ablation of the oxide and crystal surfaces were ex-situ characterized by scanning electron, atomic-force, and transmission electron microscopy combined with focused ion-beam milling, electron diffractometry, and μ-Raman spectroscopy. Laser induced damage and ablation (LIDA) thresholds were measured as functions of laser wavelength. The traditional theoretical models did not reproduce the wavelength scaling of the damage thresholds. To address the disagreement, we discuss possible novel pathways of energy deposition driven by the ponderomotive energy and field effects characteristic of the MIR wavelength regime. Copyright © 2019, The Authors. All rights reserved.

关键词： Infrared devices

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