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arXiv 2021年

作者： Xue, Lianjie Liu, Song Hang, Yang Summers, Adam M. Wilson, Derrek J. Wang, Xinya Chen, Pingping Folland, Thomas G. Hachtel, Jordan A. Shi, Hongyu Hosseini-Zavareh, Sajed Das, Suprem R. Lei, Shuting Zhang, Zhuhua Sorensen, Christopher M. Guo, Wanlin Caldwell, Joshua D. Edgar, James H. Blaga, Cosmin I. Trallero-Herrero, Carlos A. Department of Physics Kansas State University ManhattanKS66506 United States Tim Taylor Department of Chemical Engineering Kansas State University ManhattanKS66506 United States J. R. Macdonald Laboratory Department of Physics Kansas State University ManhattanKS66506 United States State Key Laboratory of Mechanics and Control of Mechanical Structures Institute of Nano Science Nanjing University of Aeronautics and Astronautics Nanjing210016 China Advanced Laser Light Source and few-cycle Inc. Institut Nationale de la Recherche Scientifique 1650 Boul. Lionel-Boulet VarennesQCJ3X 1P7 Canada Department of Industrial and Manufacturing Systems Engineering Kansas State University ManhattanKS66506 United States Department of Mechanical Engineering Vanderbilt University NashvilleTN37212 United States Center for Nanophase Materials Science Oak Ridge National Laboratory Oak Ridge37830 United States Department of Electrical and Computer Engineering Kansas State University ManhattanKS66506 United States Department of Physics University of Connecticut StorrsCT06269 United States

The non-linear response of dielectrics to intense, ultrashort electric fields has been a sustained topic of interest for decades with one of its most important applications being femtosecond laser micro/nano-machining. More recently, renewed interests in strong field physics of solids were raised with the advent of mid-infrared femtosecond laser pulses, such as high-order harmonic generation, optical-field-induced currents, etc. All these processes are underpinned by photoionization (PI), namely the electron transfer from the valence to the conduction bands, on a time scale too short for phononic motion to be of relevance. Here, in hexagonal boron nitride, we reveal that the bandgap can be finely manipulated by femtosecond laser pulses as a function of field polarization direction with respect to the lattice, in addition to the field’s intensity. It is the modification of bandgap that enables the ultrafast PI processes to take place in dielectrics. We further demonstrate the validity of the Keldysh theory in describing PI in dielectrics in the few TW/cm2 regime. © 2021, CC BY.

关键词： Photoionization

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Coordinating vehicle platoons for highway bottleneck decongestion and throughput improvement

arXiv

引用

arXiv 2019年

作者： Čičić, Mladen Jin, Li Johansson, Karl Henrik Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Malvinas väg 10 Stockholm10044 Sweden Department of Civil and Urban Engineering C2SMART University Transportation Center New York University Tandon School of Engineering 15 MetroTech Center BrooklynNY11201 USA United States

Truck platooning is a technology that is expected to become widespread in the coming years. Apart from the numerous benefits that it brings, its potential effects on the overall traffic situation needs to be studied further, especially at bottlenecks and ramps. However, assuming we can control the truck platoons from the infrastructure, they can be used as controlled moving bottlenecks, actuating control actions on the rest of the traffic. Thus properly controlled platoons can possibly improve the efficiency and throughput of the whole system. In this paper, we use a multi-class cell transmission model to capture the interaction between truck platoons and background traffic, and propose a corresponding queuing model, which we use for control design. As control inputs, we use platoon speeds, and the number of lanes platoons occupy, and we devise a control strategy for throughput improvement. This control law is applied on a highway section upstream of a bottleneck, with one on- ramp and one off-ramp. By postponing and shaping the inflow to the bottleneck, we are able to keep it in free flow, avoiding traffic breakdown and capacity drop, leading to significant reduction of total time spent of all vehicles. We tested the proposed control in a simulation study and found that by applying, we reduce the median delay of all vehicles by 75:6%. Notably, although they are slowed down while actuating control actions, platoons experience less delay compared to the case without control, since they avoid going through congestion at the bottleneck. Copyright © 2019, The Authors. All rights reserved.

关键词： Queueing theory

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Intent Pattern Recognition of Lower-limb Motion Based on Mechanical Sensors

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IEEE/CAA Journal of Automatica Sinica 2017年第4期4卷 651-660页

作者： Zuojun Liu Wei Lin Yanli Geng Peng Yang School of Control Science and Engineering Hebei University of Technology Engineering Research Center of Intelligent Rehabilitation Ministry of Education Department of Electrical Engineering and Computer Science Case Western Reserve University Hebei University of Technology

Based on the regularity nature of lower-limb motion,an intent pattern recognition approach for above-knee prosthesis is proposed in this paper. To remedy the defects of recognizer based on electromyogram(EMG), we develop a pure mechanical sensor architecture for intent pattern recognition of lower-limb motion. The sensor system is composed of an accelerometer, a gyroscope mounted on the prosthetic socket, and two pressure sensors mounted under the sole. To compensate the delay in the control of prosthesis, the signals in the stance phase are used to predict the terrain and speed in the swing phase. Specifically, the intent pattern recognizer utilizes intraclass correlation coefficient(ICC) according to the Cartesian product of walking speed and terrain. Moreover, the sensor data are fused via DempsterShafer's theory. And hidden Markov model(HMM) is used to recognize the realtime motion state with the reference of the prior step. The proposed method can infer the prosthesis user's intent of walking on different terrain, which includes level ground,stair ascent, stair descent, up and down ramp. The experiments demonstrate that the intent pattern recognizer is capable of identifying five typical terrain-modes with the rate of 95.8%. The outcome of this investigation is expected to substantially improve the control performance of powered above-knee prosthesis.

关键词： Above-knee prosthesis hidden Markov model(HMM) intra-class correlation coefficient(ICC) intent pattern recognition sensor fusion

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Testing a quantum annealer as a quantum thermal sampler

arXiv

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arXiv 2020年

作者： Izquierdo, Zoe Gonzalez Albash, Tameem Hen, Itay QuAIL NASA Ames Research Center United States USRA Research Institute for Advanced Computer Science Mountain ViewCA94043 United States Department of Electrical and Computer Engineering University of New Mexico AlbuquerqueNM87131 United States Department of Physics and Astronomy Center for Quantum Information and Control CQuIC University of New Mexico AlbuquerqueNM87131 United States Department of Physics and Astronomy Center for Quantum Information Science & Technology University of Southern California Los AngelesCA90089 United States Information Sciences Institute University of Southern California Marina del ReyCA90292 United States

Motivated by recent experiments in which specific thermal properties of complex many-body systems were successfully reproduced on a commercially available quantum annealer, we examine the extent to which quantum annealing hardware can reliably sample from the thermal state in a specific basis associated with a target quantum Hamiltonian. We address this question by studying the diagonal thermal properties of the canonical one-dimensional transverse-field Ising model on a D-Wave 2000Q quantum annealing processor. We find that the quantum processor fails to produce the correct expectation values predicted by Quantum Monte Carlo. Comparing to master equation simulations, we find that this discrepancy is best explained by how the measurements at finite transverse fields are enacted on the device. Specifically, measurements at finite transverse field require the system to be quenched from the target Hamiltonian to a Hamiltonian with negligible transverse field, and this quench is too slow. The limitations imposed by such hardware make it an unlikely candidate for thermal sampling, and it remains an open question what thermal expectation values can be robustly estimated in general for arbitrary quantum many-body systems. Copyright © 2020, The Authors. All rights reserved.

关键词： Annealing

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Localization transition induced by programmable disorder

arXiv

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arXiv 2021年

作者： Da C. Filho, Jaime L.C. Izquierdo, Zoe Gonzalez Saguia, Andreia Albash, Tameem Hen, Itay Sarandy, Marcelo S. Instituto Federal Do Pará Campus Castanhal BR 316 Km 61 Saudade II Castanhal PA 68740-970 Brazil QuAIL Nasa Ames Research Center Moffett FieldCA94035 United States Usra Research Institute for Advanced Computer Science Mountain ViewCA94043 United States Instituto de Física Universidade Federal Fluminense Av. Gal. Milton Tavares de Souza s/n Gragoatá Rio de Janeiro Niterói24210-346 Brazil Department of Electrical and Computer Engineering University of New Mexico AlbuquerqueNM87131 United States Department of Physics and Astronomy Center for Quantum Information and Control CQuIC University of New Mexico AlbuquerqueNM87131 United States Department of Physics and Astronomy Center for Quantum Information Science & Technology University of Southern California Los AngelesCA90089 United States Information Sciences Institute University of Southern California Marina del ReyCA90292 United States

We investigate the occurrence of many-body localization (MBL) on a spin-1/2 transverse-field Ising model defined on a Chimera connectivity graph with random exchange interactions and longitudinal fields. We observe a transition from an ergodic phase to a non-thermal phase for individual energy eigenstates induced by a critical disorder strength for the Ising parameters. Our result follows from the analysis of both the mean half-system block entanglement and the energy level statistics. We identify the critical point associated with this transition using the maximum variance of the block entanglement over the disorder ensemble as a function of the disorder strength. The calculated energy density phase diagram shows the existence of a mobility edge in the energy spectrum. In terms of the energy level statistics, the system changes from the Gaussian orthogonal ensemble for weak disorder to a Poisson distribution limit for strong randomness, which implies localization behavior. We then realize the time-independent disordered Ising Hamiltonian experimentally using a reverse annealing quench-pause-quench protocol on a D-Wave 2000Q programmable quantum annealer. We characterize the transition from the thermal to the localized phase through magnetization measurements at the end of the annealing dynamics, and the results are compatible with our theoretical prediction for the critical point. However, the same behavior can be reproduced using a classical spin-vector Monte Carlo simulation, which suggests that genuine quantum signatures of the phase transition remain out of reach using this experimental platform and protocol. Copyright © 2021, The Authors. All rights reserved.

关键词： Monte Carlo methods

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Proof-of-Principle Experimental Demonstration of Twin-Field Type Quantum Key Distribution

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Physical Review Letters 2019年第10期123卷 100506-100506页

作者： Xiaoqing Zhong Jianyong Hu Marcos Curty Li Qian Hoi-Kwong Lo Center for Quantum Information and Quantum Control Department of Physics University of Toronto Toronto Ontario M5S 1A7 Canada Center for Quantum Information and Quantum Control Department of Electrical and Computer Engineering University of Toronto Toronto Ontario M5S 3G4 Canada EI Telecomunicación Department of Signal Theory and Communications University of Vigo E-36310 Vigo Spain

The twin-field (TF) quantum key distribution (QKD) protocol and its variants are highly attractive because they can beat the well-known fundamental limit of the secret key rate for point-to-point QKD without quantum repeaters (repeaterless bound). In this Letter, we perform a proof-of-principle experimental demonstration of TFQKD based on the protocol proposed by Curty, Azuma, and Lo, which removes the need for postselection on the matching of a global phase from the original TFQKD scheme and can deliver a high secret key rate. Furthermore, we employ a Sagnac loop structure to help overcome the major difficulty in the practical implementation of TFQKD, namely, the need to stabilize the phase of the quantum state over kilometers of fiber. As a proof-of-principle demonstration, the estimated secure key rate from our experimental TFQKD data at the high loss region surpasses the repeaterless bound of QKD with current technology.

关键词： Optical quantum information processing Quantum cryptography Quantum optics

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Sub-pixel X-marker detection by Hough transform

Sub-pixel X-marker detection by Hough transform

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Iranian Conference of Biomedical engineering (ICBME)

作者： Ali Yazdani Hojjat Aalizadeh Farshid Karimi Saeed Solouki Hamid Soltanian-Zadeh School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran Control and Intelligent Processing Center of Excellence(CIPCE) School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran

ISBN: (纸本)9781538679531;9781538679524

High precision center detection of X-markers is required in many applications such as navigation surgery systems and camera calibration. Hough transform is a preferable tool for extracting intersecting lines in an image, which leads to center detection. In this paper, we detect X-marker centers by the sub-pixel precision, using Hough transform. Switching to Hough space helps us to apply processes like thresholding, filtering and weighted averaging on coordinates. The algorithm involves two parameters `Hough Size' and `Filter Size' required to be adjusted for best performance of the algorithm. A dataset of 900 images is used and best performance is achieved by values of 180 and 23 for the above parameters, respectively. Using this setting, 90.8% of the centers are detected successfully by the sub-pixel precision. The average distance between detected centers and reference centers is 0.51 pixels. This suggests that the proposed algorithm has the potential to be utilized for sub-pixel marker detection.

关键词： Image edge detection Transforms Feature extraction Cameras Biomedical engineering Calibration Filtering algorithms

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Outlier mining-based fault diagnosis for multiceli lithium-ion batteries using a low-priced microcontroller 33

Outlier mining-based fault diagnosis for multiceli lithium-i...

引用

33rd Annual IEEE Applied Power Electronics Conference and Exposition, APEC 2018

作者： Kim, Taesic Adhikaree, Amit Pandey, Rajendra Kang, Daewook Kim, Myoungho Oh, Chang-Yeol Back, Juwon Electrical Engineering and Computer Science Texas AandM University-Kingsville KingsvilleTX78363-8202 United States Power Conversion and Control Research Center Korea Electrotechnology Research Institute Changwon51543 Korea Republic of

ISBN: (纸本)9781538611807

Fault diagnosis for lithium-ion batteries involves detecting faulty cells and identifying types of faults. It is crucial to build safety-critical battery systems, which has not been fully integrated in conventional battery management systems. This paper proposes a novel data mining-based real-time fault diagnosis for multicell lithium-ion batteries using a microcontroller. The proposed fault diagnosis algorithm includes: 1) a model-based battery condition monitoring algorithm that estimates physical model parameters and operational states and 2) an outlier detection algorithm that detects abnormal battery cells based on the outcomes of the condition monitoring and identifies the types of faults such as internally shorted cells and anomaly aged cells. The proposed fault diagnosis method is implemented in a low-priced microcontroller and validated by experiments in a multicell battery simulation testbed. © 2018 IEEE.

关键词： Failure analysis

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Robust Energy-Efficient Beamforming in MISO Networks with Dynamic Energy Consumption Model

Robust Energy-Efficient Beamforming in MISO Networks with Dy...

引用

2019 IEEE Global Communications Conference (GLOBECOM)

作者： Yang Lu Ke Xiong Lan Zhang Pingyi Fan Zhangdui Zhong School of Computer and Information Technology Beijing Jiaotong University Beijing China State Key Lab of Rail Traffic Control and Safety Beijing Jiaotong University Beijing China Department of Electrical and Computer Engineering University of Florida Gainesville FL USA Department of Electronic Engineering Tsinghua University Beijing China Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications Beijing Jiaotong University Beijing China

ISBN: (数字)9781728109626

ISBN: (纸本)9781728109633

This paper studies the robust energy efficient beamforming design for MISO systems where only channel distribution information (CDI) is assumed to be available at the transmitter. To capture the general relationship between the data transmission and the energy consumption, the dynamic energy consumption model (DECN) is adopted. An optimization problem is formulated to maximize the system energy efficiency under the constraints of rate outage probability and total available power. The problem is difficult to tackle due to the fractional objective function and the information outage constraints. To solve it, the semidefinite relaxation (SDR) is applied at first and then, a solution approach based on the successive convex approximation (SCA) and the Dinklebach's methods is presented. It is proved that our proposed solution approach is able to converge to a stationary point of the formulated optimization problem. Numerical results demonstrate that DECN has a great impact on system EE. It is observed that there is a saturation point on the system EE in term of available power and the required power corresponding to the saturation point of EE highly depends on circuit power. Particularly, higher circuit power leads to a larger required power but a smaller maximal system EE.

关键词： Transmitters Receivers Energy consumption Linear programming Sensors Robustness Array signal processing

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Multi-sensor state estimation over lossy channels using coded measurements

arXiv

引用

arXiv 2019年

作者： Sui, Tianju Marelli, Damian Sun, Ximing Fu, Minyue School of Control Science and Engineering Dalian University of Technology Dalian China School of Automation Guangdong University of Technology Guangzhou China French Argentine International Center for Information and Systems Sciences National Scientific and Technical Research Council Argentina School of Electrical Engineering and Computer Science University of Newcastle NSW2308 Australia

This paper focuses on a networked state estimation problem for a spatially large linear system with a distributed array of sensors, each of which offers partial state measurements, and the transmission is lossy. We propose a measurement coding scheme with two goals. Firstly, it permits adjusting the communication requirements by controlling the dimension of the vector transmitted by each sensor to the central estimator. Secondly, for a given communication requirement, the scheme is optimal, within the family of linear causal coders, in the sense that the weakest channel condition is required to guarantee the stability of the estimator. For this coding scheme, we derive the minimum mean-square error (MMSE) state estimator, and state a necessary and sufficient condition with a trivial gap, for its stability. We also derive a sufficient but easily verifiable stability condition, and quantify the advantage offered by the proposed coding scheme. Finally, simulations results are presented to confirm our claims. Copyright © 2019, The Authors. All rights reserved.

关键词： Mean square error

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