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arXiv 2018年

作者： Zhou, Fuhui Wu, Yongpeng Hu, Rose Qingyang Qian, Yi Department of Electrical and Computer Engineering Utah State University United States School of Information Engineering Nanchang University 330031 China State Key Laboratory of Integrated Services Networks Xidian University Xian710071 China Shanghai Key Laboratory of Navigation and Location Based Services Shanghai Jiao Tong University Minhang200240 China Department of Electrical and Computer Engineering Utah State University United States Department of Electrical and Computer Engineering University of Nebraska-Lincoln OmahaNE68182 United States

Mobile edge computing (MEC) and wireless power transfer (WPT) are two promising techniques to enhance the computation capability and to prolong the operational time of low-power wireless devices that are ubiquitous in Internet of Things. However, the computation performance and the harvested energy are significantly impacted by the severe propagation loss. In order to address this issue, an unmanned aerial vehicle (UAV)-enabled MEC wireless powered system is studied in this paper. The computation rate maximization problems in a UAV-enabled MEC wireless powered system are investigated under both partial and binary computation offloading modes, subject to the energy harvesting causal constraint and the UAV's speed constraint. These problems are non-convex and challenging to solve. A two-stage algorithm and a three-stage alternative algorithm are respectively proposed for solving the formulated problems. The closed-form expressions for the optimal central processing unit frequencies, user offloading time, and user transmit power are derived. The optimal selection scheme on whether users choose to locally compute or offload computation tasks is proposed for the binary computation offloading mode. Simulation results show that our proposed resource allocation schemes outperforms other benchmark schemes. The results also demonstrate that the proposed schemes converge fast and have low computational complexity. Copyright © 2018, The Authors. All rights reserved.

关键词： Unmanned aerial vehicles (UAV)

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Charting brain growth in tandem with brain templates at school age

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Science Bulletin 2020年第22期65卷 1924-1934,M0004页

作者： Hao-Ming Dong F.Xavier Castellanos Ning Yang Zhe Zhang Quan Zhou Ye He Lei Zhang Ting Xu Avram J.Holmes B.T.Thomas Yeo Feiyan Chen Bin Wang Christian Beckmann Tonya White Olaf Sporns Jiang Qiu Tingyong Feng Antao Chen Xun Liu Xu Chen Xuchu Weng Michael P.Milham Xi-Nian Zuo Research Center for Lifespan Development of Brain and Mind Institute of PsychologyChinese Academy of Sciences(CAS)Beijing 100101China State Key Laboratory of Cognitive Neuroscience and Learning Beijing Normal UniversityBeijing 100875China Department of Child and Adolescent Psychiatry New York University School of MedicineNew YorkNY 10016USA Nathan Kline Institute for Psychiatric Research OrangeburgNew YorkNY 10962USA Department of Psychology University of CASBeijing 100049China Department of Psychological and Brain Sciences Indiana UniversityBloomingtonIN 47405USA Child Mind Institute New YorkNY 10022USA Department of Psychology Yale UniversityNew HavenCT 06511USA Department of Electrical and Computer Engineering Clinical Imaging Research CentreN.1 Institute for Health and Memory Networks ProgramNational University of SingaporeSingapore 117574Singapore Department of Physics Zhejiang UniversityHangzhou 310058China Binzhou Medical University Yantai 264100China Donders Institute Radboud University Medical CentreNijmegen 6525 ENNetherlands Department of Child and Adolescent Psychiatry Erasmus UniversityRotterdam 3000 CBNetherlands Department of Radiology Erasmus University Medical CentreRotterdam 3000 CANetherlands School of Psychology Southwest UniversityChongqing 400715China Institute for Brain Research and Rehabilitation South China Normal UniversityGuangzhou 510631China Institute of Children Health Changzhou Children’s HospitalChangzhou 213003China Key Laboratory of Brain and Education School of Education ScienceNanning Normal UniversityNanning 530001China CAS Key Laboratory of Behavioral Science Institute of PsychologyBeijing 100101China IDG/McGovern Institute for Brain Research Beijing Normal UniversityBeijing 100875China

Brain growth charts and age-normed brain templates are essential resources for researchers to eventually contribute to the care of individuals with atypical developmental *** present work generates age-normed brain templates for children and adolescents at one-year intervals and the corresponding growth charts to investigate the influences of age and ethnicity using a common pediatric neuroimaging *** accelerated longitudinal cohorts with the identical experimental design were implemented in the United States and *** magnetic resonance imaging(MRI)of typically developing school-age children(TDC)was obtained up to three times at nominal intervals of1.25 *** protocol generated and compared population-and age-specific brain templates and growth charts,respectively.A total of 674 Chinese pediatric MRI scans were obtained from 457 Chinese TDC and 190 American pediatric MRI scans were obtained from 133 American ***-and age-specific brain templates were used to quantify warp cost,the differences between individual brains and brain *** growth charts for labeled brain network areas were *** analyses of cost functions supported the necessity of age-specific and ethnicitymatched brain templates,which was confirmed by growth chart *** analyses revealed volumetric growth differences between the two ethnicities primarily in lateral frontal and parietal areas,regions which are most variable across individuals in regard to their structure and ***-and ethnicity-specific brain templates facilitate establishing unbiased pediatric brain growth charts,indicating the necessity of the brain charts and brain templates generated in *** templates and growth charts as well as related codes have been made freely available to the public for open neuroscience(https://***/zuoxinian/CCS/tree/master/H3/Growth Charts).

关键词： Growth charts Neuroimaging Ethnicity Brain templates Development

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Efficient dynamic coherence transfer relying on offset locking using optical phase-locked loop

Efficient dynamic coherence transfer relying on offset locki...

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2017 International Conference on Optical Instruments and Technology: Optoelectronic Devices and Optical Signal Processing

作者： Xie, Weilin Shi, Hongxiao Zhou, Qian Xia, Zongyang Qin, Jie Zhang, Lin Lin, Xi Hu, Weisheng State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University Shanghai200240 China School of Optoelectronics Beijing Institute of Technology Beijing100081 China Laboratoire Aimé Cotton CNRS-Université Paris Saclay Campus D'Orsay Orsay Cedex91405 France School of Electrical and Computer Engineering Georgia Institute of Technology North Avenue AtlantaGA30332 United States

ISBN: (数字)9781510617469

ISBN: (纸本)9781510617452

We design and experimentally demonstrate a highly efficient coherence transfer based on composite optical phaselocked loop comprising multiple feedback servo loops. The heterodyne offset-locking is achieved by conducting an acousto-optic frequency shifter in combination with the current tuning and the temperature controlling of the semiconductor laser. The adaptation of the composite optical phase-locked loop enables the tight coherence transfer from a frequency comb to a semiconductor laser in a fully dynamic manner. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.

关键词： Microwave photonics

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Design of a High Precision Seeder Control System 3

Design of a High Precision Seeder Control System

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2017 IEEE 第3届信息技术与机电一体化工程国际学术会议(ITOEC 2017)

作者： Yan Jiang Xianglong Zhou Jie Duan Jingbo Zhao College of Automation Engineering Qingdao University of Technology Shandong Provincial Key Laboratory of Computer Networks Shandong Computer Science Center(National Super computer Center in Jinan) National People’s Liberation Army Naval Submarine Academy

Aiming at the problem that the precision control of the seeder is not high,the position control system of the stepper motor with DSP as the controller is *** system uses SCI serial port to c

ISBN: (纸本)9781509053643;9781509053636

Aiming at the problem that the precision control of the seeder is not high,the position control system of the stepper motor with DSP as the controller is *** system uses SCI serial port to c

关键词： agriculture digital signal processing chips feedback frequency control position control pulse width modulation stepping motors Stepper Motor Device Component digital signal processing chips Frequency control Pulse width modulation Feedback Position control on line data service fine control agriculture Controllers locating and control system Digital signal processing Desmoplakin Gene zero crossings

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Comparison of Laguerre-Gaussian, Hermite–Gaussian and linearly polarized modes in SDM over FMF with electrical nonlinear equalizer

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AIP Conference Proceedings 2020年第1期2203卷

作者： Alaa Fareed Alaan Ghazi Aras Al-Dawoodi S. A. Aljunid Syed Zulkarnain Syed Idrus C. B. M. Rashidi Angela Amphawan Ahmed M. Fakhrudeen Ibrahim Eskandar Ibrahim Fadhel 1School of Computing Universiti Utara Malaysia Malaysia 2School of Human Development & Techno-communication Universiti Malaysia Perlis Malaysia 3School of Computer and Communication Engineering Universiti Malaysia Perlis Malaysia 4Computer Science Department College of Computer Science and Information Technology Kirkuk University Iraq 5Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge Massachusetts USA 6Networks Department College of Computer Science and Information Technology Kirkuk University Iraq 7Department of Computer and Information Systems National Institute of Administrative Science Yemen

The development of communication technologies shows that fiber optics is in the main communication improvement in the last decade. Fiber optics is moved from laboratory to be a reality. Transmission of the data using the light as a signal carrier is a revolutionary improvement in the communication era. However, to enable this technology several obstacles should be addressed, such as achieving the longest distance transmission with less possible bit error rate (BER). One of the solutions was performed by careful selection of the optical modes profiles with the help of the nonlinear electrical equalizer (NLEE) to solve the problem of the mode coupling. This paper investigates on the compensation of different modes profiles in optical communication systems over few-mode fiber (FMF) based on Space Division Multiplexer (SDM) with an electrical non-linear equalizer utilized to equalize nonlinear distortions. The result shows that the LG mode achieved the best transmission distance comparing to the other modes which make it the best option to be used. Basically, the evaluation of the system has been done based on standard evaluation metrics such as BER and Eye Diagram. These results can optimize the data transmission quality.

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Generation of 47 fs Pulses from an Er:Fiber Amplifier

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Chinese Physics Letters 2017年第7期34卷 101-104页

作者：欧尚明刘关玉雷卉张志刚张庆茂 School of Information Optoelectronics Science and Technology South China Normal University Guangzhou 510006 State Key Laboratory of Advanced Optical Communication System and Networks School of Electronics Engineering and Computer Science Peking University Beijing 100871 Guangzhou Research Institute Of O-M-E Technology Guangzhou 510663

We demonstrate a self-starting erbium fiber oscillator-amplifier system based on the nonlinear polarization rota- tion mode-locked mechanism. The direct output pulse from the amplifier is 47fs with an average power of 1.22 W and a repetition rate of 50 MHz, corresponding to a pulse energy of 24 nJ. The full width at half-maximum of the spectrum of the output pulses is approximately 93nm at a central wavelength of 1572nm so that the transform- limited pulse duration is as short as 39 fs. Due to the imperfect dispersion compensation, we compress the pulses to 47fs in this experiment.

关键词： Generation of 47 fs Pulses from an Er:Fiber Amplifier

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Vehicle tracking using surveillance with multimodal data fusion

arXiv

引用

arXiv 2018年

作者： Zhang, Yue Song, Bin Du, Xiaojiang Guizani, Mohsen State Key Laboratory of Integrated Services Networks Xidian University 710071 China Dept. of Computer and Information Sciences Temple University PhiladelphiaPA19122 United States Dept. of Electrical and Computer Engineering University of Idaho MoscowID83844 United States

Vehicle location prediction or vehicle tracking is a significant topic within connected vehicles. This task, however, is difficult if only a single modal data is available, probably causing bias and impeding the accuracy. With the development of sensor networks in connected vehicles, multimodal data are becoming accessible. Therefore, we propose a framework for vehicle tracking with multimodal data fusion. Specifically, we fuse the results of two modalities, images and velocity, in our vehicle-tracking task. Images, being processed in the module of vehicle detection, provide direct information about the features of vehicles, whereas velocity estimation can further evaluate the possible location of the target vehicles, which reduces the number of features being compared, and decreases the time consumption and computational cost. Vehicle detection is designed with a color-faster R-CNN, which takes both the shape and color of the vehicles into consideration. Meanwhile, velocity estimation is through the Kalman filter, which is a classical method for tracking. Finally, a multimodal data fusion method is applied to integrate these outcomes so that vehicle-tracking tasks can be achieved. Experimental results suggest the efficiency of our methods, which can track vehicles using a series of surveillance cameras in urban areas. Copyright © 2018, The Authors. All rights reserved.

关键词： Monitoring

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Spin dynamics of magnetic resonance with parametric modulation in a potassium vapor cell

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Chinese Physics B 2017年第3期26卷 285-290页

作者：张锐汪之国彭翔黎文浩李松健郭弘 College of Science and Interdisciplinary Center for Quantum Information National University of Defense Technology Changsha 410073 China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science and Center for Quantum Information Technology Peking University Beijing 100871 China College of Optoelectronic Science and Engineering National University of Defense Technology Changsha 410073 China

A typical magnetic-resonance scheme employs a static bias magnetic field and an orthogonal driving magnetic field oscillating at the Larmor frequency, at which the atomic polarization precesses around the static magnetic field. Here we demonstrate both theoretically and experimentally the variations of the resonance condition and the spin precession dynamics resulting from the parametric modulation of the bias field. We show that the driving magnetic field with the frequency detuned by different harmonics of the parametric modulation frequency can lead to resonance as well. Also, a series of frequency sidebands centered at the driving frequency and spaced by the parametric modulation frequency can be observed in the precession of the atomic polarization. We further show that the resonant amplitudes of the sidebands can be controlled by varying the ratio between the amplitude and the frequency of the parametric modulation. These effects could be used in different atomic magnetometry applications.

关键词： atomic magnetometer magnetic resonance parametric modulation

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Performance analysis of multi-cell millimeter wave massive mimo networks with low-precision ADCs

arXiv

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arXiv 2018年

作者： Xu, Jindan Xu, Wei Zhang, Hua Li, Geoffrey Ye You, Xiaohu School of Electrical and Computer Engineering Georgia Institute of Technology AtlantaGA30332 United States State Key Laboratory of Integrated Services Networks Xidian University Xi’an710071 China Southeast University Nanjing210096 China

—In this paper, we investigate a multi-cell millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) network with low-precision analog-to-digital converters (ADCs) at the base station (BS). Each cell serves multiple users and each user is equipped with multiple antennas but driven by a single RF chain. We first introduce a channel estimation strategy for the mmWave massive MIMO network and analyze the achievable rate with imperfect channel state information. Then, we derive an insightful lower bound for the achievable rate, which becomes tight with a growing number of users. The bound clearly demonstrates the impacts of the number of antennas and the ADC precision, especially for a single-cell mmWave network at low signal-to-noise ratio (SNR). It characterizes the tradeoff among various system parameters. Our analytical results are finally confirmed by extensive computer simulations. Copyright © 2018, The Authors. All rights reserved.

关键词： Beamforming

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Unsupervised feature learning for audio analysis

arXiv

引用

arXiv 2017年

作者： Meyer, Matthias Beutel, Jan Thiele, Lothar Computer Engineering and Networks Laboratory Eth Zurich Zurich Switzerland

Identifying acoustic events from a continuously streaming audio source is of interest for many applications including environmental monitoring for basic research. In this scenario neither different event classes are known nor what distinguishes one class from another. Therefore, an unsupervised feature learning method for exploration of audio data is presented in this paper. It incorporates the two following novel contributions: First, an audio frame predictor based on a Convolutional LSTM autoencoder is demonstrated, which is used for unsupervised feature extraction. Second, a training method for autoencoders is presented, which leads to distinct features by amplifying event similarities. In comparison to standard approaches, the features extracted from the audio frame predictor trained with the novel approach show 13 % better results when used with a classifier and 36 % better results when used for clustering. Copyright © 2017, The Authors. All rights reserved.

关键词： Long short-term memory

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