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Design of a High Precision Seeder Control System 3

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Design of a High Precision Seeder Control System

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

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

Vehicle tracking using surveillance with multimodal data fusion

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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

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

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

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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

Unsupervised feature learning for audio analysis

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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

Mobile Sink Path Planning Research for Underwater Heterogeneous Sensor Network

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Mobile Sink Path Planning Research for Underwater Heterogene...

第30届中国控制与决策会议

作者： Yifan Hu Yi Zheng Hailin Liu Zhen Wang Yufeng Mao Hua Han Institute of Oceanographic Instrumentation Qilu University of Technology (Shandong Academy of Sciences) Shandong Provincial Key Laboratory of Ocean Environmental Monitoring Technology National Engineering and Technological Research Center of Marine Monitoring Equipment Qilu University of Technology (Shandong Academy of Sciences) Shandong Computer Science Center (National Supercomputer Center in Jinan) Shandong Provincial Key Laboratory of Computer Networks School of Electronic and Electrical Engineering Shanghai University of Engineering Science

This paper provided a mobile sink path planning method for underwater heterogeneous sensor networks（UHSN）. First, a cluster topology network in which sensor nodes collect small-scale data, forward to cluster head for storage by multi-hop acoustic communication in cluster;Cluster heads collect large-scale data, upload to mobile sink by optical communication, which can save network energy consumption and expand network coverage;Particle swarm intelligent algorithm is used to optimize the position selection of the cluster head, and shorten the moving path of the mobile sink.;Lastly, the monitor center can send remote path-plan control command to the mobile sink with inter-cluster network route and change its moving path to maintain network, in order to realize remote control of the mobile sink by monitor center. The article achieved efficient and stable transmission of monitoring data by dual-modal communication of UHSN and path plan of mobile sink, and solved the bottleneck problem of the underwater communication speed and distance conflict.

关键词： Underwater heterogeneous sensor networks Cluster head selection Mobile sink Path planning Remote control Dual-mode communication

Improving the lower bound to the secret-key capacity of the thermal amplifier channel

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arXiv 2018年

作者： Wang, Gan Ottaviani, Carlo Guo, Hong Pirandola, Stefano State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Engineering and Computer Science Center for Quantum Information Technology Peking University Beijing100871 China Computer Science University of York YorkYO10 5GH United Kingdom

We consider the noisy thermal amplifier channel, where signal modes are amplified together with environmental thermal modes. We focus on the secret-key capacity of this channel, which is the maximum amount of secret bits that two remote parties can generate by means of the most general adaptive protocol, assisted by unlimited and two-way classical communication. For this channel only upper and lower bounds are known, and in this work we improve the lower bound. We consider a protocol based on squeezed states and homodyne detections, in both direct and reverse reconciliation. In particular, we assume that trusted thermal noise is mixed on beam splitters controlled by the parties in a way to assist their homodyne detections. The new improved lower bounds to the secret-key capacity are obtained by optimizing the key rates over the variance of the trusted noise injected, and the transmissivity of the parties' beam splitters. Our results confirm that there is a separation between the coherent information of the thermal amplifier channel and its secret key capacity. Copyright © 2018, The Authors. All rights reserved.

关键词： Prisms