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Generation of nanosecond 2.65μm pulses and pulse narrowing in fiber-bulk Ho3+:YAG laser pumped gain-switched Cr^2+:Cd Se laser

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Chinese Optics Letters 2020年第3期18卷 50-56页

作者： Hengkang Zhang Encai Ji Bin Zhang Yi Chen Baoquan Yao Qiang Liu Key Laboratory of Photonic Control Technology(Tsinghua University) Ministry of EducationBeijing 100084China State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China School of Electronic and Information Engineering Harbin Institute of TechnologyShenzhen 518055China National Key Laboratory of Tunable Laser Technology Harbin Institute of TechnologyHarbin 150001China

The generation of mid-infrared pulsed lasers was achieved in a Ho3+:YAG laser pumped gain-switched Cr^2+:Cd Se laser system with the shortest pulse duration of 4.15 *** a pump pulse duration of 50 ns and pump power of 2.7 W,the gain-switched Cr^2+:Cd Se laser achieved over 10 times pulse narrowing,obtaining the maximum peak power of 5.7 k *** optical-to-optical conversion efficiency was 3.7%,which could be further improved with better crystal surface polishing *** laser central wavelength was measured to be 2.65μm with a bandwidth(FWHM)of 50 *** addition,the parameter optimization for suppressing the pulse tail was discussed,while the long cavity and high output transmissivity contributed to obtaining the single-peak pulses.

关键词： Cr^2+:CdSe laser gain-switching pulse narrowing mid-infrared

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Spectrum Allocation and Aggregation in Cognitive Radio Satellite communications

Spectrum Allocation and Aggregation in Cognitive Radio Satel...

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International Conference on communications, Signal Processing, and Systems, CSPS 2018

作者： Fu, Rong Xue, Yuhong Song, Meng He, Shi Yang, Zhen Liu, Jinghui Yan, Suna Liu, Xin Beijing Institute of Control Engineering China Academy of Space Technology Beijing100094 China School of Information and Communication Engineering Dalian University of Technology Dalian116024 China

ISBN: (纸本)9789811362637

With the rapid development of satellite communications, more and more users and services are flooding into satellite communications networks, causing a shortage of network resources. The most serious of these is the shortage of spectrum resources, which has become one of the bottlenecks to the development of satellite communications. The introduction of cognitive radio technology has greatly eased this conflict. In this paper, focusing on the shortage of KU-band satellite spectrum resources, combining the cutting-edge cognitive radio and spectrum aggregation technology in the field of communications, a KU satellite spectrum allocation strategy based on cognitive radio technology is proposed. By dynamically assigning frequency resources, the use efficiency of spectrum resources is greatly improved and user satisfaction is improved. © 2019, Springer Nature Singapore Pte Ltd.

关键词： Cognitive radio

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Sensing Terminal for Big Data Oil and Gas Pipeline Corrosion Monitoring

Sensing Terminal for Big Data Oil and Gas Pipeline Corrosion...

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International Conference on Computer Network, Electronic and Automation (ICCNEA)

作者： Lin Li Yiding Wang School of Electronic Engineering Xi'an Shiyou University Shaanxi Provincial Key Lab of Oil and Gas Well Measurement and Control Technology Xi'an China

ISBN: (数字)9781728170831

ISBN: (纸本)9781728170848

Facing the construction requirements of big data pipelines, a distributed sensor terminal for multi-parameter monitoring of oil and gas pipeline anti-corrosion was designed. The terminal uses the microprocessor S3C2440A as the core, and several sensors form a multi-parameter sensor array monitoring circuit, and realizes the data transmission of the Internet of Things through the 4G DTU communication module and TCP protocol. The device can sense the temperature value, reference potential value, programmable power supply current and voltage output value of the long-distance pipeline in real time, and realize the data interaction with the cloud server. Tests show that the device is practical in realizing the application of big data pipeline monitoring value.

关键词： Pipelines Monitoring Temperature sensors Power supplies Oils Electric potential Temperature distribution

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Establishment and Application of Big Data Processing Platform

Establishment and Application of Big Data Processing Platfor...

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International Conference on Computer Network, Electronic and Automation (ICCNEA)

作者： Ruixia Liu Qizhi Zhang Xi'an Shiyou University School of Electrical Engineering Shaanxi Provincial Key Lab of Oil and Gas Well Measurement and Control Technology Xi'an China

ISBN: (数字)9781728170831

ISBN: (纸本)9781728170848

With the advent of the era of big data, more and more enterprises begin to use big data technology to deal with related analysis work. Hadoop is the dominant processing platform in the field of big data, an ecosystem that integrates distributed computing, storage, and management. The Spark framework, on the other hand, is a faster, more versatile distributed computing platform. However, it is only a computing platform and does not provide distributed storage and management per se, and computing remains dependent on distributed file system HDFS and cluster Resource Manager Yarn in the Hadoop ecosystem. Therefore, the combination of Spark and Hadoop to build a big data processing platform can better improve the algorithm efficiency and processing scale. This article explains the setup process and running state of Hadoop and Spark in detail, and verifies its feasibility through several ways.

关键词： Sparks Big Data Virtual machining Yarn Software Firewalls (computing) Optimized production technology

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Research on Dynamic Voltage Rise control Driven by IGBT

Research on Dynamic Voltage Rise Control Driven by IGBT

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International Conference on Computer Network, Electronic and Automation (ICCNEA)

作者： Yuntao Li Hailong Liu Lin Li School of Electronic Engineering Xi'an Shiyou University Shaanxi provincial key laboratory of oil and gas well measurement and control technology Xi'an China

ISBN: (数字)9781728170831

ISBN: (纸本)9781728170848

In order to suppress the turn-off voltage spikes caused by the turn-off of high-power insulated gate bi-polar transistors, a method of sampling the turn-off change rate through a small capacitor and performing closed-loop control is proposed. This circuit makes up for the defects of the traditional dynamic voltage rise control circuit that the magnification is not adjustable and shuts off the oscillation, which improves the stability and reliability of the circuit. Finally, through SABER simulation and experimental verification, the simulation results and experimental results confirm the feasibility of the program.

关键词： Insulated gate bipolar transistors Voltage control Integrated circuit modeling Clamps Threshold voltage Logic gates Oscillators

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Research on an Improved Single Neuron PI control Strategy

Research on an Improved Single Neuron PI Control Strategy

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International Conference on Computer Network, Electronic and Automation (ICCNEA)

作者： Lin Li Mingshuai Luo School of Electronic Engineering Xi'an Shiyou University Shaanxi Provincial Key Lab of Oil and Gas Well Measurement and Control Technology Xi'an China

ISBN: (数字)9781728170831

ISBN: (纸本)9781728170848

In the control system of AC variable frequency speed regulation of asynchronous motor, vector control method is adopted in most of them, and PI control strategy is usually used in speed loop of vector control system. For pulse load system, such as sports training treadmill, the parameters of PI controller in vector control system can't be modified timely according to the characteristics of pulse load, so it can't obtain high-efficiency smooth speed regulation characteristics. Therefore, a single neuron PI control strategy is proposed, which can improve the online performance of single neuron PI controller by establishing a learning algorithm of single neuron gain K Real time adjustment capability. The motor control system based on motion training treadmill is studied in this paper. The model of asynchronous motor vector control system is built in Matlab / Simulink environment. The PI algorithm and single neuron PI algorithm are compared, and the influence of single neuron PI algorithm on the control quality of the whole system is discussed.

关键词： Neurons Induction motors Mathematical model Machine vector control PI control Adaptive systems Rotors

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Dc Voltage control Strategy for Z-source Inverter Based on LADRC

Dc Voltage Control Strategy for Z-source Inverter Based on L...

引用

International Conference on Computer Network, Electronic and Automation (ICCNEA)

作者： Shuhao Xu Hailong Liu Lin Li School of Electronic Engineering Xi'an Shiyou University Shaanxi provincial key laboratory of oil and gas well measurement and control technology Xi'an China

ISBN: (数字)9781728170831

ISBN: (纸本)9781728170848

In this paper, linear active disturbance rejection control (LADRC) is applied to the capacitance voltage control of z-source inverter, which contains linear extended state observer (LESO) and linear error feedback control rate. The input voltage of the inverter is stabilized by stabilizing capacitor voltage. The Z source network capacitor voltage can be quickly restored to the reference voltage when the DC supply voltage fluctuates. Thus, the anti-disturbance ability of z-source inverter is improved. Compared with nonlinear ADRC, the parameter setting process is simplified Simulation results show the validity of the theory.

关键词： Inverters Voltage control Mathematical model Capacitors Capacitance-voltage characteristics Observers Feedback control

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Design of a Fast Response Coriolis Flowmeter Converter Based on Zynq

Design of a Fast Response Coriolis Flowmeter Converter Based...

引用

Chinese control Conference (CCC)

作者： Lijun Sun Chunhui Li Chunli Ma School of Electrical and Information Engineering Tianjin University Tianjin China Walsn Measurement and Control Technology (Hebei) Co. Ltd Langfang China

ISBN: (数字)9789881563903

ISBN: (纸本)9781728165233

Coriolis flowmeters are designed based on the Coriolis force principle. It has high accuracy in mass flow measurement and provides additional multi-parameter measurements such as density, temperature, and volume flow. It is widely used in industrial flow measurement. Under the condition that the flowrate of single-phase flow is stable, the control and real-time tracking of most Coriolis flowmeters can meet the measurement requirements and obtain accurate real-time flow measurement results. However, when the flow conditions change rapidly, the converter system is often unable to track the flow changes in real time, and the measurement results may lag behind or even be erroneous. In this paper, a new prototype based on Zynq for the Coriolis flowmeter converter is developed in order to solve the problem of lagging behind in the measurement results. The fast sampling rate and more computational power from Zynq can realize the real-time measurement for rapidly changing flow. An experimental study using the prototype system was carried out under water flow conditions. Preliminary results showed that the repeatability under various test conditions down to one-second batch runs is within 0.1%. This verifies that the prototype system can measure rapidly changing flows.

关键词： Flowmeters Electron tubes Real-time systems Field programmable gate arrays Temperature measurement Calibration Prototypes

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Performance analysis of intelligent reflecting surface assisted NOMA networks

arXiv

引用

arXiv 2020年

作者： Yue, Xinwei Liu, Yuanwei Key Laboratory of Modern Measurement and Control Technology Ministry of Education School of Information and Communication Engineering Beijing Information Science and Technology University Beijing100101 China School of Electronic Engineering and Computer Science Queen Mary University of London LondonE1 4NS United Kingdom

Intelligent reflecting surface (IRS) is a promising technology to enhance the coverage and performance of wireless networks. We consider the application of IRS to non-orthogonal multiple access (NOMA), where a base station transmits superposed signals to multiple users by the virtue of an IRS. The performance of an IRS-assisted NOMA networks with imperfect successive interference cancellation (ipSIC) and perfect successive interference cancellation (pSIC) is investigated by invoking 1-bit coding scheme. In particular, we derive new exact and asymptotic expressions for both outage probability and ergodic rate of the mth user with ipSIC/pSIC. Based on analytical results, the diversity order of the m-th user with pSIC is in connection with the number of reflecting elements and channel ordering. The high signal-to-noise radio (SNR) slope of ergodic rate for the m-th user is obtained. The throughput and energy efficiency of nonorthogonal users for IRS-NOMA are discussed both in delaylimited and delay-tolerant transmission modes. Additionally, we derive new exact expressions of outage probability and ergodic rate for IRS-assisted orthogonal multiple access (IRS-OMA). Numerical results are presented to substantiate our analyses and demonstrate that: i) The outage behaviors of IRS-NOMA are superior to that of IRS-OMA and relaying schemes;ii) With increasing the number of reflecting elements, IRS-NOMA is capable of achieving enhanced outage performance;and iii) The M-th user has a larger ergodic rate compared to IRS-OMA and benchmarks. However, the ergodic performance of the m-th user exceeds relaying schemes in the low SNR regime. Copyright © 2020, The Authors. All rights reserved.

关键词： Signal to noise ratio

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GCBF: Grouped Cross-Band Fusion Network for Multispectral Scene Classification

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IEEE Transactions on Geoscience and Remote Sensing 2025年 63卷

作者： Li, Jin Liu, Yu Zhao, Wenda Jiang, Zhizhuo Wang, Xueqian Zheng, Bolun Tsinghua University Shenzhen International Graduate School Shenzhen518055 China Tsinghua University Department of Electronic Engineering Beijing100084 China Dalian University of Technology Key Laboratory of Intelligent Control and Optimization for Industrial Equipment Ministry of Education School of Information and Communication Engineering Dalian116024 China Hangzhou Dianzi University School of Automation Hangzhou310018 China

Remote sensing scene classification is a crucial task for remote sensing image interpretation. Existing multispectral scene classification methods have overlooked the interrelationships between different spectral bands, which limits the mining of complementary information within the images. Addressing this issue, we propose a grouped cross-band fusion (GCBF) network for remote sensing multispectral scene classification to take full advantage of complementary information between various spectral bands. Firstly, we separate the various bands of the given multispectral image into different groups to better capture the characteristics of each spectral band. Then, we use the existing UniFormer as a feature extractor to learn the representations of red, green, and blue (RGB) bands. For the spectral bands other than RGB, we propose a new network called multi-stage grouped spectral feature extraction (MGSFE) network to learn discriminative representations. We also draw inspiration from the band combination in the field of remote sensing and introduce a cross-band attention fusion (CBAF) module designed to adaptively merge features from both the RGB bands and other spectral bands. Extensive experiments on three widely used remote sensing multispectral scene classification datasets of BigEarthNet, SEN12MS, and EuroSAT demonstrate the superiority of our proposed method compared with several state-of-the-art (SOTA) methods. © 1980-2012 IEEE.

关键词： Photointerpretation

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