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Table of Content

15 April 2016 Volume 29 Issue 4
  
    Articles
    Effects of PT Seed Layer on Crystallization and Piezoelectric Properties of PZT Thin Films
    LI Lei,YU Yuangen,JIANG Tao,ZHU Yuankun,WANG Xianying,ZHENG Xuejun
    . 2016, 29(4):  1. 
    Abstract ( 500 )   PDF (1164KB) ( 340 )  
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    Pb (Zrx,Ti1-x)O3 (PZT) and PbTiO3 (PT) thin films were fabricated on Pt/Si substrate by solgel method.The effects of annealing temperature and PT seed layer on the crystallization and piezoelectric properties of PZT thin films are studied.Xray diffraction (XRD) analysis shows that PZT thin film is of polycrystalline phase with perovskite tetragonal structure.Compared with the PZT film without PT seed layer,PZT thin films with PT seed layer show larger grain size,stronger (100) orientation,and better crystallization.AFM analysis shows that the surface of PZT film is smooth,uniform and crackfree.PFM analysis shows that the average piezoelectric coefficient d33 of PZT film with PT seed layer is 128~237 pm/V,and the average d33 of PZT film without PT seed layer is 21~29 pm/V.With increasing of annealing temperature,the grain size and surface roughness as well as the average piezoelectric coefficient of PZT films increases,and the (100) orientation with perovskite structure is preferred when the heating rate is 10 ℃/s and the soaking time is 10 min.PT seed layers can effectively improve the crystallization and piezoelectric properties of PZT thin films.

    Effect of Fe Content on Microstructure and Electrical Properties of AlFe Aluminum Alloys
    LIU Hang,LIU Xinkuan,LIU Ping,CHEN Xiaohong,LI Wei,HE Daihua
    . 2016, 29(4):  6. 
    Abstract ( 540 )   PDF (926KB) ( 332 )  
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    The influence of Fe content on the microstructure,conductivity and corrosion resistance of AlFe alloy is tested and analyzed by SEM,EDS,electrochemistry,metallographic examination and chemical analysis.Research results indicate that Fe forms second phase in Al matrix.The increase of Fe content in Al matrix yields more second phases with no evident change of morphology and scale.On macroscopic scale,the hardness increases while the conductivity decreases.Moreover,the second phase FeAl3 of AlFe alloy leads to better corrosion resistance.

    Design and Implementation of Wireless Monitoring and Control Based on Laser Interferometer
    REN Shaohua,LU Qingjie,HAN Sen
    . 2016, 29(4):  9. 
    Abstract ( 601 )   PDF (736KB) ( 362 )  
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    A wireless automatic control system designed and implemented according to save the need to manually adjust the optical components in traditional laser interferometers.The system can regulate the location of the laser interferometer optical components by wireless technology.The nRF2401 wireless radio frequency technology is used and the transmitted information is coded with oddeven check and CRC check,thus an obvious decreased error rate compared with that by the traditional nRF2401.Because of the use of the closed loop,the laser interferometer has an enormous improvement in precision and stability,avoiding the optical components of excessive regulation of laser interferometer.

    Research on and Simulation of Static Induction Transistor Based on Silicon Substrate
    WANG Fuqiang,QU Yibin,MA Xingkong
    . 2016, 29(4):  12. 
    Abstract ( 524 )   PDF (847KB) ( 370 )  
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    The practice process of static induction transistor (SIT) stays ahead of theoretical research.A theoretical research on the electrical performance of the SIT based on Silicon by is performed from the point of device simulation using the Silvaco Tcad software.The results show that the IV performance of the device is the class pentode saturation characteristic,with a device current of about 10-5 A and prepinch off channel state at about 0 V reverse bias gate voltage and 0~20 V drain voltage.Secondly,under the condition of -1.5 V reverse bias gate voltage and 0~300 V drain voltage,the IV performance of the device shows the class triode unsaturated characteristic curve,with a device current of approximately 10-6 A and completely pinched off channel.

    Design of Pv Charging System Based on MPPT
    GUI Ren,HAO Runke,ZHANG Yan
    . 2016, 29(4):  16. 
    Abstract ( 589 )   PDF (744KB) ( 370 )  
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    Energy storage device charging system is an important part of the photovoltaic power generation system,in which the selection of charging method plays a decisive role.This paper introduces a charging system based on taking STM32 as the main core processor,adopting a new type of intelligent charging method combined with MPPT algorithm to charge the device of energy storage.This method can effectively improve the charging efficiency of lithium batteries while preventing the battery overcharging with such functions as overdischarging,overcurrent,shortcircuit and temperature protection and temperature compensation.

    Study on the Model of Trajectory Precision for Industrial Robot Based on ADAMS
    FEI Jiaren,ZHU Jianmin,HUANG Chunyan
    . 2016, 29(4):  20. 
    Abstract ( 502 )   PDF (924KB) ( 341 )  
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    The purpose of this paper is to explore a prediction model of trajectory precision based on ADAMS,which can improve the high precision processing using industrial robots.The main factors influencing trajectory precision are the structural parameters of industrial robots and nominal value and the joint angle deviation.A structural parameters identification scheme is proposed and verified by a laser tracker and analyze the relationship of the joint angle deviation and the change of working condition.A prediction model of trajectory precision in ADAMS is built.Finally,an experiment system is established to verify the prediction model with the API III laser tracker aimed at UR5 as the measuring device.The experiment results show that the prediction model is valid with the precision of prediction close to 0.5 mm,and the trajectory precision is less than 1mm with error compensation.

    RFID Missing Data Cleaning Algorithm Based on Adaptive Sliding window
    CHU Tian,PAN Jinman,DU Lei
    . 2016, 29(4):  24. 
    Abstract ( 415 )   PDF (947KB) ( 302 )  
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    The original RFID data must be cleaned to ensure the accuracy of data due to the problem of RFID missing data in reading.In view of problems that exist in the SMURF,which is the most effective cleaning algorithm based on slidingwindow in the current,this paper proposes an improved algorithm for accurately detecting the tag's dynamic changing with a more reasonable mechanism to set slidingwindow.The experimental results show that the proposed algorithm enjoys fewer errors and better performance than the SMURF algorithm during the cleaning.

    Research on Matlab based Adjacent Channel Interference of CBTC System
    CHEN Yulin
    . 2016, 29(4):  29. 
    Abstract ( 434 )   PDF (693KB) ( 374 )  
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    The paper explains the IEEE 802.11g standard which is widely applied in CommunicationBased Train Control system.Then for the features of IEEE 802.11g standard,a function of adjacent channel interference is introduced as a quantitative research method of adjacent channel interference of the system.The quality of the accepted signal between different channel schemes is analyzed and calculated by simulating a practical scenario,leading to the conclusion that greater channel spacing effectively improves the quality of received signals and system throughput.

    An HSFC based Cloud Source Discovery Algorithm
    DU Xiaofeng,CHEN Shiping
    . 2016, 29(4):  32. 
    Abstract ( 397 )   PDF (841KB) ( 302 )  
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    A cloud resource discovery algorithm is proposed for the fuzzy query of cloud resource in cloud computing.Based on a hierarchical Chord model and combined with Hilbert Space Filling Curve (HSFC),this algorithm realizes dimensionality reduction of multidimensional attributes and then completes cloud source discovery.In addition,the source space is divided into several multidimensional intervals,and the concept of neighbor interval is put forward,with which the fuzzy query of cloud resource is resolved.Every attribute is given a weight to reduce requests in the network.The experimental results show that the algorithm not only resolves the fuzzy query of cloud resource,but also reduces delay as much as possible to improve query efficiency.

    Particle Swarm Optimization (PSO) with Sinusoidal Changing Inertia Weight for Heat Exchange Network Synthesis
    ZHOU Jing,CUI Guomin,PENG Fuyu,XIAO Yuan
    . 2016, 29(4):  37. 
    Abstract ( 511 )   PDF (736KB) ( 313 )  
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    The local optimum often arises when the Particle Swarm Optimization (PSO) optimization is used to optimize heat exchanger networks synthesis problems.The orthogonal experiments in population size,iterative steps,maximum velocity and the inertia weight show that the inertia weight is an important factor in the PSO improvement.Based on a comprehensive analysis of the standard PSO algorithm,this paper proposes a strategy of inertia weight according to the sinusoid.The performance of the algorithm is verified using the standard test functions.The presented case reveals the effectiveness of the proposed strategy in the heat exchange network synthesis.

    Threeobjective Adaptive Mutation Particle Swarm Optimization for Reactive Power Optimization
    MA Lixin,WANG Jiyin,LUAN Jian,HUANG Yanglong
    . 2016, 29(4):  41. 
    Abstract ( 394 )   PDF (737KB) ( 318 )  
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    Power system reactive power optimization is an important link in improving the power quality and ensuring the power grid to operate.This paper establishes a reactive power optimization model of considering minimization of loss and voltage deviation and maximum of voltage stability margin.The adaptive mutation particle swarm optimization is introduced for the threeobjective reactive power optimization.This algorithm monitors particle group status of gathering dynamically by group fitness variance and adopts the method of adding random disturbance to vary gathered particles,using weight of inertia adaptive adjustment to jump out of local optimal and prevent premature,thus higher convergence speed and accuracy.The algorithm is implemented on the IEEE14 bus system.Comparison with other algorithms shows the superiority and practicability of this model and algorithm in solving multiobjective power system reactive power optimization problems.

    An Improved Hybrid Collaborative Filtering Recommendation Algorithm
    . 2016, 29(4):  45. 
    Abstract ( 479 )   PDF (720KB) ( 337 )  
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    Traditional collaborative filtering algorithms suffer from poor similarity computation and sparse data,which lead to inaccurate recommendation information.In this paper,a new hybrid collaborative filtering algorithm is proposed to improve the quality of recommendation.The method of similarity computing is improved by using the weighted method,and the new framework is based on the memory of the two kinds of collaborative filtering algorithm.Experiment with the data set provided by Netflix shows that the algorithm has better effect than the traditional collaborative filtering algorithm.

    An Algorithm for Vectoring SMS Based on Word2vec
    WANG Guixin,ZHENG Xiaozong,ZHANG Haoran,ZHANG Xiaochuan
    . 2016, 29(4):  49. 
    Abstract ( 455 )   PDF (796KB) ( 374 )  
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    This paper proposes a new method of feature extraction of SMS for better spam message filtering.The method uses the latest results and tools of Word2vec based on deep learning theory.With the content and structure characteristics of Chinese short messages in mind,an algorithm of Vectoring SMS is designed based on this tool.The algorithm can effectively match each text message with a vector.The classification's experiments on the spam messages are carried out using the proposed algorithm on the deep belief networks.The results show that the performance of the proposed algorithm is improved by 5% compared with the previously reported results.

    A New Algorithm for Vertical Handoff Between LTE and WLAN
    WANG Ruishan,GUO Mingxiao,HAO Bin
    . 2016, 29(4):  54. 
    Abstract ( 813 )   PDF (797KB) ( 320 )  
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    In order to improve the quality of service in heterogeneous networks and reduce the pingpong effect caused by handover,this paper presents a new algorithm for vertical handoff in LTE and WLAN networks.The algorithm takes into account the fading impact on the received signal strength,selects the target network based on RSS,and then selects the best network according to the user's mobile speed and the cost function.In the cost function,the analytic hierarchy process is used to determine the weight of the delay and the parameters of the price and the user's preference.The simulation results show that the vertical handoff algorithm proposed in this paper can effectively reduce the “pingpong effect” and improve the service quality of the communication network.

    Wireless Sensor Network Localization Algorithm Based on PSOBP Neural Network
    YAN Chi
    . 2016, 29(4):  56. 
    Abstract ( 559 )   PDF (799KB) ( 338 )  
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     Positioning is the basic function of Wireless Sensor Network.The paper presents an algorithm that optimizes the distance data measured in ranging stage by combining the PSO algorithm and BP neural network.By taking the PSO algorithm as a learning algorithm of BP neural network,it shortens the training time of BP network and speeds up the convergence rate of the algorithm.The simulation results show that the positioning accuracy is significantly improved by up to 27.3% over those by other algorithms.

    Kinematic Analysis and Simulation of Ship borne Stable Platform
    . 2016, 29(4):  59. 
    Abstract ( 552 )   PDF (928KB) ( 287 )  
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    A shipborne stable platform is developed to eliminate the influence of the waves based on the characteristics of ship navigation.The linear relationship of the pitch part and drive motor is found by solving the mathematical model of movement between the pitching frame and drive motor.Then the workspace of the platform is obtained.Finally,a motion simulation on the platform is established,and the results show that the design of the platform is rational and feasible.

    Optimization of Intraprediction for H.264 Decoder
    ZHANG Yayun,MENG Lilin,JING Boli
    . 2016, 29(4):  63. 
    Abstract ( 355 )   PDF (933KB) ( 315 )  
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    To optimize the intraprediction of the H.264 coding standard for improving the speed of intraprediction,a 4×4 block pipeline is adopted instead of serial processing method.A adaptive pipeline is adopted which harmonizes the intraprediction under different blocks and different prediction modes,using the fourchannel parallel multifunction processing element to calculate the prediction values of four pixels in a column in one cycle.The “seed” method is adopted to replace the way of calculate directly in planar prediction mode.The optimized intraprediction circuit is designed by using FPGA development platform.The verification results show that the optimized intraprediction circuit only needs 196 clock cycles in average to process a macro block.

    Design of Vehicle Interior Environment Monitoring System Based on ZigBee
    CHANG Shulin,LU Feng,QIU Chengqun
    . 2016, 29(4):  66. 
    Abstract ( 903 )   PDF (990KB) ( 346 )  
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    A vehicle interior environment monitoring system based on ZigBee is designed.The monitoring system is established on the wireless communication technology to set up a wireless communication network.The CC2530's TI chip data transmit through the IAR software.The C language program compiled and debugged on IAR displays the received data value and quantity for intelligent monitoring of the vehicle interior environment,such as the realtime light intensity and temperature on wireless network.The experiment indicates that the design system reduces the error effectively with rapid response.

    Design and Implementation of Multistream Hddecoder Based on Cuda
    TANG Kunpeng,CHEN Qingkui
    . 2016, 29(4):  71. 
    Abstract ( 465 )   PDF (889KB) ( 398 )  
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    A GPU multistream parallel decoding implementation based on compute unified device architecture (CUDA) platform is designed to solve the high CPU load problem in multivideo decoding and display.The data structure of the graphics processing unit (GPU) device and video decoder are defined.By calling the decoding function interface,the decoder can be used in variety of video players efficiently.The experimental results show that this decoder can greatly reduce the CPU utilization.Also,compared with the JM reference software decoder,CPU utilization is remarkably reduced by 30% when decoding the single road 720 p high definition video synchronously.So the decoder based on hardware enjoys higher efficiencyin video parallel decoding.Besides,the system performance and resource reuse rate are improved together with lower energy consumption.

    Water Extraction Method Combining DEM for Hillshade Removal
    PANG Kechen,CHEN Lifu,WANG Siyu
    . 2016, 29(4):  76. 
    Abstract ( 728 )   PDF (681KB) ( 418 )  
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    In view of the great impact of hillshades on water extraction accuracy of SAR images,this paper proposes a method for quickly,accurately and automatically removing the hillshade in water extraction.This method uses an improved Otsu method to segment the DEM data,and then match the elevation values large data and water crude extract data for determining and removing the hillshade.The experiments show that this method can improve the accuracy of the water extraction with lower water extraction false alarm rate.

    Design of and Research on Independent and Security Intelligent Home Server System
    ZHOU Chengming,WU Chunxue,LI Rui,YANG Guisong,WU Zhigang
    . 2016, 29(4):  79. 
    Abstract ( 416 )   PDF (1021KB) ( 400 )  
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    A secure intelligent home system combining Android,ZigBee,GSM and sensor technology is designed.The sensor node is responsible for collecting information of home appliances,ZigBee for the transmission and the ARM server for processing the information,the GSM module for sending alarm message,while the Android client for displaying the status of appliances and control home appliances.With the realtime and security requirements in mind,we focus on the server's hardware communication,guardian process,data receiving and parsing,and message queue management.The experimental results show that household appliances control can be realized mobile phone with little delay.The system run on its own without human intervention.The data is stored in the local server,not through the others;each time the user logs on to the server,the server will check the number,password and IMEI,and thus security is guaranteed.

    Study and Application Based on OpenStack Horizon Frame
    CHENG Cheng,ZHU Zhixiang,LIANG Xiaojiang
    . 2016, 29(4):  84. 
    Abstract ( 436 )   PDF (906KB) ( 354 )  
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    As the most popular open source projects in cloud computing,OpenStack has been used by many enterprises as Iaas platform.In view of the low efficiency of the platform interface development and difficult function expansion,this paper presents the potential general pattern of the horizon framework for convenient secondary development of OpenStack interface,based on which quick interface function expansion is realized.This pattern can help enterprises design cloud computing platform products with multi functions and characteristics of enterprises.

    Design of Data Analysis System Based on Matlab/GUI
    LI Yali,XIN Shangzhi,ZHENG Chunlei
    . 2016, 29(4):  88. 
    Abstract ( 582 )   PDF (816KB) ( 370 )  
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    The seismic exploration method in petroleum exploration requires many cables and sensors for collecting the data of wave reflection of the crust and recording data on tapes for data analysis.A data analysis interface created by Matlab/GUI is proposed to directly import and show data storage folders collected by different sensors on the interface to time domain and frequency domain analysis.The results show that all the design requirements are met,with significant saving of cost and time in petroleum exploration.

    Fault Monitoring Technology for CNC Machine Spindle System
    FU Chengjian,LI Haolin
    . 2016, 29(4):  92. 
    Abstract ( 419 )   PDF (749KB) ( 363 )  
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    The spindle system plays an important role in CNC Machine,providing cutting torque and the cutting speed for metal removal.Its performance has a direct influence on the processing precision and efficiency of the machine.This paper analyzes the failure mechanism of the major component of CNC machine spindle system,and a series of monitoring schemes are designed on basis of the failure mechanism by means of operating information of the key component from the collecting Spindle System of the outer sensor.The wavelet is also adopted to analyze its operating information so as to monitor literally for the spindle system.The results indicate that this scheme can detects the fault condition of the key component of machine spindle system effectively.

    Design of Avionics System Network File System
    DUAN Haijun,CHEN Fu,FENG Junbo,HAN Chunyang
    . 2016, 29(4):  95. 
    Abstract ( 377 )   PDF (1157KB) ( 370 )  
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    A network file system based on China's proprietary airborne multiple partitions realtime operating system is designed for the file sharing among multiple application computers in the avionics system.The network file lock realizes multiple partitions mutually exclusive access files by locking and unlocking files,the access validation controls user access to files,and the log files save the whole operation process of NFS.The NFS client and server design and the network packing format are described and the schematic NFS is given.

    Workpiece Location and Recognition Based on Machine Vision
    CHEN Zening,ZHANG Xuexi,PENG Zerong,ZHONG Kaiyu
    . 2016, 29(4):  99. 
    Abstract ( 410 )   PDF (959KB) ( 381 )  
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    The noncontact realtime machine vision system enjoys stability and high precision.In this paper,the machine vision is used to study the localization and recognition of the workpiece.The center coordinates and rotation angles are obtained by solving the contour center moment and the minimum value of the two order derivative of the axis of the workpiece.The contour similarity metric function is used to identify the types of artifacts by extracting the template of artifacts Hu invariant moments and Hu invariant moments of the workpiece contour.The experimental results show that the workpiece can be accurately located and identified by the extraction of the workpiece contour.

    A Webbased Stadium Booking System
    LIU Meiqi,LI Wanping,SUN Fangbin,FU Guoqiang
    . 2016, 29(4):  104. 
    Abstract ( 595 )   PDF (831KB) ( 324 )  
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    An efficient webbased stadium booking system is proposed based on the Horizon framework of the potential universal model to offer information display,user registration,booking information submission,booking status and backend management.The frontend web interface is realized by using HTML,CSS,and JavaScript (JQuery).The server end is developed by adopting ThinkPHP and MySQL.Tests show that the proposed system has friendly interface and easy use.

    Color Image Fusion Algorithm Based on NSCT and Fuzzy Logic
    WANG Kui,LI Weihua,LI Xiaochun
    . 2016, 29(4):  107. 
    Abstract ( 554 )   PDF (867KB) ( 246 )  
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    Aiming at the problems of single color and poor visual effect,a multi focus color image fusion algorithm based on NSCT and fuzzy logic is presented.Firstly,the color image is transformed by IHS,after which the intensity component is composed by NSCT.The Gauss membership function is used to determine the adaptive weighting coefficient of the low frequency coefficient,and the high frequency coefficients are fused by rule of "absolute value maximum selectivity".Then,the fused intensity component can be obtained by the inverse nonsubsampled Contourlet transform.Finally,the hue component and saturation component of the fusion image are computed using the fused intensity component.Experimental results show that the proposed method offers distinctive color fusion images with clear edge details that are more consistent with the human vision.

    Design and Realization of Network Driver Model in Embedded System
    MEI Tao,HUANG Baolei,XU Xiaoguang
    . 2016, 29(4):  111. 
    Abstract ( 535 )   PDF (985KB) ( 408 )  
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    A model of network driver in embedded system is proposed with emphasis on its function.There is an abstract midlayer between the network protocols and network drivers,which separates the upper layer network protocols from network drivers effectively,thus making concrete network drivers detail transparent to network protocols.The midlayer is an abstract layer of network driver,which supports driver function abstraction while supporting command exchange between the network protocols upper layer and drivers.The cost of network driver designing is decreased because of the midlayer.The validation and testing experiments are carried out.The results show that of network drivers in embedded system designed based on this model work correctly and reliably with normal network communication.

    Research on Method for MCS Automatic Identification and Tracking Based on FY Satellite Cloud Image
    DUAN Lian,GUO Gengchang
    . 2016, 29(4):  116. 
    Abstract ( 737 )   PDF (1064KB) ( 271 )  
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    According to the criteria of the identification of mesoscale convective system (MCS),this paper researches on identifying and tracking MCS automatically by means of image processing and fuzzy pattern recognition technology.The SUSAN edge detector is used to extract the boundary contour,thus realizing cloud tracking via building tracking templates with brightness temperature histograms and multiple cloud cluster characteristics.The experiments on tracking MCS during the time 12 to 17 hour of May 10,2014 show that the method has the ability of identifying MCS automatically and quickly and tracking MCS of multitime effectively.

    Design and Implementation of Security System Based on GSM Network
    LU Ning,YAO Xue,MA Xiaoming
    . 2016, 29(4):  120. 
    Abstract ( 418 )   PDF (820KB) ( 301 )  
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    A security and defense system based on GSM network is designed and implemented.The system adopts the computer,wireless network and image sensor technologies to realize the remote control and warning timely security system in GSM.The system can be used for early warning of all kinds of risks that may occur in the family along with theft prevention.The system enjoys easy operation,advanced technology and timely and accurate alarm.

    Experimental Research on Circumferential Localization of Pipeline Defects Based on Guided Wave Energy Difference
    DOU Linbin,CHEN Zhiwei,YAN Youqi
    . 2016, 29(4):  123. 
    Abstract ( 480 )   PDF (827KB) ( 215 )  
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    Current ultrasonic guided wave detection can acquire information on the pipepline's health by analyzing the echo signal,but it fails to provide circumferential information on the pipeline defects.This paper studies the circumferential localization of pipeline defects by analyzing the energy distribution of ultrasonic guided waves when they pass through the defect of the pipe and the theory of circumferential localization.The F(1,3) mode guided wave has only one circumferential wave.Based on this fact,we present the quadrant energy difference locating defect method.Experimental results show that this method precisely judges the circumferential position of the defects.

    HEMP Coupling Characteristics of Overhead Cable into Civil Air Defense Work
    YUAN Jigang,CHEN Hailin,MAO Ziwen
    . 2016, 29(4):  127. 
    Abstract ( 430 )   PDF (617KB) ( 253 )  
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    The huge power produced by high altitude nuclear explosion (HEMP) can be coupled into civil air defense shelters via long conductors (for example,overhead power and communication cables),resulting in the damage of power or electric equipments connected with them.The transmission line model above lossless ground is used in this paper.The coupling characteristics between HEMP and parameters including the length and height of overhead lines,load impedance,and ground soil conductivity are obtained by numeric simulation,which will provide the reference for electromagnetic pulse protection of civil air defense shelters.Calculation shows that under the illumination of HEMP,the amplitude of induced voltage produced in the load of overhead cables ranging from 50 m to 1 km can reach up to tens of kilovolts to hundreds of kilovolts with a rise time of induced voltage of about 20 ns.

    Design of Xband LTCC Ferrite Circulator
    ZHANG Shuai,PENG Long,XU Yang
    . 2016, 29(4):  130. 
    Abstract ( 493 )   PDF (699KB) ( 388 )  
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    To solve the technical problems of matched cofiring of microwave ferrite material,low temperature metallic slurry and LTCC ceramic material,an xband single Y junction LTCC ferrite circulator is designed by eigen mode design method using simulation of microwave HFSS and AutoCAD software and the impedance matching technology.The device model demonstrates ring features in the 10.9~12 GHz  frequency range with a bandwidth of 1.1 GHz,an insertion loss≤0.5 dB,a return loss≥10 dB,isolation degree≥13 dB,standing wave ratio≤ 1.5 dB.This design is expected to effectively combine the microwave circulator with low temperature cofiring ceramic (LTCC) technology.

    Design and Production of a 5output Broadband Wilkinson Microstrip Power Divider
    XU Yang,PENG Long,ZHANG Shuai
    . 2016, 29(4):  133. 
    Abstract ( 916 )   PDF (735KB) ( 350 )  
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    The power divider is used in power amplifier,phased array antenna,mixer and multiplex relay communication equipment.The performance of the system directly affects the distribution and synthesis efficiency of the whole system energy.A microstrip onepoint fivebroadband power divider operating at 0.7~2.5 GHz is designed based on the optimization results.Collaborative simulations in Ansoft designer,Serenade and HFSS show good performance of the proposed power divider in the whole frequency range in communication,power distribution synthesis system.The device test results agree with simulation results.

    A Calibration Method for Standing Wave Accurate Measurement of Antenna Feeding System
    WU Guangde,CHEN Jin
    . 2016, 29(4):  136. 
    Abstract ( 436 )   PDF (703KB) ( 265 )  
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    A calibration method for standing wave accurate measurement of antenna feeding system is proposed in this paper.The reason why the detection precision is not high enough is analyzed and then a method which utilizes the threepoint calibration method for increasing the detection precision is proposed.This method is based on vector with more dimensions in consideration,thus more comprehensive information to improve the detection precision of standing wave ratio.A variety of adverse effects caused by the system which may appear in the testing process are removed,and the test result does not change with the form of detection signals.The stability and reliability of the test result is improved.The correctness and effectiveness are demonstrated by experiment.

    Mathematical Modeling And Loss Analysis of LLC Resonant Converter
    FENG Jijun,ZHANG Zhenguo,LIU Dong,XIN Libin,WANG Shunping
    . 2016, 29(4):  140. 
    Abstract ( 561 )   PDF (945KB) ( 430 )  
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    Aiming at the loss caused by the switching tube and magnetic element in the working process of the LLC resonant converter.The switching losses and switching losses of the LLC resonant converter are analyzed,and the mathematical model of the switching loss is established according to the theoretical formula.Combined with the synchronous rectification technology,the key factors that affect the efficiency of the converter are analyzed by using Mathcad software.Through the simulation analysis,it is verified that the synchronous rectification technology can improve the efficiency of the LLC converter resonator.

    Accurate Detection of Output Signal Level of Wideband Power Amplifier
    FENG Xingang,XU Ping
    . 2016, 29(4):  144. 
    Abstract ( 476 )   PDF (568KB) ( 284 )  
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    A high precision power detection method for wideband power amplifier is proposed base on theoretical analysis.The relation between the power under test and the detected voltage in the circuit is obtained by simple measurement to solve the uncertainty of the variation of circuit component parameters with frequency,thus improving the detection precision.The difference between detected and measured results of power amplifier at 40~56 dBm is less than 0.8 dB.

    Design of Miniaturized IF Band Filter Based on LTCC
    YANG Shaolin,ZHANG Qingzhong,XI Wang,LIANG Xiaobin,SHI Yu
    . 2016, 29(4):  147. 
    Abstract ( 488 )   PDF (595KB) ( 226 )  
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    Large inductor value will cause multiple problems such as difficulties in manufacturing and complexity in parasitic parameters while implementing filters using LTCC technology.Due to partialelement equivalentcircuit model (PEEC),delta and starconnected circuit equivalent transformation,three inductors of the second order direct coupling filter can be replaced by two parallel coupling inductors,leading to lowering in the complexity of design,improving in standardization and consistency and smaller packing.Finally a small size intermediate frequency filter of 70 MHz center frequency,14.28% relative bandwidth,1.83 dB insertion loss and less than -15 dB return loss is achieved.

    Design of Digital Power Based on UCD9240
    LIAO Haiqian
    . 2016, 29(4):  150. 
    Abstract ( 451 )   PDF (791KB) ( 295 )  
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    The traditional power supply design has the problems of low switching frequency,high frequency fluctuation,large electromagnetic interference,and can not be adjusted in real time.In this paper the ucd9240 control chip to complete a project of hardware platform of digital power supply scheme,the design of hardware circuit and software configuration parameters,and the theoretical calculation and the actual value were compared.The results show that the design can satisfy the design requirements.

    Research on and Simulation of LDPCOFDM Coded Modulation Based on Passive Optical Network
    XIAO Xiao,ZHAO Lu,NIU Bao
    . 2016, 29(4):  154. 
    Abstract ( 455 )   PDF (701KB) ( 238 )  
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    The lowdensity paritycheck codes and orthogonal frequency division multiplexing are used in the passive optical network in this paper,and the downlink transmission performance of PON system based on LDPCOFDM is simulated by using Optisystem and Mablab.The results show that the 10 Gbit·s-1 LDPCOFDM coded modulation signal can be realized in the downlink transmission in passive optical network.The transmission performance of the system based on LDPCOFDM is improved by 4.2 dB over that of the uncoded modulation at the bit error rate of.When the SNR is greater than 2.6 dB,the Gallager method has better error rate performance than the Mackay method and BIBD method,and the system has better performance with LLRBP or its improved algorithm when the SNR is greater than 4.6 dB.

    Analysis of Highspeed Target Tracking Error in Active Protection System
    MA Ke,XI Yuntian,LI Huimin
    . 2016, 29(4):  158. 
    Abstract ( 472 )   PDF (647KB) ( 208 )  
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    Interception point error in active protection system (APS) is discussed.We simulated the application of Kalman filter,alphabeta filter and least square filter algorithm for APS highspeed targets and analyzed the interception point error.The target tracking method is described.The interception point error with different speed targets using this method is simulated.Result shows that the error of new method is better than those of the traditional ones.

    Radar Target Simulation Based on FPGA
    XING Yiyi,CHEN Wei
    . 2016, 29(4):  161. 
    Abstract ( 471 )   PDF (733KB) ( 230 )  
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    Target simulation both speeds up project development and reduces the costs in radar development and production.In this paper,the method of radar target simulation based on FPGA is studied and the hardware platform is built with the Virtex6 series chips of the Xilinx Company as the core.The system is capable of realtime simulation of the point target echo and adaptation to complex modulation waveforms.System performance is tested by pulse compression methods combing the authentication with chirp signals,and the radar echo information is analyzed.Simulation results show that at a theoretical distance of 1 200 m and a lower latency of 8 μs,the actual distance error is only 11 m with a delay time error of 0.07 μs,within the allowable range in this project.

    Design and Implement of Radar Signal Simulator Software Interface Based on Qt
    HU Yang,LIU Xindan
    . 2016, 29(4):  165. 
    Abstract ( 522 )   PDF (794KB) ( 379 )  
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    A radar signal simulator software interface based on Qt is designed and implemented on the Windows operating system in this paper,including the generation and management of interface elements,the interface communication mechanism,and the event response.Tests show that both the local operation and remote control of the proposed software interface function correctly with good stability.

    Radar IQ FiberOptical Data Acquisition and Transmission System Based on FPGA
    SUN Gaojun,LIU Zhiying
    . 2016, 29(4):  169. 
    Abstract ( 506 )   PDF (732KB) ( 210 )  
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    In view of the highspeed and realtime transmission problem of radar IQ fiberoptic data stream,a radar IQ Fiberoptical data acquisition and transmission system is designed based on the Stratix II GX series FPGA,the CPCI international standard bus and other hardware devices.Some key technologies such as data rate automatic identification,pingpang cache,realtime interrupt processing are applied in this system.Emphasis is put on the structure of the data acquisition and transmission system and its design principle.Hardware design,FPGA design and software design are also introduced.Experiments results show that this system has stable performance.

    Radar& Telemetry Cooperative Tracking Strategy for Seaskimming Targets
    LU Changhai
    . 2016, 29(4):  173. 
    Abstract ( 409 )   PDF (785KB) ( 209 )  
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    Tracking and measuring of the low angle of the seaskimming target is one of the difficult problems to be solved by the TT&C.The radar and Telemetry collaborative tracking is achieved by integrating design and use of a common antenna surface and the servo system with the desired results,which verify the effectiveness of this strategy.

    Analysis of Distribution Overhead Line Thunder Electric Wave Overvoltage Accident in Mining Area
    ZHAO Yuqing
    . 2016, 29(4):  176. 
    Abstract ( 389 )   PDF (948KB) ( 235 )  
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    Contrary to the problem of mining machine into line overhead line lightning,lightning protection standards from the differences and intensification of into line with protect clearance and line insulator insulation coordination,maked out reform measures that reducing line lightning arrester grounding resistance grounding body and replace the wind machine room with double zigzag lightningproof transformer .When lighting current takes 5mA,the line side fan room impulse voltage 81.33 kV reduced to 12.56 kV.At the same time,using ATPEMTP transient simulation software to simulation the line insulator parallel gap and line lightning arrester grounding resistance,validation the effect of lightning protection measures .

    A Public Key Traitor Tracing Scheme Based on Random Sequence
    HE Shaofang
    . 2016, 29(4):  180. 
    Abstract ( 489 )   PDF (763KB) ( 208 )  
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    Based on the discrete log representation problem and employing random sequence,an anonymous public key traitor tracing scheme is presented in this paper.This scheme employs the polynomial function and the filter function as the basic means of constructing the traitor tracing procedures.When a pirate decoder is confiscated,single input and output suffices to decide the traitor.If it is necessary to revoke or recover traitors,the scheme can safely revoke or recover the private keys of traitors without updating the private keys of other receivers.The performance analysis shows that the proposed scheme not only has low cost of secure storage,calculation and communication,but also is capable of full collusion resistance,full revocability,full recoverability and blackbox traceability.

    New Modulation Technique with Doubled Frequency and Current
    LI Shaolong,XU Yanchao,LI Dong,YANG Xiaojie,CHANG Jiarong,TANG Yusong
    . 2016, 29(4):  183. 
    Abstract ( 400 )   PDF (741KB) ( 184 )  
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    This paper describes an optimized SPWM modulation technique with new topology for doubling the frequency and current while minimizing hardware costs.Double output current is achieved without the need for increasing the frequency of the switch and complex hardware in the output voltage multiplier.Matlab/Simulink simulation of an asmodulated inverter is performed to verify the feasibility of the proposed modulation technique and topology.Practical application also demonstrates good equalization effect and low MOSFET temperature and thus frequency is doubled and capacity is enlarged.

    Design and Development of Computer Room Network Architecture and Security System Based on VPN
    LIAO Shan
    . 2016, 29(4):  187. 
    Abstract ( 473 )   PDF (822KB) ( 217 )  
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    With the campus computer network as an example,the network technology and network security involved in the construction of computer room system are discussed.A computer network based on the VPN technology is designed and developed with an innovative network topology,in which the VLAN division is adjusted.The VPN technology is introduced for better computer network stability and efficiency.A security protection system based on firewall,intrusion detection system is also provided.Tests show all the design requirements are met.

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