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Table of Content

15 April 2015 Volume 28 Issue 4
  
    Articles
    A Practical Multi-Database Quantum Private Queries Protocol
    HE Xiaoyun,CHEN Lixin,PEI Changxin,YI Yunhui
    . 2015, 28(4):  1. 
    Abstract ( 674 )   PDF (760KB) ( 469 )  
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    This paper,based on the QKD technology which is mature now,proposes a practical QPQ protocol for multi-database retrieval optimized for current multi-databases in cloudy storage.For different sizes of the database,by adjusting the parameters θ and k,the information can be retrieved,while the safety of database and privacy of the user are ensured.Performance analyses indicate that the protocol has a low communication complexity and a high success ratio in information retrieval,and is easy to implement.

    Study of the Fast Semi-Blind Equalization Algorithm for the QAM Communication System
    XUE Haiwei,FENG Dazheng,LI Jin
    . 2015, 28(4):  4. 
    Abstract ( 686 )   PDF (797KB) ( 676 )  
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    Due to the inter-symbol interference(ISI) and co-channel interference(CCI) of the MIMO convolutional communication system driven by QAM signals,a combined semi-blind equalization algorithm (CSBEA) is proposed by utilizing the selectivity of the soft decision directed(SDD) algorithm and the geometric properties of constellation of QAM signals.This algorithm overcomes the maladjustment in the steady state of constant modulus algorithm and multimodulus algorithm and avoids the problems of a rapidly increased computational load of SDD algorithm of high order QAM systems.Furthermore,the gradient Newton method is adopted to optimize the cost function of the proposed CSBEA,which brings about a faster convergence speed and a better steady state performance than that of gradient-type algorithms.Finally,several experiments are provided to illustrate the effectiveness of the proposed method.

    Diversity of Cellular Genetic Algorithm
    LIN Zhilong,LU Yuming
    . 2015, 28(4):  9. 
    Abstract ( 614 )   PDF (691KB) ( 432 )  
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    This paper discusses the significance of cellular genetic algorithms population diversity for exploration/exploitation balance (EEB),proposes diversity measures based on the neighborhood structure of the cellular genetic algorithm.By changing the genetic operators of the cellular genetic algorithm,the diversity of the population of the evolutionary process is maintained.The algorithm is to embed grid population space into the cellular space to simulate genetic operation between neighboring individuals.The algorithm not only improves the exploration/exploitation search ability,but it also has certain advantages in terms of maintaining the diversity of the population.

    Application of Ant Colony Algorithm in Fire Evacuation Platform
    FENG Weiwei,QIU Jiong
    . 2015, 28(4):  13. 
    Abstract ( 719 )   PDF (800KB) ( 476 )  
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    In order to ensure the quick and safe evacuation from the fire,database is used to store information of traffic nodes and the static and dynamic states of the channel of buildings with the help of fire information from the fire detection system.On the basis of the building spatial structure model,the optimal path of evacuation is found by the improved ant colony algorithm,and then the direction is dynamically shown through intelligent indicators.Other related personnel can make a real time and quick scheduling according to the visual interface and then send maps and paths to people who are in fire.Experiments show that this method can make people find the exit more quickly,so it can reduce the loss of personnel and property in fire.

    Research of Underwater Autonomous Search Path Planning Based on Improved A* Algorithm
    RONG Shaowei
    . 2015, 28(4):  17. 
    Abstract ( 531 )   PDF (779KB) ( 405 )  
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    This paper studies the underwater path planning of the underwater vehicle.It puts forward an underwater unmanned underwater vehicle autonomous search path planning algorithm based on the improved A* algorithm.The general path planning can be done by a variety of algorithms.Among them,the A* algorithm is simple and easy to realize,and can theoretically guarantee the convergence of the global optimal solution;and its program is simple,so that it can be used in the system of low power consumption and low frequency.Because the traditional A* algorithm does not have the minimum turning radius and other constraints,we improve the traditional A* algorithm since underwater vehicles run either at a high or at a low speed,so that it can be applied in both cases.

    Realization and Simulation of an Underwater Image Enhancement Algorithm
    HUANG Bo,GU Qing
    . 2015, 28(4):  20. 
    Abstract ( 551 )   PDF (602KB) ( 725 )  
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    The characteristic and complexity of the underwater environment makes the underwater image poor in quality and low in contrast.An image enhancement algorithm based on spatial domain is put forward in this paper.This algorithm utilizes the average algorithm to estimate the background image first,then subtracts the background image,and finally sharpens the image which has had its background subtracted.An analysis of the simulation result demonstrates that the contrast of images processed meliorates distinctly and the edge of the target is much clearer.

    Design of a Classifier Based on the SVM Algorithm
    WEI Ao
    . 2015, 28(4):  23. 
    Abstract ( 614 )   PDF (897KB) ( 488 )  
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    The basic idea of the Support Vector Machine(SVM) algorithm and the concept of data classification is introduced.An analysis of the traditional SVM general characteristics is also made.A classifier based on the SVM algorithm is designed with Libsvm toolbox,and is tested by data set from public databases.The paper focuses on the selection of training samples,as well as the effect and optimization of parameters.The experimental results show that suitable training samples and parameters help to improve the accuracy of the classifier.

    Improved SL0 Algorithm for Compressive Sensing Signal Reconstruction
    QI Huanfang,XU Yuanhao
    . 2015, 28(4):  27. 
    Abstract ( 686 )   PDF (671KB) ( 609 )  
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    The smoothed l0 norm algorithm (SL0) is a reconstruction algorithm in compressive sensing based on approximate l0 norm.It is to use a smooth function to approximate the l0 norm and then solve an optimization problem.Currently people use the Gauss family function as a smooth function.This paper makes a breakthrough in the use of the composite trigonometric function,instead of the traditionally used Gauss family function,which is used to approximate the l0 norm.And a new efficient and more accurate algorithm named DNSL0 (Damp Newton Smooth l0 Norm) is proposed based on the smoothed l0 norm and the revised Newton method and the damped Newton method.Experimental results show that the DNSL0 algorithm is greatly improved in both the peak value signal-to-noise ratio and matching degree compared with the SL0 algorithm and NSL0 algorithm under the same experimental conditions.

    A kind of Real-Time Backup Technology Based on SPB
    XU Mengqiong,CHEN Linqiang
    . 2015, 28(4):  31. 
    Abstract ( 487 )   PDF (698KB) ( 523 )  
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    SPB's distributed network equipment causes data forwarding interruption in the event of a failure.To solve this problem,this paper proposes a new non-stop data forwarding technology,NSR.By this technology,the SPB data on the control board is encapsulated,and communication between boards is done by reliable mechanisms and thus real-time data backup is achieved.Simulation shows that the standby board will become the control board when the control board breaks down to restore the backup data,thus avoiding the interruption of data forwarding.

    Nonlinear Least Squares Method of Power System Frequency Tracking
    GAO Yinglong,WANG Xiaohua,LU Jin,ZHU Huaiyi
    . 2015, 28(4):  34. 
    Abstract ( 664 )   PDF (760KB) ( 466 )  
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    Power system frequency is one of the most important parameters of power quality,the tracking measurement of frequency is the basis of the normal operation,adjustment and control of the electrical power system.The paper proposes a realization of frequency tracking algorithm which is based on the nonlinear least-square method,a detailed simulation has been done for a variety of signal model,and use FPGA to realize the algorithm,the design is completed in the Cyclone III series chip EP3C80F780C8,frequency of using 50 MHz,the results show that the system has the characteristics of simple design,high reliability,good effect of the frequency tracking,etc,It has a good practical value.

    An Improvement to DSR Routing Protocol
    SU Jiaorao
    . 2015, 28(4):  38. 
    Abstract ( 910 )   PDF (743KB) ( 454 )  
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    DSR is one of the most frequently-used on-demand routing protocols in the mobile Ad Hoc networks.DSR protocol is high in energy costs and low in packet delivery fraction because DSR finds and maintains routing table by the flooding mechanism.To this problem,a localized routing discovery method is proposed to control the routing request hops.Also,the routing discovery process is improved so that the storage of the routing information,network jam and energy costs are effectively balanced.The analysis shows that the improved DSR protocol controls the routing request packets to a certain network area.In this way,the data transmission delay and the networks energy costs are reduced.The simulation results show that the improved DSR protocol has the advantages of packet delivery fraction and routing load over the traditional one on choosing the proper maximum hops.

    Design and Implementation of Voltage Starting Software Based on DSPI Data Transfer
    LIU Ming
    . 2015, 28(4):  43. 
    Abstract ( 534 )   PDF (701KB) ( 447 )  
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    This paper studies the key technologies of the design and implementation of the software controlling fuel chip voltage based DSPC data transfer and control.The technologies cover data structure,DSPI drive,interaction between DSPI and the fuel chip,and function classification and interaction of control data.Finally,the voltage diagram is collected,and software is loaded in the injection software.Experiments show that the injection can work normally.This paper studies the key technologies of the design and implementation of the software controlling fuel chip voltage based DSPC data transfer and control.The technologies cover data structure,DSPI drive,interaction between DSPI and the fuel chip,and function classification and interaction of control data.Finally,the voltage diagram is collected,and software is loaded in the injection software.Experiments show that the injection can work normally.

    FPGA Implementation of Rate Control Algorithm for DNxHD Video Codec
    XUE Weipeng,XIAO Tiejun,YU Jinhua
    . 2015, 28(4):  46. 
    Abstract ( 531 )   PDF (846KB) ( 438 )  
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    Rate control is the key problem in video codec.In essence,it is rate distortion optimization under the constraint of a given rate.In order to meet high-speed applications,the DNxHDcodec rate control algorithm was designed and implemented on the platform of Kintex7 Xilinx FPGA.This design takes the advantage of the pipeline structure and time division multiplexing strategy.The experiment result shows that the design gains good control result and runs stable on FPGA.

    Improvement of OMP Image Reconstruction Algorithm Based on Compressed Sensing
    MA Xiaowei
    . 2015, 28(4):  51. 
    Abstract ( 735 )   PDF (775KB) ( 511 )  
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    Compressed sensing(CS) theories and the reconstruction algorithm of signals are discussed.Research is done on the matching pursuit algorithms.An improvement scheme for OMP algorithm is given.To increase the convergence speed of the OMP algorithm,the image to be processed is divided into some blocks.The new scheme could significantly improve the computation efficiency.With identical conditions,the algorithm is better than the traditional one in both objective and subjective reconstruction.

    Research on and Simulation of the Radar Imaging Technique
    WANG Jungang
    . 2015, 28(4):  54. 
    Abstract ( 619 )   PDF (730KB) ( 804 )  
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    This paper introduces the synthetic aperture radar and radar imaging technique.Due to the imaging problem of the shipboard synthetic aperture radar,compressed sensing is applied to simulate its target detection imaging under given simulation conditions.The results of simulation show that with the decrease of the amount of data acquired CS is better in target imaging,so that the effectiveness of the CS algorithm is testified.

    Vehicle Logo Recognition Based on Discriminative Low-rank Matrix Recovery and Sparse Representation
    CAO Mengmeng,LI Xinye,FAN Yuekun
    . 2015, 28(4):  57. 
    Abstract ( 845 )   PDF (902KB) ( 435 )  
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    In consideration of the problem that the existing vehicle logo recognition methods cannot handle the vehicle logo recognition under unsatisfactory situations,such as shadows,occlusions,stains,which cause low recognition rate.Therefore,an algorithm based on discriminative low-rank matrix recovery and sparse representation is proposed.First,discriminative low-rank matrix recovery is used to correct the unsatisfactory training samples,and then it learns a low-rank projection matrix to correct the corrupted testing sample by projecting the sample onto its corresponding underlying subspaces.Finally,the sparse representation method is used to classify the testing sample.Comparative experiments made on Medialab LPR Dataset show that the performance of the method is better than other vehicle logo recognition methods.

    Optical Flow Algorithm Based on the Medical Flexible Endoscope System
    LIU Qiao,LI Han,HE Lingjie
    . 2015, 28(4):  61. 
    Abstract ( 550 )   PDF (829KB) ( 457 )  
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    Manually steering the tip of a flexible endoscope to navigate through an endoluminal path relies on the physician's dexterity and experience.According to the drawbacks of manually steering the flexible endoscope,we propose a robot flexible endoscope system based on the LK optical flow algorithm.Using the endoscopic images to control the flexible endoscope directed towards the center path of the lumen can improve endoscopic intelligence,simplify the technique required of the operating physician,and reduce the incidence of medical malpractice.Taking the example of conventional gastroscopy,the commonly used image intensity algorithms are analyzed and compared.Experimental results show that the LK optical flow algorithm based on the center path of the lumen is more precise.

    Design of and Research on an Automatic Water Level Monitoring System
    HUANG Wei,HAO Runke,YIN Gang,LUAN Jian
    . 2015, 28(4):  65. 
    Abstract ( 660 )   PDF (861KB) ( 509 )  
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    An automatic water level monitoring system is designed using the ultrasonic technology.The system consists mainly of two parts:the transfer station of data and the collection terminal of data of water level.The collection terminals of water level get the data through ultrasonic and send the data to the transfer station by means of wireless transmission.Then,the transfer station sends the data to the remote terminal.The system can transfer the data with high accuracy and has the capacity of wireless transmission and remote monitoring.

    Research on Monitoring of Workers' Helmet Wearing at the Construction Site
    LIU Yunbo,HUANG Hua
    . 2015, 28(4):  69. 
    Abstract ( 709 )   PDF (869KB) ( 417 )  
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    To monitor workers' helmet wearing in the construction site and keep its statistics,this paper proposes a method of monitoring workers helmet wearing in the construction site based on computer vision.First,using the background difference method the foreground is extracted from the video image,its binary image is obtained and the moving target is split;second,it is distinguished whether the moving target is representing a person according to the characteristics of the moving targets by the scaling filtering method and so on,and the moving target representing a person needs to be tracked and marked;finally,two test lines are set in the middle of the road.When a moving target representing a person reaches the middle of the two lines,the distribution of pixel color values in its upper third area is detected to determine whether a person is wearing a helmet and the color of the helmet.Experimental results demonstrate that this method can meet the requirements on accuracy and efficiency.

    Research on and Implementation of a High-performance Distributed Search Engine Solr
    ZHAO Pu,ZHU Zhixiang,ZHANG Kangyi
    . 2015, 28(4):  73. 
    Abstract ( 747 )   PDF (650KB) ( 608 )  
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    The traditional search technology cannot provide efficient and reliable services for users because of the increasingly expansion of information resources.This paper designs and implements a distributed search with good performance based on Solr.By using Zookeeper cluster management,the search modules are distributed within the system.using the Solr for index processing,indexes are created parallel on multiple nodes.And the construction of the SolrCloud and Mongodb is connected.Tests show that the SolrCloud can improve the database search function.

    Study of the Demonstration System of the “Digital Signal Processing” Course Based on GUI
    LI Jiancheng,BING Rui,ZHAO Youshi
    . 2015, 28(4):  76. 
    Abstract ( 856 )   PDF (1153KB) ( 531 )  
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    The GUIDE of Matlab is a quick development environment specially used in the graphical user interface.In the demonstration system for the course Digital Signal Processing developed by this tool,the user login interface,the main interface selected by the system,and two sub-module interfaces are designed and programmed.For the two content sub-modules some Matlab aided analysis and design of experiments such as typical sequence generation,basic operations,discrete linear time invariant systems,time domain Discrete Fourier Transform(DTFT),Discrete Fourier Series(DFS),DFT,applications of the DFT and FFT,filter design and speech signal processing are developed.The system interface is friendly and open,which is beneficial for students to comprehend the DSP theory and greatly improve the teaching effect and efficiency.

    Analysis of Energy Consumption by Micro Module Data Center in Cold Regions
    WANG Chunhong
    . 2015, 28(4):  80. 
    Abstract ( 581 )   PDF (840KB) ( 449 )  
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    Starting from the target of reducing energy consumption in the data center,this paper analyzes energy consumption of the water chiller unit working in the natural cold scenario and calculates the PUE value throughout the year.Researchers suggest selecting the micro module as the core technical framework,and using the water chiller unit with the Free Cooling technology for refrigeration for the data center constructed in cold areas.Simulation shows that an increase of the output water by 1℃ will increase the refrigerating output of the chiller unit by 3%~4% and power consumption by 1%,thus saving electric energy,decreasing carbon emission and reducing cost.

    Development of a Mobile Agent Based Web Retrieval Prototype System
    LIANG Wu,SU Yan
    . 2015, 28(4):  84. 
    Abstract ( 545 )   PDF (606KB) ( 437 )  
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    With the development of information searching,distributed computing and e-commerce,this paper virtualizes the whole network into a unity so that users can enjoy optimal services in the network.A Web retrieving prototype system based on mobile Agent is designed.Simulation shows that the prototype system can meet the individualized needs of users in real life,and improves the speed and quality of retrieval.It also serves as a reference for the development of other applications.

    A Lightweight Task Management Mechanism Based on Osek/Vdx
    WANG Rui
    . 2015, 28(4):  86. 
    Abstract ( 604 )   PDF (860KB) ( 423 )  
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    A lightweight task management mechanism based on OSEK/VDX is designed to solve the problem of hardware resource shortage in the Vehicle System.The mechanism consists of an improved task information structure,a packet scheduling method and a event handling method which are based on the interrupt mechanism.Its performance analysis and comparison with other task management mechanisms show that the mechanism will improve the memory consumption and scheduling efficiency.The mechanism can be used in the existing vehicles' electronic control unit without additional cost and therefore is of practical value.

    Temperature and Humidity Monitoring System Based on SOPC and Embedded Ethernet
    LI Yalong,ZHANG Caizhen
    . 2015, 28(4):  91. 
    Abstract ( 732 )   PDF (835KB) ( 500 )  
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    In order to realize the real-time remote monitoring of temperature and humidity data,this paper puts forward the design scheme of a temperature and humidity monitoring system based on the SOPC and embedded Ethernet interface.The system makes full use of the rich resources of the SOPC system.The hardware architecture of the building has Nios II soft core CPU and the peripheral IP as the core in the software of Quartus Qsys.By porting the μ C/OS Ⅱ operating system as a software platform,using LwIP as the network communication protocol,and combining LAN91C111 with FPGA to constitute an embedded Ethernet interface,the temperature and humidity data is transmitted and controlled.Due to its flexible design,extendibility,resource-effectiveness,and cost-effectiveness,the circuit structure is greatly simplified,making the design simple and easy to implement.

    Design of an Electrocardiogram Acquisition Instrument Based on Cortex-M3
    DUAN Shuiping
    . 2015, 28(4):  95. 
    Abstract ( 641 )   PDF (618KB) ( 617 )  
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    This paper introduces a portable data acquisition system for acquiring ECG signals,which is easy to operate.The system adopts the STM32 processor,the AgCl electrode and Ⅲ lead wire collecting human ECG signals from environments with strong noise.The signals are then filtered and amplified through the analog front end which has OP07,AD620A,and OPA2604 as the core component.Finally the signals are digitalized by using STM32 SCM with signals which can reflect the actual ECG features obtained and displayed on the LCD in real time.The design has the advantages of simplicity,low power consumption,high stability,and is therefore suitable for families of cardiovascular patients.

    Design of a Sound-and-Light Controlled LED Lamp Based on Adaptive Ambient Noise
    JIN Yonggao,WANG Binggang
    . 2015, 28(4):  98. 
    Abstract ( 489 )   PDF (901KB) ( 428 )  
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    A sound-and-light controlled LED lamp based on adaptive ambient noise is designed in this paper.The designed LED lamp gathers voltage signals of ambient noise in real time,and the average level value,which is compared with the average of the previous noise level,will be calculated through A/D conversion.Then the LED lamp can be controlled adaptively according to the size of level difference,thus overcoming the problem of false triggering by ambient noise,and realizing intelligent triggering of the LED lamp under different ambient noises.Experiments show that the LED lamp has the advantages of simple circuit structure,micro-power consumption,high operation stability and low cost,which can be widely used in corridors,public toilets and so on.

    Study of Nonlinear Output Capacitance of the Wide-band Power Amplifier
    YU Jiansheng,SANG Lei,SUN Shitao,WANG Hua
    . 2015, 28(4):  102. 
    Abstract ( 783 )   PDF (1005KB) ( 480 )  
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    The relationship between nonlinear output capacitance Cout of GaN HEMT and the efficiency of the wide-band power amplifier is studied.Through the analysis of an established nonlinear circuit model,it is shown that the accuracy requirement on harmonic impedance can be reduced by using Cout controlling the waveform of the drain,which can enlarge the high efficiency zone.A highly efficient amplifier based on the principle is designed by using a Cree GaN HEMT device at 2~3 GHz band.It provides a drain efficiency of 81.7% and a power-added efficiency of 78.3% at a saturated power of 40.75 dBm.The method established in this paper can not only be used in wide-band microwave GaN PA,but it is also useful to other PA designs.

    Transmitting and Receiving Characteristics of the Three Step-wave Signal of the Array Induction Logging
    WU Jie,WANG Huan,LIANG Jianfen
    . 2015, 28(4):  106. 
    Abstract ( 678 )   PDF (1621KB) ( 473 )  
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    The characteristics of transmitting and receiving of the three step-wave signal of an array induction logging tool are investigated.First,we derive the three step-wave signal's Fourier expansion.Second,in noise free conditions,the characteristic of transmitting and receiving of the three step-wave signal which is composited by eight term harmonics are simulated with LabView software.The characteristic of transmitting and receiving is simulated when it has 30%'s Random Gauss white noise.Finally,we analyze the actual characteristic of transmitting and receiving of an array induction logging tool which is based on the 3 frequency signals.The results are close to the theory simulated.The research results are of great significance to the design and implementation of the array induction logging tool.
    Design of Hard Disk Storage Array of SATA SSD Based on PowerPC
    MENG Qi,ZHANG Jie,FAN Xiaoxing
    . 2015, 28(4):  111. 
    Abstract ( 645 )   PDF (1061KB) ( 461 )  
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    The paper puts forward a solid-state storage array system based on the SATA interface.The design selects FPGA as the hardware platform and the embedded PPC440 as CPU to control the whole system.The storage array based on the SATA solid disk adopts RAID0 technology and is used to improve hard disk drive storage and bandwidth.The design can implement the functions of real-time data storage,transmission and management and achieve offline operation.

    A Compact and Enhanced AI-EBG
    ZENG Qiuyun
    . 2015, 28(4):  116. 
    Abstract ( 601 )   PDF (880KB) ( 448 )  
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    A compact and enhanced electromagnetic band-gap(EBG) structure based on alternating impedance electromagnetic bandgap(AI-EBG) is proposed in this paper,which can provides -40 dB noise suppression performance from 0.4 GHz to 9.5 GHz for efficient and ultra-wide band suppression of the ground bounce noise in multilayer PCB.The paper discusses the problem of signal integrity when the EBG structure is applied in real high speed circuits.Differential signals can be used to obtain good signal integrity.

    Research on Wireless Ethernet Interface Conversion and its Application
    ZHOU Yi,ZHOU Yanxia,CIREN Zhouma,YE Jun
    . 2015, 28(4):  120. 
    Abstract ( 588 )   PDF (1044KB) ( 432 )  
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    Wireless Ethernet technology possesses the characteristics of efficiency and flexibility in transmission,and the study if its interface conversion technology could enable traditional measurement and control instruments to use wireless Ethernet for data transmission.Data converters have been applied to Wiegand code simulators and tested.The results show that the converter could ensure the reliability and timeliness of the converted data.

    A Method for Digital Modulation Recognition Based on Decision Theory
    FENG Xiaodong,ZENG Jun
    . 2015, 28(4):  124. 
    Abstract ( 582 )   PDF (656KB) ( 533 )  
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    An improved method is proposed to identify the types of the digital modulation signals based on the decision theory.By this method,only 4 relatively simple characteristic parameters are needed to identify the seven digital modulation signals,2ASK,4ASK,2FSK,4FSK,2PSK,4PSK and 16QAM.Computer simulations show that the complexity of the improved method is reduced greatly,and the correct recognition rate is increased significantly.It performs specially well in identifying the four digital modulation signals,2ASK,4ASK,MFSK/MPSK and 16QAM,in the case of low signal to noise rate.

    Design of A X-band Broadband T/R Module
    HAO Jinzhong,ZHANG Yu
    . 2015, 28(4):  128. 
    Abstract ( 659 )   PDF (766KB) ( 456 )  
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    The implementation of an X-band four-channel broadband T/R module is given.It includes the microwave circuit,DC/DC power,and the functions of beam control,power failure detection and temperature measurement in a small-size module.Structurally,the input port,output port and power port are all on the same side.The paper analyzes and expatiates the complicated function and special structure of the module and the assembly process problem it brings.An X-band broadband T/R module whose performance meets the indicators has been manufactured.This module has the advantages of good performance,light weight,and high reliability due to the delicate techniques.Tests show that it meets the indicators of electric and structural properties and is technically satisfying.

    DDR2 High-speed PCB Design and Signal Integrity Analysis
    DENG Siwei,LING Kai
    . 2015, 28(4):  132. 
    Abstract ( 611 )   PDF (891KB) ( 535 )  
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    With the development of modern high speed circuit design,DDR2 has become more designers' choice due to the great pre-reading capability of its memory.However,DDR2 simulation is time consuming,and its simulation of EMI is difficult,which constitute difficulties for PCB design.The problem of signal integrity in high speed circuit DDR2 is analyzed in detail and the key points of design of PCB are put forward.Taking a PCB design of a single DDR2 memory with a controller for instance,this paper describes how to complete an available design successfully with decreased simulation work.

    Research on the VxWorks-based Compact PCI Interruption Mechanism
    YANG Shuai,XI Zhihong
    . 2015, 28(4):  135. 
    Abstract ( 606 )   PDF (916KB) ( 462 )  
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    The compact PCI is a type of standard computer bus with the characteristics of hot-plugging.This result in the fact that the CPU accesses the extend device in a different way from the non-hot-plugging system,especially that the mechanism of interruption is very complex.Researchers not only need to understand the hardware interruption structure well,but also master the drivers of the PCI device and the implementation of the interruption service.This article analyzes both the software and hardware of interruption,and takes Compact PCI board as an example in the discussion of the programming essentials of communicating information with the CPU which runs VxWorks via interruption,the purpose of which is to have a thorough understanding of the Compact PCI-based interruption mechanism,and to provide theoretical guidance and programming ideas for developers.

    Research on Noise FM Jamming and its Realization on FPGA
    LI Yongsong,L Hao,LIU Yujiao
    . 2015, 28(4):  139. 
    Abstract ( 806 )   PDF (858KB) ( 569 )  
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    This paper analyzes the waveform and spectrum of the linear noise FM signal and its effect on the pulse compression radar.Based on the theory above,this paper introduces the realization of noise FM signal on FPGA,analyzes the time-frequency characteristics of the noise FM signal produced on FPGA,and displays the characteristics directly.It can be used as a reference for related radar jammer hardware implementation.

    Design of a Multi channel Analog Collection System in Relay Protection
    DING Xiaobo
    . 2015, 28(4):  142. 
    Abstract ( 595 )   PDF (783KB) ( 479 )  
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    This article describes an operating principle and design method to achieve a multi-channel collection system based on high-performance floating-point DSP chip TMS320C32,CPLD chip XC95288 and A/D sampling chip AD976.By applying a special voltage to the first channel,the value of the sample buffer in the CCS development environment is read.The sampling data is transformed in full-wave Fourier using the Matlab.This system has been widely used in relay protection.Practice shows that this system can achieve the collection of multi-channel analog and ensure the security and reliability of sampling data.

    Design of a High Frequency High Voltage Power Supply Voltage Doubler
    SUN Jun
    . 2015, 28(4):  146. 
    Abstract ( 497 )   PDF (546KB) ( 803 )  
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    As an important part of high voltage power supply,the voltage doubler plays a special role in improving the performance of the power supply.The influence of pressure device related parameters on the performance of the power supply is discussed.Using the method of theoretical analysis,a half arm type voltage doubler is designed and tested.The simulation and test results show that the voltage doubler parameter optimization has a significant influence on the performance of the power supply and thus the design of the voltage doubler is optimized.

    Application of Image Watermark Technology in the Electric Power System
    HU Yajun,CHEN Qing
    . 2015, 28(4):  149. 
    Abstract ( 599 )   PDF (1236KB) ( 389 )  
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    In order to protect the information security of the power system,the watermarking technology is used.This article describes the main features of the image watermarking technology and analyzes the basic theory of wavelet transform.It also analyzes the application of wavelet changes in electricity transaction with actual project case.According to the results,the image watermarking technology helps to improve the covert communication and authenticity of the power system,so that it is of practical value in application.

    Research on the Trojan Horse Technology
    CHEN Hongchang
    . 2015, 28(4):  154. 
    Abstract ( 517 )   PDF (838KB) ( 387 )  
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    The openness of the Internet brings people both convenience and security problems.Malicious codes are spreading quickly.Hackers use Trojans hidden in the affected user's computer to steal information,destroy data,monitor user behavior and so on.This paper introduces the principles of the computer Trojan horse,the basic module,implant technology and hidden technology.By studying the latest antivirus software's killing principle,it realizes the bypassing of both the killing of featured codes in antivirus software and active defense technologies.It is killing exempt in installing the Windows 7 operating system which has antivirus software with the two functions and can successfully bypass the killing of antivirus software.

    Research on the Distributed Key Escrow Scheme Based on RSA
    MAO Zhiqin,CHENG Yuanyuan
    . 2015, 28(4):  158. 
    Abstract ( 466 )   PDF (607KB) ( 508 )  
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    Based on RSA cryptography system,this paper carries out a further research on and optimization of the secret key escrow scheme,called Multi-prime RSA Cryptosystem.This optimization scheme satisfies the coordination between the user secret key security management and the judicial department's investigation and evidence collection,effectively solving the problem of “once monitoring,permanent monitoring”.And each escrow agent can verify the validity of the sub-key it manages to realize the optimization of distributed hosting,and avoid such troubles as “subliminal channel attack” and abuse of power by the hosting department.

    Design of a Fiber-optic Gyroscope Auto-testing System
    LI Pengbo
    . 2015, 28(4):  160. 
    Abstract ( 596 )   PDF (1261KB) ( 418 )  
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    Due to its significant characteristics of high precision,simple structure,long lifespan and low cost,the FOG(fiber-optic gyroscope) has been widely used in areas such as aviation,aerospace and navigation.Based on virtual instrument technology,this paper implements a fiber optic gyroscope auto-testing system,which can be used to determine whether the performance of FOG can meet the standards.The hardware unit design and system software design of this system are discussed in detail.The hardware unit circuit contains the signal isolation circuit,memory circuit,Ethernet circuit and power supply circuit etc.The design of the system software is mainly about the embedded software design based on SOPC and the PC software design based on LabWindows/CVI.It is easy to operate and the result is more precise.The test system can fully meet the requirements of research and production of FOG.

    Design of an Infrared Remote Control Switch
    GAO Xiumei,HU Chengzhong
    . 2015, 28(4):  166. 
    Abstract ( 532 )   PDF (740KB) ( 374 )  
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    This paper introduces a remote switch controller which can be used as an input signal.It designs the switch controller to replace the traditional mechanical one,which has the disadvantages of big contact resistance,short life span,and easy wear-out.This controller has the advantages of simple structure,convenient manufacture,low cost,strong anti-interference ability,and high reliability.Experiments show its feasibility and the correctness of the design.

    Research on a Technique for Laser Ranging System with the Capacity of Anti-interference Based on CDMA
    LEI Ming,ZHAO Liping
    . 2015, 28(4):  170. 
    Abstract ( 591 )   PDF (665KB) ( 406 )  
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    There is a problem with the traditional laser ranging system,it's capacity of anti-interference is bad.In order to resolve that problem,this paper proposes a method of laser ranging system based on CDMA.This system uses the FPGA chip as the master chip,adopts the multiple access modulation method to generate random pulse to send,at the same time it uses the threshold detection to receive signals after detects echos,this method can filter the interference signal,only make the real signal through the threshold detection and trigger the counter stop to count,then it can complete the ranging process.The experimental result shows that this method do filter light disturbance effectively,improve  laser ranging system anti-interference performance.

    Preparation of Porous Carbon and the Effect of HMTA on its Microwave Dielectric Properties
    WANG Yan,YANG Zi,HUANG Yunxia,HUANG Minsong,YUAN Yiyi,CHEN Pan
    . 2015, 28(4):  173. 
    Abstract ( 590 )   PDF (841KB) ( 450 )  
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    Porous carbons were synthesized by using pyrolysis precursors from furfural (F) and resorcinol (R) as reactant and hexamethylene-tetramine (H) as catalyst via sol-gel method.As-products were characterized and tested for microwave absorption applications.From X-ray diffraction and scanning electron microscopy,it was found that the porous carbons possess the graphite-like structure.The vector network analyzer was used to evaluate the microwave dielectric properties of the samples in the frequency range of 8.2 ~12.4 GHz.The results show that the dielectric loss of the RH75 sample reaches the highest value,which is 1.01 at 11.35 GHz.The proposed mechanisms for producing dielectric loss in the porous carbon samples are discussed.

    Optimization of Solar Building Appearance and Surface Photovoltaic Component Laying
    SHANG Miao,ZHANG Haibo,ZHANG Chi,GU Weidong
    . 2015, 28(4):  176. 
    Abstract ( 566 )   PDF (868KB) ( 393 )  
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    This paper focuses on the design of the solar building appearance and the optimization of the photovoltaic array laying scheme.First,by establishing a model to achieve the maximum radiation of the five outer surface of the building and using a simulated annealing method,the appearance design is presented with the consideration of the building design requirements.Second,according to the superior order and the constraints of the battery performance,the battery laying scheme of the building appearance is proposed by using a greedy algorithm.Finally,the investment payback period and the economic benefits in the lifetime are given.

    Means of Teaching for Increasing Students' Interests in Sports in the Network Times
    SONG Baojie
    . 2015, 28(4):  179. 
    Abstract ( 430 )   PDF (620KB) ( 420 )  
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    In the information age,how to relieve students from the computer so that they develop a love of sports and are willing to do physical exercises is what university physical education teachers should consider.By enriching classroom instruction forms and contents,innovating physical education teaching methods,and making the classroom more interesting and practical,we can increase college students' interests in sports and help them develop an awareness of doing physical exercises,so as to realize the real purpose of university physical education.

    Research Status and Development Trends of Large Scale Antenna Systems in 5G Wireless Communications
    LIU Ning,YUAN Hongwei
    . 2015, 28(4):  182. 
    Abstract ( 867 )   PDF (797KB) ( 1698 )  
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    This paper introduces the research status of large scale antenna technology,which is the key technology of the 5th generation communication systems.It summarizes the research results of Bell Lab,Rice University,Datang Telecom,Huawei,ZTE,CETC54 and so on,on the basis of which the development trends of the 5G large scale antenna system are analyzed.It draws a conclusion that the active integrated antenna is necessary for the 5G large scale antenna systems.The challenges for active antennas used in 5G are also discussed.

    A Survey of Digital Image Blind Detection Based on Tampering Trace
    WANG Chenlu,ZHU Tingge
    . 2015, 28(4):  186. 
    Abstract ( 560 )   PDF (666KB) ( 496 )  
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    With the development of digital image processing,it is more and more easy to edit image,which brings great challenge to the security of digital image.So  blind detection has become a research hot spot in the field of image security.This paper firstly describes the analysis of research status of blind detection.Secondly,according to different forensic features,several blind detection techniques based on the traces left by the tampering process are analyzed.Finally the future direction is presented.

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