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Table of Content

15 September 2012 Volume 25 Issue 9
  
    Articles
    Inductively Coupled Plasma Etching of Si by Cl2/Ar
    GUO Shuai, ZHOU Hong-Yi, CHEN Shu-Hua, GUO Xia
    . 12, 25(9):  1. 
    Abstract ( 1342 )   PDF (791KB) ( 851 )  
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    This paper introduces the inductively coupled plasma (ICP) etching of silicon with photoresist (PR) mask by the Cl2/Ar mixed-gas process.The effects of process parameters such as gas combination,ICP and RF power on the etch rate of Si and the selectivity of Si/photoresist and on the sidewall profile are investigated.It is found that the ratio of Cl2 to Ar flow rate significantly affects the etch rate,due to the trade-off between physical and chemical component of etching.The etch rate of Si decreases with the increase of percent of Ar,and the selectivity has the same trend.With the increase of ICP power,the etch rate of Si increases first and then decreases,and the selectivity increases with the ICP power.The etch rate and selectivity increases monotonously with RF power.Besides,ion-induced sputtering is an important factor in the Cl2/Ar mixed-gas etching.In the etching process,Microtrenching and sidewall surfaces can be smoothed by rising the ICP power.Besides,we study the profiles of Si with SiO2 mask under different pressures,and find that plasma grass will be controlled at a low pressure.

    Nondestructive Testing System for Sugar Content of Pears Based on Near Infrared Spectroscopy
    WANG Wei-Ming, ZHANG Wen-Tao, DONG Da-Ming, XIONG Xian-Ming
    . 12, 25(9):  6. 
    Abstract ( 919 )   PDF (778KB) ( 908 )  
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    A nondestructive portable detection system for sugar content of pears based on near infrared spectrum is developed,and the relationship between the near-infrared spectrum and sugar contents of pears is established.A nondestructive testing device for sugar content is designed using the laser diode of 850 nm as the background and that of 905 nm as the characteristic source.The model for calibration is set up by the partial least squares (PLS) method.The correlograms between the standard Brix value and predictive value of the calibration set and the prediction set are obtained which give good predictions of the sugar content of pears,with corresponding r values of 0.991 9 and 0.826 2,and standard errors of predictions of 0.002 and 0.008.It is proved that the device designed can be used for nondestructive testing of the sugar content of pears of the same variety.

    Wafer-level Adhesive Bonding with Benzocyclobutene for the Accelerometer
    LIU Lei, ZHAN Ming-Hao, LI Su-Su, CHEN Bo
    . 12, 25(9):  9. 
    Abstract ( 908 )   PDF (950KB) ( 925 )  
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    The wafer-level adhesive bonding based on BCB is studied.It is the packaging trend for the MEMS accelerometer and is essential to the industrialization of the MEMS accelerometer.A novel MEMS wafer level packaging method is achieved by the BCB bonding technique with the BCB 3000 as a bonding material.The wafer level packaging at low temperature (250 ℃) and proper pressure(≤2.5 bar) is realized.The related process parameters of spin coating,bonding,atmosphere,and bonding pressure and etc.are optimized.

    Operational Performances of the Near-space Platform
    AN He-Zhi, LI Ping, WANG Lei-Lei, ZHANG Wen-Hui
    . 12, 25(9):  13. 
    Abstract ( 815 )   PDF (499KB) ( 852 )  
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    The near space platform with its prominent feature has a broad application prospect and is of great military value.This paper aims to analyze the operational performances of the near space platform.The metrics of the near-space platform,the metrics,such as communication coverage,resolution,retention time,transmission delay,and transmission wastage is discussed.Simulation shows that the near-space platform,used as the communication center,has greater coverage range,higher sensitivity,higher received power and less delay.The strategic significance of the future near space platform is fully affirmed.

    Development of an Image Analyzer for Field Plant Disease Based on the WM System
    HUANG Hua-Sheng, LIU Fu-Chang, ZHONG Xiao-Le, DENG Ji-Zhong, LI Wei-Shao
    . 12, 25(9):  16. 
    Abstract ( 918 )   PDF (834KB) ( 831 )  
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    Lesion area estimation of plant leaf is a common method of investigating filed plant diseases.However,the conventional artificial estimation method,which depends on human eye identification,has a series of questions such as inaccuracy of plant disease rating,heavy workload of investigator,variation of scale from one investigator to another and so on.It will improve the accuracy of computation and plant disease rating to apply digital image recognition technology in calculating leaf lesion area.With the smart phone based on Windows Mobile system as development platform,this paper develops an image analyzer for field plant disease by employing C# programming technology.The analyzer collects leaf image of field plant by the photo function of smart phone.It can also analyze the percentage of lesion area to obtain the severity of plant diseases.The simulation test shows that this analyzer operates siThe lesion area estimation of plant leaf is a common method of investigating filed plant diseases.However,the conventional artificial estimation method,which depends on human eye identification,has a series of questions such as inaccuracy of plant disease rating,heavy workload of investigator,and variation of scale from one investigator to another.It will improve the accuracy of computation and plant disease rating to apply the digital image recognition technology in calculating the leaf lesion area.With the smart phone based on the Windows Mobile system as the development platform,this paper develops an image analyzer for field plant disease by employing the C# programming technology.The analyzer collects leaf images of field plants by the photo function of smart phones.It can also analyze the percentage of lesion area to obtain the severity of plant diseases.The simulation test shows that this analyzer has the advantages of easy operation and accurate analysis.Furthermore,the analysis functions can be expanded by software development.

    Wireless Dial-up Terminals Based on the S3C2440 and Linux
    WANG Bei-Bei, ZHOU Dong-Mei
    . 12, 25(9):  19. 
    Abstract ( 1120 )   PDF (512KB) ( 801 )  
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    Taking S3C2440 and Linux as the platform,this paper designs and implements a wireless dialing-up Internet terminal based on the 3G mode,and introduces the composition of hardware,the software development platform,the analysis of program,the method for detecting the driving,and the test of dial-up.The actual test results show that the system is stable,reliable,and has application potential.

    Modeling of the Intelligent Electronic Device According to SCL in the IEC61850
    SONG Jin-Hui, KANG Yi, ZHANG Xu, GUO Li-Jie
    . 12, 25(9):  21. 
    Abstract ( 837 )   PDF (859KB) ( 816 )  
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    IEC 61850 is the latest substation automation network communication standards promulgated by the ISO.SCL is the substation configuration language recommended by the IEC61850.The use of SCL can describe the device configuration information clearly and can realize sharing of different equipment.Based on the research of the development trend of current transformer substation,this paper introduces the rules of communication model in line with the IEC61850 standard,and describes a simple model according to the requirements of the SCL model construction.The model is tested with its correctness confirmed.

    Design of Remote Temperature Monitoring System for a Large-scale Server
    CAI Yun-Hui, ZHENG Li-Ping, CHEN Ping
    . 12, 25(9):  25. 
    Abstract ( 876 )   PDF (524KB) ( 981 )  
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    A type of remote control system has been designed to monitor the temperature of a large-scale server in this paper.In the hardware design,microcontroller is used to collect data at spot,PC is applied in monitor terminal,with RS485 bus implementing remote communications.In addition,the software design is introduced.The system has met the requirements for monitoring temperature of a large-scale sever in the test,and the actual application has proves that this system is reliable,which shows that the design has a high application value.

    Optimization and Design of a Riverway Monitoring System in the Cantonal Area of Luohe River
    SHI Yong-Peng
    . 12, 25(9):  28. 
    Abstract ( 848 )   PDF (395KB) ( 860 )  
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    An optimization method for the existed  riverway monitoring system in the cantonal area of Luohe river is presented.It is proposed that the pyroelectric infrared detector be applied to the riverway monitoring.Combined with the voice alarm system,a new riverway monitoring system with simple circuit structure and strong reliability is designed.

    Key Techniques for the City Public Security Video Surveillance System
    LI Gui-Peng
    . 12, 25(9):  30. 
    Abstract ( 863 )   PDF (681KB) ( 836 )  
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    The city public security video surveillance system uses the computer and network communication technology to achieve effective monitoring of urban security.It plays an important role in urban law and order management.In this paper,the construction scheme for the city police and monitoring technology system is proposed.It is based on demand and application and aims at usability,creativity and sustainability.It can serve as a reference for comprehensive city public security monitoring.

    Graphic Analysis of the Crossing Problem
    WEN Hong-Hang, WEN Hong-Xiang, REN Xiao-Li
    . 12, 25(9):  33. 
    Abstract ( 810 )   PDF (672KB) ( 757 )  
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    This paper proposes using 2D coordinate points to show the personnel combination state in the crossing process at each time point.It also classifies and analyzes the coordinate points and gives tentative suggestion on the range of carrying capacity n to solve the problem.To conclude,the author hopes the application of the graphic method to solve the crossing problem will cast light on the general systematic study of such problems.

    FPGA Implementation of the Intelligent Traffic Light Control System for Crossroads
    WANG Wei-Song, WANG Jin-Sheng, ZHANG Wei, LIANG Ji
    . 12, 25(9):  37. 
    Abstract ( 1726 )   PDF (636KB) ( 801 )  
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    To solve the increasingly serious problem of city traffic congestion,this paper proposes a new method of traffic lights control and FPGA implementation for city crossroads.In order to solve the problem of crossroads traffic resource's wastage caused by the unbalanced traffic flow in all the lanes,the asynchronous traffic signal control method in opposite lanes is used in the designed intelligent traffic control system which is capable of reducing the traffic resource's wastage and improving vehicle's operating efficiency of crossroads.

    Project Management Based on the Workflow Management
    ZHOU Xin-Miao, TANG Jin-Shuan
    . 12, 25(9):  40. 
    Abstract ( 903 )   PDF (824KB) ( 788 )  
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    This study utilizes a project management model based on work flow management and discusses Work Breakdown Structure (WBS) in project management.In view of the product development process,this study adopts the object-oriented ideology,computer technology and database technology to build an integrated structure model of workflow management and project management.The project management function module in the Product Data Management (PDM) system is also designed.Finally,we conduct a case study in the Product Data Management system of an air conditioning manufacturer for a discussion of practical application of project management module based on the workflow management.

    Design and Implementation of an OCR Recognition Technology Based on the Android Platform
    NIU Huai-Zhong
    . 12, 25(9):  45. 
    Abstract ( 1320 )   PDF (1023KB) ( 888 )  
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    The working principles of OCR word processing and identification as well as the advantages of OCR when used on mobile platforms are introduced.A program of the Secretary software on the Android-based phone is designed.This software uses OCR technology to indentify Chinese and English agenda.Emphasis is put on the analysis of the functions of the OCR recognition software.A scheme is designed to achieve the program and finally the OCR schedule reminding function is realized.After testing the software system functions,the results show that the OCR recognition software can complete the daily character identification and extraction function.

    Wireless PDA Terminal Based on the Embedded Internet of Things
    ZHOU Heng-Heng, QUAN Quan, ZHU Zhi-Qing
    . 12, 25(9):  49. 
    Abstract ( 1082 )   PDF (509KB) ( 809 )  
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    A logistics management system is achieved.The system has a host computer program,a microcontroller,a wireless communication module and a PDA terminal.The host computer and PDA terminal achieves cargo storage,delivery and query simultaneously.With digitization and automation as philosophy,we have designed a set of solutions for the low efficiency of the current artificial logistics management system with satisfactory results obtained.

    Image Retrieval Method Based on the Integrated Color and Texture Features of Interest Points
    CHEN Xiao-Ning, YANG Run-Feng, ZHAO Jian
    . 12, 25(9):  52. 
    Abstract ( 795 )   PDF (613KB) ( 942 )  
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    This paper presents a method for image retrieval based on the local area of interest points and integrated color and texture feature of an image.By this method representative features of the local area of an image are extracted.The study puts emphasis on the selection oft the interest points and the interest regions and the subsequent extraction of the color and texture of the interest regions.Experiments show that this method improves the efficiency and accuracy of image retrieval.

    Analysis of Tinyos Migration and its Application to Cc2430
    WANG Bo, XIN Yun-Hong
    . 12, 25(9):  55. 
    Abstract ( 1157 )   PDF (1076KB) ( 773 )  
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    This paper briefly outlines the essentials of the operating system and sensor nodes of the wireless sensor network.The main features of the current mainstream operating system TinyOS are analyzed in detail from the design,architecture,operation principle and compilation process.On the basis of this,the article puts forward the TinyOS migration methods as well as the process to realize it.Finally,TinyOS has been migrated into the CC2430 platform successfully.According to the result of the experiment,the TinyOS after transplantation can run on the CC2430 platform with stability.It can also achieve the wireless network between sensors reliably.

    Use of Support Vector Machines to Model the Learning Process
    LIU Hong-Yi
    . 12, 25(9):  60. 
    Abstract ( 1105 )   PDF (655KB) ( 783 )  
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    In the field of the artificial intelligence for game development,the learning process is very important.In the classical learning process much time is taken to forget old rules learn new rules.In order to solve the problem,this paper puts forward the method of Support Vector Machines.By introducing the time concept for this method,the system can easily forget old rules.This paper also brings forward an effective solution to both the limit of amount of Support Vector Machines and the limit of CPU's consumption.

    Virtual Driving on Mountain Roads for Driving Simulators
    WANG Zhen-Jun, DU Bao-Jiang, GONG Li-Jing, LIU Po
    . 12, 25(9):  63. 
    Abstract ( 830 )   PDF (752KB) ( 762 )  
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    In view of the feature of the virtual driving experience on mountain roads,this paper puts forward a method of controlling the virtual vehicle in real time by predefining and calculating road surface induction.The trajectory of the vehicle is predefined in the virtual scene and the linear interpolation method of controlling position and orientation by time is adopted to make it run.For the driving model,this paper calculates the position and orientation of the vehicle through the steering wheel signal and the space coordinate of tires in the ground,making the driving suitable for the gradient slope and roughness of the road and thus improving the real sense of safe driving on the mountain road.

    Design and Implementation of an Inertial Navigation System Based on LEA-6R
    HE Jin-Er, CAI Jing-Mei
    . 12, 25(9):  67. 
    Abstract ( 1072 )   PDF (520KB) ( 826 )  
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    In order to quickly obtain the desired GPS location data in the tunnel and inter-city high-rise,we have designed and implemented a combination of high sensitivity sensor inertial navigation system based on the LEA-6R chip by U-Blox Company.The details of the peripheral circuits,antenna monitoring circuit,and programming in WinCE6 systems are introduced.Practice has shown that when the satellite is not visible,the system can still calculate the accurate positioning data uninterrupted in the tunnel and inter-city high-rise.The positioning accuracy can meet normal demand.

    Detection System for Transformer Partial Discharge
    SUN Ke, ZHANG Qiang, LU Xin
    . 12, 25(9):  70. 
    Abstract ( 1090 )   PDF (690KB) ( 788 )  
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    The main reasons for transformer partial discharge (PD) is that electrostatic charge would dissociate at the position with weak insulation performance through the extraneous voltage.This pulse discharge type can cause insulation degradation,and even cause transformer faults.We propose an on-line system of partial discharge based on FPGA+DSP.In the system,FPGA plays the part of data acquisition and storage,and DSP performs TCP/IP embedded design,so that the data acquired can be passed by the Internet to computers to display.On-the-spot testing shows that the system realizes the goal of design.

    Bandstop Filter Circuit Design and Parameter Optimization Based on Matlab
    CHEN Xiao-Chong, QE Lei
    . 12, 25(9):  72. 
    Abstract ( 766 )   PDF (502KB) ( 703 )  
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    Various filter circuits often arise in analog circuit design.As the values of resistors and capacitors are not continuous in actual projects,the calculation of circuit parameters would be trivial and computationally intensive in designing the circuit.In addition,hand-calculation result would not be an optimal solution.This paper,by means of the powerful computation capacity of MATLAB,establishes a corresponding standard circuit model and parameter optimization model according to the transfer function of the band-stop filter,and finally circuit parameters which meet the requirements can be quickly obtained using the mathematical toolbox of MATLAB to program the corresponding solver,which greatly improves the design efficiency and is of great applicability.

    Study of Single-loop and Double-loop Dual-mode Filters with Microstrip SIR
    CHENG Wei-Wei, YIN Zhi-Ping, LV Guo-Qiang
    . 12, 25(9):  75. 
    Abstract ( 1029 )   PDF (731KB) ( 836 )  
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    A type of microstrip dual mode filter based on the step-impedance resonator is designed,which consists of the step-impedance square-loop instead of the conventional uniform impedence square-loop.To enhance the out-band and harmonic suppression,the structure of this filter is extended from single loop to double loop coupled by the bias-feeding microstrip.The design and simulation of a filter with a 2.5 GHz operating frequency and 300 MHz passband shows that the double-loop dual mode filter with SIR shows superiority in size and has such advantages as multiple transmission zeros and good out-band and harmonic suppression.

    Fiber-optical Current Transducer Based on the Lock-in Amplifier
    WU Zai-Qun
    . 12, 25(9):  79. 
    Abstract ( 1084 )   PDF (648KB) ( 947 )  
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    In order to test the rotation amount caused by the Faraday effect in the fiber-optic current transformer,a method using the lock-in amplifier for DC signal processing is proposed.This method improves the traditional method of dividing the AC component by the DC component.The acquired signal is used for single-ended voltage input testing and differential voltage input testing respectively,the testing results are compared,and the relationship between the output amplitude and the measured current is analyzed qualitatively.The testing results show that the relationship between the output amplitude and the measured current is linear.Compared with the single-ended voltage input,the differential voltage input has a larger amplitude and better linearity and suppression against outside interference.This work provides a foundation for further study of the fiber-optic current transformer based on the rotation effect.

    Linear Doherty Power Amplifier
    CHEN Chen, YANG Min-Wu
    . 12, 25(9):  82. 
    Abstract ( 1146 )   PDF (542KB) ( 784 )  
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    This paper briefly describes the history of the development of the linear power amplifier.The ADS software is used for Doherty power amplifier simulation.A Doherty multiple amplifier connected in parallel is designed.The power amplifier is compared with the classic Doherty power amplifier in efficiency.The results show that multistage parallel Doherty power amplifier circuit has the advantages of high efficiency,simple circuit,low cost,and stable performance over the traditional power amplifier.

    Improvement of TBM's Impact-point Prediction Precision
    LI Sen, LIU Hong-Jun, CHENG Zhong
    . 12, 25(9):  85. 
    Abstract ( 782 )   PDF (597KB) ( 800 )  
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    The generation of the trajectory and the impact-point prediction of the ballistic missile are studied based on the model of two body movements,and a method for improving the prediction precision is proposed.The method which uses the sliding window and average processing for the measured trajectory data can improve the prediction precision of the ballistic missile impact-point.Simulation results are presented to validate the proposed method.

    Design of a High Precision and Low Temperature Drift Bandgap Reference
    LI Shuai-Ren, ZHOU Xiao-Ming, WU Jia-Guo
    . 12, 25(9):  88. 
    Abstract ( 1122 )   PDF (632KB) ( 798 )  
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    A High Precision CMOS voltage reference circuit is designed by the TSMC 40 nm CMOS process.Spectre simulation shows that the temperature coefficient is 10×10-6/℃ in the temperature range from -40 to 125.The change of the voltage reference is 0.42 mV,and the change rate is 0.23 mV/V in the power supply voltage range of 1.5~3.3 V.PSRR is 72 dB after using the cascode current mirror.

    Design of a Full-Bridge Synchronous Rectifier and its Application
    WANG Xian-Jiang, SHI Yu, LI Gong-Fu
    . 12, 25(9):  91. 
    Abstract ( 4060 )   PDF (860KB) ( 1237 )  
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    Generally a full-bridge rectifier is added to the AC/DC switching power supply input stage to convert the AC voltage grid into a pulsating direct current for later processing by the DC-DC converter.As the traditional rectifier diode bridge rectifier has a voltage drop of about 1 V,it will consume some energy when the system power is large.This energy loss makes extra heat treatment necessary in the design of the system.And this loss also reduces the AC/DC power system efficiency.In this paper,with the N-channel enhancement-mode MOSFET we build a full-bridge synchronous rectifier control signal and introduce its corresponding control signal for full-bridge synchronous rectification.The simulation result meets the requirement of the design.

    Engineering Design and Realization of the Control Platform of a Radar Training Simulator System
    MA Hui-Ping, NIE Chang-Long, HOU Shao-Ling, LIU Peng
    . 12, 25(9):  94. 
    Abstract ( 1113 )   PDF (763KB) ( 727 )  
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    The equipment simulator system which aims mainly to train operators is called the equipment training simulator system.The radar is a type of large military equipment.The design and realization of its training simulator system is representative.The radar training simulator system mainly does functional simulation,or phenomenon simulation.This paper present an engineering design method for the control platform of a radar training simulator system.By this method,the control platform of the radar training simulator system has been designed and realized.This method can also be used for the design and realization of other equipment training simulator systems.

    Design of a Navigation Radar Display Based on the Camera Interface
    LIU Di
    . 12, 25(9):  97. 
    Abstract ( 878 )   PDF (709KB) ( 788 )  
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    This paper introduces the design of a navigation radar display based on the Camera interface.The radar echo signal is converted to an ITU-R BT601/656 video signal by FPGA.The video signal is then sent to the camera interface of ARM and is stored in the frame buffer memory.The display controller of ARM reads the frame buffer data in the way of DMA,mixes it with the human-machine interface data,and then send the mixed signal to the displayer to show it directly.The design achieves the synchronous display of the radar echo and human-computer interface,meets the requirements of the navigation radar display.The result of electronic engineering shows that the design is efficient.

    Design of the CAN Bus Interface Extension and Driver
    BI Guo-Xin, YUAN Hai-Tao
    . 12, 25(9):  100. 
    Abstract ( 1409 )   PDF (427KB) ( 840 )  
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    The CAN-Bus interface expansion program based on the S3C6410 is introduced.The CAN bus is extended through the SPI interface.The specific hardware circuit is also given.Emphasis is put on the CAN controller MCP2515 driver based on the embedded operation system WINCE.The related code is designed under the CAN-bus specification and MCP2515 features.The CAN bus stream interface driver is designed.The experimental results show that the CAN-Bus communications is good.

    Data Display of LED Digitron Dynamic Scanning by PLC
    ZHANG Xu
    . 12, 25(9):  103. 
    Abstract ( 955 )   PDF (350KB) ( 865 )  
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    According to the characteristics that the PLC performs scanning periodically,a method of driving two digitrons by a few PLC fan-outs is introduced.This paper also realizes displaying changing at two digitrons.Its software and hardware design are also introduced.This method can meet the requirement of industrial control and lower the cost.

    Characteristic Analysis and Object Recognition for Seismic Signals of Moving Terrestrial Targets
    WANG Bin
    . 12, 25(9):  105. 
    Abstract ( 997 )   PDF (732KB) ( 831 )  
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    The feature extraction of seismic signals that ground targets produce is the critical technology of object recognition.In order to pick up the seismic signal produced by moving targets such as humans or vehicles,Firstly,we did an experiment and established the signal sample database containing information which reflects the target attribute characteristics.Through an analysis of the Zero-Crossing Number method,we have obtained the time domain feature of seismic signal,and two targets of single man and vehicles have been distinguished.Finally,the Welch spectral method is used to analyze the signal frequency domain,and we have distinguished two targets of single and more than a random man.The experiments show that the two methods have the advantages of simple operation,easy implementation and good recognition effect.

    A Power Supply Used in Single-Phase Online Fault Indicator of the Distribution Network
    CUI Fang, WANG Chun-Chun, CAO Sheng
    . 12, 25(9):  108. 
    Abstract ( 905 )   PDF (738KB) ( 801 )  
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    The one-way ground fault indicator of the distribution network has found wide applications in distribution automation,but the energy it needs for online fault diagnosis can not rely on the low-voltage side.It can only be obtained in the high voltage side.Therefore,we have designed a special power taking circuit and control circuits.According to the needs of various components of the fault indicator the power supply can provide 5 V,-4 V and 3.2 V three-way voltage to meet the needs of the fault indicator signal in its acquisition,processing and wireless communications.The whole experimental results show that the power supply can provide a power of not less than 1.5 W when the current of overhead lines change from 15 A to 800 A.It can meet the requirement of the fault indicator.

    Application of Pspice to Circuit Software Design
    WANG Jie
    . 12, 25(9):  112. 
    Abstract ( 1125 )   PDF (534KB) ( 810 )  
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    PSpice software,one of the most distinctive software in circuit system simulation,has the function of improving the design of electronic circuits and optimizing the design circuit.This paper discusses the composition and function of PSpice software and its applications in electronic circuit design.It is shown that PSpice is powerful and can improve and optimize the design of electronic circuits.It has superiority from the aspect of PSpice software system simulation and therefore becomes an indispensable tool for electronic circuit designers.

    Design of the Ultrasonic Distance Measurement System with High Precision Based on ATMEG8
    XU Hong-Mei
    . 12, 25(9):  115. 
    Abstract ( 1008 )   PDF (521KB) ( 1167 )  
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    In view of the low measurement accuracy of the common ultrasonic telemeter system,this paper introduces a real-time system of ultrasonic distance measurement instrument controlled by ATMEGA8 SCM.The circuit adopts the high precision interval measuring chip TDC-GP21 and the temperature compensation measures to ensure the measurement accuracy and low power dissipation.

    Design and Implementation of a Real-time Control Module Based on the Embedded System
    GU Liang
    . 12, 25(9):  118. 
    Abstract ( 1110 )   PDF (498KB) ( 919 )  
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    The author proposes a case of performing in a communications test set the real-time control function in an embedded system using C51,presents the software and hardware design scheme,and points out the key of the scheme.The design has been applied to a communications test set,and realized the anticipative goal of real-time control.

    Design of a Portable Low-Power Temperature Detector
    ZHOU Xiao, ZHANG Chun-Sheng, ZHANG Xi-Wen, LI Ying-Xue, WANG Jian-Shun
    . 12, 25(9):  121. 
    Abstract ( 896 )   PDF (489KB) ( 819 )  
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    The portable low-power temperature detector is composed mainly of an integrated smart temperature sensing module,an nRF905wireless data transceiver module and an LCD temperature data module.The detector has the advantages of small size,easy portability and low power consumption.It is widely used in building automation to acquire temperature data,test temperature,and measure and control the temperature and humidity in the store house.

    Digital Copyright Identifier Technology Based on Digital Fingerprints
    SHAN Run-Hong
    . 12, 25(9):  124. 
    Abstract ( 880 )   PDF (720KB) ( 864 )  
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    Facing the copyright protection challenge in the NET field,the digital copyright identifier system,a new model of copyright public service,and its general technological framework are proposed.Then the digital copyright identifier technology based on digital fingerprints is analyzed.The technology is of increasing significance to the surveillance and monitoring module in the digital copyright identifier system.

    Application of the Composite Karnaugh Diagram in the Design of a Multi-output Assembly Logic Circuit
    LI Meng-Juan, ZHOU Li-Na, LU Chao
    . 12, 25(9):  126. 
    Abstract ( 803 )   PDF (432KB) ( 1063 )  
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    It is desired to simplify the designed multi-output assembly logic circuit to the greatest extent.If the composite karnaugh diagram is used to reduce the output function to find the public items of various items,the expression obtained may not be the simplest.However,by looking for a public and use as many common logic gates as possible in the circuit to reduce the number of logic gates used,so that the circuit is simplified.The results indicate that the use of the composite karnaugh diagram can simplify the circuit.

    Research on Serial RapidIO Switch Technologies
    XIE Li-Bin, LIU Kai, SHANG Yu
    . 12, 25(9):  129. 
    Abstract ( 975 )   PDF (639KB) ( 657 )  
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    Requirements for high-performance embedded signal processing system inter-connect between chips and chips,boards and boards on bandwidth,cost,flexibility and re-liability have ever-increased,which the traditional interconnect way can't meet.In view of this,the networking technologies and switch principle of RapidIO,which is the sole stan-dard for embedded system interconnect,has been researched.After that,a reconfigurable n-etworking solution for distributed parallel processing based on Tsi578 has been designed.T-he system performance proved to be stable and has the ability of static and dynamic rec-onfigurable.

    Structural Design and Implementation of FPGA-based 24-point Discrete Fourier Transform
    SUN Chong-Lei
    . 12, 25(9):  132. 
    Abstract ( 1147 )   PDF (586KB) ( 683 )  
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    A structure of 24-point Discrete Fourier Transform (DFT) for FPGA implementation is designed based on the Good-Thomas mapping algorithm and the ISE Fast Fourier Transform (FFT) IP core in this paper.The proposed 24-point DFT module employs the pipeline structure and is composed mainly of three 8-point FFT modules and one 3-point DFT module.The proposed 24-point DFT module can stably work at a clock frequency of 200MHz,and it only requires 14 multipliers.Firstly,according to the Good-Thomas mapping algorithm,the 24-channel input signals are divided into three groups,each of which contains 8-channel input signals.Secondly,a parallel-to-serial conversion is performed on each group of signals,respectively.Thirdly,an 8-point FFT is performed on each group of conversed signals via the FFT IP core provided by the ISE10.1 software.Fourthly,the output signals of the above three 8-point FFT modules are simultaneously transferred into a 3-point DFT module.Lastly,each channel of the output signal from the 3-point DFT module is converted into 8-channel signals via a serial-to-parallel conversion,and then the final 24-channel output signals are obtained.In addition,the proposed DFT structure has good extensibility.By simply modifying the corresponding parameters of the employed FFT IP core,the above structure of 24-point DFT can adapt to the DFT implementation with a length of N=3×2n.

    Review on the Study of Faceted Search
    GUO Li-Jie, LI Xin-Ye, SONG Jin-Hui
    . 12, 25(9):  136. 
    Abstract ( 794 )   PDF (544KB) ( 677 )  
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    For the traditional information retrieval,researchers focus on the precise inquiry technology,by which a large number of results,which may not be highly correlated,are returned for each search.The successful search results sorting algorithm usually returns the top K relevant results to meet most of the inquiry.However,most real search tasks are exploratory and inaccurate,and the user needs to explore the information space,discover the relationship between concepts,and narrow down the scope of choice in a guided way.So a exploring access paradigm called faceted search has emerged to satisfy this need.Its appearance overcomes the shortcomings of the traditional methods and lays a foundation for interactive information retrieval.This paper presents some definitions of faceted search and makes a study around the key technology,hot points,the latest progress and application prospect of faceted search.

    Improvement of Training Programs for the Electronic Information Engineering Specialty Based on Races
    YANG Jie, WU Yong-Ling, LIU Hai-Min, YE Jing-Jing
    . 12, 25(9):  139. 
    Abstract ( 702 )   PDF (513KB) ( 619 )  
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    This article first analyzes the existing electronic information engineering training program.In view of the expertise and models required by the national undergraduate electronic design contest,it is found that the electronic information specialty training program has put too much emphasis on the theory and software and neglected practice and hardware.Therefore,students still have difficulty dealing with problems in practice even though they have learned some related courses.In response to these problems,this paper proposes a method for improvement:courses specially targeted should be offered so that students can adapt to the current work.

    Construction of a Virtual Laboratory
    YANG Bai-Long, GUO Wen-Pu, XU Dong-Hui
    . 12, 25(9):  141. 
    Abstract ( 646 )   PDF (559KB) ( 893 )  
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    The general structure of a virtual laboratory is given,and the current construction of virtual laboratories both home and abroad is analyzed.The advantages and limitations of the virtual laboratory are also presented.It is argued that the virtual laboratory should be constructed by scientific methods,strict quality standards and sound mechanisms.

    Innovation of the Teaching Reform for the Course of Web Design
    ZHANG Ming-Zhu
    . 12, 25(9):  144. 
    Abstract ( 688 )   PDF (369KB) ( 653 )  
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    Web design is a practical course,and the traditional teaching form has various drawbacks.This article puts forward a new teaching pattern based on the task driving method and optimizes the assessment model.Its application in practical teaching has enhanced students' initiative and enthusiasm,cultivated students' creativity,and improved the teaching effect.

    Embedded Teaching System Based on ARM
    YANG Jun-Cheng
    . 12, 25(9):  146. 
    Abstract ( 995 )   PDF (385KB) ( 690 )  
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    In view of the characteristics of the embedded system,this paper analyzes the problems of the embedded teaching system.According to the teaching reform and practice,this paper proposes the corresponding reform measurements from the aspects of teaching methods,textbook readjustment,practice teaching and interest cultivation.The actual project is integrated into classroom teaching,so that what is taught is close to engineering and thus students' capacity both theoretical and practical can be improved.

    Press Information Management
    GENG Xiao-Peng
    . 12, 25(9):  148. 
    Abstract ( 733 )   PDF (574KB) ( 618 )  
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    With the rapid development of China's economy and technology,the domestic and foreign competition between publishers have gradually transferred from the book publishing level to the management level.The management of the press becomes,therefore,an important factor.With the rapid development of the computer network communication technology,multimedia technology,publishers' the management and operation mode needs to be digitalized,networked,and automated so that publishers can win the competition.

    Stereo Teaching Resource Construction for the Course of SCM Application Technology
    LI Ting-Gui
    . 12, 25(9):  151. 
    Abstract ( 911 )   PDF (543KB) ( 593 )  
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    In order to improve the quality of teaching and open the premium teaching resources of the excellent curriculum,it is necessary to develop stereo teaching resources construction.This paper focuses on the content of stereo teaching resources construction of the course SCM Application Technology,mainly including textbook construction,teaching team construction,the curriculum of the network courses,and the training base construction.

    Study on Video Stream Hierarchical Division
    ZHOU Han, YU Wen-Bin
    . 12, 25(9):  154. 
    Abstract ( 668 )   PDF (575KB) ( 692 )  
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    An frame hierarchy based video stream division scheme is proposed,which is combined with the different importance of video frame and video division principles.The division information is protected by unequal error protection in simulations.The simulation results show that the proposed division scheme excels the traditional video frame division scheme.

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