Table of Content

15 May 2012 Volume 25 Issue 5
    Design and Analysis of the Band-gap Voltage Reference Source
    ZHAO Qiang, LV Ming, ZHANG Jian
    . 2012, 25(5):  1. 
    Abstract ( 1203 )   PDF (580KB) ( 1390 )  
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    The development and basic working theory of reference source are introduced.The bandgap circuit structure,which is a universal voltage reference source form,is discussed in detail.A circuit of bandgap based on Banba structure is designed,and the relationship between output voltage and temperature is analyzed.The design can provide reference voltage for serial voltage regulator circuits and A/D & D/A converters and serve as the stable voltage power supply or driving source of most sensors.

    Realization of True Color Display for OLED Based on FPGA
    ZHANG Hui, LI Li-Guo, ZHAO Zhi-Chao
    . 2012, 25(5):  4. 
    Abstract ( 1480 )   PDF (813KB) ( 999 )  
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    Using the FPGA control module,a dynamic true color image drive control circuit of OLED is designed.In this paper,the method for realizing the external OLED circuit and the 256-level gray scale display by using the FPGA is introduced;the role of the module in the circuit and the work process of the entire circuit is also analyzed.Based on Altera's FPGA technology and using the Verilog HDL language the circuit system is designed.The Modelsim simulation results show that the program can achieve the target of realizing 480×RGB×640 color OLED screen and 256-level gray scale display.

    Analysis of Parameters of the Uniform Circular Array
    HUANG Ke
    . 2012, 25(5):  8. 
    Abstract ( 1422 )   PDF (419KB) ( 899 )  
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    In recent years,because of its good system performances,uniform circular array(UCA) antennas have been found broad applications in communication,radar detection,navigation guidance and other fields.In this paper,based on a UCA with a discretionary max-radiation direction,it analyzes the performance of the array pattern with the change of array radius and array unit number.It is found that the greater the radius,the smaller the half power beam width is;however,with the increase in radius,the array occupies more space,which is undeniable for conformal mobile carriers,thus requiring balance.But the number of array units has only minor impact on the array characteristics;therefore it suffices to take the minimum value that can meet the design requirement.

    Method for Catastrophic Faults Location in Analog Circuits Based on Wavelet Transform and Mahalanobis Distance
    PU Jian-Kai, HU Zhi-Zhong, ZHU Qiong, SHAO Yuan-Chao
    . 2012, 25(5):  10. 
    Abstract ( 1688 )   PDF (602KB) ( 972 )  
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    To solve the catastrophic fault of analog circuits,this paper proposes a fast location method based on Mahalanobis distance.Firstly,a simulation of circuit and fault modeling is made in PSPICE for the Continuous-Time Sate-Variable Filter in the ITC'97 Analog and Mixed-Signal Benchmark Circuits.Secondly,simulation data of both fault-free and faulty circuit is imported into Matlab using PSPICE and Matlab software data interface technology.Then,wavelet transform and Mahalanobis distance calculation of the simulation data is done in Matlab.Finally,the faulty component would be detected based on the Mahalanobis distances of both fault-free and faulty circuits.Tests show that this method with quick positioning ability has the advantage of simplicity and small online computational amount.

    Design of High-speed Data Acquisition Control Module Based on FPGA
    ZHOU Qian
    . 2012, 25(5):  14. 
    Abstract ( 1526 )   PDF (563KB) ( 1076 )  
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    This data acquisition control module adopts the FPGA of Spartan-3E serials,AD10242 converter and MXP-123MD-F optical transceiver to realize high-speed data acquisition and optical fiber transmission.In this module,the FPGA acts as the kernel part to achieve functions of data control,dual-part RAM,8B/10B encoding/decoding and so on.This module has the characteristics of stability,good real-time performance,high integration and flexible expansibility.Its function has been validated through test.

    System Design and Simulation of Class D Amplifier Using ΣΔ Modulator
    GAO Ai-Guo
    . 2012, 25(5):  17. 
    Abstract ( 986 )   PDF (525KB) ( 990 )  
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    In view of the fact that pulse width modulation may cause electromagnetic interference (EMI) in Class D Amplifier,this article applies a five-order low pass Σ Δ modulator to A class D amplifier with a feedback loop structure.The output signal spectrum properties are studied by establishing a nonideal model of class D amplifier.Simulation results show that this model can reduce the noise and harmonic distortion in low frequency band,achieve higher signal-to-noise ratio in baseband.Its application in the class D amplifiers can improve the electromagnetic interference performance effectively compared with traditional pulse width modulation.

    Simulation Analysis of Coupling Loss of Leaky Coaxial Cable with Eight-Shaped Slot
    LI Ming-Ru, HUANG Xiao-Yong, WEI Jing, YANG Ye
    . 2012, 25(5):  20. 
    Abstract ( 1795 )   PDF (593KB) ( 975 )  
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    Leaky coaxial cable is widely used in confined areas such as subways,tunnels,underground malls,mines and other buildings in blind zones.It requires different electrical properties due to different applications.Therefore,analyzing factors that affect the leaky coaxial cable coupling loss and other electrical properties,and exploring their variation rules,have important application value in engineering.The rules of coupling loss varying with the angle,length and pitch of eight-shaped slots are simulated and analyzed.A method for adjusting the slot pitch is proposed with changing the distance of the adjacent eight-shaped slot pairs,while unchanging the geometrical structure parameters of a single eight-shaped slot pair.An actual calculation example using this method is given subsequently,and simulation results are consistent with the experimental results.

    Switch Door Automatic Lighting Simulation Circuit
    WU Jing
    . 2012, 25(5):  24. 
    Abstract ( 1241 )   PDF (312KB) ( 1055 )  
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    The circuit simulation is composed of DC power supply,Holzer sensor,the monostable trigger and D trigger switch door automatic lighting circuit,in order to achieve when people push the door,indoor lighting automatic light;and when someone pushed out the door,the lamp will automatically extinguish control function.

    Slow Time-varying Channel Estimation Based on Part-data-dependent Superimposed Training
    WANG Peng-Peng, HU Jin-Hui, HOU Hai-Tao
    . 2012, 25(5):  26. 
    Abstract ( 1475 )   PDF (749KB) ( 843 )  
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    This paper researches the OFDMA communication system,and proposes a new channel estimation algorithm using part-data-dependent superimposed training (PDDST).Recovery method of data at the receiver is given.Time-varying channel is modeled by complex-exponential basis expansion model (CE-BEM).The pilots of the OFDMA system have been designed carefully.In the frequency domain,the data is to be launched minus a sequence based on part of the data.After the Fourier transform,a part of data which will be sent has lower power in time domain,and errors produced by Channel estimation are greatly reduced.Since the signal launched has been distorted,we propose compensation for information data to avoid reducing the performance of data recovery.Simulations prove that this method can significantly improve the performance of channel estimation.

    Design of a Leaky Coaxial Cable for Railway Wireless Communication
    WANG Zhen, JIANG Lan, ZHANG Ming-Ming, LIU Hong-Xi, LIU Dong-Cai
    . 2012, 25(5):  30. 
    Abstract ( 1416 )   PDF (860KB) ( 1048 )  
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    This paper describes main electrical characteristics and their relationships of leaky coaxial cables with periodic slots,and analyzes the influence factors of main electrical characteristics theoretically.The effect of the angle and length of eight-shaped slots on electrical characteristics are investigated,and a leaky coaxial cable with periodic eight-shaped slots is designed by computer full wave simulation method.The measurement results are in agreement with the simulation results,and the design meets the standards of the leaky coaxial cables for railway wireless communication.

    Design and Realization of Power Line Simulation System on FPGA
    FENG Heng, LI Shu-Qing
    . 2012, 25(5):  34. 
    Abstract ( 1583 )   PDF (632KB) ( 830 )  
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    The research on power line communication equipment requires a standard test platform which can simulate the power line in real time,including overall test and verification on channel characteristics and channel noise.There is no such platform at present.In this paper,power line channel characteristics and noise are studied,and a method for implementing a hardware-based power line simulation system is proposed.Matlab simulation verifies its feasibility and practical value.

    Source Synchronous Timing Simulation Based on the Cadence
    PIAO Wei-Jie, CHENG Hao
    . 2012, 25(5):  38. 
    Abstract ( 1123 )   PDF (640KB) ( 847 )  
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    As the clock frequency becoming more and more high,the PCB design has become more and more complex,and signal Integrity simulation becomes more and more important.In this paper,according to the source synchronization of some basic issues in the Cadence simulation environment,simulate the source synchronous timing,and get simulation process and results.

    Research into Group Delay with Microwave Single-port Network
    BI Dan-Hong
    . 2012, 25(5):  41. 
    Abstract ( 1011 )   PDF (470KB) ( 809 )  
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    Group delay with microwave single-port group network is deduced in this paper.The relevance between the S-parameter and Q-factor of resonator is obtained by deducing the group delay characteristic of shunt-resonant circuit and series-resonance circuit.The variation of group delay characteristics with two different loads are analyzed,indicating the fact that single-port network does not vary with the change in loads,a valuable conclusion for the study of external coupling characteristics of the resonator.

    FMCW Radar System and Design of its Data Acquisition Module
    QI Hao-Chen, XIE Guang-Jun, ZHANG Jian
    . 2012, 25(5):  44. 
    Abstract ( 1074 )   PDF (678KB) ( 786 )  
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    FMCW (frequency modulation continuous wave) radar is widely applied in automobile anti-collision systems.The development of automobile anti-collision systems in recent years is introduced.Based on a FMCW millimeter-wave radar device,the theory and framework of the system are presented.As the important parts of data acquisition module,the preamplification and analog-to-digital converter for the radar signals are designed and introduced.

    Simulation of AMTI Inhibitory Effect on Chaff Clutter
    ZHANG Tao, LEI Cheng-Cheng
    . 2012, 25(5):  47. 
    Abstract ( 1086 )   PDF (679KB) ( 852 )  
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    Airborne Moving Target Indication (AMTI) is widely used in airborne radar system,to inhibit background echo signal of stationary object such as surface features.According to the basic principle of AMTI,this paper puts forward that chaff slow-moving clutter can be inhibited by AMTI,and builds a model of airborne radar signal processing system based on AMTI,using the system model to make simulation of signal processing for echo signal of target aircraft and chaff clouds.The comparative simulation results verify that AMTI can inhibit chaff cloud clutter significantly,and so provides theoretical basis of using AMTI to inhibit chaff clutter in the air battle.

    Design of an Improved Class AB Audio Power Amp
    HAN Hui, XUE Chao-Yao, MA Ren-Yue
    . 2012, 25(5):  51. 
    Abstract ( 1066 )   PDF (722KB) ( 862 )  
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    A fully differential OP-AMP with a high gain and a class-AB output stage is designed in this paper.The technology of eliminating the current is used to achieve a high gain and an improved Class AB push-pull output stage is used to achieve a large current ability and a wide output swing.The operational amplifier is designed and simulated in a 0.35 μm CMOS process.With a 5 V power supply,the amplifier achieves an open loop gain of 97.4 dB with an output swing of 0.07~4.91 V,and dissipates 2.96 mW.The area of the power tube was less than 0.2 Square millimeters which diminishes the area of IC enormously in the premise of guaranteeing a certain index.

    A Method for Velocity Measurement of Low PRT Radar
    LI Bang-Qin
    . 2012, 25(5):  56. 
    Abstract ( 1171 )   PDF (690KB) ( 840 )  
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    Because the pulse repetition frequency of the low pulse repetition frequency (PRF) radars is very low and there is terrible ambiguity in radial velocity measurement,it is necessary to make low-pulse repetition frequency radar be capable of velocity measurement.This paper puts forward a method for velocity measurement of Low PRT Radar,using FFT to achieve 8-channel narrow-band filter banks.Velocity measurement is achieved by using velocity mixing,velocity difference and velocity estimate.The simulation results verify the availability and practical value of the method.

    Design of the Main Control Unit of the Time Synchronization System Based on ARM and FPGA
    LIU Peng
    . 2012, 25(5):  58. 
    Abstract ( 1170 )   PDF (734KB) ( 759 )  
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    This paper presents the design of main control unit of time synchronization system.We have designed main control unit based on ARM and FPGA.S3C2440A is selected as the core control module of main control unit;FPGA is selected as an auxiliary control unit.We have completed the functions of human computer interaction,the parameter settings,message handling and remote control.This paper has researched the mode of human computer interaction,and completed concise HCI as keyboard control,LED and LCD display;We complete the parameter settings based on the mode of human computer interaction;messages are transported by the Ethernet and the CRC checkout is used to checking the messages in the transmission to keep the message transport safety;and the mode of remote control is completed by Telnet.

    Analysis of TRAD Decoying Capability of Terminal-guided Missile
    ZHANG Xiao-Jie, LUO Lu-Qin, ZHAN Wang-Bao
    . 2012, 25(5):  62. 
    Abstract ( 974 )   PDF (486KB) ( 826 )  
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    TRAD is an effective jamming to the terminal-guided missile.This paper analyzes the mode of TRAD angle deception against the monopulse radar angle tracking system of terminal-guided missile and the mode of jamming to signal ratio for missile seekers.Simulation and analysis is made of the decoying capability under different conditions.Simulation results show that the greater the seeker angle,the better the decoying effect is.

    A Design of Slow-threshold Constant False Alarm Processing Circuit Based on FPGA
    XUE Ping-Bing
    . 2012, 25(5):  64. 
    Abstract ( 1090 )   PDF (597KB) ( 824 )  
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    The detection of radar signal always processes with background noise,not only high signal noise ratio but also constant false alarm device are required to reduce constant false alarm.Constant false alarm processing is an important part of radar signal processing;therefore the research on false alarm processing is crucial in radar technology.Slow-threshold constant false alarm aim at the heat noise of receiver,a constant false alarm processing circuit based on FPGA embedded design is proposed in this paper,and the simulation model and simulating results are also presented.The circuit has been used in a practical detector with big economic benefit.

    Simplified Analysis and Simulation of Soft Starter in Turn-off Angle Controlled Type
    WANG Ling
    . 2012, 25(5):  66. 
    Abstract ( 1136 )   PDF (587KB) ( 861 )  
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    For the three-phase ac regulation voltage circuit of soft starter with turn-off angle controlled type using thyristor,the circuit is equivalent to a reactance which changed with turn-off angle.In combination with asynchronous motor's simplified equivalent circuit model,an equivalent circuit of the soft-start main circuit is obtained.On this basis,this paper analyzes the relation between turn-off angle,stator current,electromagnetic torque,maximum electromagnetic torque,and critical slip ratio,with the conclusion that turn-off angle could effectively control starting current of the motor.The simulation results show that theoretical analysis is effective and feasible.

    Design of a Home Security Automatic Alarm System
    ZHANG Lei, PENG Hao, PAN Xiao-Yong
    . 2012, 25(5):  70. 
    Abstract ( 1015 )   PDF (536KB) ( 815 )  
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    With the constant change of people's work and lifestyle,home security becomes more and more important for property safety.This paper designs a sensor SCM intelligent security system based on modern micro-electronics and computer,which can make automatic alarm,SMS notifications and even video picture monitoring when the property is in danger.

    Designs of the USB2.0 Interface of the Digital Synthetic Sweeper
    SUN Xue-Jun, BAI Pu-Wei
    . 2012, 25(5):  73. 
    Abstract ( 880 )   PDF (528KB) ( 818 )  
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    Based on a summary of the hardware architecture of digital synthetic sweeper,the paper gives a detailed description of the design of USB2.0 interface based on ISP1362,including the hardware design of USB2.0,USB firmware design,USB driver program design and the application program design.Experimental results show that the design meets the design requirements with a data transporting rate up to 33 Mbit·s-1.

    A Novel NTRU Encryption Scheme Based on R-LWE Problem
    ZHANG Jian-Hang, HE Jian, HU Yu-Pu
    . 2012, 25(5):  76. 
    Abstract ( 1030 )   PDF (466KB) ( 831 )  
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    NTRU encryption scheme has no proof of security.In light of this weakness,a novel NTRU encryption scheme which is based on the Ring-Learning With Error problem is given.The new scheme is provably secure in the standard model.First,the ring in NTRU encryption is modified.Then,a pair of keys is generated by Gaussian sampling algorithm.Finally,the encryption process is modified.The improved scheme is secure in standard model for indistinguishable chosen-plaintext attacks.

    Design of the Data Acquisition and Signal Processing System Based on LabVIEW
    YAO Li, LIU Dong-Dong
    . 2012, 25(5):  79. 
    Abstract ( 1597 )   PDF (1057KB) ( 890 )  
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    In order to collect and process data effectively,express the visual advantage of LabVIEW,this paper presents a design method for collecting and processing data in more channel using PMD-1608 based on LabVIEW.The system can realize eight channel data collection,signal analysis and the storage of data synchronization.

    A Digital Traditional Chinese Medicine Pulse Diagnosing System Based on Mobile Communication Terminal
    HUANG Yan-Li, SHi Die-Fu, GUO Ning, WU Yang
    . 2012, 25(5):  82. 
    Abstract ( 1098 )   PDF (635KB) ( 812 )  
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    This system adopts traditional Chinese diagnosis method of Three Parts Nine Steps,in which a digital pulse fleeting pulse acquisition system is used for real-time accurate information collection and storage,with smart phones as mobile communication terminal to accomplish safe data transmission.The backend server uses intelligent information pulse processing techniques to conduct scientific analysis of information and diagnosis,and patients' privacy is well protected by the access control mechanism.This system combines the traditional Chinese medicine theory with modern science to promote daily health care,disease prevention and treatment,and is of great significance in the inheritance of traditional Chinese medicine.

    Vertical Pipe Interior Ultrasonic Flow Measurement Based on the Correlation Method
    XU Hui, YAN Zeng-Tian
    . 2012, 25(5):  85. 
    Abstract ( 1167 )   PDF (887KB) ( 830 )  
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    In some specific circumstances,it is inconvenient to install probes in the pipe wall.In view of this,this paper presents an ultrasonic flow measurement method and corresponding device that puts the probe in the pipe and parallel to the direction of flow.When calculating the time difference,we use the method of correlation algorithm to calculate the time difference.The method of correlation algorithm itself has some characteristics such as filtering and denoising to improve the accuracy of the time difference.The hardware system consists of ultrasonic transmitting,receiving and amplifying circuits,using the high speed A / D converter for digitizing the received signal.The experimental results show that the circuit emitting circuit can produces impulse with high amplitude and narrow width.This circuit can effectively stimulate the ultrasonic transducer.The error between the actual value and the calculation value after waveform treatment of correlation algorithm is very small.The improved accuracy of the time difference facilities the flow calculation better.

    Design of Management Software for the Cable-Channel Monitoring System
    YANG Bo, SUN Wan-Rong, FENG Zhan-Peng, LI Jing-Jing, XUE Dan
    . 2012, 25(5):  89. 
    Abstract ( 1301 )   PDF (1279KB) ( 807 )  
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    This paper presents a design of management software for cable-channel monitoring system.The software consists of two parts:the data transmission part,which receives the real-time data in the channel from the workstation PC according to Socket which is the network communication function of Java;and the upper layer management part,which manages data information from the workstation PC.This part based on Web is designed by the design framework of JSP Model2.The overall planning of management platform,main function and specific implementation method are given.The system module not only realizes the engineering automation of channel management,but also acquires real-time data and alarm data in the channels,thus greatly improving the management model and efficiency.

    Remote Sensing Image Fusion Based on Curvelet Transform and Fractal
    MA Yao, NA Yan, ZHANG Shou-Jiang, LIU Zhen
    . 2012, 25(5):  94. 
    Abstract ( 1250 )   PDF (844KB) ( 781 )  
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    In this paper,an algorithm based on curvelet transform and fractal is proposed in light of the fact that the curvelet transform can keep the spectrum information and the principle of fractal can extract the texture information of the image.A fusion experiment is done using the panchromatic image and the multi spectral image,and a comparison is made with the algorithm based on the wavelet transform and high frequency coefficients.The result shows that the proposed method has a good performance on getting the spectrum and texture information.

    Research on the Robust SVM
    JI Wei-Wei, TAN Xiao-Yang
    . 2012, 25(5):  97. 
    Abstract ( 1635 )   PDF (843KB) ( 773 )  
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    Most methods of face recognition use amounts of corrected labeled samples to learn recognition models with high curate.Collecting face images and labeling them will consume plenty of manpower.In order to label the possession images,researchers have done many works and have made many contributions,but due to personal reason,the labels may be not correct entirely,we call the incorrect labels class noise.The paper is aimed at face recognition with class noise,point that SVM suit for these problems and explain the reason why SVM is robust to noise according to influence of support vectors' position to classification.Discarding certain samples which were judged as noise based on SVM improves the robustness.Amounts of experiences in PubFig dataset verify the efficiency of SVM and the improvement algorithm in noisy learning.

    Medical Image Segmentation Based on C-V model
    WEI Ming-Xiang, CHEN Jun
    . 2012, 25(5):  101. 
    Abstract ( 1158 )   PDF (812KB) ( 868 )  
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    This paper focuses on two different GAC models:Li Chunming model based on gradient information and C-V model based on region information.In light of the drawbacks and advantages of these two models,we introduce penalty-function to C-V mode,and propose a C-V model without re-initialization.A comparison between the two models shows that the proposed model incorporates the segmentation speed of Li Chunming model and the segmentation performance of C-V model.

    Random Network Coding Based on Hadamard Matrix
    YU Su-Fu-Jiang-·Yi-La-Yi-Mu, REN Ping-An
    . 2012, 25(5):  105. 
    Abstract ( 962 )   PDF (474KB) ( 1008 )  
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    This paper introduces and analyzes the superiority of the random network coding applied to the wireless network coding;meanwhile,it conducts a study of the properties of Hadamard matrix.The random network coding method based on Hadamard matrix is proposed,and practical application shows that the coding coefficient based on Hadamard matrix not only realizes the effective network coding transmission,but also guarantees the security of the data transmission as well as decreasing the complexity of the existing random network coding algorithm.

    DCM Dynamic Reconfiguration Design Based on Virtex-4
    FANG Huo-Neng, XING Kai-Yu, CAO Xiao-Man
    . 2012, 25(5):  108. 
    Abstract ( 1067 )   PDF (779KB) ( 803 )  
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    This paper introduces the structure and related characteristics of Digital Clock Manager (DCM) in Xilinx FPGA,proposes a scheme reconfiguring the DCM dynamically based on Xilinx FPGA,and gives the specific implementation system.With just a few external control signal lines connected to Xilinx XC4VFX100,this system can enable DCM to change frequency accurately and quickly between 50 MHz and 300 MHz under the 100 MHz input clock source conditions.This design system features a simple interface,real time and high stability,and has already been applied to some satellite system successfully.

    Sketch-Based 3D Free-Form Modeling
    DENG Yuan-Jie, WANG Qian
    . 2012, 25(5):  111. 
    Abstract ( 1015 )   PDF (883KB) ( 773 )  
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    This article presents a 3D modeling approach that uses the varational implicit surface as a geometric representation for free-form shapes.The modeling processes are described in detail and the problems that deserve special attention in each step are pointed out.A robust program for sketching free-form silhouette is designed.Program running tests show that the varational implicit surface modeling is smooth and closed,and convenient for fusion and other follow-up operations.

    The Design and Implementation of Bluetooth Software Based on Android Health Service Terminal
    LI Li-Guo, ZHANG Hui, CHENG Hao
    . 2012, 25(5):  115. 
    Abstract ( 1313 )   PDF (797KB) ( 887 )  
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    Based on the Android operating system in a health service terminal,this paper introduces a Bluetooth application programming method.On the basis of analyzing the Bluetooth and the Android operating system,we focus our research on operating system support of Bluetooth.Then,we design the Bluetooth application software based on the Android operating system.Practical tests show that the application software meets the design requirement and is of practical value.

    A Multi-objective Optimization Algorithm Based on Differential Evolution with the Bidirectional-search Mechanism
    SONG Tong, ZHUANG Yi, GUO Yun
    . 2012, 25(5):  119. 
    Abstract ( 1089 )   PDF (610KB) ( 871 )  
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    In order to avoid the situation of falling into local optimum when solving the Multi-objective Optimization Problem (MOP) with Differential Evolution Algorithm (DE),we design a bidirectional search mechanism which can improve the ability of local search of the DE and reduce the risk of local optimum,as well as make the Pareto fronts more evenly distributed.Experimental results show that the proposed method is more efficient than similar algorithms such as NSGA-II with better precision and distribution of Pareto optimal solution.

    n-n-1:Fuzzy Steady-state Reliability of G System
    GUO Yang-Yang, SONG Yue, LI Gang-Ping
    . 2012, 25(5):  123. 
    Abstract ( 961 )   PDF (445KB) ( 775 )  
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    The constant assumption of failure rate and repair rate on Classical Markov model does not accord with the reality,such as the failure rate and repair rate influenced by factors like climate or environment.It is of greater practical significance to use fuzzy number to represent the failure rate and the repair rate.In this paper,A fuzzy Markov modeling method is put forward and an algorithm for calculating the fuzzy steady maintainability equation of n-n-1:G system is established using fuzzy probability theory and fuzzy mathematics theory analysis.The reliability of each state are given in the form of cut set,and finally the steady-state system availability is worked out by remove fuzzy.

    Improved Association Rule Mining Algorithm Based on Two Matrixes
    CAO Feng-Hua
    . 2012, 25(5):  126. 
    Abstract ( 1043 )   PDF (640KB) ( 986 )  
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    Apriori and its improved algorithms can be generally classified into two kinds:SQL-based and on memory-based.In order to improve association rule mining efficiency,after analyzing the efficiency bottlenecks in some algorithms of the second class,an improved efficient algorithm is proposed.Two matrixes are introduced into the algorithm:one is used to map database and the other to store frequent 2-itemsets related information.Through the operation of two matrixes,its time complexity and space complexity decrease significantly.The experiment indicates that the method has better performance.

    Algorithm for Background Update in Video Vehicle Detection Based on DSP
    WANG Min, ZHENG Jia-Hao, WANG Jin-Bao
    . 2012, 25(5):  129. 
    Abstract ( 955 )   PDF (1025KB) ( 818 )  
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    A multi-frame average algorithm and a self-adaptive update algorithm are described and implemented on ADSP-BF561 DSP platform.Both algorithms are commonly used in background update in video vehicle detection.The accuracy of the two algorithms is proved by testing,and the real-time performance is compared and analyzed.

    A TI DM642 Based Implementation of OpenSURF
    YU Hai
    . 2012, 25(5):  133. 
    Abstract ( 1176 )   PDF (1117KB) ( 846 )  
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    In order to satisfy the increasing need for embedded,real time and robust image feature extraction algorithms in the field of machine vision,OpenSURF is ported to TI DM642 digital signal processor,and optimized based on the characteristics of the device.Test results have confirmed that the ported version of OpenSURF has the capability of processing video in realtime.Meanwhile,this implementation is highly portable.

    Design and Realization of Frame Synchronization Used in G3-PLC
    LI Shu-Qing, FENG Heng
    . 2012, 25(5):  137. 
    Abstract ( 1283 )   PDF (804KB) ( 662 )  
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    The large number of subcarriers in G3-PLC system causes too many samples of preamble in time domain.Traditional synchronization algorithm based on cross-correlation needs large operations and is hard to realize when used in this system.According to the characteristic of preamble in G3-PLC,a new synchronization algorithm is put forward,which reduces the operation by two orders in magnitude with slight performance degradation.The algorithm is realized in FPGA.

    Low Complexity Algorithm for PAPR Suppression in OFDM System Based on PTS
    WU Jia-Yi, CHEN Jian-Chun
    . 2012, 25(5):  142. 
    Abstract ( 1019 )   PDF (478KB) ( 642 )  
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    In order to lower the complexity of PAPR suppression techniques based on the partial transmit sequences (PTS) algorithm,research on the relevance between the positions of top highest values in OFDM time-field signal and those of top highest values through PTS algorithm is conducted.On the basis of the research,a simplified algorithm in which the sampled data replace the original data on searching for the optimized phase agent series is proposed.By the new algorithm,adopted data is much less than the original data,and the calculating complexity of PTS decreases greatly.The simulation demonstrates that the new algorithm can reduce the data amount by 50% while the performance loss ranges only from 0.2 dB to 1 dB.

    Application of Grey Correlative Analysis in the Analysis of Primary Factor Influencing Products Cost
    CHEN Bao-Ping
    . 2012, 25(5):  145. 
    Abstract ( 828 )   PDF (523KB) ( 689 )  
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    There are too many factors effecting product cost.The determination of primary factor is critical to the economic profitability of the enterprise.In this paper,the grey association analysis method is applied to get the primary factor of influencing products cost by establishing a mathematical model to calculate the comprehensive correlative degree of each contributing factor to product cost.An example is provided to illustrate procedures of the method.The result shows that gray correlative analysis method has lower requirements for sample size and sample regularity without inconsistency between quantitative and qualitative results.The method is also quick and simple in calculation.

    Design of Factory Information Monitoring System Via Cloud Computing
    XU Zhi-Bo, LIU Zhao
    . 2012, 25(5):  148. 
    Abstract ( 1401 )   PDF (584KB) ( 675 )  
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    Factories in manufacturing require efficient monitoring to ensure product quality and production safety,but the traditional distributed model can not manage efficiently and meet the growing production demands.In view of this situation,this paper introduces the cloud computing technology into the factory information monitoring,and proposes a factory information monitoring system design via cloud computing.The design takes full advantages of cloud computing in management and services,improves the management of the factory efficiency,and lowers its operating cost.


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