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Table of Content

15 May 2011 Volume 24 Issue 5
  
    Articles
    Fast Interpolation of Wind Angel RCS Calculation of Electrically Large Objects with Open Cavities
    CHENG Qiong-Nian, XIE Yong-Jun, LEI Zhen-Ya, FAN Jun, MO Yuan-Nan
    . 2011, 24(5):  1. 
    Abstract ( 1613 )   PDF (728KB) ( 920 )  
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    An interpolation technique which combines Chebeshev approximation and shooting and bouncing ray (SBR) method is proposed to calculate wide angel radar cross section (RCS) of electrically large object with open cavities.The nodes of Chebyshev within a given angel range are found firstly,and the RCS at these nodes are computed by SBR method.Then the wide angels RCS can be obtained at any angel within the given angel range via the Chebeshev approximation.The numerical results show that this method is efficient and accurate,and can save more than 60% computing time.

    Time-Frequency Beam Forming Based on the OFDM System
    HAN Shuang-Lin, CHEN Jian-Chun
    . 2011, 24(5):  4. 
    Abstract ( 1840 )   PDF (416KB) ( 1092 )  
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    The combination of smart antennas and OFDM can improve the system performance.The paper first introduces two beam forming algorithms in OFDM-Smart Antennas system: time beam forming and frequency beam forming,then proposes  the time-frequency beam forming algorithm,and finally simulates and compares the three algorithms.The result shows that the time-frequency beam forming algorithm has better performance than the time beam forming in the multiple-path environment.Compared with the frequency beam forming algorithm,the time-frequency beam forming algorithm has a greatly simplified structure and is easy to implement.

    An Algorithm for Fast Estimation of MPSK Carrier Frequency
    WANG Wei
    . 2011, 24(5):  7. 
    Abstract ( 1175 )   PDF (362KB) ( 937 )  
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    Aiming at the carrier frequency recovery problem of MPSK signals,we propose a carrier frequency fast estimation algorithm by combining spectral detection theory and nonlinear transformation in this paper.The algorithm theory is introduced in detail,and the algorithm performance simulation is given.The results show that the proposed algorithm can achieve the aim to estimate MPSK carrier frequency quickly and accurately.

    Research on the Network Configuration Management System Based on the Finite State Machine
    DING Zhen-Guo, DING Li-Ying, ZHAO Yong-Jie
    . 2011, 24(5):  10. 
    Abstract ( 1458 )   PDF (687KB) ( 919 )  
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    To help the administrator obtain device information and configure the network device with easy and rapidity,this paper introduces the design of the finite state machine model and achieves the unified conversion of different commands from devices.The system realizes the configuration to the remote devices through the telnet commands based on the unified conversion.The visualization configuration of the equipments is more convenient through the SNMP.Finally,the testing environment is created,and each function of the configuration management system is tested.The results show that the system can monitor and configure the remote device flexibly.

    A Classification Method Based on RVM Regression
    WANG Li-Kun, YANG Xin-Feng
    . 2011, 24(5):  14. 
    Abstract ( 1694 )   PDF (549KB) ( 929 )  
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    The support vector machine is a state-of-the-art technique for regression and classification.However,it suffers from a number of disadvantages,notably the absence of probabilistic outputs,the requirement to estimate a trade-off  parameter C and the need to utilize ‘Mercer’ kernel functions.The Relevance Vector Machine suffers from none of the above disadvantages,and obtains comparable generalization performance.The RVM requires dramatically fewer kernel functions.In this paper,we introduce a new classification method based on RVM regression,which is called RVRC.Experiments demonstrate its practicability.

    The Matlab Simulation of the GPS Signal and the Interference
    MA Ru, HU Jian-Wei, YANG Li-Cheng
    . 2011, 24(5):  17. 
    Abstract ( 1965 )   PDF (794KB) ( 1095 )  
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    This paper simulates the parameter of the GPS signal(data signal,C/A code) and the different interference methods of GPS with Matlab as emulation mode.The relation between JNR and the BNR in different interference methods is analyzed.

    An Laundry Management System Based on HF RFID Technology
    LUO Bin
    . 2011, 24(5):  23. 
    Abstract ( 1906 )   PDF (673KB) ( 2830 )  
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    In this paper,the principle of RFID 13.56 MHz is introduced.Based on RFID technology,a laundry management system is proposed,which can effectively identify the washing times,the types and quantities of clothes or linen to substantially increase the efficiency of the management of industrial laundry business.

    Application of the Equality Circuit Law in the Analysis of Amplifying Circuits
    LI Hong-En
    . 2011, 24(5):  26. 
    Abstract ( 1390 )   PDF (418KB) ( 969 )  
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    The article introduces several common types of amplifying circuit,and then take transistor amplifying circuit for example to illustrate the procedure of Equality Circuit Law.The analysis applies to field-effect tubes and MOSFET-based amplifying circuits.

    Design and Realization of a Multichannel Temperature Collection System Based on MAX6675
    HU Zhao-Ji, REN Ai-Feng, WANG Qiao-Yu, XIONG Xin
    . 2011, 24(5):  29. 
    Abstract ( 2258 )   PDF (563KB) ( 1018 )  
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    In this article,MAX6675 is applied to design a multiplex temperature collection system with type-K thermocouple based on CPLD.The article introduces the instruction of the system hardware circuit and the process of logical circuit designing inside of CPLD according to the working principle of the chip.Finally the article gives the statistic figures of temperature data of the system in two different temperature cases.The statistic figures prove the good performance of the system.

    Design of a 16×16 Phased Array of Multi-beam width
    SHI Jing, LEI Zhen-Ya, WANG Yong-Guang, XING Lian-Fa, JIN Li
    . 2011, 24(5):  32. 
    Abstract ( 1437 )   PDF (587KB) ( 1136 )  
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    A new 256-element circularly polarized patch antenna array in the Ka-band is presented.The antenna array has the features of multi-beam scanning and a wide scanning range.Chebyshev weighting is used to realize multi-state and multi-beam scanning.The results achieved show that the scanning range is about ±40 ° and the beam width is controllable at the center frequency of 31 GHz.

    Application of Z-FFT Transform in Station Demodulation of Cab Signals
    WANG Li-Ping, MIAO Cheng-Wei
    . 2011, 24(5):  35. 
    Abstract ( 1670 )   PDF (456KB) ( 877 )  
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    Based on Z-FFT transform demodulates station's ZPW-2000A track circuit signal,the closed loop detection of locomotive's signal code of the station in real time is realized.The design is based on the dual cores of the TMS320F2812 DSP.Z-FFT transform demodulates the low frequency and carrier frequency signal in the dual DSP,and compare information demodulated through the SPI port of DSP in real-time,thereby greatly enhancing the system reliability.

    Research on Channelization-based Tuned Ratio Measurement
    CHEN Hai-Feng, LIN Cun-Hua
    . 2011, 24(5):  38. 
    Abstract ( 1170 )   PDF (438KB) ( 868 )  
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    This paper expounds the characteristics of the orthogonal double channel signal.It gives the 16 and 32 road channel model.On the basis of this,the linear frequency modulation signal,triangle frequency-modulated signal,and the sine frequency-modulated signal to be measured are made to pass the two channels.The method of orthogonal double channel is used to take envelope.Each channel tuning rate is obtained by envelope.The difference in the number of channels and the effect of different tuning modes on the result of the test are also covered.

    Design of a Frequency Response Analyzer Based on DSP
    WEN Shi-Xiang, ZHAO Jing
    . 2011, 24(5):  41. 
    Abstract ( 1967 )   PDF (496KB) ( 912 )  
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    The paper proposes a method of designing a low cost,digital and intelligent frequency tester,with the use of modern digital signal processing and display technology based on Direct Digital Synthesis.The system realizes the frequency and phase measurement of tested network from a range of 20 Hz to 150 MHz,and completes the function of the data storage,-3 dB bandwidth calculation,peak search and so on.The structure achieves a range of precision of 1dBm and phase detection accuracy of 1 degree.

    Design and Realization of a Signal Processing Board Based on TMS320F28335
    LIU Yu
    . 2011, 24(5):  44. 
    Abstract ( 1197 )   PDF (729KB) ( 830 )  
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    This report introduces the design and realization of digital signal processing board of Deviation Surveying Instrument based on TMS320F28335.The functional properties and some periphery connection of TMS320F28335 DSC made by TI Company are outlined,the specific function application and basic hardware structure of the signal processing board are described,and the whole system software structure and specific implementation of specific software modules are analyzed.The whole system realizes the sampling of the analog signal,DSC digital signal processing,EEPROM's reading and writing and communication with upper computer.Using the interrupt technology of TMS320F28335,every functional module can normally run in its own interrupt thread without mutual interference,thus avoiding the system chaos.

    Realization of Multi-tone Parallel Modulation Based on DSP Platform
    HE Wei
    . 2011, 24(5):  48. 
    Abstract ( 1871 )   PDF (833KB) ( 928 )  
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    This paper takes 32-tone parallel modulation as an example to realize multi-tone parallel modulation with DSP hardware platform.The realization of its main modules is provided.Owing to its sophistication,low cost and high cost efficiency,the parallel mode is helpful in improving data transmission speed and eliminating multipath fading.

    Research on the Influence of Changing the Frequency of Phase Detector on the Linearity of the Frequency Modulated Continuous Wave Signal
    WANG Kun-Feng, NIU Zhong-Qi, YANG Bo, ZHU Wei
    . 2011, 24(5):  53. 
    Abstract ( 1542 )   PDF (503KB) ( 1004 )  
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    A scheme for producing a linear frequency modulation signal generated by rapidly changing the division ratio of the phase locked loop is studied in this wok.The impact of the phase detect frequency of the phase detector on the linearity of the sweeping signal is discussed.By analyzing the results of ADS modeling simulation,it is concluded that a FMCW signal with high precision and good linearity can be observed with an appropriate interval of the change of division radio and a higher frequency of the phase detector leads to better linearity of the FMCW signal.

    Design and Realization of the Wireless Sensor Network MAC Controller Based on FPGA
    LI Zi-Xue, HU Fang-Ming, REN Yong
    . 2011, 24(5):  56. 
    Abstract ( 1785 )   PDF (594KB) ( 922 )  
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    A design for the MAC controller of wireless senor networks implemented by FPGA is presented,The top-down approach is adopted to design each module and is simulated in quartus II8.0.It supports the IEEE802.15.4 protocol.The testing result shows that he proposed MAC architecture can operate at a rate of 20~250 kb·s-1 and correspond with the IEEE802.15.4 protocol.

    1553B Bus Board Based on BU-61580 Design
    LI Na, LI Zhan-Ming, LIU Fang-Dong
    . 2011, 24(5):  59. 
    Abstract ( 1505 )   PDF (439KB) ( 948 )  
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    In recent years,owing to its advantages of simple construction,good reliability,high transfer rate,mature technology,and good extendibility,MIL-STD-1553B bus has been widely adopted in aerospace observe and control network.BU-61580 interface protocol chip,manufactured by DDC Company of America for realizing the converting from microprocessor to 1553B bus signal,has the characteristics of BC/RT/M integrative design,single power supply,and electromagnetism compatibility that meet the requirements of Army standard.The 1553B bus board based on BU-61580 design is introduced in this article,which can be widely used in aviation and communication for strong ability of extending and functions.

    Design of a Soymilk Grinder Based on SH69P42 Microcontroller
    LIU Fen
    . 2011, 24(5):  62. 
    Abstract ( 1889 )   PDF (431KB) ( 978 )  
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    In this paper,design of an efficient time-saving soymilk grinder based on SH69P42 microcontroller is proposed in view of long pulping time problem of existing soymilk grinder.It does not change the basic structure and function of soymilk grinder,while the spindle of motor is installed on a simple defoaming device.Control strategies of heating and pulping parallel processing and heating and defoaming parallel processing are adopted,which can shorten half of the pulp time and can greatly improve the efficiency.It is proved that the design is feasible and has greater market potential.

    A Novel Digital Capacitive Liquid Level Sensor
    LI Yi-Fang, ZHU Hua-Ming, TONG Xin
    . 2011, 24(5):  65. 
    Abstract ( 1203 )   PDF (743KB) ( 1277 )  
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    Based on the principle of capacitance changed with dielectric constant between the two plates,a kind of technology for measuring liquid level of automobile fuel tank is introduced,and the amount of residual fuel and temperature in tank is displayed by LCD.With the automatic-compensation function of capacitive probe for signal acquisition,the temperature and impurities of fuel have no effect on the results.A highly-integrated capacitance-to-digital converter is used to detect capacitance signal to improve the measurement accuracy.The signal transmission network can be integrated with automotive body-network system easily and the accurate and real-time result is displayed.

    Design of a Novel Frequency Sweeper
    MA Wen-Rui, YANG Pei-Jun
    . 2011, 24(5):  69. 
    Abstract ( 1822 )   PDF (577KB) ( 1139 )  
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    A new RF sweeping system based on a structure composed of DSP and FPGA is presented,with focus on the design of the sweeping signal generator.The trend of frequency synthesizers is discussed.After introducing the theory of phase locked loop and direct digital frequency synthesis technology,a design of signal generator based on the DDS+PLL structure is put up in the end of this paper.

    Design of an Intelligent Data Acquisition System for the Pointer Instrument
    WANG Yi, ZHAO Jing, WEN Shi-Xiang
    . 2011, 24(5):  73. 
    Abstract ( 1835 )   PDF (759KB) ( 867 )  
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    The system designed with ADSP-BF533 + FPGA EP1C6T144C8 architecture achieves image acquisition,target identification and meter reading,USB transmission and RS485 bus transmission network function.DSP processes the collected image gray-scale transformation,edge detection and Hough transform,to achieve recognition of the pointer instrument dial,pointer positioning and calculating the reading,and to achieve data broadcast of the pointer reading and storage.FPGA accepts DSP's instructions to achieve acquisition and control of the COMS camera,scanning the keyboard and other device chip-select signal generation.Using SQLSERVER database technology programs for host computer can manage the measuring data and backup.

    A Double Channel Receiver
    LI Jian-Guo, SHI Jian
    . 2011, 24(5):  78. 
    Abstract ( 1341 )   PDF (334KB) ( 907 )  
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    In engineering,logarithmic amplifier receivers have very wide dynamic range,but it can hold only the frequency and phase information while amplitude information is lost.Linear receivers have very small a dynamic range when AGC is not established,but can reserve all amplitude information.This article introduces a double channel receiver design methods,by which the receiver has a linear channel and a logarithmic channel.Logarithm channel output is used to expand linear channel transient response range.

    Infrared and Visible Image Registration by Combination of Second-order Mutual Information and Alignment
    KUANG Ya-Bin, WANG Jing-Dong, LI Peng
    . 2011, 24(5):  80. 
    Abstract ( 1811 )   PDF (1287KB) ( 989 )  
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    In this paper,a registration algorithm that combines second-order mutual information with alignment as a similarity function is proposed.Firstly,the consistency lines are extracted from visible/IR images by using Hough transform.Secondly the alignment metric of consistency lines is calculated.Finally,these different images are registered by adjusting the proportion of alignment metric in the new similarity function.Experiment results demonstrate that the proposed similarity function shows higher accuracy and robustness than the conventional similarity functions.

    Design of an Intelligent Control System for Energy-saving Public Lighting
    FU Li
    . 2011, 24(5):  85. 
    Abstract ( 1879 )   PDF (623KB) ( 915 )  
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    On the basis of the traditional human body phyoelectric infrared switch,motor-based mechanical parts are added to drive the pyroelectic sensor moving cyclically,so that the pyroelectric sensor can scan human body even they keep still for a long time.An Atmega8 microcomputer-based controller is also added,and in cooperation with the software,the intelligent system is able to judge the environment and make a rapid action correctly.The system can be used in classrooms,offices and other place where high quality lighting is required.To save energy,the system controls the lights on where there are people,and lights off elsewhere.In addition,installation of the system requires only minor changes to the original lines.

    Application of FMEA in Product Reliability Improvement
    WEN Xiu-Qin
    . 2011, 24(5):  89. 
    Abstract ( 1330 )   PDF (365KB) ( 860 )  
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    In this paper,we analyse the fault modes existing in ramp test for X-type Automatic Direction Finder systematically by FMEA method,find the effect and fault inclement degree of each fault mode on the product itself,the system and the aircraft,propose the design improvement measurement and apply it into improved product,and finally realize the reliability improvement target by tests.

    A Lightweight FAT File System
    DANG Xiao-Yu
    . 2011, 24(5):  91. 
    Abstract ( 1238 )   PDF (524KB) ( 808 )  
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    This paper introduces the features of Petit FatFs.As a lightweight FAT file system,Petit FatFs gives a rather ideal solution for the low-end microcontroller to read and write SD card and another mass storage device.

    Mixed Adaptive Image Denoising Algorithm Based on Noise Isolation and Wavelet Thresholding
    WAN Qian, XUE Ming
    . 2011, 24(5):  94. 
    Abstract ( 1788 )   PDF (884KB) ( 893 )  
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    In view of the limit of Visushrink thresholding and the cases of mixed noises,a mixed adaptive image denoising algorithm based on noise isolation and wavelet scale is proposed.Firstly,the impulse noise and Gaussian noise are separated by extreme value detection,and then the impulse noise is processed by multi-window median filter,while the improved wavelet thresholding is applied to the Gaussian noise.Experiments show that the mixed filter algorithm can effectively remove impulse noise and Gaussian noise in the image and preserve the image details as well.

    Research on Yunnan Standard Yi Language Fonts Design and Character Coding
    LI Yun-Pan, WANG Jia-Mei, ZHENG Sheng
    . 2011, 24(5):  97. 
    Abstract ( 1405 )   PDF (1089KB) ( 1008 )  
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    Yi language is spoken in Sichuan,Guizhou and Yunnan Provinces in Southwest China.More new words are derived from changing the position of character' structure,increasing the strokes and other methods.Therefore the Yi language words have obvious features of the glyph structure.This paper uses the Yi language words' special glyph structure,and design fractal coding scheme for Yunnan standard Yi language,and then achieves the input method of Yunnan standard Yi language by Windows IME API,and designs and manufactures the Yunnan standard Yi language' fonts,which are beautiful and practical and guarantee the quality of the output Yi language words.It plays an active role in protection and research on Yunnan standard Yi language and other parts of the Yi languages.

    Design of a Fingerprints Entrance Guard System Based on ARM and PoE
    CHEN Xian-Ming, LI Meng-Xiang
    . 2011, 24(5):  102. 
    Abstract ( 1565 )   PDF (507KB) ( 914 )  
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    A fingerprints entrance guard system design based on the ML67Q5250 and PoE's implementation scheme is proposed with a description of the system structure,working principle,and software and hardware design.The system has the advantages of high speed fingerprint identification,fingerprint data protection,Ethernet power supply,simple structure,low power consumption,and low cost,and can meet the needs of fingerprint identification system with a good application prospect.

    Design and Implementation of a Helicopter Virtual Instrument DLL
    SHI Chun-Hu, QU Hong-Xing, CHEN Lei
    . 2011, 24(5):  104. 
    Abstract ( 1268 )   PDF (782KB) ( 921 )  
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    A virtual instrument DLL method is adopted in helicopter computer-based training system in order to simplify the division of labor and make the system easier to be expanded and maintained.GL Studio is used to develop virtual instrument with 3D MAX and Photoshop for texture making.With model created,interface function defined and behavior code finished,virtual instrument program is compiled to DLL for main program to transfer.This method makes the design and maintenance efficient.

    A System of Wireless-Answering for Teaching
    WANG Ke-Zhong, SONG Zhi-Chao
    . 2011, 24(5):  108. 
    Abstract ( 1398 )   PDF (850KB) ( 845 )  
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    A Wireless Answering Question Implement with statistics function is designed to substitute raising hands to facilitate teaching.The Answering Question Implement is based on the chip SOC-CC2530 form TI witch support IEEE 802.15.4.The article analyses the protocol for the implement,describes the process of transmission and reception,and gives the gist of hardware and software design.Experiment shows that the implement meets the need of teaching with good stability and reliability.

    A New Image Watermarking Algorithm Based on DCT and SVD
    LV Dong-Yue, XU Gui-Li, LI Kai-Yu, TIAN Yu-Peng
    . 2011, 24(5):  112. 
    Abstract ( 1373 )   PDF (713KB) ( 885 )  
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    Among all watermarking algorithms based on singular value decomposition (SVD),using the orthogonal matrices assures non-replacement of watermark,but it will affect the accuracy of the watermark if the orthogonality is not maintained.In order to solve this problem,a novel binary watermark algorithm based on discrete cosine transform (DCT) and SVD is proposed.The left orthogonal matrices of host image's sub-blocks' DCT coefficients are modified according to the orthogonality of trigonometric function to embed watermark bits in the proposed algorithm.Experimental results show that compared with current algorithms using SVD,the orthogonality of the left orthogonal matrices is maintained.The results also show higher extracting accuracy in resisting JPEG compression and salt and pepper noise.

    A Review of Brain-computer Interface Development
    LIU Hui, DU Yu-Xiao, PANG Jie, LI Wei-Yan
    . 2011, 24(5):  116. 
    Abstract ( 2330 )   PDF (610KB) ( 1121 )  
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    A brain-computer interface (BCI) is a novel communication system that translates human thoughts or intentions into external devices control signal.In this paper,we present the rationale and the methodology of BCI's technology,the recent progress and some vital aspects.The challenges in the future development are also described.

    Application of CAN Bus in the Automotive Sector
    WANG Wen-Hai
    . 2011, 24(5):  120. 
    Abstract ( 1414 )   PDF (366KB) ( 839 )  
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    CAN bus technology,owing to its unique design,high reliability and excellent features,is widely used in field bus,especially for industrial process control equipment interconnection.In the automotive industry,many cars have adopted the CAN bus technology.This paper analyzes the development and the characteristics of automotive CAN bus technology,and discusses in depth its applications in automotive sector.

    Existing Problems and Countermeasures of Web Programming Teaching Interaction
    ZHANG Hong-Sheng
    . 2011, 24(5):  122. 
    Abstract ( 1181 )   PDF (531KB) ( 885 )  
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    Aiming at the above four problems existing in current classroom teaching of Teacher-student interaction,the author puts forward some effective countermeasures,namely,through the study of interactive computer classroom teaching,to cultivate students' consciousness of participation,and to enhance their ability of operating and thinking.Experiments show that effect of teaching is improved and teaching goals are fulfilled.

    Scientific Outlook on New Teaching Modes of Electrical Engineering Practice
    OU Zhou-Feng, WANG Jian-Li
    . 2011, 24(5):  125. 
    Abstract ( 1233 )   PDF (544KB) ( 832 )  
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    This article presents some ideas and views on the status and development of the Training center and Electrical Engineering Department of the university.In line with national practice teaching evaluation and selection of teaching demonstration center,and based on the characteristics of professional disciplines,the paper explores and proposes a new model of education reform to adapt to today's society and to meet the complex human needs.

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