• Volume 39,Issue 10,2016 Table of Contents
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    • >Research&Design
    • Digital management technology of LCD driver chip test based on EtherCAT

      2016, 39(10):1-5.

      Abstract (1180) HTML (0) PDF 3.26 M (1532) Comment (0) Favorites

      Abstract:LCD drive chip testing throughout the whole design, manufacturing and application process, the chip test is an important means to ensure the quality of the drive chip. Because the test system needs to match many different models of the driver chip, the test items and test signals of a single model chip are huge, if use the way of manual record, the test efficiency will be low and management costs will be high. It is necessary to develop digital management technology for the whole test system under this situation, the test equipment, persons and data can be managed through using this new technology. In order to make the data exchange realtime and efficient, the EtherCAT technology has been used in this system. After that, the client of the equipment and server can work closely. The test of system shows that the technology can conveniently record the data in the test process; it also has strong scalability, if want to update the whole system only need to add client device or hardware module and upgrade of the system software.

    • Operation analysis of microgrids control method based on masterslave configuration

      2016, 39(10):6-10.

      Abstract (1023) HTML (0) PDF 992.18 K (1706) Comment (0) Favorites

      Abstract:According to the masterslave structure of microgrids control strategy, three micro source low voltage microgrids simulation model is built using the general large electromagnetic transient simulation software PSCAD / EMTDC, in grid connected operation, using PQ control, micro source maximum power output; in the islanding operation, the main control of micro sources using V / F control, for the stable operation of microgrids provides voltage and frequency support. Masterslave structure of microgrids system respectively in the operation of grid connected and islanded operation dynamic characteristics are analyzed by electromagnetic transient simulation software PSCAD / EMTDC. The simulation results verify the effectiveness and feasibility of the proposed control strategy. To lay the foundation for further research on the control strategy of the master slave structure.

    • Control Strategy research based on current reconstruction for PWM rectifier

      2016, 39(10):11-15.

      Abstract (1212) HTML (0) PDF 1.12 M (1676) Comment (0) Favorites

      Abstract:The control strategy is proposed after deep research of the topology and mathematical model of PWM rectifier, which is based on phase current reconstruction and virtual flux. The threephase alternating current can be reconstructed according to the DC bus voltage and switch signal. After conditioning filter, the reconstructed current can create a virtual grid flux to get the information needed to estimate the angle of voltage and current for coordinate transformation. The control strategy can not only be used as an sensorless control strategy for PWM rectifier, but also can be use as an alternate control strategy to reduce the impact caused by sensor failure and improve the reliability of system. The experimental platform was designed which is based on RTLAB realtime simulation hardware circuitry and digital processors TMS320F28335. The experiment result shows the correctness and feasibility of this control strategy.

    • Research on high coupling energy storage inductance used for pulse power supply

      2016, 39(10):21-25.

      Abstract (1116) HTML (0) PDF 994.89 K (1697) Comment (0) Favorites

      Abstract:Coupling inductance is a key factor in inductive storage pulse power supply. Starting from STRETCH Meat grinder circuits, the concept of high coupling inductance is described first in this paper, then high coupling energy storage inductance models are given by analyzing key factors influencing coupling degree, and mathematical derivation is carried out for inductance value and magnetic field calculation of coupling inductance. In order to further understand magnetic field distribution of coupling inductance, finite element simulation is performed against it, and magnetic induction intensity distribution map and energy distribution map of coupling inductance are obtained. In consideration of flux leakage, simulating calculation is conducted for flux leakage of coupling inductance in the end part of this paper. Research work in this paper provides certain theoretical basis for optimization design of the high coupling storage inductance used for pulse power supply.

    • Research on the temperature character of the detector of smalldiameter natural gamma ray spectrum logging tool

      2016, 39(10):26-29.

      Abstract (1042) HTML (0) PDF 958.68 K (1592) Comment (0) Favorites

      Abstract:The size and temperature character of the gamma ray detector are primary factors which influence the quality of well logging directly in developing smalldiameter natural gamma ray spectrum logging tool. The spectrum response of the detector is measured at various temperatures in natural radioactive background. By comparing the changes of gamma ray spectrum and the character of the logging tool’s spectrum stabilization by highvoltage at different temperatures, it is able to obtain that, the total rate and the address of element K’s characteristic peak in gamma ray spectrum changes slowly when the environment temperature is below 150 degree centigrade. And under 125 degree centigrade, the resolution of detector works in high condition. So it is said the tool’s best working temperature is below 125 degree centigrade.

    • Research on performance verification of airborne AIS based on flight test

      2016, 39(10):30-33.

      Abstract (1371) HTML (0) PDF 774.92 K (1619) Comment (0) Favorites

      Abstract:By processed the test data, the paper analyzes the performance of airborne AIS. First introduces airborne AIS and its performance to be required, and then gives the way of test and the required data to performance analyses. Using the test data, the paper analyses the some performance of airborne AIS which included processing capacity and receiving capability in orientation and distance. The results of analysis were shown that the output capacity of airborne AIS is more than 500/tcap, and the quantity and quality of messages to be received by Airborne AIS is sensitive toorientation and distance. The results of statistics on the test data of airborne AIS will be provided user with reference.

    • Application of milk sterilization system based on parameter selftuning fuzzyPID

      2016, 39(10):34-36.

      Abstract (1128) HTML (0) PDF 591.06 K (1550) Comment (0) Favorites

      Abstract:This paper introduces the technology characteristic and control requirement of Liquid milk sterilization system.To solve the problems such as low precision and parameters cannot be adjusted according to the working condition which existence in the temperature PID control system ,this paper put forwards a new algorithm which combine fuzzy control with traditional PID control, to optimize the traditional PID temperature control system. This fuzzy control algorithm is realized by Siemens PLC based on the method of lookup table. In order to test the performance of this system, simulation experiments are carried out base on MATLAB. the result shows that the parameter selftuning fuzzy PID control compared to the classic PID control the liquid milk sterilization system has higher control accuracy, faster response speed and, better robustness.

    • Series standard voltage transformers for 750 kV transformer calibration cart system

      2016, 39(10):37-41.

      Abstract (1116) HTML (0) PDF 762.32 K (1644) Comment (0) Favorites

      Abstract:In order to solve the problems of huge equipment, workload and security risks in 750kV Transformer error onsite testing, this paper introduces a new design of 750 kV transformer calibration cart for field test. It uses series resonant boost and comparison method to complete the test, and the most distinctive features of the design is the series standard voltage transformers (SSTV). SSTV based on the theory of voltage summation method and parted type structures, it can be divided into two stages and be connected by high voltage isolation transformers (HVIT). This method can greatly reduce the equipment volume and insulation requirements on the premise of meeting the requirements of accuracy and the compressive strength significantly, the bottom is independently used in 330 kV voltage level test and greatly improve the utilization of the equipment. In addition, we introduce the capacitive standard method and the error analysis of the environmental impact of the SSTV. The final practical application example compares the results between the capacitive standard and SSTV, it shows that two results are basically identical, so the transformer calibration cart has the value of practical application.

    • Research on design of information detection technique based on semantic

      2016, 39(10):42-45.

      Abstract (1122) HTML (0) PDF 1.01 M (1609) Comment (0) Favorites

      Abstract:Information interaction and acquisition are now gradually breaking through the limit of time and space, Text detection technology based on semantic domain has become the new research in this field. This paper proposes topic link detection correlation model based on semantic technology, which involves the basic researches of text comprehension and semantic analysis in relevance determination. It is of great importance for subsequent researches in topic temporal detection. The core of this method is to establish the semantic structures for specific topics, by which the relevance determination can be achieved automatically reacting to the semantic information.

    • >Theory and Algorithms
    • Testing algorithm of overcurrent protection in coal mine highvoltage grid based on sparse matrix

      2016, 39(10):51-56.

      Abstract (1543) HTML (0) PDF 740.07 K (1604) Comment (0) Favorites

      Abstract:In order to avoid override trip or protection reclosure in practical running process and ensure power supply safety of coal mine highvoltage grid, this paper gives a testing algorithm of overcurrent protection in coal mine highvoltage grid based on sparse matrix, it combines overcurrent protection testing algorithm and sparse matrix, obtains power supply relationship matrix between branch nodes, gives computing methods of fault current, acquires final switch matrix that needs to execute trip operation, and executes trip operation for corresponding switch in coal mine highvoltage grid diagram. According to consequence of switch trip, it can determine whether present overcurrent protection setting is reasonable or not.

    • Research on indoor location algorithm based on RBF neural network

      2016, 39(10):57-60.

      Abstract (1538) HTML (0) PDF 1.44 M (2268) Comment (0) Favorites

      Abstract:Located in indoor environment of wireless sensor network, the traditional RSSI (Received Signal Strength Indicator) localization algorithm has the shortcomings of inaccurate distance measurement and imprecise location because of the influence of shelter and the multipath effect. Aimed to solve the problem, a RSSI localization algorithm used RBF (radial basis function) neural network is proposed. Offline stage, the mapping relation between the RSSI value that the reference node received and its spatial coordinate is established. Online stage, the RSSI value is collected and the well trained neural network is performed to locate the node without the known orientation. The experimental results show that the proposed algorithm can effectively improve the positioning accuracy compared with the traditional RSSI localization algorithm.

    • Mechanical model of displacement signal measuring tire unbalanced mass

      2016, 39(10):61-64.

      Abstract (1130) HTML (0) PDF 724.40 K (1416) Comment (0) Favorites

      Abstract:Balance based on the analysis of the dharma wheel load quickened, on the basis of measurement system is insufficient, improve the supporting structure of tire dynamic balance testing device, sensor types and connection mode, the improvement of tire dynamic balance test system, establishes the system amplitude displacement as input variables, tire uneven quality as output variables of multivariable mathematical model, using a laser noncontact measuring method to obtain the displacement signals, finally through the signal processing method of autocorrelation sequence comparison on load tire dynamic balance system displacement sensor and the force sensor signal collected by the timedomain diagram, the method is proven to be to improve stability and sensitivity test system has a better role in promoting.

    • Research on terahertz synthetic aperture radar imaging based on indoor experimental data

      2016, 39(10):65-71.

      Abstract (1332) HTML (0) PDF 1.98 M (1688) Comment (0) Favorites

      Abstract:Synthetic aperture radar to achieve high resolution is based on the premise that the platform is an ideal uniform linear motion. Relative to the traditional microwave SAR, because of the short wavelength of terahertz wave, SAR platform of high frequency micro vibration impact on conventional microwave band SAR is almost negligible but terahertz synthetic aperture radar (THzSAR) must be fine processing.It is necessary to study the imaging compensation algorithm suitable for THzSAR. In this paper, the echo model of THzSAR is established, and the effect of motion error on the echo is analyzed from the time domain and frequency domain respectively. A motion compensation algorithm for THzSAR imaging based on echo data is proposed, the SAR system with center frequency 0.3 THz is used to carry out the experiment, and the 2D image of the corner reflectors is obtained. The experimental results verify the feasibility of the system and the effectiveness of the algorithm, which lays the foundation for the field vehicle or airborne THzSAR imaging.

    • Study on power factor control of doublyfed motor

      2016, 39(10):72-75.

      Abstract (1108) HTML (0) PDF 738.64 K (1613) Comment (0) Favorites

      Abstract:doublyfed motor; power factor; ACAC converter;bivariable; six pulse

    • Spectrum sensing method based on SOMSVM

      2016, 39(10):76-80.

      Abstract (1657) HTML (0) PDF 808.65 K (1630) Comment (0) Favorites

      Abstract:The technology of spectrum sensing plays a key part in cognitive radio(CR). This paper proposed the SOMSVM spectrum sensing model. This model takes the advantage of the clustering of SOM which can contain the same input samples together and decrease the input samples near by the center of the other clustering. SVM is trained by the representative training set after compressed by 20% in SOM. In this paper, sample sets are generated by laboratory instruments, verifying that the SVMbased spectrum sensing model also can obtain good performance under the condition of actual communication environment. The simulation results show that in low SNR the probability of detection is 100% and the probability of error detection is improved by SOMSVM spectrum sensing model.

    • Research on realtime imaging algorithm for multimode SAR with GPU

      2016, 39(10):81-86.

      Abstract (1002) HTML (0) PDF 2.44 M (1535) Comment (0) Favorites

      Abstract:The SAR imaging system is timeconsuming, which is developed based on central processing unit (CPU), because of the huge computation of SAR image processing, making realtime imaging impossible. Based on Computed Unified Device Architecture, This study proposes a new plan for realtime SAR imaging operated on graphic processing unit (GPU) which works for multiple workingmode SAR. This new proposal makes the plan work with small GPU memory by dividing SAR data into pieces, uses the asynchronous execution of multistream technology to cut down the time wasting in data transfer, optimizes memory management to get less access time of memory and uses lightweight function of special function unit (SFU) to reduce clock cycle. All computational resources are totally exploited because this plan is suitable for multi GPU. It has been shown by an experiment on an NVIDIA GT740M and INTEL Q6600 that the proposed plan has an acceleration ratio of nearly 150. The proposed realtime SAR imaging system improves the imaging efficiency greatly and has a better application future.

    • Motion error estimation for SAR systems based on regularized total least square

      2016, 39(10):87-94.

      Abstract (1154) HTML (0) PDF 3.38 M (2389) Comment (0) Favorites

      Abstract:The deviations from the reference track of airborne synthetic aperture radar (SAR) systems decrease the resolution in SAR imagery, and motion error estimation based on raw data is an important step for motion compensation. According to the research of motion error estimation, a new approach for estimation of motion errors based on regularized total least square (RTLS) is proposed. This new method fully considers the effects of the heteroscedasticity of phase estimation error in different range cells, the error of model coefficient matrix and the illconditioned problem in the motion error estimation. It combines weighted method, total least square with regularization method while in process to eliminate the heteroscedasticity and decrease the effects of coefficient matrix error and illconditioned problem. It also utilizes the Lcurve method to realize the automatic regularization parameter selection. The experimental results show that the proposed method is validated and accurate to motion estimation.

    • >Information Technology & Image Processing
    • Video target tracking using strong tracking UKF

      2016, 39(10):95-99.

      Abstract (1101) HTML (0) PDF 814.35 K (1418) Comment (0) Favorites

      Abstract:Aiming to the slow tracking and steadystate errors that exist when UKF(unscented Kalman filter) applied in nonlinear systems state estimation, an algorithm of video target tracking using strong tracking UKF was presented. Based on the unscented transformation, combined with the advantages of strong tracking filter and UKF filter, this algorithm adjusts Kalman gain with introducing timevarying fading factor in priori error covariance matrix to force the output residuals to maintain orthogonal, extract useful information in the residuals and improve the tracking capability to status change. The simulation results show that, moving target tracking in vedio utilizing strong tracking UKF has higher tracking accuracy and smaller MSE in state filtering.

    • Research on an improved neural network license plate recognition algorithm

      2016, 39(10):100-103.

      Abstract (1064) HTML (0) PDF 1.56 M (1482) Comment (0) Favorites

      Abstract:According to the actual application requirements, the requirements of recognition of license plate recognition system with high accuracy, proposes an improved neural network license plate recognition algorithm based on neural network recognition algorithm on the standard was improved in the standard neural network algorithm in the method of increasing the inertia impulse batch processing is improved and tested by training a large number of samples, the experimental results show that the neural network recognition algorithm improved the recognition rate and processing speed is greatly improved compared with the standard neural network character recognition has not improved algorithm has been applied in residential parking lot, achieves the application requirements, and proves that compared the improved neural network license plate recognition algorithm and standard the neural network algorithm in the realtime recognition accuracy has been greatly improved.

    • >Embedded Technology
    • Energy saving application of highway tunnel lighting system based on internet of things

      2016, 39(10):104-107.

      Abstract (1029) HTML (0) PDF 1.64 M (1480) Comment (0) Favorites

      Abstract:Based on the technology of internet of things, an energy saving system of highway tunnel lighting is designed. Through collecting the illumination intensity of the tunnel and monitoring the vehicle flow rate, a data manage ARM system which can collect, save and send dates are constructed, and a remote data server based on TCP/IP is built. By using fuzzy strategy, the lighting control system in tunnel is realized according to the realtime vehicle flow rate and the illumination intensity, which can save the energy of tunnel lighting. Practical system shows that the proposed system based on the Internet of things is stable, it also can lower 20% lighting energy, and it is easy to promote to other cases.

    • Sensing system based on WiFi probing

      2016, 39(10):108-113.

      Abstract (1035) HTML (0) PDF 1.96 M (1513) Comment (0) Favorites

      Abstract:In order to obtain the number of mobile devices WiFi on in some region, a WiFi device sensing system based on MT7620A chipset and embedded operation system OpenWrt was designed. The principle how a mobile device was studied, and then suitable hardware and software platform were chosen. After that, the system was set to monitor mode. With the help of sniff pro, probe requests from mobile devices were captured and media access control addresses were parsed. Implementation mechanism and key technology of the sensing system were elaborated, which include the creation of swap partition on a U disk and the algorithm of how related data captured and saved. The experiment result shows that our system can capture Probe Request stably and is ease to use, and it has some commercial value.

    • >Test Systems and Modular Components
    • Design of MRI communications and pulse generation module

      2016, 39(10):119-123.

      Abstract (1042) HTML (0) PDF 1.25 M (1365) Comment (0) Favorites

      Abstract:To satisfy the require of the MRI main control board, this paper puts forwards a new design which uses FPGA development board as main control board and uses Nios II as a coprocessor. We transplant the μC/OSII operating system and protocol stack lwIP to achieve the network communication with computers. Then we use the hardware language Verilog to write pulse sequence generation module to achieve the analysis and execution of the command. Eventually it produces user's pulse sequence. Final test results show that the communication rate of the main control board and pulse sequence which is obtained by oscilloscope can satisfy the requirements of the MRI system. Compared with the past of the whole software design, this design make the MRI system higher precision and more stable.

    • Life test of stepping motor control base on RTX

      2016, 39(10):124-129.

      Abstract (911) HTML (0) PDF 2.61 M (1359) Comment (0) Favorites

      Abstract:Stepping motor is playing an increasingly important role in modern control. In order to guarantee the reliability of the product, the stepping motor’s life becomes especially important. The evaluation system based on Windows can solve the problem very well. However due to the Windows operating system has poor realtime performance, the driving signal timing produced by it can’t meet the requirements of stepping motor which requires precise timing. This paper adopted the hard realtime solution RTX based on Windows which is produced by Ardence. Combining with the experiments of project about stepping motor life, the paper summarized the design method and development process of RTX realtime application system. It is proved by experiments that drive signal generated based on RTX can satisfy the demands of stepping motor. Additionally, it is not affected by the external events and has good repeatability. As a result, the method is realtime, stable and reliable.

    • >Intelligent Instrument and Applications
    • Numerical transform of industrial sewing machine based on DSP

      2016, 39(10):135-139.

      Abstract (987) HTML (0) PDF 3.44 M (1461) Comment (0) Favorites

      Abstract:According to the degree of automation of mechanical drive industrial sewing machine parts of the low, slow response speed, transmission mechanism between the gear accuracy and weak synchronization, mechanical shaft is easy to appear the mechanical resonance, noise and so on, this article will use the 3 motor independent control of three motor units, industrial sewing machine. The motor control system with single takes DSP as the control chip and related peripheral circuit composed of three closed loop DC speed control system (speed loop, current loop, position loop). Experimental results show that the motor control system can achieve good dynamic performance and wide speed range, and the system has the advantages of simple structure, speed error within 2%, reliable operation, and has high use value.

    • Research on the design of small intelligent modularization distributor based on SSPC

      2016, 39(10):140-144.

      Abstract (1125) HTML (0) PDF 1.05 M (1392) Comment (0) Favorites

      Abstract:To solve the problem of spacecraft power supply and distribution system weight and volume constraints, and to increase the proportion of effective load, using a miniaturization intelligent distribution solution which chooses single chip microcomputer (SCM) as the core processor, solid state power controller (SSPC) for power output devices, RS422 data bus to data transmitting. In place of the traditional design using relay and breaker as power output device and cable as Instruction transmission medium, the design realizes reliable power supply and distribution of electric load of spacecraft. It can not only effectively reduce the weight and volume of the instrument and equipment on the spacecraft, but also improve the working reliability and data transmission rate of power supply and distribution system, and achieved remarkable results in fault isolation, surge suppression and other important functions of the power supply and distribution system. It also has a referential significance to other spacecraft electrical system design.

    • >Sensor and Non-electricity Measurement
    • Design and implementation of liquid level of tank car detecting measurement system based on LabVIEW

      2016, 39(10):145-149.

      Abstract (1440) HTML (0) PDF 6.78 M (1680) Comment (0) Favorites

      Abstract:Traditional methods of Tank Car Volume verification is the use of artificial color liquid plus Tsquare to measure the level of empty high. Traditional manual method of verification being low efficiency, low safety factor, the high cost of human, manual reading error caused a great impact on the measurement accuracy. A high precision and multi channel liquid level measurement system based on LabVIEW is designed. First, through the serial port number and baud rate setting system, and then use DRUCK PTX 1830 level sensor for data collection tanker car level, after filtering and processing complex algorithms, realtime display system and liquid level height curve, so as to achieve highprecision automated verification of Tank car volume purposes. Tank car system level data for data acquisition, arithmetic processing, display, storage, alarm, PC automatically analyzes the data and export EXCLE forms and other functions. By actual laboratory and field test results show that the system is effective and accurate height change of the reaction liquid level measurement accuracy of ± 1 ‰, it has some promotional value.

    • Electromagnetic analysis of 3D inductive torque sensor for EPS

      2016, 39(10):150-153.

      Abstract (1499) HTML (0) PDF 1.62 M (1349) Comment (0) Favorites

      Abstract:Torque sensor is a core member of automotive electric power steering system (EPS), a new threedimensional magnetoelectric torque sensor based on electromagnetic induction principle is designed. First the cylindrical structure and working principle of the sensor are introduced, then the electromagnetic induction system of sensor is simulated by using Ansoft Maxwell, the magnetic field distribution and quiescent output voltage when current is 100 mA are obtained by static analysis, and by simulating sensors work process with transient modules, it comes to that the dynamic output signal is high frequency induced voltage,whose amplitude sinusoidally changed with the relative position of system. finally the adder detection circuit is designed according to the characteristics of the output signal.

    • Research on the technical of vibration sensor calibration

      2016, 39(10):154-157.

      Abstract (1225) HTML (0) PDF 1.90 M (1420) Comment (0) Favorites

      Abstract:In view of the status that the time of airborne vibration transducer calibration is long and the efficiency of calibration is low, the solution proposed in this article is adding a switching table on the shaking table..Through indepth research of CS18MF intermediate frequency calibration system, design and product the switching platform, and use ANSYS software to do the natural modal analysis, then get the resonance frequency. It is concluded that the natural frequency is more than 39 kHz will resonate, far higher than the required frequency of the airborne vibration sensor. Through laboratory test shows that various types of vibration sensor can installed on the switching table and multiple sensors can be installed at the same time to calibration. The switching platform used for airborne vibration calibration can greatly improve the work efficiency and the calibration accuracy can meet the requirements of less than 5%.

    • >Photoelectric Detection
    • The design of the portable chloride ion detector

      2016, 39(10):158-161.

      Abstract (1125) HTML (0) PDF 753.27 K (1518) Comment (0) Favorites

      Abstract:High content of chloride ions inindustrial water will accelerate the corrosion of metal equipment, A Scattering light measuring instrument which based on silver nitrate turbidimetry is used for Chloride ion detection quickly and accurately. The hardware part of the system—including the light source driving circuit,the structure beam collimation and optical current signal detection module which used Atmega128 as processor, with the use of an PIN photodetector to realize photoelectric conversion and use of a lownoise amplifier AD795 to realize currenttovoltage conversion. By measuring the standard solution, We can conclusion that it has a good stability in short time and the relative error less than 4.08%. It is proved that this scheme has good application value.

    • >Data Acquisition
    • Data acquisition system for ADC testing

      2016, 39(10):162-165.

      Abstract (1063) HTML (0) PDF 6.00 M (1794) Comment (0) Favorites

      Abstract:A design of data acquisition system for 100 MHz sampling rate ADC testing, and gives its hardware design principle and method, then briefly introduces the PC software working process. The system is adopted a form of FPGA+USB and mainly used for testing the dynamic parameters of 8 or 16 bit 100MHz sampling rate ADC. Among of them, FPGA is responsible for the collection of data caching and transmission, then through the USB to upload data to the host computer and use the control algorithm to calculate the ADC parameters and display them, thus obtains the result of the test ADC. The system has been used in routine testing, and has achieved good results.

    • Research of denoising method of bridge strain signal based on empirical mode decomposition method

      2016, 39(10):166-170.

      Abstract (1121) HTML (0) PDF 2.91 M (1571) Comment (0) Favorites

      Abstract:This paper proposes a denosing method for bridge strain signal based on empirical mode decomposition. When the noise appears in some certain frequency and blends with signal, the existing denoising method such as wavelet threshold filtering method can not work well in this regard. This paper carries on empirical mode decomposition method for actual bridge strain signal and then picks out intrinsic mode functions which contain much noise. For these IMFs we carry on specific threshold filtering process method. After this, we use remaining IMFs, processed IMFs and the residual component to reconstruct the signal. The result shows that, this method can eliminate noise of bridge strain signal under the premise of preserving features of original signal.

    • Kaband sliding spotlight SAR signal processing method based on DBFSCORE

      2016, 39(10):171-177.

      Abstract (1107) HTML (0) PDF 1.29 M (1837) Comment (0) Favorites

      Abstract:Kaband millimeterwave SAR with high resolution and clear outline imaging characteristics has drawn great attention among researchers. With the development of Kaband devices, makes KaSAR system a hot research topic in many countries. Digital beamforming (DBF) scanonreceve (SCORE) can avoid overlarge peak transmit power, meanwhile provides adequate system gain, which efficiently solves the power consumption issue in millimeterwave systems. Besides, sliding spotlight mode ensures the high azimuth resolution without restricting the size of the azimuth antenna. According to this, the paper presents a sliding spotlight SAR system based on DBFSCORE, and then provides the imaging flow diagrams, as well as the analytical expressions. Finally, the effectiveness of the algorithm is verified by simulation experiments.

    • >Communications Technology
    • Energy efficient routing protocol for wireless sensor network

      2016, 39(10):183-187.

      Abstract (1347) HTML (0) PDF 904.74 K (1554) Comment (0) Favorites

      Abstract:LEACH routing protocol for wireless sensor networks and a number of its improvements are proposed. Most of them use random selection of clusterhead node election. It is found that node’s energy consumption increases with its more random selection. Then performance of the network is affected because node’s energy consumed quickly. This paper proposed an improved routing algorithm that determines threshold of clusterhead node according to the node’s present remaining energy, distance to all surviving nodes and average distance between the node and convergence node. Routing is done by the threshold. Simulation shows that network performance and life cycle could be improve effectively.

    • Adaptive backoff algorithm based on traffic

      2016, 39(10):188-191.

      Abstract (2073) HTML (0) PDF 682.61 K (1466) Comment (0) Favorites

      Abstract:This paper presents the design, analysis and performance evaluation of a algorithm, called Adaptive backoff mechanism. This algorithm is based on the relationship of length of queue and network traffic and the duty cycle. The basic idea of this algorithm is changing the size of the contention window according to the flow, thus relieving network traffic in high contention level and reducing the time of overhead in low contention level. Finally, analyzed through the NS2.35. The results showed that it is better than using a random backoff mechanism of SMAC protocol in the network delay, energy consumption and throughput.

Editor in chief:Prof. Sun Shenghe

Inauguration:1980

ISSN:1002-7300

CN:11-2175/TN

Domestic postal code:2-369

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