Table of Content

15 June 2012 Volume 25 Issue 6

  

Articles

Face Detection Based on LARK Feature Extraction

WANG Yin, TAN Xiao-Yang

. 2012, 25(6):  1. 

Abstract ( 1399 )   PDF (756KB) ( 972 )  

References | Related Articles | Metrics

This paper studies the LARK feature extraction methods and finds that the method can be used to collect information on the face image,and tries to apply it to face detection.Before detection,the detected image is transformed into a gray image so that the features of the each part of the human face can be fully displayed.This procedure is easy to perform and can reduce the complexity of calculation.

Research on and Design of the Cluster System Based on a Linux Server

YAO Li-Ying

. 2012, 25(6):  4. 

Abstract ( 1171 )   PDF (524KB) ( 829 )  

References | Related Articles | Metrics

A Linux server based cluster system which has the function of load balancing is designed.The system is able to complete the task of a real server in the internal network performing multiple requests forwarded from an extranet and constantly monitor the status of the cluster.

A Method of Moving Target Detection Based on Omni-directional Vision

ZHANG Zhong-Min, LI Ying-Jing, JIA Yan-Li

. 2012, 25(6):  6. 

Abstract ( 1355 )   PDF (835KB) ( 745 )  

References | Related Articles | Metrics

This essay proposes a method of moving target detection based on omni-directional vision,which detects a moving target by using the three frame difference and the mixture Gaussian model.Not only can it overcome the weakness of the three frame difference model that it fails detect all information of the target,but also it can avoid the false phenomenon of two objectives emerging by the background subtraction method.The effect is much better when the background color is close to the target color.Experimental results show that the proposed method can detect moving objects accurately in real time.

An Improved Fusion Algorithm of Infrared and Visible Images Based on the Curvelet Transform

JI Xiao-Tao

. 2012, 25(6):  10. 

Abstract ( 1125 )   PDF (653KB) ( 809 )  

References | Related Articles | Metrics

For the fusion of infrared and visible images,an improved image fusion algorithm based on the second generation Curvelet transform is proposed.First,the Curvelet transform was performed on the two source images to obtain the transform coefficients on different scales and in various directions.For low frequency coefficients,according to the different imaging characteristics of infrared and visible images,an adaptive fusion strategy based on the local statistical properties was employed;for high frequency coefficients on different scales and in various directions,a program for coefficient selection based on local-region energy matching was employed.Finally,the fusion image was obtained through the inverse Curvelet transform.Through comparative analysis of the experimental results,the proposed algorithm can effectively reflect the characteristics of the original images,and the fusion effect is improved significantly.

Small Target Detection Algorithm for Infrared Images Based on the 5×5 Template

ZHOU Yuan-Yun, HANG Juan

. 2012, 25(6):  14. 

Abstract ( 1034 )   PDF (522KB) ( 859 )  

References | Related Articles | Metrics

In view of the characteristic of small targets in the sky background,an algorithm used for detection of small targets in the infrared image is presented.In the target of more than 9 points,the traditional image processing based on the 3×3 template does not reach the expected effect.Therefore,this paper uses the middle and top-hat filter to process the infrared image based on the 5×5 and 4×4 template.The design adopts the FPGA.Experiments on real infrared images in the sky background show that the algorithms can detect the small target in the infrared image effectively.

Eye State Detection Based on Comparison of Eye Gray Area Feature and Eyelid Curvature

ZHAO Heng-Wei

. 2012, 25(6):  17. 

Abstract ( 949 )   PDF (573KB) ( 874 )  

References | Related Articles | Metrics

In order to improve the defects of current eye state detection when used for fatigue monitoring,this paper proposes a new vision sensor-based comparison of eye gray area and eyelid curvature.Under the premise that the eyes area is found,the eye state is determined by extracting the features of the gray area and eyelid curvature characteristic features.Eye state detection in such complex environments as different backgrounds,changing illuminations,eye tilting and rotation,and wearing glasses shows that the algorithm has faster processing speed and robustness.

Application and Design of an Army Aviation Combined Tactics Training Simulation System

ZHAO Lin

. 2012, 25(6):  20. 

Abstract ( 1024 )   PDF (779KB) ( 783 )  

References | Related Articles | Metrics

A simulation system framework of army aviation combined tactics training is proposed in this paper.This simulation system framework supports commanders and staff members of land army division headquarters and army aviation corps to develop combined tactics training.It can also be connected with the army aviation helicopter simulator to train airman's operation ability.Finally,by describing several battle modes,this training system application flow is shown.

Design of a Multichannel Data Gathering System

LIU Hua

. 2012, 25(6):  24. 

Abstract ( 870 )   PDF (504KB) ( 940 )  

References | Related Articles | Metrics

The paper introduces the design of a multichannel data gathering system based on FPGA and DS with its hardware design and circuit explained.It also presents the external communication interface and the process of data acquisition.Simulation results by Quartus II8.0 and CCS 2 show that the design of the system is feasible.

Design of the Car's BCM Automatic Test System Based on Embedded Qtopia

MA Chao, LUO Wen-Guang, CHEN Jian, SU Xin

. 2012, 25(6):  27. 

Abstract ( 1115 )   PDF (778KB) ( 792 )  

References | Related Articles | Metrics

The car's BCM plays a pivotal role in the body function control system.Therefore,both the enterprise and the consumer attach great importance to the detection of car's BCM before they leave the factory.Most of current enterprises still use manual testing methods.This test system uses samsung's S3C2440 as the core controller,uses the Qtopia application development platform control interface under the embedded Linux system to add a testing and control program,and realizes automatic detection through the interface board which connects car's BCM.

Design of a Data Acquisition System Based on AD7762 and FPGA

WANG Lin-Yu, ZHANG Jian-Hong

. 2012, 25(6):  30. 

Abstract ( 1080 )   PDF (683KB) ( 751 )  

References | Related Articles | Metrics

In order to meet the higher requirements on frequency and resolution technology indexes in the audio data acquisition process,this paper proposes a high speed data acquisition device.This design uses the Altera company's Cyclone series EP1C4F400 FPGA chip to control the AD7762 A/D converter by the ADI company and realizes data acquisition using Verilog language in QuartusⅡ environment.Serial port is used to transmit data to the PC,which accomplishes the function of data analysis and display.FPGA controls the acquisition timing of the whole system.

Wireless Fire alarm System for High-rise Buildings Based on ZigBee Technique

LI Juan, HU Fang-Ming

. 2012, 25(6):  34. 

Abstract ( 1452 )   PDF (933KB) ( 826 )  

References | Related Articles | Metrics

A novel simplified model of the fire alarm system is designed by employing the chip CC2430 to constitute a star network of ZigBee.The fire information of each room is transmitted over this wireless network,including the carbon monoxide concentration and temperature information.Then according to the predefined rules,the control center determines whether there's a fire occurring.The security of the high-rise building is also reported regularly.The system has good application prospect and economic benefits.

A Method for Choosing δ Based on the LLL Lattice Reduction Algorithm

XIAO Jian

. 2012, 25(6):  38. 

Abstract ( 1172 )   PDF (679KB) ( 729 )  

References | Related Articles | Metrics

LLL lattice reduction is a powerful algorithm which can output a group of nearly orthogonal reduced lattice basis from original basis.Recently,LLL lattice reduction has been found useful for precoding in wireless MIMO systems.There is a factor δ in LLL lattice reduction which should be specified manually.Algorithm execution time and quality of reduced lattice basis depend on the factor δ.On the base of the LLL lattice reduction algorithm,this paper propose an improved algorithm for choosing the factor δ automatically according to a specific input matrix H to meet the tradeoff between the quality of reduced lattice basis and algorithm execution time.

Portable Unloader for Data of Flight Parameters Based on the μC/OS-II

JIANG Tao, LIU Wen-Bo

. 2012, 25(6):  41. 

Abstract ( 1104 )   PDF (704KB) ( 777 )  

References | Related Articles | Metrics

The portable unloader for the data of flight parameters is generally used in civil and military aircraft.It also plays an important role in ground maintenance,prevention and investigation of flight accidents and flight quality evaluation.With higher requirements and larger data of flight parameters,some problems are exposed and have had many negative effects.Both high error rates and slow data unloading are the key elements that affect its work.A new portable unloader for the data of flight parameters is therefore introduced in this paper.By the embedded technology,we achieve a small,modularized and visual unloader which realizes high flight efficiency,low error rates and a high-speed data transcription.

Expansion of CAN Bus Based on the Mcp2515

LV Bao-Feng

. 2012, 25(6):  44. 

Abstract ( 1227 )   PDF (632KB) ( 768 )  

References | Related Articles | Metrics

With the wide application of digital signal processor TMS320F2812,it has become a trend to expand the CAN bus interface of TMS320F2812.In order to meet the overall design requirements of a test equipment in Shaanxi Lingyun Electronics Group CO.,LTD.,we achieve the CAN bus expansion of the TMS320F2812 by using stand-alone CAN controller MCP2515 which has an SPI interface through the SPI interface of TMS320F2812 and meet the control accuracy and processing speed of the test equipment as well as the design requirement of the external double redundancy CAN bus interface.It is of great practical value.

Study of on-Chip Network Communication Architecture for the Multi-core Processors System

WANG Jian, ZHANG Lei, ZHAO Zhong-Hui, WANG Shao-Xuan, CHEN YA-Ning

. 2012, 25(6):  47. 

Abstract ( 1361 )   PDF (937KB) ( 720 )  

References | Related Articles | Metrics

In recent years,Multi-core architectures have been the mainstream design of the processors as well as the mainstream processing platform of various communication and multimedia applications.The communication structure becomes one of the core technologies of Multi-core processors.The efficiency of communication between the inter-core is the key indicator of Multi-core processor performance.There are three main types of communication architecture:Bus system,Cross-bar network and On-Chip Network.Bus structure designs have the advantages of convenience,low hardware consumption and low cost.Cross-bar design is  suitable for the switching network structure of building large-capacity systems.On-Chip Network is larger and more sophysicated on-chip network,which can completely solve the problem of Multi-core architecture and therefore becomes one of the most promising solutions for the Multi-core system.The paper discusses the principle,system structure and function of the NOC communication architecture and presents the realization of some units.

Calculation of the Capacitance of Leaky Coaxial Cable with Eight-Shaped Slot By the Three-Dimentional Finite Difference Method

XU Yue, LI Ming-Ru, GUO Yan-Lin, LI Min, WANG Zhen

. 2012, 25(6):  53. 

Abstract ( 1107 )   PDF (631KB) ( 729 )  

References | Related Articles | Metrics

The capacitance of the Leaky Coaxial Cable (LCX) with eight-shaped slot is calculated by the Three-Dimensional Finite Difference Method.The differential equation of electrical potential in the Closed segment and Slotted segment of the LCX is derived from Laplace equation.The boundary conditions between interfaces and their discrete forms are given.The expressions for electrical potential and capacitance are obtained.The effect of the accuracy of this method on the calculation result is discussed.The result is compared with the measured value of LCX with the same specifications,which validates the effectiveness of this method.Finally,the influence of the slot angle on the capacitance of the LCX is analyzed.

Implementation and Comparison of the Range-free Localization Algorithm in Wireless Networks

WANG Li-Kai, LUO Pei

. 2012, 25(6):  56. 

Abstract ( 1289 )   PDF (621KB) ( 782 )  

References | Related Articles | Metrics

In the WSN,the node location technology is a basic function to guarantee the effectiveness of other application,and the positioning process can be divided into two stages:distance estimation and position calculation.This paper introduces three algorithms of distance estimation:Sum-Dist,DV-Hop,and Euclidean,and simulates them in Matlab.The result shows that in the response of the environment all the algorithms perform well and can be further improved.

TOFS-based Beam Space Wideband DOA Estimator

XIE Jian, CHEN Ying-Ying

. 2012, 25(6):  60. 

Abstract ( 1054 )   PDF (717KB) ( 818 )  

References | Related Articles | Metrics

Test of orthogonality of frequency subspace (TOFS) is an important method for wideband signal direction-of-arrival (DOA) estimation.Since TOFS avoids focusing operation and preliminary DOA estimation,its performance is better than other methods in middle signal-to-noise ratio (SNR) ranges.However,the SNR resolution threshold for TOFS is higher than others.An improvement based on beam space method is proposed to reduce the SNR threshold and computational complexity.Simulation results show that the proposed method has better performance than TOFS algorithm.

Research on an Indoor Positioning Technology Based on RSSI Ranging

WANG Qi

. 2012, 25(6):  64. 

Abstract ( 1682 )   PDF (634KB) ( 818 )  

References | Related Articles | Metrics

An indoor positioning experimental platform based on ZigBee technology was constructed.In the laboratory corridor,two experiments including RSSI(Received Signal Strength Indicator) ranging and positioning were done on the platform.First,linear regression analysis is used on the data collected from the RSSI ranging experiment to obtain the specific ranging model in the current environment.Then a positioning algorithm based on RSSI has been implemented by designing software for both beacon and unknown nodes.Positioning accuracy evaluation results show that the algorithm proposed by the paper has its average positioning error of 2.3 m which meets the requirement of most indoor scenes.

Modeling and Simulation of Coordinates Transform and Data Processing for Airborne Radar

XU Wan-Cheng, WANG Gang

. 2012, 25(6):  67. 

Abstract ( 1669 )   PDF (717KB) ( 1173 )  

References | Related Articles | Metrics

According to the basic theory of coordinates transform and data processing of radar,this paper introduces the detailed algorithms,and also gives the simulation model and specific simulation process based on those algorithms.Results show that the coordinates transform algorithms can achieve the required accuracy and the data processing can track targets stability.

A Constant Beam Width Wideband Adaptive Beamforming Algorithm

REN Ze-Yu, LUO Ding-Li

. 2012, 25(6):  71. 

Abstract ( 1203 )   PDF (680KB) ( 786 )  

References | Related Articles | Metrics

Wideband beam forming is a difficult problem for phased array radar digital signal processing.The present wideband beam forming methods only satisfy one advantage of constant beam width or adaptive.For the radar to incorporate both advantages,this paper presents a wideband adaptive beam forming method based on the RLS algorithm.Firstly,an adaptive reference beam pattern is obtained,then the constant beam pattern range is determined and other frequency weights is worker out by RLS algorithm,and finally wideband beam forming can be obtained.This method can not only ensure constant beam width,but also realize adaptive null control.The validity is investigated through a series of simulations.

Software Defect Prediction Based on Cost-Sensitive Neural Networks

MIAO Lin-Song

. 2012, 25(6):  75. 

Abstract ( 1259 )   PDF (551KB) ( 884 )  

References | Related Articles | Metrics

Software defect prediction has been studied as an important research topic for 30 years in software engineering.Recently,with the development of machine learning techniques,traditional machine learning has been applied in software defect prediction based on static code attributes successfully.However,the traditional machine learning does not consider the cost-sensitive problem and class-imbalance problem in software defect prediction applications.We study the application of cost-sensitive neural networks based on over-sampling and threshold-moving to software defect prediction.The experimental results on NASA software defect prediction benchmarking dataset demonstrate the algorithm's efficacy.

Matching Method Based on the Feature Descriptor

LI Juan

. 2012, 25(6):  79. 

Abstract ( 820 )   PDF (706KB) ( 807 )  

References | Related Articles | Metrics

A fingerprint identification method based on the characteristic descriptor is proposed.This method has high efficiency and matching and small storage space.By this method fingerprint matching is realized and applied to the embedded system.Because automatic fingerprint identification is usually realized in an embedded system,it has a high requirement on the complexity,calculation speed and storage space of an algorithm.Therefore,a popular characteristic based matching method is used.This algorithm is fast in calculation.Experiments show that this algorithm has the advantages of simple calculation,high speed easy determination of the reference point and good robustness on the rotation and translation of the image.By this algorithm,the matching of the characteristics of the random local descriptor based on the characteristic descriptor can be improved.

Self-adaptive Denoising for SAR Image Based on Shearlet Transform

LIU Cheng-Hao, LIU Wen-Bo, ZHANG Gong

. 2012, 25(6):  83. 

Abstract ( 1624 )   PDF (955KB) ( 851 )  

References | Related Articles | Metrics

In view of the characteristics of relevant speckle noise of SAR images,this paper proposes a self-adaptive shrinkage method for denoising based on Shearlet transform.First,the image is processed with Shearlet transform.Then,the Shearlet coefficient is contracted by the self-adaptive shrinkage method considering the noise measurement and the relevance of multi-scale spaces.Finally,one image is reconstructed through the inverse Shearlet transform using the amended coefficient.The experiments indicate that the algorithm can wipe off the relevant speckle noise of SAR images and has strong capability of maintaining the edge.

An Overview on the Improved Algorithm of the Snakes Model

CHEN Jun, WEI Ming-Xiang

. 2012, 25(6):  87. 

Abstract ( 1031 )   PDF (1154KB) ( 745 )  

References | Related Articles | Metrics

This article discusses an improved model  of the Snake model,which is based on the vector field convolution model.This model serves as the general form for the GVF model.The convolution model is applicable to a wider range and has better robustness than the traditional model.By comparing the classic and traditional Snakes models and analyzing the contours,noise sensitivity and complexity of the algorithm,it is shown that VFC does not have a high requirement on noise and initial contour sensitivity and that its design remains to be improved.

Development of a Temperature Auto-Control System Used for Foot-Washing

XU Hua-Rong, ZHOU Han-Yi, GU Hong-Gang, WANG Xin-Yu

. 2012, 25(6):  91. 

Abstract ( 1124 )   PDF (644KB) ( 799 )  

References | Related Articles | Metrics

This paper introduces the theory and methods of realizing an automatic temperature control system in a foot massage machine based on MCU implementations.This system achieves the functions of real-time temperature display and target temperature adjustment by buttons and solves the problem of over heating or cooling of the wire during the heating or cooling process with the perfect performance of traditional 51 series MCU,highly efficient and stable power supply,external pin interrupt,timers,PID algorithm and DS18B20 temperature sensor.It has the advantages of low cost,high precision of temperature control,adjustable target temperature and stable and reliable operating process.

A High Speed Low Power LVDS Receiver Design

SUN Jin-Zhong, XIE Feng-Ying

. 2012, 25(6):  95. 

Abstract ( 1130 )   PDF (1045KB) ( 815 )  

References | Related Articles | Metrics

LVDS system link structure and data transmission principle,LVDS standard receiver circuit,based on 65 nm digital CMOS process design to achieve a high-speed low-power LVDS receiver circuit.The simulation results show that the supply voltage of 2.5 V,the LVDS receiver with 2 Gbit·s^-1 data transfer rate,average power consumption is 3 mW.

Design of a Dual-Band Dassband Microstrip Filter

WEI Liu-Tai

. 2012, 25(6):  98. 

Abstract ( 1034 )   PDF (460KB) ( 915 )  

References | Related Articles | Metrics

In this paper,a dual-band passband filter with two H-resonators by fringe coupling is presented.The dual-band resonator consists of two parallel microstrip lines that are connected by a microstrip line and can show dual-frequency resonance.The two external quality factors change oppositely when the distance between the feed point and the center microstrip line becomes larger.As the distance between the two resonators becomes larger,the coupling coefficients of the dual-band resonator reduce simultaneously.Thus,a dual-band passband filter can be obtained by combining the two H-resonators.

Design of Wideband Low-noise Amplifier

ZHANG Yan-Xiong

. 2012, 25(6):  100. 

Abstract ( 924 )   PDF (529KB) ( 743 )  

References | Related Articles | Metrics

In recent years,with the development of optical and satellite communication toward broadband,the bandwidth of the filter is increasingly wide.A low-noise amplifier,which owns a very low noise figure (NF) and a wide frequency band,is designed in this paper.The LNA owns a low gain flatness,which is less than 1 decibel.The matching of the input and output of this LNA and its stability are well.

Design of a Signal Generator Based on DAC0832 and AT89S52

LI Ting-Gui

. 2012, 25(6):  104. 

Abstract ( 1292 )   PDF (756KB) ( 736 )  

References | Related Articles | Metrics

The signal generator has the microcontroller AT89S52 and D/A converter DAC0832 as the hardcore.Controlled by the AT89S52,DAC0832 produces the required current.Then the operational amplifier LF393 linearly converts the current to a 0~5 V voltage.Through the control of the program,the system can produce a series of regular waves.The system has the advantages of high precision,strong anti-interference,stable performance,easy upgrade and high practical value.

A New ICI Self-Cancellation Method Using Symmetric Transmission for OFDM System

TIAN Hai-Feng

. 2012, 25(6):  107. 

Abstract ( 1113 )   PDF (743KB) ( 812 )  

References | Related Articles | Metrics

In this paper we propose a symmetric transmission scheme for inter-carrier interference in OFDM system.The scheme is bases on two-path phase rotation conjugate cancellation(PRCC) scheme,but uses two way mirror symmetry signals instead of the original conjugate signals with a phase rotation factor at transmitter.At the receiver through reduction treatment,phase rotation can be done automatically.Compared with PRCC,the proposed scheme saves the need for frequency offset estimation and phase factor feedback process and has lower complexity and higher transmission efficiency.

Hardware Design of a General Digital Circuit Board Testing System

ZHOU Bo, LIU Wen-Bo

. 2012, 25(6):  110. 

Abstract ( 924 )   PDF (925KB) ( 882 )  

References | Related Articles | Metrics

The conventional method of using an oscilloscope,multimeter,logic analyzer or other equipment for digital circuit board testing is complex,time consuming and not reliable.In this paper,the hardware design of a general digital circuit board testing system is introduced.Unlike traditional digital circuit board testing systems,this design has better performance and parameters:the testing frequency can reach 50 MHz and can be set as integer division of 100 MHz;the testing level is compatible to -6 V~+9 V and can be programmed by 100 mV;there are up to 32 channels,each channel having 1 Mbit memory depth and 50 mA current drive capability with overload protection,and can work either as input or output for three-state synchronously.

A Dual-band Inverted-C Shaped CPW-Fed Antenna for WLAN Application

ZHOU Cheng-Sen

. 2012, 25(6):  115. 

Abstract ( 1249 )   PDF (491KB) ( 726 )  

References | Related Articles | Metrics

A novel coplanar waveguide (CPW)-fed monopole antenna that resonates at 2.5 GHz and 5.5 GHz,respectively,is proposed.The antenna comprises a circular-monopole with a corner cut and becomes an inverted-C monopole.The simulation results by HFSS show good dual-band operations with -10 dB impedance bandwidths of 10.4% and 27.8% at the two resonant frequencies,respectively,which cover the 2.35~2.61 GHz and 4.96~6.46 GHz.These cover the WLAN operating bands.In addition,the cost is reduced due to its small volume.

A Method for Radar Signal Detection Based on Polyphase Filtering

XIE Min-Rui, SHEN Zhi-Bo

. 2012, 25(6):  118. 

Abstract ( 1075 )   PDF (1124KB) ( 843 )  

References | Related Articles | Metrics

This paper studies a technique for radar signal detection based on polyphase filtering.A receiver model is proposed,and the detection of different forms of radar signals is analyzed in detail.Possible problems in signal detection are discussed.Simulation results verify the correctness and efficiency of the algorithm.

Channel Estimation Using Superimposed Training for OFDM System

DUAN Peng

. 2012, 25(6):  121. 

Abstract ( 1368 )   PDF (728KB) ( 785 )  

References | Related Articles | Metrics

In this paper a novel superimposed pilot channel estimation method is proposed,which extracts the pilot from unknown data completely according to the character that the energy of periodic sequence mainly concentrates on a few frequency points.Based on the auto-correlation of PN sequence,the impact of noise on pilot is further reduced in time domain,which increases the accuracy of channel estimation efficiently.The extensive experiment results show that proposed algorithm has the high bandwidth efficiency,the performance of which is superior to other existing algorithms.

Airborne Radar Display and Control Terminal Simulation under Windows Platform

FENG Xiao-Yu

. 2012, 25(6):  125. 

Abstract ( 893 )   PDF (1024KB) ( 745 )  

References | Related Articles | Metrics

The airborne radar display and control terminal is the most important interactive interface between radar and operators.In the simulation system,radar interface not only shoulders the task of the radar display,but also controls the whole system.This software uses the VS2005 building environment and to the AN/APG-68 (V5) radar A scope,B scope and pie scope design under Windows platform.By experimental verification the software has the features of friendly interface,portability and high reliability.

The Maneuver Analysis of Fighters in Anti-radiation Operatio

WANG Ti-Ming, LI Yan-Zhi, LU Jian-Hua, ZHAN Wang-Bao

. 2012, 25(6):  129. 

Abstract ( 1018 )   PDF (656KB) ( 719 )  

References | Related Articles | Metrics

This paper introduces the whole anti-radiation operation,classifies the maneuver of fighters in anti-radiation operation into danger-based and striking-based maneuver.It also analyzes bearing-cross location and the striking based maneuver of fighters.Finally,this paper analyzes the maneuver rule of fighters in the whole anti-radiation operation and factors which influence anti-radiation operation.

Engineering Realization of DAGC Technology in the Three Pad Monopulse Radar Receiver

LI Bang-Qin

. 2012, 25(6):  133. 

Abstract ( 1203 )   PDF (640KB) ( 751 )  

References | Related Articles | Metrics

This paper analyzes the basic theory of the DAGC monopulse radar receiver,gives the digital realization methods as well as the structural and block diagram of corresponding hardware and software of the sensitivity time (STC) control,manual gain control and automatic gain control.Besides,on the basis of practical experience it discusses several problems such as fluctuation in attenuation,the shock oscillation in the IF circuit caused by the NC attenuator,the channel gain of frequency agility state and the realization of gain control for the receiver by the digital AGC technology,all of which should be considered in the engineering design of the digital AGC.The solutions to these problems are also given.

A Fault Identification Method for Rolling Bearing Based on SLS_SVM

CHAI Mei-Juan, LIU Gui-Guo

. 2012, 25(6):  136. 

Abstract ( 1328 )   PDF (640KB) ( 780 )  

References | Related Articles | Metrics

To improve the rate of correct training of the fault identification sorter of rolling bearing and shorten the training time,LS_SVM is combined with semi-supervised learning according to the fact that the training sets have both labeled and unlabeled examples.Full use is made of the effective information in the training sets and a novel SLS_SVM based fault identification method for rolling bearing is proposed.A comparison of this method with the standard SVM and semi-supervised learning based on the SVM method shows that this method can not only improve the rate of correct training but also shorten the training time.The diagnostic tests show that it is an effective and efficient method.

Design and Installation of Lecture Hall Lighting and Acoustic Equipment

WEN Hong-Chun

. 2012, 25(6):  140. 

Abstract ( 831 )   PDF (633KB) ( 860 )  

References | Related Articles | Metrics

Professional lighting and acoustic engineering is a comprehensive project which has a high technical standard.It involves construction,electrical engineering,electronics,acoustics,optics and other professional fields.In a specific project implementation process,it is divided into such stages as site visits,analysis of calculation,design selection,construction and commissioning.This article aims to discuss the design and adjustment of the lighting system and acoustic equipment and analyze the installation of equipment.It is of practical value for the design and installation of lighting and acoustic equipment for the lecture.

Influence of the Stepper Motor's Starting Frequency on the Efficiency of Solar Energy Power Generation

CHANG Ling

. 2012, 25(6):  142. 

Abstract ( 838 )   PDF (628KB) ( 655 )  

References | Related Articles | Metrics

This article focuses on the energy consumption of the solar tracking system and studies the impact of stepper motor's starting frequency on the efficiency of electric power generation.Optimization methods of improving the efficiency of power generation by reducing the frequency of stepper motor's starting frequency is given in theory.Matlab simulation results have shown that lower starting frequency of the stepper motor can reduce the energy consumption of the solar tracking system itself,thereby improving system efficiency of power generation.

Simulation and Analysis of the Amplifiers drive circuit Based on Multisim8

LIU Gang, ZHANG Xin, YANG Fang

. 2012, 25(6):  145. 

Abstract ( 1041 )   PDF (784KB) ( 648 )  

References | Related Articles | Metrics

The amplifiers drive circuit is simulated and analyzed using Software Multisim8,and simulation results are consistent with theoretical analysis.According to the characteristics of the amplifiers driving circuit,the sub circuit-level management module circuit is build.As Multisim8 can complete the tasks of circuit simulation and analysis,the use of simulation technology in the analysis and design of integrated electronic circuits is very important.

A Method for Breaking the Text-based CAPTCHA with Character Features

GAO Yuan

. 2012, 25(6):  149. 

Abstract ( 896 )   PDF (869KB) ( 887 )  

References | Related Articles | Metrics

This paper introduces a method for breaking the text-based image CAPTCHA based on feature recognition.It also describes the procedures of breaking SPD Bank CAPTCHA in details:preprocessing,extraction,and recognition.In the recognition phase,we propose three feature-based recognition methods for SPD Bank:color-filling,three-lines and full scan.The success rate and the speed of the results are desirable.The experiments show that our attack achieves a success rate of as high as 78%.Both the feature recognition method and the crack method are also applicable to other non-adhesion of the text-based CAPTCHA.

A C55x DSP Serial Boot Procedure Encryption Method

LI Zhen-You, YANG Bin

. 2012, 25(6):  153. 

Abstract ( 772 )   PDF (501KB) ( 738 )  

References | Related Articles | Metrics

The TI TMS320VC5509A and SST's SST25LF080A,for example,introduces a second load and encryption methods Flash program through the serial port mode. The article also gives the associated hardware connections,the bootstrap table. Experiments show that the boot loader with a strong practical,can improve the confidentiality of the DSP software.

Review on Radio Digital Signal Processing and Software Radio Technology

SANG YA-Lou, RUAN Zheng-Xin

. 2012, 25(6):  155. 

Abstract ( 1097 )   PDF (543KB) ( 893 )  

References | Related Articles | Metrics

Software radio technology,broadband,multi-band antenna technology,high-speed digital signal processing,and analog-digital conversion are the key technologies.Their combination can achieve design goals and application requirements.This paper introduces and analyzes the digital signal processing and radio key technologies.

A New Type of Digital Library Management System

CHENG Wen-Fang

. 2012, 25(6):  158. 

Abstract ( 828 )   PDF (511KB) ( 880 )  

References | Related Articles | Metrics

The development of the digital management of the library in China is introduced.By analyzing the characteristics of the existing digital library management system,its deficiencies and shortcomings are presented,which will restrict the role of the library as a resource of information.A new standardized digital library management system is proposed.Through a standardized database and software architecture resource sharing and database docking can readily be achieved and resources can be enriched,thereby laying the foundation for future information platform construction.

Internet of Motor Vehicles Based on Remote RFID

WANG Ai-Le, ZHOU Chang-Neng

. 2012, 25(6):  160. 

Abstract ( 1172 )   PDF (597KB) ( 688 )  

References | Related Articles | Metrics

A solution is suggested for motor vehicle information identification and monitoring.The solution is aimed to construct a cheap intelligent traffic system and internet of motor vehicles.The system includes the remote RFID with motor vehicle information,the collector of motor vehicle information fixed at a road cross and the mobile collector equipped for traffic police.These collectors will send motor vehicle information to the monitor center.The system can help to monitor the flow of motor vehicles,to trace suspicious motor vehicles and to identify false licenses.

Overview on Speaker Recognition

YANG Di, QI Yin-Cheng, LIU Ming-Jun, ZHANG Hua-Fang-Zi, WU Jun-Na

. 2012, 25(6):  162. 

Abstract ( 1561 )   PDF (654KB) ( 927 )  

References | Related Articles | Metrics

Based on the analysis of the principles and methods of speaker recognition,the development of speaker recognition in recent years is reviewed.Several features and pattern recognition methods in the mainstream speaker recognition technologies are summarized and analyzed.Finally,the research prospects and development trends in the future are given.