Table of Content

15 April 2018 Volume 31 Issue 4

  

Articles

Effect of Rough GaAs (001) Surface on the Growth of In015Ga085As Film

YANG Xiaoshan, GUO Xiang, LUO Zijiang, et al.

. 2018, 31(4):  1. 

Abstract ( 505 )   PDF (694KB) ( 499 )  

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AbstractDifferent morphology of GaAs(001) surfaces were prepared by reducing the substrates temperature with different contant speed in molecular beam epitaxy(MBE) and scanning tunneling microscope(STM) system, the Effect of rough GaAs (001) surface on the growth of In015Ga085As film was studied and analyzed through scanning probe image processor(SPIP) and Bauer rule, the results show that surface energy was increasing because of numberous islands and pits on the rough GaAs surface, thus the In015Ga085As was apt to form a flat surface by layer growth. compared with the flat GaAs(001) surface with 100×100 nm2, surface energy of the rough GaAs(001) increased by 4.6× 103 eV per，which is larger than the strain energy of 15 ML In015Ga085As film(2.3×103eV)，it is shown that the epitaxial growth mode of In015Ga085As film on the surface of rough GaAs (001) is layer-by-layer.

The Design and Simulation of Biomedical Signal Pre-amplifier

KUANG Xiaofei,TAO Qi,FAN Fuxuan

. 2018, 31(4):  5. 

Abstract ( 592 )   PDF (853KB) ( 429 )  

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Biomedical signals are of small amplitude and low frequency so that it is easily disturbed by the external environment, leading to superimpose a lot of noise. For the sake of increasing the accuracy of measurements, a pre-amplifier with good performance in order to extract biological signals effectively is proposed. The pre-amplifier is cascaded by instrumentation amplifier and variable gain amplifier so that it can achieve a signal amplification of 1000 times, and can achieve good performance. The simulation results indicate that the pre-amplifier has low equivalent input reference noise of 1.584 2 μV and low consumption of 2.92 μW under the operation voltage of 1 V, it is applicable in the field of biomedical signal acquisition.

The Measurement System Design of Progressive Addition Lens Focal Power and Astigmatism Based on Collimator

GUO Hang,FU Dongxiang,XIANG Huazhong

. 2018, 31(4):  9. 

Abstract ( 599 )   PDF (1013KB) ( 392 )  

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The existing equipment can not obtain precision, convenience and stable at the same time when measuring the processed lens, so design this system. using Hartmann－Shark sensors to collect the data, using F550 Collimator as the light source, and using Single lens to narrow the light beam, realize the connection between two pupils. Write software through the QT to collect the data, the Zernike coefficients are obtained, finally we get value of focus the focal power and the value of astigmatism. The dates collect by this system is basically the same with the datas detected by Wanxin Optical, the accuracy and reliability of the system are verified.

Vehicle Re-identification Method Based on Feature Fusion and L-M Algorithm

WANG Panpan,LI Yuhui

. 2018, 31(4):  12. 

Abstract ( 657 )   PDF (628KB) ( 440 )  

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Vehicle re-identification is a technique for matching the same vehicle target under different conditions in a video surveillance system. In the case of vehicle re-identification, the images of the same vehicle in different cameras are different, and the single feature is difficult to describe the image stably, using a variety of features fusion characteristics of the vehicle, the method combines HSV and LBP features of vehicle images, and the fusion feature matrix singular value decomposition, feature extraction. In view of the slow convergence rate and low precision of traditional BP algorithm, the Levenberg-Marguardt adaptive adjustment algorithm is adopted to optimize the BP neural network. The experimental results show that the recognition rate of the method is 97.5%, and it is robust to illumination changes and angle changes.

Research on Laser Surface Treatment of Titanium Alloy Based on Gold Nanoparticles

SHI Lin, TONG Yanqun, YE Yunxia

. 2018, 31(4):  16. 

Abstract ( 528 )   PDF (687KB) ( 379 )  

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The surface quality of the titanium alloy determines the survival rate of the implant directly. For the shortcomings of the traditional surface treatment method, this paper proposed a surface treatment method based on time domain finite difference method, which used a gold nanoparticle with diameter of 200 nm on alloy titanium alloy. The influence of laser parameters on the field distribution on titanium alloy surface were studied. The results show that the near-field enhancement region excited by 200 nm gold nanoparticles is annular, and the enhancement ratio is more than 6500 times. By increasing the angle of the incident light, the enhancement ratio can be further improved, while the background refractive index of the gold nanoparticles has a small effect on the enhancement effect, which indicated that this method can be surface treated in a variety of media.

Document Image Binarization Based on Contrast Enhancement and Background Estimation

WANYAN Yong

. 2018, 31(4):  20. 

Abstract ( 563 )   PDF (1088KB) ( 343 )  

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Aiming at the impact of degradation of document image on its binarization, this paper presents a binary image algorithm based on contrast enhancement and background estimation, which is used to binarize the degraded document image. The algorithm uses the different contrast enhancement algorithm to enhance the document image according to the difference of the luminance information of the different sub-regions. The background of the document image is removed by processing the enhanced document image by using a morphological closed operation, and the binarized image of the document image is obtained by combining the Ostu and Sauvola algorithms. The broken handwriting repair is performed by the distribution of the neighborhood of the edge pixels gray value.The experimental results show that the F-Measure （FM） is 90.47%, the peak signal-to-noise ratio （PSNR） is 19.15dB, the negative rate index （NRM） is as low as 0.0538, and the classification error measure （MPM） is reduced to 0.00033. The validity of the binarization algorithm proposed in this paper is verified.

Design of Speaker Recognition System Based on Fast MFCC Calculation

BI Zaorong, TONG Dongbing, CHEN Qiaoyu

. 2018, 31(4):  25. 

Abstract ( 504 )   PDF (674KB) ( 348 )  

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The speaker recognition is an important research direction of speech recognition. The feature extraction is a key technology in the speaker recognition system. This paper proposes an efficient scheme for Mel Frequency Cepstral Coefficients （MFCC） computation. It exploits the triangular structure of the frequency response function of the MFCC filters. The simulation results show that the scheme proposed in this paper reduced the access time by 83.6% in single frame memory and the proposed scheme gained better latency with less memory.

Feature Analysis of High-Resolution Range Profiles （HRRP） of Ship Target

CHEN Hongkun，LU Jianbin

. 2018, 31(4):  29. 

Abstract ( 840 )   PDF (987KB) ( 320 )  

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The uncertain of target position, fluctuation of sea surface and radar parameters cause difficulties in radar HRRP automatic target recognition. Regarding the issues above, a ship scattering center model is built, the HRRP of ship is simulated, and the sensitivity of HRRP to attitude angle, sea-surface fluctuation, radar bandwidth and windowing is studied. Finally, the simulation results are validated by CST Microwave Studio. The results show that HRRP has a strong sensitivity to attitude angle, whereas within a certain range of angles, there is similarity between HRRPs; the narrower the radar bandwidth, the lower the angle sensitivity; the more calm the sea-surface, the more multipath effect be pronounced; windowing can inhibit the distance side lobes, whereas widen the main lobe, which reduce radar distance resolution.

Research on Security of Pervasive Computing System Based on Wireless Sensor Networks

YANG Han

. 2018, 31(4):  33. 

Abstract ( 357 )   PDF (541KB) ( 359 )  

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The development of pervasive computing accelerates the innovation of computing model, but the challenge of security has become the bottleneck in its development. Information security played an important role in the normal work of pervasive computing system based on embedded control. Due to the possibility of private information leakage in covert channels, the research on covert channel technology to avoid the perimeter security has not been paid enough attention. A new the secret channel security technology based on wireless sensor was proposed, in a way that cannot be detected by other systems, to optimize the parameter data of wireless sensor, to realize the secret channel transmission in the way of data encryption, to ensure the information security of pervasive computing system, has a certain practice and guidance significance.

The Image Fusion of Compressive Sensing with Adaptive Deviation Feature

ZHANG Ye

. 2018, 31(4):  36. 

Abstract ( 702 )   PDF (992KB) ( 323 )  

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For the problem that the traditional compression domain fusion algorithm combines single and poor fusion results, an adaptive rule of high frequency feature fusion is proposed.First,making a NSCT decomposition to the infrared image and visible light image, and after that to fuse them using regional energy criterion for the high frequency sub-bands to obtain a better fusion result than the traditional low frequency coefficients. Next,Since the decomposed high-frequency sub-band coefficients have high sparsity,they are compressed by CS and adopted adaptive fusion rule.Finally, it gets fusion image by reconstruction of compressive sensing and inverse NSCT transform for data which has been fused. When compared with the traditional compressive sensing method, The new method combines the background information and infrared target information ,which effectively improves the image fusion effect.

Design and Development of the Remote Monitoring System for High Pressure Diaphragm Pump Operation

ZHANG Zhaolin,FAN Yugang

. 2018, 31(4):  40. 

Abstract ( 524 )   PDF (1091KB) ( 271 )  

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High-pressure diaphragm pump is the power source of slurry pipeline transportation system. With the operation of unattended pump station, it is urgent for us to solve the problem that how to monitor the operation of high-pressure diaphragm pump remotely. In order to do this, the paper States a design of a remote monitoring system based on STM32. This system collects the one-way valve vibration signal in real-time, after that, it transmits the collected vibration signal data to the remote server through Ethernet. In the server, this system adopts the Intrinsic Time scale Decomposition (ITD) method. Finally, it analyzes the vibration signal of the check valve of the high pressure diaphragm pump. This is the process of remote monitoring for the high-pressure diaphragm pump running status. The experimental results show that in this system, the collection of information is accurate, the transmission speed is fast and stable, so we can conclude that this system is highly recommend to be used in the industrial sector.

Finite Element Analysis of Dry Air-core Reactor

CHANG Yunjie,XU Zhichao,LAI Hua, et al.

. 2018, 31(4):  45. 

Abstract ( 470 )   PDF (956KB) ( 265 )  

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The electric power is the main factor of the encapsulation cracking of the dry air-core reactor. In order to make the advance warning of the failure of the reactor, it is very important to analyze the electric power distribution of the dry air-core reactor. In this paper,Ansys Maxwell software is used to establish the three-dimensional model of the reactor, and analyze the distribution of the electric power with the model BKGKL-20000/35 under the rated condition and overvoltage conditions by the field-magnetic coupling model. The simulation results show that the maximum value of the electromotive force along the surface distribution is 2649 8×1011 N·m-2, and the overvoltage case is 1024 6×1013 N·m-2. It means that the overvoltage case is more likely to cause the reactor to crack and then cause the accident.

Research on a Technology of Missile Fault Automatic Diagnosis Based on BP Neural Network

YANG Jiayi

. 2018, 31(4):  48. 

Abstract ( 420 )   PDF (520KB) ( 324 )  

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Given that the precision-guided airborne missile is a sophisticated system, timely and accurate fault identification and diagnosis for missiles are crucial measures to address and prevent risks. Due to the complexity of the missile failure mode, it is difficult to identify and diagnose them. Taking a typical testing problem of a airborne missile as an example, this paper proposed a BP-neural network-based approach of automated fault identification and diagnosis for missiles. By collecting and sorting the missile test data, a data sample was formed. The learning and judgment ability of the neural network system was used to automatically identify and diagnose missile faults. A Matlab neural network toolbox was adopted to verify stimulation for this approach, which showed that the technology could identify and diagnose missile faults quickly and accurately.

Design of DFT Hardware Accelerator Used in LTE Uplink

SUN Yuanxin, QIN Shuijie

. 2018, 31(4):  52. 

Abstract ( 453 )   PDF (751KB) ( 236 )  

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Aiming at the multi-mode requirement of DFT pre-coding in LTE uplink, a DFT hardware implementation scheme based on ASIC was proposed. Radix-4/2/5/3 butterfly unit based on WFTA algorithm was used to achieve 35 different lengths of DFT operation. The two-dimensional cache structure was utilized to achieve pipeline processing of butterfly unit. The chip occupied 0.87mm2 core area and 12.5mW power consumption at 200 MHz frequency and SMIC 40 nm technology. The simulation and synthesis results showed that the DFT hardware accelerator had the advantages of high computing speed and less storage resources, which was suitable for LTE engineering applications.

Influence of Geometric Dimension of Slot Ridge Waveguide on Light Field Distribution

LIU Ruonan,LI Zhihua,LI Bin, et al.

. 2018, 31(4):  55. 

Abstract ( 807 )   PDF (873KB) ( 351 )  

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The influence of the width of the slot in the slot ridge waveguide, the width of the waveguide on both sides of the slot, the thickness of the drapped waveguide in the slot on the distribution of the light field in the slot ridge waveguide were studied by FDTD simulation. In the slot ridge waveguide, the normalized optical power firstly increased and then decreased with the increase of the slot width. Similarly, the optical power also increased first and then decreased with the increase of the waveguides on both sides of the slot; with the increase of slot etching depth, the normalized optical power was gradually increased. And the experimental results showed that the normalized optical power reached the maximum 13.54% when the width of the slot was 40 nm, the width of the two sides of the waveguide was 220 nm, and the silicon of the slot was completely etched. The simulation results were expected to optimize the integration of the slit ridge waveguide with the modulator.

Combined Location Method of Beidou/GPS and Its Application in Transmission Line Inspection

DAI Di,LIU Meihong

. 2018, 31(4):  60. 

Abstract ( 479 )   PDF (777KB) ( 242 )  

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Aiming at the application requirements of flexible gas-seal technology in aeroengine, CFD numerical analysis technique is used to analyze the sealing performance of flexible support cylindrical gas-membrane. Firstly, the seal parametric model of cylindrical gas film was established and the gas film sealing principle was analyzed. Then, based on the finite element analysis method of Linear Soid, ANSA meshing software was used to divide the mesh to obtain a non-groove cylindrical gas film Static pressure, velocity and shear stress distribution data, and analysis of cylindrical structure parameters, groove parameters and operating parameters on the flexible support cylindrical membrane sealing performance. The experimental results show that the operating parameters such as viscosity, pressure difference and rotational speed can significantly affect the sealing performance of flexible support cylindrical gas film.

Improvement of Newtons Iteration Method in Sketch Constrained Optimization Problem

ZHANG Long,WEI Chenge,CHANG Wei,et al.

. 2018, 31(4):  64. 

Abstract ( 705 )   PDF (565KB) ( 268 )  

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In order to solve the problem of sketch constraint quickly and efficiently, a hybrid Newton iterative algorithm based on artificial bee colony is proposed to solve the sketch constraint problem. It first uses the colony algorithm to search the initial value, and obtains the initial value as the initial value of the Newton method to solve the problem of the sketch constraint, which ensures the iterative speed and fully combines the advantages of the two to achieve the goal of speed and success. The simulation results show that the algorithm is reliable and has strong numerical stability. It is a good method to solve the problem of sketch constraint.

Design and Implementation of A Small Intelligent Mowing Robot

GAO Fei，DING Xueming，LI Jian

. 2018, 31(4):  68. 

Abstract ( 1051 )   PDF (736KB) ( 360 )  

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For the traditional mower pollution, high noise and the need for long artificial operation etc, combined with market demand, develop a small intelligent mowing robot that can make an appointment to work and independent recharge. On hardware, the system is composed of STM32, which consists of a control system, a power system, a sensor system, a communication system and an interactive system; On algorithms and software, Using the self-recharging scheme, the robot can work many times under the reservation mode and reduce the manual operation. In order to solve the robot in slope is incapable of straight line, a slope compensation algorithm is proposed in this paper. To improve the efficiency of robots, an algorithm of self-seeking grass is proposed. System design conforms to the international safety design index, after a long time to test, the machine can work stable and reliable in the reservation mode, self-charging mode and searching grass mode.

Analysis of the Influence of Group Delay on Hybrid Spread-Spectrum Reception

ZHANG Zongpan，WANG Nan，LIU Ruizhu

. 2018, 31(4):  73. 

Abstract ( 512 )   PDF (629KB) ( 256 )  

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Aiming at the problem of quantify the influence of the channel group delay distortion on the performance of DS/FH hybrid spread spectrum signals, in this paper, from the point of view of correlation characteristics of hybrid spread spectrum signals, the expressions of correlation characteristics after the effects of group delay distortion are derived, and the correlation peak loss and its position deviation under different group delay distortion types are calculated by numerical integration, in this way, the influence of group delay distortion on the reception performance of hybrid spread spectrum signals is quantified. Calculation results show that with the gradual deterioration of group delay distortion the relative peaks will continue to decrease until they disappear, meanwhile, the group delay distortion also causes the fission and position offset of the related peaks, which has a negative effect on the spread spectrum signal applied to the measurement system.

Design and Implementation of CCSDS Packet Telemetry in Spacecraft Communication

LIANG Lei, YI Yusheng, CHEN Chunliang

. 2018, 31(4):  77. 

Abstract ( 433 )   PDF (1060KB) ( 280 )  

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The communication link is the data channel between the spacecraft and the ground station, and data security is very important for spacecraft. Space communication of spacecraft has the characteristics of long link and large amount of data, which is easy to be interfered. A packet telemetry strategy of consultative committee for space data system is presented for spacecraft space communication, and combined with space communication protocol specification, a method for communication between spacecraft space network and ground station is designed. Through the experimental verification in the space communication link, this method can acquire and analyze the telemetry data from the space communication network. Besides, modular software design of the method can be easily transplanted in a variety of spacecraft models.

Analysis and Study of Typical Indoor Electromagnetic Environment Protection Control

LIU Yang, LI Kai, TAN Kangbo

. 2018, 31(4):  81. 

Abstract ( 389 )   PDF (729KB) ( 227 )  

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When the electromagnetic wave intensity of antenna radiation reaches a certain threshold, it may have potential adverse effects on the living organism, which has been widely concerned in the society. To assess the relative relationship between the electromagnetic effect and the relative configuration of the radiation source and the influence of the buildings radiation structure on the structure of the building, the electromagnetic radiation intensity in different position of the relative mobile communication antenna and in the room was studied in this paper. Besides, the potential impact of electromagnetic radiation on organisms was explored based on "Electromagnetic Radiation Protection Regulations" (GB8702-88). This paper analyzed the effect of different window position and window size on the electromagnetic wave intensity in the room, and put forward targeted protection control rules.

Research on the Construction Method of IT Operation and Maintenance Data Management System Based on Large Data Technology

ZHANG Xuejian,ZHANG Yu,CHUAN Tao, et al.

. 2018, 31(4):  84. 

Abstract ( 612 )   PDF (472KB) ( 408 )  

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With the construction and application of various information systems constantly, the monitoring data generated by the information system increases in series.It becomes a new challenge for enterprises that how to Efficiently storage and real-time analysis and processing of massive operation and maintenance data. Therefor, this paper proposes a solution of IT operation and maintenance data management system based on big data technology,which divides the data management system into four layers: data integration, data storage, data calculation and data access,they are independent but also cooperative, for giving full play to the advantages of large data technology in data storage, parallel computing, large-scale data analysis, mining and other aspects. The solution provides efficient processing ability and unified data management mode for the storage of mass data in Information Center, and fully supports the application of data analysis, so as to promote the construction of intelligent operation and maintenance.

Design of Calculating Image Coordinates of Feature Point Based on Vivado HLS

HE Kai, LIANG Bei, YANG Fashun

. 2018, 31(4):  87. 

Abstract ( 329 )   PDF (752KB) ( 284 )  

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Aiming at the problems of traditional embedded processors such as high power consumption, the hardware acceleration of the software was proposed to improve the computing performance of the image processing system program. In this paper, With the usage of Vivado HLS, a high-level synthesis tool, OpenCV and C++ algorithms were translated into RTL hardware through hardware-software co-design. The design results showed that the scheme effectively improved the computing performance of the system and shorten the hardware development cycle.

Multitarget Tracking Technique Based on Extended Kalman Algorithm

JIA Jianbing,LIAO Jiawei,ZHOU Yu

. 2018, 31(4):  91. 

Abstract ( 451 )   PDF (901KB) ( 276 )  

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Under the framework of RFS theory, the traditional three filter algorithms based on Gaussian mixture was only applicable to linear Gaussian system. In order to extend to nonlinear Guassian system, three algorithms based on EK method were presented. Nonlinear problem was changed into linear problem approximatly by Taylor series expansion. Besides, the tracking performance of the three algorithms for targets with constant turning speed was compared. The simulation result indicated that the three algorithms can be applied to target tracking in nonlinear Gaussian system.