中国科学院机构知识库网格系统: 检索

An embedded infrared image enhancement system based on DSP and FPGA (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Manufacturing Engineering and Process, ICMEP 2012, April 21, 2012 - April 22, 2012, Kunming, China
作者: Zhang T.

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According to the disadvantage of the large noises of histogram equalization algorithm a new adaptive image enhancement algorithm is presented. First the statistical histogram of the infrared image is done. Then the threshold of plateaus Equalization is calculated and the statistical histogram is modified. Finally the bright values of the pixels of the image are changed. An embedded high speed image enhancement processing system on high performance DSP TMS320DM642 and FPGA was designed. Experimental results with real images shown that the system can improve the contrast of the infrared image limit the noises of the enhancement image and effectively enhance the infrared image the running time of the program is shorter so it can meet the requirements of real-time in the project. (2012) Trans Tech Publications.

A novel miniature absolute metal rotary encoder based on Single-track Periodic Gray Code (EI CONFERENCE) 会议论文 OAI收割
2012 2nd International Conference on Instrumentation and Measurement, Computer, Communication and Control, IMCCC 2012, December 8, 2012 - December 10, 2012, Harbin, Heilongjiang, China
作者: Sun Y.; Yang S.-W.; Sun Y.; Wan Q.-H.

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In order to improve the resolution and enhance the impact resistance and vibration resistance of encoders a novel absolute metal rotary encoder based on Single-track Periodic Gray Code is presented. The configuration and working principle of the encoder is introduced and then the metal code disc which can realize full scale absolute encoding on one single track and its corresponding metal slit disc are proposed. Finally the data acquisition and processing system based on FPGA of encoder is presented. The resolution of the encoder can reach 5.27through electronic subdivision and calibration between the precision code and the coarse code with its volume only 4840mm. The encoder has some advantages such as small volume low cost high resolution and strong impact resistance. 2012 IEEE.

The new approach for infrared target tracking based on the particle filter algorithm (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者: Sun H.; Han H.-X.; Sun H.

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Target tracking on the complex background in the infrared image sequence is hot research field. It provides the important basis in some fields such as video monitoring precision and video compression human-computer interaction. As a typical algorithms in the target tracking framework based on filtering and data connection the particle filter with non-parameter estimation characteristic have ability to deal with nonlinear and non-Gaussian problems so it were widely used. There are various forms of density in the particle filter algorithm to make it valid when target occlusion occurred or recover tracking back from failure in track procedure but in order to capture the change of the state space it need a certain amount of particles to ensure samples is enough and this number will increase in accompany with dimension and increase exponentially this led to the increased amount of calculation is presented. In this paper particle filter algorithm and the Mean shift will be combined. Aiming at deficiencies of the classic mean shift Tracking algorithm easily trapped into local minima and Unable to get global optimal under the complex background. From these two perspectives that "adaptive multiple information fusion" and "with particle filter framework combining" we expand the classic Mean Shift tracking framework.Based on the previous perspective we proposed an improved Mean Shift infrared target tracking algorithm based on multiple information fusion. In the analysis of the infrared characteristics of target basis Algorithm firstly extracted target gray and edge character and Proposed to guide the above two characteristics by the moving of the target information thus we can get new sports guide grayscale characteristics and motion guide border feature. Then proposes a new adaptive fusion mechanism used these two new information adaptive to integrate into the Mean Shift tracking framework. Finally we designed a kind of automatic target model updating strategy to further improve tracking performance. Experimental results show that this algorithm can compensate shortcoming of the particle filter has too much computation and can effectively overcome the fault that mean shift is easy to fall into local extreme value instead of global maximum value.Last because of the gray and fusion target motion information this approach also inhibit interference from the background ultimately improve the stability and the real-time of the target track. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).

Target characteristic extraction algorithm based on block structure variables (EI CONFERENCE) 会议论文 OAI收割
2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China
作者: Zhou Y.; Yang H.; Yan F.; Yan F.

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In image processing system the target recognition is very crucial. An optimized algorithm based on the definition of block is presented. In this algorithm two structure variables are self-defined to calculate the areas and centroids of targets. The labeling conflicts are resolved by tracking and correcting which means that if there is a conflict trace the neighbored blocks and correct the labels of them. Finally the characteristics of blocks which have the same label are accumulated. This method has outstanding advantages in saving memory compared with Pixel labeling algorithm and Run-length code algorithm. The new algorithm is simple and the results of target characteristics are easy to be analyzed and handled in the following processes. 2010 IEEE.

OFDM baseband modulation technology based on VHDL (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE International Conference on Advanced Computer Control, ICACC 2010, March 27, 2010 - March 29, 2010, 445 Hoes Lane - P.O.Box 1331, Piscataway, NJ 08855-1331, United States
Lin L.; Qiao Y.-F.; Su W.-X.

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In order to improve the transmission velocity in mulitipath fading wireless channel two main advantages are obtained via discussing spectrum utilization ratio of OFDM. Then the high speed OFDM technology receives increasing attentions in mobile communication. Modulation programs are designed with VHDL based on the principle of OFDM in the paper. First from the results of VHDL simulation after OFDM fundamental is introduced the realization of baseband operations such as interleaver subcarrier modulation IFFT and adding CP are presented. Finally implemented programs are validated on the actual implement system. Experimental results indicate that setup time corresponding to transmission velocity is only 71.05s and steady time is approximately 6 times as setup time that is not only achieving the high speed transmission but also supplying adequate modulation time. 2010 IEEE.

Design of aspherical surfaces for panoramic imagers using multipopulations genetic algorithm (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, November 19, 2008 - November 21, 2008, Chengdu, China
作者: Jin C.-S.; Wang L.-P.; Liang Z.-Z.

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A design method of aspherical surface for panoramic imaging system with two mirrors using multi-populations genetic algorithms is proposed. Astigmatism induced by mirrors may significantly compromise image resolution. To solve this problem we induced algebraic expression of astigmatism in panoramic imager based on generalized Coddington equation and theory of geometric optics. Then we propose an optimization process for mirror profile design to eliminate astigmatism and provide purposely-designed projection formula with aid of MPGA. A series of polynomial expressions of aspherical surfaces are obtained and procedures of the design are presented. In order to facilitate ray tracing and aberration calculation even asphere surface model is obtained by using of hybrid schemes combining MPGA and damped least squares. Finally a prototype of the catadioptric panoramic imager has been developed and panoramic ring image is obtained. 2009 SPIE.

Estimation algorithm of mobile OFDM CFOs based on step-size (EI CONFERENCE) 会议论文 OAI收割
2009 International Conference on Information Engineering and Computer Science, ICIECS 2009, December 19, 2009 - December 20, 2009, Wuhan, China
Lin L.; Qiao Y.-F.; Su W.-X.

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In order to maintain orthogonality among subcarriers for mobile OFDM a CFOs step-size estimation model is established to avoid severe performance degradation caused by ICI and algorithmic stability step-size parameter the error of CFOs estimate and etc are investigated. First after an averaging window algorithm is introduced the mathematic model of step-size estimation algorithm is obtained through step-size parameter and time-varying CFOs. Then based on the results of MATLAB simulation the determination of step-size parameter the advantages of step-size algorithm and precision are discussed. Finally time sequence plots of added CP interleaver and subcarrier modulation with VHDL are presented. Experimental results indicate that the maximum of CFOs errors is 0.00987 in 3 variance interval when mobile velocity is 400 km/h according with verdicted principle that in order for the ICI effects to be negligible the error of CFOs estimation must be accurate within 1-2% of the subcarrier spacing and programs can correctly implement on circuit board. 2009 IEEE.

Analysis and modelling of no-reference video quality assessment (EI CONFERENCE) 会议论文 OAI收割
2009 International Conference on Computer and Automation Engineering, ICCAE 2009, March 8, 2009 - March 10, 2009, Bangkok, Thailand
Tian Y.; Zhu M.

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Video processing system may introduce some amounts of distortions in the video signal. It is crucial to measure the video quality blindly for most image processing applications which could not obtain the original image. Different Video Quality Assessment (VQA) methods are analysis in this paper. A state of art in the field of No- Reference (NR) VQA is presented. Finally an ideal NR VQA model is proposed. 2009 IEEE.

Simulations and experimental studies of diffuser/nozzle pumps (EI CONFERENCE) 会议论文 OAI收割
4th International Symposium on Precision Mechanical Measurements, August 25, 2008 - August 29, 2009, Hefei/Jiuhua Mountain, Anhui, China
作者: Li W.; Li W.

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An investigation of diffuser/nozzle micropumps is presented. Numerical simulations are done using CFD program ANSYS/Flotran. The simulations show when the opening angel is small the flow in the diffuser/nozzle is steady the mass flow is increasing with the adding opening angle. But when the opening angel continues increasing the pressure grads will be bigger than zero. It means that the static pressure is gradually going up along the diverging direction. The fluid near the wall stops flowing because the velocity decreases rapidly and the dynamic pressure is not big enough to overcome the increasing of the static pressure. Finally the fluid flows reversely from the backward position of higher pressure area this makes the separation flow of fluid the diffuser is full of reverse fluid. And this results in the dropping of mass flow at last. The simulations also show that the performance of diffuser with a round inlet is better than that with a sharp inlet. The mass flow of micropumps with different opening angles different inlets are measured. The experimental results agree well with the simulations. 2008 SPIE.

Research and development on the valve-less piezoelectric pump with unsymmetrical corrugation chamber bottom (EI CONFERENCE) 会议论文 OAI收割
2006 IEEE International Conference on Information Acquisition, ICIA 2006, August 20, 2006 - August 23, 2006, Weihai, Shandong, China
作者: Zhang J.; Li D.; Zhang J.; Zhang J.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

The valve-less piezoelectric pump is more suitable for minimization and microminiaturization than the valve piezoelectric pump especially for the Microelectromechanical System (MEMS) because of its simple structure. However in order to control the flow direction of the fluid through the pump some assembles have to be attached outside the chamber. And it is no doubt that these assembles will take some space and hinder its further microminiaturization. In this paper a novel valve-less piezoelectric pump with unsymmetrical corrugation chamber bottom (UCCB) is presented. It ingeniously takes advantage of the space of the chamber by developing its bottom into a unsymmetrical corrugation shape along the axis of the inlet and outlet. As a result a series of diffuse pipes and nozzle pipes (or wedge-shaped pipes) which substitute the regular diffuse/nozzle elements fitted outside the chamber are alternatively formed between the unsymmetrical corrugation chamber bottom (UCCB) and the piezoelectric vibrator. The piezoelectric vibrator is opposite to the UCCB. And these diffuse pipes and nozzle pipes are able to force the fluid in the chamber to flow along a single direction when the pump works. And then the mathematic model is established to present the relationship between the mean energy loss and the flow rate of the pump. Basing on the mathematic model the theory on the pump working is analysed. Finally a real UCCB valve-less piezoelectric pump is manufactured and the test with it is carried out to verify the theory above-mentioned. 2006 IEEE.