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浏览/检索结果: 共15条，第1-10条 帮助

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The impact of proxy selection strategies on a millennium-long ensemble of hydroclimatic records in Monsoon Asia 期刊论文  OAI收割
QUATERNARY SCIENCE REVIEWS, 2019, 卷号: 223, 页码: 14
作者:  Schneider, Lea;  Ljungqvist, Fredrik Charpentier;  Yang, Bao;  Chen, Fahu;  Chen, Jianhui
  |  收藏  |  浏览/下载：31/0  |  提交时间：2020/06/03
The impact of proxy selection strategies on a millennium-long ensemble of hydroclimatic records in Monsoon Asia 期刊论文  OAI收割
QUATERNARY SCIENCE REVIEWS, 2019, 卷号: 223, 页码: 14
作者:  Schneider, Lea;  Ljungqvist, Fredrik Charpentier;  Yang, Bao;  Chen, Fahu;  Chen, Jianhui
  |  收藏  |  浏览/下载：76/0  |  提交时间：2020/05/19
Pseudo low rank video representation 期刊论文  OAI收割
PATTERN RECOGNITION, 2019, 卷号: 85, 期号: 1, 页码: 50-59
作者:  Yu, Tingzhao;  Wang, Lingfeng;  Guo, Chaoxu;  Gu, Huxiang;  Xiang, Shiming
  |  收藏  |  浏览/下载：69/0  |  提交时间：2019/01/08
A new low-bandwidth and wireless transmission scheme for CCd image (EI CONFERENCE) 会议论文  OAI收割
2012 International Symposium on Photonics and Optoelectronics, SOPO 2012, May 21, 2012 - May 23, 2012, Shanghai, China
作者:  Zhang Y.
收藏  |  浏览/下载：40/0  |  提交时间：2013/03/25
The CCD (Charge-coupled Device) image sensor with its high resolution is capable of providing high definition image. However  transmission requires high bandwidth  which makes it very difficult to process and transmit in a long distance. The purpose of this paper is to propose a new method to process and transmit CCD image  which can guarantee a low-bandwidth and long-distance data transmission. The innovation is that the transmission content of CCD image data can be flexibly selected and compressed firstly  which will reduce the transmission data. Then it is processed on the base of communication protocol so that it can be fit for wireless transmission. At last  it is transformed into wireless signal and transmitted using 3G technology. As a result  the paper presents a wireless transmission scheme with the rate of 1.5Mbps for CCD image. 2012 IEEE.  
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.
收藏  |  浏览/下载：34/0  |  提交时间：2013/03/25
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.  
Image compression based on contourlet and no lists SPIHT (EI CONFERENCE) 会议论文  OAI收割
2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China
作者:  Zhang S.
收藏  |  浏览/下载：57/0  |  提交时间：2013/03/25
The volume of raw image data captured by the high resolution camera is extremely huge. Thus the efficient image compression method should be used to decrease the bit rate. The image compression method based on wavelet is used more widely nowadays. However  two dimensional wavelet is only the tensor product of the one dimensional wavelet whose support region of basis function is extended from interval to square. Contourlet is an image multiscale geometric analysis tool  which could represent image sparsely and has strong capability of nonlinear approximation. The basis function of contourlet is multidirectional and anisotropic. Nevertheless  contourlet is redundant. So the non-redundant Wavelet Based Contourlet Transform (WBCT) is used in this paper. The SPIHT algorithm is very efficient way to coding the significant coefficients. And the improved no lists SPIHT is more easy to implemented by hardware. Image compression method based on the combination of both wavelet based contourlet transform and no lists SPIHT coding is proposed in the paper. Experiment shows that compared to wavelet based scheme the contourlet scheme can reserve the texture of the image. For barbara test image when coding at low bit rate the PSNR can improve about 0.2dB. 2010 IEEE.  
Design of driving circuit for binocular CCD image system (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology, April 26, 2010 - April 29, 2010, Dalian, China
作者:  Zhang X.;  Zhang X.;  Zhang X.
收藏  |  浏览/下载：48/0  |  提交时间：2013/03/25
The paper designs a driving circuit of high sensitive  wide dynamic and high signal-to-noise ratio for binocular CCD imaging system which adopts a Dalsa-made high resolution full-frame 33-mega pixels area CCD FTF5066M. Inner structure and driving timing of the FTF5066M sensor are presented. Field Programmable Gate Array (FPGA) is used as the main device to accomplish the timing design of the circuits and power driver control of the two sensors. By using the Correlated Double Sampling (CDS) technique  the video noise is reduced and the SNR of the system is increased. A 12- bit A/D converter is used to improve the image quality. The output rate of the imaging system designed with integrated chip can reach to 1.3 frames per second through bi-channel. For its good performance  low power consumption and small volume  the driving system can be applied to aeronautics and astronautics field. With a further improvement  a maximum data output rate of 2.7 frames per second can be reached through all the eight channels of the two CCDs. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Adaptive resolution storage system based on LOG-POLAR transform for multi-target trackers (EI CONFERENCE) 会议论文  OAI收割
2010 International Conference on Computer Application and System Modeling, ICCASM 2010, October 22, 2010 - October 24, 2010, Shanxi, Taiyuan, China
作者:  Zhang Y.
收藏  |  浏览/下载：31/0  |  提交时间：2013/03/25
The main constrained problem of the video monitoring and storage system is the contradiction between large field of view and storage space limitations. Not all of the video information introduced by the image sensors need to be recorded especially for some tracking system which has appointed functions to track specifically kinds of targets. For instance  the system not only works for single target  if the monitor is appointed for human face tracking  but also can work for multi-targets. High reconstruction resolution in the fovea region enables the successive application of recognition modules without sacrificing their performance  the best system appears to be concentrating on human face only and all the others considered being background  the low reconstruction resolution in the periphery helps to reduce the video data. 2010 IEEE.  the background regions needn't to be recorded in detail. For this purpose  this letter presents a real-time foveate storage system  which efficiently represents the video image in log-polar coordinates  with the foveate point centered on the target  
Design of high-resolution fourier transform lens (EI CONFERENCE) 会议论文  OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Advanced Optical Manufacturing Technologies, July 8, 2007 - July 12, 2007, Chengdu, China
作者:  Zhang L.;  Zhang L.
收藏  |  浏览/下载：30/0  |  提交时间：2013/03/25
With the development of optical information processing  high-resolution Fourier transform lens has often been used in holographic data storage system  spatial filtering and observation of particles. This paper studies the optical design method of high-resolution Fourier transform optical lenses system  which could be used in particles observation and holographic data storage system. According to Fourier transform relation between object and its frequency plane and the theory of geometrical optics  the system with working wavelength 532nm and resolution 3 m was designed based on ZEMAX. A multi-configuration method was adopted to optimize the system's lenses. In the optical system  a diaphragm was placed at the system's spectrum plane and the system demanded a low vacuum to cut down the influences of atmosphere and other particles. The result of finite element analysis indicated that the influences of vacuum pumping to optics spacing and mirror surface shape very minor  and the imaging quality not being affected. This system has many advantages  such as simple structure  good image quality and a high resolution of 3 m. So it has a wide application prospect and can be used both in holographic data storage system and particles observation.  
Design and implementation of high-speed digital CMOS camera driving control timing and data interface (EI CONFERENCE) 会议论文  OAI收割
Sixth International Symposium on Instrumentation and Control Technology: Sensors, Automatic Measurement, Control and Computer Simulation, October 13, 2006 - October 15, 2006, Beijing, China
作者:  Wang Y.;  Wang Y.;  Wang Y.;  Sun H.;  Sun H.
收藏  |  浏览/下载：45/0  |  提交时间：2013/03/25
High-speed digital cameras are progressing rapidly with the development of CMOS image sensor in these few years. In order to develop a high-speed CMOS industrial digital camera  the CMOS image sensor MI-MV13 is used. The sensor drive pulse and control timing based on Xilinx Virtex-II Pro FPGA is designed. A novel format of digital image transporting based on Camera Link data port is defined in this paper. It is implemented 1280 (H) 1024 (V) SXGA resolution digital image transported at a high frame rate of 300 fps (frames-per-second) with 5 Pixels 10 bit compatible Camera Link Medium Configuration. In addition  these functions that adjustments of exposure beginning time  integral time  AOI (Area of Interest) output and so on  are realized in a FPGA chip. All of the function modules are embedded in a SOPC (System on a Programmable Chip)  and further functions can be easily added to the chip at the second time development. Experimental results show that the design of driving control timing and data interface in FPGA is suitable for high-frame rate  low power  intelligent and miniaturization digital video camera.