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浏览/检索结果: 共22条,第1-10条 帮助

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紫色土旱坡地氮流失通量对减肥配施秸秆的响应 期刊论文  OAI收割
环境学报, 2020, 卷号: 41, 期号: 4, 页码: 1930-1940
作者:  
熊子怡;  王子芳;  龙翼;  严冬春;  徐国鑫
  |  收藏  |  浏览/下载:93/0  |  提交时间:2020/04/29
Impact of BDS-3 experimental satellites to BDS-2: Service area, precise products, precise positioning 期刊论文  OAI收割
ADVANCES IN SPACE RESEARCH, 2018, 卷号: 62, 期号: 4, 页码: 829-844
作者:  
Zhang, Rui;  Tu, Rui;  Liu, Jinhai;  Hong, Ju;  Fan, Lihong
  |  收藏  |  浏览/下载:22/0  |  提交时间:2021/11/29
Adaptive reliability analysis based on a support vector machine and its application to rock engineering 期刊论文  OAI收割
APPLIED MATHEMATICAL MODELLING, 2017, 卷号: 44, 页码: 508-522
作者:  
Ru, Zhongliang;  Zhao, Hongbo;  Li, Shaojun
  |  收藏  |  浏览/下载:23/0  |  提交时间:2018/06/05
LED display image correction based on computer simulation (EI CONFERENCE) 会议论文  OAI收割
2012 International Applied Mechanics, Mechatronics Automation Symposium, IAMMAS 2012, September 7, 2012 - September 9, 2012, Shenyang, Liaoning, China
Zheng X.-F.; Chang F.
收藏  |  浏览/下载:26/0  |  提交时间:2013/03/25
For the purposes of correcting the LED display image  a method based on computer simulation is proposed. First  the development of the LED display panel is introduced. Second  analyze the causes of the problem which image in LED display panel has serious high nonuniformity  and introduce the existed correction techniques which are used to reduce the nonuniformity of LED display image. Simultaneously  point out the ground for shortcomings of these techniques. Third  describe the principle of correction method based on computer simulation detail from two steps  which are the luminous collection and luminous copulation. Forth  describe the realization steps of this method in accordance with the third step. Finally  this method is supplied in a LED display panel  whose resolution is 640480. Experimental results show that this method is able to reduce the non-uniformity of images from 11.06% to 0.98%. (2012) Trans Tech Publications  Switzerland.  
LED display panel grayscale modulation based on computer calculation (EI CONFERENCE) 会议论文  OAI收割
2012 International Applied Mechanics, Mechatronics Automation Symposium, IAMMAS 2012, September 7, 2012 - September 9, 2012, Shenyang, Liaoning, China
Wang R.-g.; Chang F.
收藏  |  浏览/下载:25/0  |  提交时间:2013/03/25
In order to improve the method of the LED display panel grayscale modulation a method based on computer calculation is proposed. First the development history and trends of the LED display panel are introduced. Second present the structure of the LED display panel and the existed modulation method. Simultaneously point out the ground for shortcomings of the existed method. Third describe the principle modulation method based on computer calculation detail from two steps which are the data signal transformation and the grayscale modulation. Forth describe the realization steps of this method in accordance with the third step. Finally this method is supplied in a LED display panel whose resolution is 320240. Experimental results show that this method is able to increase the grayscale from 14-bit to 16-bit and can enhance the display result of the LED display panel significantly. (2012) Trans Tech Publications Switzerland.  
A hybrid median filter for enhancing dim small point targets and its fast implementation (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Multimedia and Signal Processing, CMSP 2011, May 14, 2011 - May 15, 2011, Guilin, Guangxi, China
Yang Q.
收藏  |  浏览/下载:22/0  |  提交时间:2013/03/25
Weak stars and middle altitude orbit satellites or high altitude orbit satellites are presented as dim point targets in images of astronomical observation. They have low intensity and occupy few pixels in image. In most situations  the background of sky is always ununiform and there exists pulse noises. Thus results in targets submerging in background noises and low signal noise ratio (SNR). Median filter is an effective method for removing pulse noise. But it can blur image after modifying gray of non-noise pixels when image has low SNR. A hybrid median filter algorithm is proposed to process low SNR dim point targets image. The newly proposed method can suppress the pulse noises  also can increase target $SNR$ and does not add extra fake targets. The time complexity of median filter is O(N2)(N is the widow size) and is difficult to implement in hardware. For quasi real time application  a fast implementation of our hybrid median filter is proposed to reduce the time complexity to O(N). Experimental results show that the newly proposed algorithm is superior to ordinary median filter and fast median filter by comparing visual effect and performance. 2011 IEEE.  
Numerical simulation on efficient spinning technology based on multi-point adjusting principle (EI CONFERENCE) 会议论文  OAI收割
2nd International Conference on Manufacturing Science and Engineering, ICMSE 2011, April 9, 2011 - April 11, 2011, Guilin, China
Gong X. P.
收藏  |  浏览/下载:29/0  |  提交时间:2013/03/25
In order to realize high efficiency and flexible manufacturing for rotary surfaces  equivalent stress in sheet metal's center region and bendable rollers active region exceeds yield stress  efficient spinning technology (EST) is researched. It is the combination of multi-point forming and traditional spinning. Principle of EST is described  and plastic deformation is generated  traditional spinning method is compared with it  experimental result accords with simulation result. Feasibility of EST is validated by simulation and experimental results. (2011) Trans Tech Publications.  and characteristics of it are analyzed. Finite element analysis (FEA) model of disc-shape part is established  EST process is analyzed  equivalent stress and plastic strain distributions are analyzed. EST equipment is developed  and the experiments are made. Results indicate: EST process consists of four stages  
Laser pulse coded signal frequency measuring device based on DSP and CPLD (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Laser Sensing and Imaging; and Biological and Medical Applications of Photonics Sensing and Imaging, May 24, 2011 - May 26, 2011, Beijing, China
作者:  
Zhang H.-B.;  Wang T.-F.;  Guo R.-H.;  Li Y.;  Li Y.
收藏  |  浏览/下载:38/0  |  提交时间:2013/03/25
Laser pulse code is an anti-jamming measures used in semi-active laser guided weapons. On account of the laser-guided signals adopting pulse coding mode and the weak signal processing  it need complex calculations in the frequency measurement process according to the laser pulse code signal time correlation to meet the request in optoelectronic countermeasures in semi-active laser guided weapons. To ensure accurately completing frequency measurement in a short time  it needed to carry out self-related process with the pulse arrival time series composed of pulse arrival time  calculate the signal repetition period  and then identify the letter type to achieve signal decoding from determining the time value  number and rank number in a signal cycle by Using CPLD and DSP for signal processing chip  designing a laser-guided signal frequency measurement in the pulse frequency measurement device  improving the signal processing capability through the appropriate software algorithms. In this article  we introduced the principle of frequency measurement of the device  described the hardware components of the device  the system works and software  analyzed the impact of some system factors on the accuracy of the measurement. The experimental results indicated that this system improve the accuracy of the measurement under the premise of volume  real-time  anti-interference  low power of the laser pulse frequency measuring device. The practicality of the design  reliability has been demonstrated from the experimental point of view.  
Adaptive Wiener filtering with Gaussian fitted point spread function in image restoration (EI CONFERENCE) 会议论文  OAI收割
2011 IEEE 2nd International Conference on Software Engineering and Service Science, ICSESS 2011, July 15, 2011 - July 17, 2011, Beijing, China
作者:  
Yang L.;  Zhang X.;  Zhang X.;  Zhang X.;  Yang L.
收藏  |  浏览/下载:44/0  |  提交时间:2013/03/25
In the imaging process of the space remote sensing camera  there was degradation phenomenon in the acquired images. In order to reduce the image blur caused by the degradation  the remote sensing images were restored to give prominence to the characteristic objects in the images. First  the frequency-domain notch filter was adopted to remove strip noises in the images. Then using the ground characters with the knife-edge shape in the images  the point spread function of the imaging system was estimated. In order to improve the accuracy  the estimated point spread function was corrected with Gaussian fitting method. Finally  the images were restored using the adaptive Wiener filtering with the fitted point spread function. Experimental results of the real remote sensing images showed that almost all strip noises in the images were eliminated. After the denoised images were restored  its variance and its gray mean gradient increased  also its laplacian gradient increased. Restoration with Gaussian fitted point spread function is beneficial to interpreting and analyzing the remote sensing images. After restoration  the blur phenomenon of the images is reduced. The characters are highlighted  and the visual effect of the images is clearer. 2011 IEEE.  
The research of the accurate measure of static transfer function for the TDI CCD camera (EI CONFERENCE) 会议论文  OAI收割
3rd International Photonics and OptoElectronics Meetings, POEM 2010, November 2, 2010 - November 5, 2010, Wuhan, China
Guo-Ning L.; Long-Xu J.; Jian-Yue R.; Wen-Hua W.; Shuang-Li H.
收藏  |  浏览/下载:25/0  |  提交时间:2013/03/25
In the test course of static transfer function of TDI CCD camera  because of the influence that gets environmental and artificial etc. factor  the value of static transfer function measured at any time is between unceasing fluctuation  so  make accuracy reduce. To solve this problem  a kind of accurate measurement technique of static transfer function is put forward. First  before carrying out the measure of static quiet of transfer function  the best test point of transfer function of the TDI CCD camera must be determined  it is parallel to guarantee the rectangle target surface of parallel optical pipe and camera focal plane maintenance parallel  and again guarantee target strip in rectangle target and TDI CCD in camera focal plane maintenance vertical. TDI CCD catches rectangle target image  per 1000 lines of target mark image as a measures sample of static transfer function  exclude because of atmosphere tremble twisted  vague rectangle target mark image  retain 500 distinct and steady target mark image as measure sample set. Then  calculate the static transfer function of each measure sample respectively  take the average of all static quiet transfer function in measure sample set as the static transfer function of camera. Finally  the measure of the static transfer function for TDI CCD camera makes error analysis. Experimental results indicate that the value of the static transfer function of TDI CCD camera measured with this kind of method is 0.2923  with before measurement technique comparison  the value of static transfer function has raised 0.02  makes the accuracy of the measure of static transfer function have gotten raising.  
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