中国科学院机构知识库网格系统: 检索

Water-Facing Distribution and Suitability Space for Rural Mountain Settlements Based on Fractal Theory, South-Western China 期刊论文 OAI收割
LAND, 2021, 卷号: 10, 期号: 2, 页码: 14
作者: Yu, Hui; Luo, Yong; Li, Pengshan; Dong, Wei; Yu, Shulin

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收藏 | 浏览/下载：82/0 | 提交时间：2021/03/29

fractal characteristics natural geographical features water-facing distribution suitable space rural mountain settlements

Water-Facing Distribution and Suitability Space for Rural Mountain Settlements Based on Fractal Theory, South-Western China 期刊论文 OAI收割
LAND, 2021, 卷号: 10, 期号: 2, 页码: 14
作者: Yu, Hui; Luo, Yong; Li, Pengshan; Dong, Wei; Yu, Shulin

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收藏 | 浏览/下载：17/0 | 提交时间：2021/04/25

fractal characteristics natural geographical features water-facing distribution suitable space rural mountain settlements

Structural design for lightweight off-axis TMA space telescope (EI CONFERENCE) 会议论文 OAI收割
2011 2nd International Conference on Digital Manufacturing and Automation, ICDMA 2011, August 5, 2011 - August 7, 2011, Zhangjiajie, Hunan, China
作者: Li Z.; Li Z.

收藏 | 浏览/下载：36/0 | 提交时间：2013/03/25

A kind of small space telescope with 1m focal length was designed. By adopting finite element analysis technique the structure of the space telescope was analyzed. The analysis results indicate that the surface profile accuracy of the mirrors reach to RMS 8.0nm with the working circumstances 4C uniform temperature change and space micro-gravity the base frequency of the structure was 115 Hz. It shows that the designed structure has sufficiently high dynamic and static stiffness and thermal dimensional stabiLity. This space optical telescope is very suitable for little satellite application. 2011 IEEE.

An improved destripe noises method for TDI-CCD images (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Mechatronic Science, Electric Engineering and Computer, MEC 2011, August 19, 2011 - August 22, 2011, Jilin, China
作者: He B.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

The new destriping method using lifting wavelet transform by means of the improved threshold function is presented in this letter. It can overcome the deficiency of the hard and soft threshold function. As compared with the known threshold functions the quality of the denoised images using the improved threshold function is much better. The results based on several image quality indexes present that the destriped images are not only visually more plausible but also suitable for analysis. Also it is reasonable in computer time and storage space to use the lifting wavelet transform. 2011 IEEE.

Design and demonstration of micro multi-step mirrors and light source in micro FTIR (EI CONFERENCE) 会议论文 OAI收割
6th IEEE International Conference on Nano/Micro Engineered and Molecular Systems, NEMS 2011, February 20, 2011 - February 23, 2011, Kaohsiung, Taiwan
Liang Z.; Fu J.; Feng C.; Liang J.

收藏 | 浏览/下载：43/0 | 提交时间：2013/03/25

To obtain high resolution high signal-to-noise ratio (SNR) high reliability and real time in wide spectral range we study the space modulation Micro Fourier Transform Spectrometer (FTS) based on multi-step mirrors covering the spectral range of 3-5m and 8-12 m in theory and experiment. The influences of spectrum reconstruction caused by the diffraction and extended light source in Fourier Transform Infrared Spectrometer (FTIR) are analyzed. A method to reduce the noises in spectrum reconstruction and the relationship between coherent intensity and solid angle of light source are discussed. An extended light source with suitable size is chosen considering the requirement of SNR and spectrum resolving power in the optical design. Furthermore the fabrication of micro multi-step mirrors which is the core part of FTS is investigated. Three methods for fabricating multi-step micro mirrors are demonstrated. 2011 IEEE.

Destriping of TDI-CCD remote sensing image (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: He B.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

Based on the characteristic of striping noise in remote sensing images a new destriping technique for the improved threshold function using lifting wavelet transform is presented in this letter. It can overcome the shortcoming of the hard threshold function and soft threshold function. The lifting wavelet transform is easily realized. Also it is inexpensive in computer time and storage space compared with the traditional wavelet transform. We also compare the improved threshold function with some traditional threshold functions both by visual inspection and by appropriate indexes of quality of the denoised images. Evaluations of the results based on several image quality indexes indicate that image quality has been improved after destriping. The destriped images are not only visually more plausible but also suitable for computerized analysis and it did better than the existed ones. 2010 IEEE.

An improved fast parallel SPIHT algorithm and its FPGA implementation (EI CONFERENCE) 会议论文 OAI收割
2010 2nd International Conference on Future Computer and Communication, ICFCC 2010, May 21, 2010 - May 24, 2010, Wuhan, China
作者: Jin L.-X.; Tao H.-J.; Wu Y.-H.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

In view of the current stringent need to the real-time compression algorithm of the high-speed and high-resolution image such as remote sensing or medical image and so on in this paper No List SPIHT (NLS) algorithm has been improved and a fast parallel SPIHT algorithm is proposed which is suitable to implement with FPGA. It can deal with all bit-planes simultaneously and process in the speed of 4pixels/period so the encoding time is only relative to the image resolution. The experimental results show that the processing capacity can achieve 200MPixels/s when the input clock is 50MHz the system of this paper need 2.29ms to complete lossless compression of a 512x512x8bit image and only requires 1.31ms in the optimal state. The improved algorithm keeps the high SNR unchanged increases the speed greatly and reduces the size of the needed storage space. It can implement lossless or lossy compression and the compression ratio can be controlled. It could be widely used in the field of the high-speed and high-resolution image compression. 2010 IEEE.

Analysis of inertia dyadic uncertainty for small agile satellite with control moment gyros (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE International Conference on Mechatronics and Automation, ICMA 2010, August 4, 2010 - August 7, 2010, Xi'an, China
作者: Zhang L.; Zhang L.; Sun Z.

收藏 | 浏览/下载：20/0 | 提交时间：2013/03/25

With the increasing demands for the agility of the next earth imaging satellite control moment gyro (CMG) is considered to be the most suitable actuator because of its torque amplification capability. However a CMG system may introduce uncertainty of inertia dyadic to a satellite's attitude control system. The uncertainty is negligible for large space vehicles but it has not been tested whether it can be ignored for small agile satellites. How to model the CMG system inertia dyadic varying with gimbal angles and what influence it will put on the performance of attitude control system haven't been test accurately as well. All of them are dealt with mathematically and accurately in this paper. This paper firstly gives mathematic descriptions of the inertia dyadic of the 4-CMG pyramid configuration system varying with gimbal angles and then designs a variable structure control law for small agile satellite using CMGs. Finally numerical simulation suggests that the inertia dyadic variation of a 4-CMG pyramid configuration system is approximately centesimal of the total inertia dyadic of the satellite and that the designed variable structure control law is of good robust performance for an example of large-angle attitude maneuver despite of the variation of the inertia dyadic. 2010 IEEE.

An efficient color transfer algorithm for recoloring multiband night vision imagery (EI CONFERENCE) 会议论文 OAI收割
Enhanced and Synthetic Vision 2010, April 6, 2010 - April 6, 2010, Orlando, FL, United states
作者: Xu S.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

A color transfer method is presented to give fused multiband nighttime imagery a natural daytime color appearance in a simple and efficient way. Instead of using the traditional nonlinear l space the proposed method transfers the color distribution of the target image (daylight color image) to the source image (fused multiband nighttime imagery) in the linear YCBCR color space. The YCBCR transformation is simpler and more suitable for image fusion compared to the l conversion. The YCBCR transformation can be extended into a general formalism. And the paper mathematically proves that for color transfer using color spaces conforming to this general YC BCR space framework can produce same recoloring results as using the YCBCR space. Experimental results demonstrate that the YCBCR based color transfer method works surprisingly well for transferring natural color characteristics of daylight color images to false color fused multiband nighttime imagery and moreover can also be successfully applied to recoloring a variety of color images. 2010 SPIE.

Study on bandwidth mutual-benefit between the azimuth and pitch in an optoelectronic tracking system (EI CONFERENCE) 会议论文 OAI收割
MEMS/MOEMS Technologies and Applications III, November 12, 2007 - November 14, 2007, Beijing, China
作者: Guo J.; Guo J.; Chen J.

收藏 | 浏览/下载：16/0 | 提交时间：2013/03/25

Two-axis optoelectronic tracking equipments generally use such mode that azimuth and pitch system are independently controlled. It leads to the two structures completely uncoupled therefore and reduces the state space dimension. But the main problem is that the rotational inertia of azimuth is much larger than that of pitch it is an effective control mode to the two-axis photoelectric tracking equipments. which leads its dynamic tracking performance is worse. So to find a more suitable mechanics and more effective control strategy is necessary. Considering the tracking ability this paper designs BMC (bandwidth mutual compensation) to uniformly correct the error of both the azimuth and pitch system in real time it is realized by cross coupling control to the azimuth and pitch. The simulation result verified that compared with classical uncoupling system BMS not only guarantees the state space dimension but improves systematic tracking performance about 2