中国科学院机构知识库网格系统: 检索

A grid-based tropospheric product for China using a GNSS network 期刊论文 OAI收割
JOURNAL OF GEODESY, 2018, 卷号: 92, 期号: 7, 页码: 765-777
作者: Zhang, Baocheng; Li, Wei; Yuan, Yunbin; Zhang, Hongxing; Ou, Jikun

|

收藏 | 浏览/下载：47/0 | 提交时间：2018/12/29

Global navigation satellite systems (GNSS) Zenith tropospheric delay (ZTD) IGGtrop model Grid-based tropospheric product (GTP) Undifferenced and uncombined precise point positioning (UU-PPP)

Stability Analysis for a Class of Systems: From Model-Based Methods to Data-Driven Methods 期刊论文 OAI收割
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, 2014, 卷号: 61, 期号: 11, 页码: 6463-6471
作者: Wang, Zhuo

收藏 | 浏览/下载：23/0 | 提交时间：2015/08/12

Bounded-input/bounded-state (BIBS) and bounded-input/bounded-output BIBO) stabilities continuoustime and discrete-time systems data-driven methods model-based methods stability of the equilibrium point

Passive behavior of a bulk nanostructured 316L austenitic stainless steel consisting of nanometer-sized grains with embedded nano-twin bundles 期刊论文 OAI收割
Corrosion Science, 2014, 卷号: 85, 页码: 331-342
T. S. Li; L. Liu; B. Zhang; Y. Li; F. K. Yan; N. R. Tao; F. H. Wang

收藏 | 浏览/下载：19/0 | 提交时间：2015/01/14

Passive films Passivity Stainless steel XPS AFM electrochemical corrosion behavior iron-chromium-alloys mixed-conduction model ni-based superalloy point-defect model anodic oxide-film high-temperature electrolyte dynamic plastic-deformation sulfuric-acid-solution fe-cr alloys

LABTM control system based on FPGA (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Mechatronics and Applied Mechanics, ICMAM 2012, December 8, 2012 - December 9, 2012, Taiwan
作者: Wang Y.; Yu P.; Yu P.; Wang Y.; Wang Y.

收藏 | 浏览/下载：153/0 | 提交时间：2013/03/25

This paper presents the digital PI control method for design and simulation of a high precision limited angle brushless torque motor control system in Field Programmable Gate Array device (FPGA). The direct drive structures which are widely applied in many servo control fields. Matlab Xilinx System GeneratorR toolbox based on Fixed-Point Arithmetic is used to design the digital PI controller using DSP architecture plot the responses of the control system and generate the VHDL source code. The control system model consists of a digital PI a real LABTM and a real absolute Inductosyn encoder to rpm and position blocks. Through loading generated codes in process of the simulation that built by the digital discrete model it is verified that the rising time of current loop is only 1.2ms and rate loop is 8ms overshoot is rarely 4.2%. Finally the comprehensive positioning accuracy of system can reach up to 5 arc sec and the rate jitter achieves 5% with the 4 arc sec accuracy absolute Inductosyn. (2013) Trans Tech Publications Switzerland.

Comparison and simulation of subpixel imaging modes for linear CCD (EI CONFERENCE) 会议论文 OAI收割
2012 3rd International Conference on Information Technology for Manufacturing Systems, ITMS 2012, September 8, 2012 - September 9, 2012, Qingdao, China
作者: Li Y.; He B.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：37/0 | 提交时间：2013/03/25

Subpixel technique of linear CCD is effective to enhance the spatial resolution without increasing the focal length of optics and reducing the pixel size. To compare image quality of two main subpixel imaging modes quincunx sampling and four-point sampling a method to quantitatively evaluate image quality of subpixel based on MTF was proposed. The MTF of quincunx and four-point sampling modes were derived. Analytical results shows that theoretical limiting resolution of quincunx sampling and four-point sampling is improved to 1.4 and 1.86 times respectively and MTF values at Nyquist frequency of two modes are increased by 0.1106 and 0.1679 respectively. MTFA in (0 0.5) of two subpixel imaging modes were calculated and results illustrates that four-point sampling offers much more improvement with image quality than quincunx sampling at the cost of double amount of data. A model for simulating subpixel imaging using Matlab was established and simulation results of spoke target verify the theoretical analysis. (2012) Trans Tech Publications Switzerland.

Multi-scale decomposition of point process data SCI/SSCI论文 OAI收割
2012
作者: Ma T.; Pei T.

收藏 | 浏览/下载：44/0 | 提交时间：2014/12/24

Density based clustering method Homogeneous point process Wavelet transform MCMC EM kth nearest distance nearest-neighbor method delaunay triangulation density-estimation genetic algorithm spatial-patterns cluster-analysis model features inference space

三维模型处理和植物场景真实感绘制 学位论文 OAI收割
工学博士, 中国科学院自动化研究所: 中国科学院研究生院, 2011
作者: 李红军

收藏 | 浏览/下载：93/0 | 提交时间：2015/09/02

三维模型处理植物建模真实感绘制点云重建造型植物森林扫描数据分割 three-dimensional model processing plant modeling realistic rendering point cloud-based reconstruction topiary plant forest scan data segmentation

3R intersection target positioning in real time based on distance (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
Nengwei W.; Juan C.; Jian C.

收藏 | 浏览/下载：13/0 | 提交时间：2013/03/25

The positioning error based on angle angle-distance or single station positioning increases with the distance increasing. 3R target positioning based on distance can obtain the high precision measurements in long distance. Here we give the 3R model for the intersection positioning provide the two necessary conditions for getting the optimum intersection point. The experimental results show that the intersection precision based on angle is over 2m and will degrade greatly with the increasing of distance while the one based on 3R model will improve and the error decrease gradually. That the precision of the distance measurement is about 1m means the 3R model is better than the angle positioning which can compensate the drawbacks of the angle positioning at short distance. 2010 IEEE.

Design of ground-based physical simulation system for satellite-borne TDI-CCD dynamic imaging (EI CONFERENCE) 会议论文 OAI收割
Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China
作者: Zhang L.; Zhang L.; Sun Z.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

As we know the existence of image motion has a bad effect on the image quality of satellite-borne TDI CCD camera. Although many theories on image motion are proposed to cope with this problem few simulations are done to justify the proposed theories on ground. And thus in this paper a ground-based physical simulation system for TDI CCD imaging is developed and specified which consists of a physical simulation subsystem for precise satellite attitude control based on a 3-axis air bearing table and an imaging and simulation subsystem utilizing area-array CCD to simulate TDI CCD. The designed system could realize not only a precise simulation of satellite attitude control whose point accuracy is above 0.1 and steady accuracy above 0.01/s but also an imaging simulation of 16-stage TDI CCD with 0.1s its integration time. This paper also gives a mathematical model of image motion of this system analogous with satellite-borne TDI CCD and detailed descriptions on the principle utilizing area-array CCD to simulate TDI CCD. It is shown that experiment results are in accordance with mathematical simulation and that the image quality deteriorate seriously when the correspondence between the image velocity and signal charges transfer velocity is broken out which suggest not only the validity of the system design but also the validity of the proposed image motion theory of TDI CCD. 2010 SPIE.

Earth elevation map production and high resolution sensing camera imaging analysis (EI CONFERENCE) 会议论文 OAI收割
Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China
作者: Dai L.

收藏 | 浏览/下载：141/0 | 提交时间：2013/03/25

The Earth's digital elevation which impacts space camera imaging has prepared and imaging has analysed. Based on matching error that TDI CCD integral series request of the speed of image motion statistical experimental methods-Monte Carlo method is used to calculate the distribution histogram of Earth's elevation in image motion compensated model which includes satellite attitude changes orbital angular rate changes latitude longitude and the orbital inclination changes. And then elevation information of the earth's surface from SRTM is read. Earth elevation map which produced for aerospace electronic cameras is compressed and spliced. It can get elevation data from flash according to the shooting point of latitude and longitude. If elevation data between two data the ways of searching data uses linear interpolation. Linear interpolation can better meet the rugged mountains and hills changing requests. At last the deviant framework and camera controller are used to test the character of deviant angle errors TDI CCD camera simulation system with the material point corresponding to imaging point model is used to analyze the imaging's MTF and mutual correlation similarity measure simulation system use adding cumulation which TDI CCD imaging exceeded the corresponding pixel horizontal and vertical offset to simulate camera imaging when stability of satellite attitude changes. This process is practicality. It can effectively control the camera memory space and meet a very good precision TDI CCD camera in the request matches the speed of image motion and imaging. 2010 SPIE.