中国科学院机构知识库网格系统: 检索

Back analysis of geomechanical parameters for rock mass under complex geological conditions using a novel algorithm 期刊论文 OAI收割
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY, 2023, 卷号: 136, 页码: 13
作者: Li, Hui; Chen, Weizhong; Tan, Xuyan; Tan, Xianjun

|

收藏 | 浏览/下载：1/0 | 提交时间：2025/06/27

Back analysis Geomechanical parameters Particle swarm optimization Support vector machine Tunnel

天山区域典型灌区生长季土壤盐分含量时空差异分析 学位论文 OAI收割
北京: 中国科学院大学, 2020
作者: 徐红涛

|

收藏 | 浏览/下载：86/0 | 提交时间：2021/12/10

机器学习支持向量回归土壤盐渍化建模变量和模型参数同步优选时空变化 Machine learning Support vector regression Soil salinization Simultaneous optimization of feature subset and model parameters temporal and spatial changes

Rock Cracking Indices for Improved Tunnel Support Design: A Case Study for Columnar Jointed Rock Masses 期刊论文 OAI收割
ROCK MECHANICS AND ROCK ENGINEERING, 2016, 卷号: 49, 期号: 6, 页码: 2115-2130
作者: Jiang, Quan; Feng, Xia-Ting; Hao, Xian-Jie; Li, Shao-jun; Hudson, John A.

|

收藏 | 浏览/下载：27/0 | 提交时间：2018/06/05

Support design method Rock cracking indices method Hard rock Tunnel Support parameters Support installation time

Study on the theory and methods of bolt-shotcrete support for weak surrounding rock based on reliability analysis 会议论文 OAI收割
Kunming, PEOPLES R CHINA, JUL 17-19, 2013
作者: Ou, Zhe; Chen, Congxin; Cheng, Guanwen; Zheng, Yun

|

收藏 | 浏览/下载：25/0 | 提交时间：2018/06/05

weak surrounding rock reliability analysis bolt-shotcrete support design parameters

Structural design of primary mirror subassembly for space telescope (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: Xu H.

收藏 | 浏览/下载：67/0 | 提交时间：2013/03/25

In order to design a large aperture primary mirror with the diameter of 1150 mm the parameters impacting on gravity deformation of the mirror were analyzed and discussed in detail including material selection diameter-thickness ratio the number of the support points location selection and lightweight structure etc. A novel space mirror structure system was put forward and its back was opened and supported by six points on back. The dynamic and static and thermal characteristics were analyzed based on the finite element method. Analysis results showed the surface figure accuracy reached to RMS 14.5nm under the action of gravity load along the optical axis direction and the first-order natural frequency was 214Hz which met to the designed indexes requirements. (2013) Trans Tech Publications Switzerland.

Structural design of large aperture rectangular mirror for space telescope (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Civil Engineering and Transportation, ICCET 2012, October 27, 2012 - October 28, 2012, Guilin, China
作者: Li Z.; Li Z.

收藏 | 浏览/下载：49/0 | 提交时间：2013/03/25

Structural design of large aperture mirror is one of the key technologies for space telescope development. To meet the requirements of high stiffness strength and thermal dimensional stability some factors such as support scheme materials selection lightweight design and flexible support design were taken into account. The three supports location of the mirror was determined according to the modal analytical solution. By adjusting the parameters of flexure hinge influences of gravity assembly stress and thermal stress on the mirror were reduced obviously. Finite element analysis (FEA) results indicate that the surface accuracy reach to rms10.2nm and 10.8nm under the gravity along optical axis direction and 5C uniform temperature rise respectively the fundamental frequency of the mirror component is 268Hz. Dynamics test shows that the first order natural frequency is 256Hz which shows an error less than 5% compared to FEA results. (2013) Trans Tech Publications Switzerland.

Assessing the potential of support vector machine for estimating daily solar radiation using sunshine duration SCI/SSCI论文 OAI收割
2013
Chen J. L.; Li G. S.; Wu S. J.

收藏 | 浏览/下载：25/0 | 提交时间：2014/12/24

Daily solar radiation Sunshine duration Models Support vector machine Liaoning province measured meteorological data neural-networks china models parameters trends kernel turkey

Classification of hyperspectral image based on SVM optimized by a new particle swarm optimization (EI CONFERENCE) 会议论文 OAI收割
2012 2nd International Conference on Remote Sensing, Environment and Transportation Engineering, RSETE 2012, June 1, 2012 - June 3, 2012, Nanjing, China
作者: Gao X.; Yu P.; Yu P.

收藏 | 浏览/下载：26/0 | 提交时间：2013/03/25

Support Vector Machine (SVM) is used to classify hyperspectral remote sensing image in this paper. Radial Basis Function (RBF) which is most widely used is chosen as the kernel function of SVM. Selection of kernel function parameter is a pivotal factor which influences the performance of SVM. For this reason Particle Swarm Optimization (PSO) is provided to get a better result. In order to improve the optimization efficiency of kernel function parameter firstly larger steps of grid search method is used to find the appropriate rang of parameter. Since the PSO tends to be trapped into local optimal solutions a weight and mutation particle swam optimization algorithm was proposed in which the weight dynamically changes with a liner rule and the global best particle mutates per iteration to optimize the parameters of RBF-SVM. At last a 220-bands hyperspectral remote sensing image of AVIRIS is taken as an experiment which demonstrates that the method this paper proposed is an effective way to search the SVM parameters and is available in improving the performance of SVM classifiers. 2012 IEEE.

An efficient global sensitivity analysis approach for distributed hydrological model SCI/SSCI论文 OAI收割
2012
作者: Xia J.

收藏 | 浏览/下载：13/0 | 提交时间：2012/09/04

response surface methodology sensitivity analysis support vector machines RSMSobol method Huaihe River Basin environmental-models uncertainty methodology parameters systems design

Analysis of laser jamming to satellite-based detector (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging, June 17, 2009 - June 19, 2009, Beijing, China
作者: Guo L.-H.; Guo R.-H.; Wang S.-W.

收藏 | 浏览/下载：34/0 | 提交时间：2013/03/25

The reconnaissance satellite communication satellite and navigation satellite used in the military applications have played more and more important role in the advanced technique wars and already become the significant support and aid system for military actions. With the development of all kinds of satellites anti-satellite laser weapons emerge as the times require. The experiments and analyses of laser disturbing CCD (charge coupled detector) in near ground have been studied by many research groups but their results are not suitable to the case that using laser disturbs the satellite-based detector. Because the distance between the satellite-based detector and the ground is very large it is difficult to damage it directly. However the optical receive system of satellite detector has large optical gain so laser disturbing satellite detector is possible. In order to determine its feasibility the theoretical analyses and experimental study are carried out in the paper. Firstly the influence factors of laser disturbing satellite detector are analyzed in detail which including laser power density on the surface of the detector after long distance transmission and laser power density threshold for disturbing etc. These factors are not only induced by the satellite orbit but dependence on the following parameters: laser average power in the ground laser beam quality tracing and aiming precision and atmospheric transmission. A calculation model is developed by considering all factors which then the power density entering into the detector can be calculated. Secondly the laser disturbing experiment is performed by using LD (laser diode) with the wavelength 808 nm disturbing CCD 5 kilometer away which the disturbing threshold value is obtained as 3.5510-4mW/cm2 that coincides with other researcher's results. Finally using the theoretical model the energy density of laser on the photosensitive surface of MSTI-3 satellite detector is estimated as about 100mW/cm2 which is largely exceed the disturbing threshold and therefore verify the feasibility of using this kind of laser disturbing the satellite-based detector. According to the results. using the similar laser power density absolutely saturate the requirements to laser disturbing satellite-based detector. If considering the peak power of pulsed laser even decrease laser average power it is also possible to damage the detector. This result will provide the reliable evidences to evaluate the effect of laser disturbing satellite-based detector. 2009 SPIE.