中国科学院机构知识库网格系统: 检索

Assessing the integrity of soil erosion in different patch covers in semi-arid environment 期刊论文 OAI收割
JOURNAL OF HYDROLOGY, 2019, 卷号: 571, 页码: 71-86
作者: Zhou, Ji; Fu, Bojie; Yan, Dongchun; Lu, Yihe; Wang, Shuai

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收藏 | 浏览/下载：91/0 | 提交时间：2019/04/22

Structural equation modeling Logistic regression Patch cover Restoration Soil erosion Ecological structure and function

Dissecting Solidago canadensis-soil feedback in its real invasion 期刊论文 OAI收割
ECOLOGY AND EVOLUTION, 2017, 卷号: 7, 期号: 7, 页码: 2307-2315
作者: Dong, Li-Jia; Yang, Jian-Xia; Yu, Hong-Wei; He, Wei-Ming

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收藏 | 浏览/下载：13/0 | 提交时间：2022/03/28

abiotic effect biotic effects community structure and function competitive tolerance and suppression invader-soil feedback structural equation modeling

The indirect effects of habitat disturbance on the bird communities in a tropical African forest 期刊论文 OAI收割
BIODIVERSITY AND CONSERVATION, 2015, 卷号: 24, 期号: 12, 页码: 3083-3107
Mammides, Christos; Schleuning, Matthias; Boehning-Gaese, Katrin; Schaab, Gertrud; Farwig, Nina; Kadis, Costas; Coulson, Tim

收藏 | 浏览/下载：43/0 | 提交时间：2015/11/19

Bird conservation Tropical forests Structural equation modeling Species richness Anthropogenic habitat disturbance Vegetation structure and composition

Modeling and variable structure control of a vehicle flexible manipulator (EI CONFERENCE) 会议论文 OAI收割
10th World Congress on Intelligent Control and Automation, WCICA 2012, July 6, 2012 - July 8, 2012, Beijing, China
作者: Wang Z.; Li Y.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

In this paper the mathematical modeling and the application of a new trajectory tracking control technique for hydraulic-driven rigid-flexible manipulator are concerned. To get a closer dynamic behavior of the real system both the flexible manipulator linkage and the actuator dynamics are considered. The exact dynamic model of flexible manipulator is derived using Lagrange principle and assumed modes method. The partial decoupled dynamic equation is derived using nonlinear decoupling feedback control method. The whole dynamic model is established by a driven Jacobin matrix which represents the coupling between hydraulic servo system and mechanical system. A variable structure controller with inverse dynamics is designed for trajectory tracking. To weaken the chattering of control signal saturation function is used to instead of sign function. The experimental results investigate the effectiveness of the proposed approaches. 2012 IEEE.

水土保持背景下黄土丘陵区农业产业资源系统耦合关系研究——基于农户行为的视角 期刊论文 OAI收割
中国生态农业学报, 2012, 卷号: 20, 期号: 03, 页码: 369-377
夏自兰; 王继军; 姚文秀; 吕明权

收藏 | 浏览/下载：37/0 | 提交时间：2014/06/24

农业产业 Agro-industry and resources system 资源系统 Coupling relationship 耦合关系 Structure equation model 结构方程 Farmer behavior 农户行为 Loess 黄土丘陵区吴起县

Composite-structure frequency selective surface with tripole elements (EI CONFERENCE) 会议论文 OAI收割
8th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2008, November 2, 2008 - November 5, 2008, Kunming, China
作者: Gao J.

收藏 | 浏览/下载：72/0 | 提交时间：2013/03/25

Two composite symmetry structure is proposed in this paper. Based on the integral equation method the frequency response with large incident angle effect is analyzed. As a result of the numerical analysis it is shown that the composite symmetry structure with single FSS screen is efficient to stabilize the drift of FSS resonant frequency with the steering of incident angle though transmission loss increased. Especially the structure that the FSS is embedded centrally in the dielectrics has better frequency characteristic with flat top and sharp skirts. The studies have indicated the versatility of the proposed structure. 2008 IEEE.

Study on navigation control method for CyberCar based on machine vision (EI CONFERENCE) 会议论文 OAI收割
2007 IEEE International Conference on Robotics and Biomimetics, ROBIO, December 15, 2007 - December 18, 2007, Yalong Bay, Sanya, China
Zhang R.-H.; Wang R.-B.; You F.; Jia H.-G.; Chen T.

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

The guiding principle and composition of CyberCar based on machine vision was introduced. Applying IM sequence signals as input response signals and least squares method to establish the dynamic equation for CyberCar steering system by system identification experiments firstly and then combined with the preview kinematics model and two-degree steering dynamic model of vehicle. Therefore it can trace the path steadily and reliably. 2008 IEEE. the steering control mathematics model based on preview kinematics for CyberCar was established. And then the switching hyper plane is designed by applying the optimal control theory during the change of the curve curvature radius is little the curve tracking of the intelligent vehicle is carried out by adopting sliding variable structure controller. Aim at the parameter uncertainty of tire a vehicle steering system uncertain model was founded and analyzed. A H optimal controller is designed with the method of H control theory to solve the problem about model uncertainty. The simulation and experiment results show that the controller designed by the proposed method has good robustness and adaptability

Dynamics simulation on control technology for 4WS vehicle steering performance (EI CONFERENCE) 会议论文 OAI收割
ISECS International Colloquium on Computing, Communication, Control, and Management, CCCM 2008, August 3, 2008 - August 4, 2008, Guangzhou, China
Rong-Hui Z.; Hong-Guang J.; Tao C.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

By combining visual preview kinematics dynamic equation of steering system and 2-DOF steering dynamistic model of 4WS it can easily attenuate the change and uncertainty of model. 2008 IEEE. we establish the two degree of freedom model of four-wheel steering vehicle. And then the switching hyper plane is designed by applying the optimal control theory. During the change of parameter is little 4WS steering performance is carried out by adopting sliding variable structure controller. To improve the steering performance of 4WS especially state variables convergent velocity Kalman filter for 4WS is designed. And the robust optimal controller is designed for model and parameter is uncertainty. The simulation results show that the controller designed by the proposed method has good robustness

Platform and steady kalman state observer design for intelligent vehicle based on visual guidance (EI CONFERENCE) 会议论文 OAI收割
2008 IEEE International Conference on Industrial Technology, IEEE ICIT 2008, April 21, 2008 - April 24, 2008, Chengdu, China
Rong-hui Z.; Rong-ben W.; Feng Y.; Hong-guang J.; Tao C.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

State observer design is one of key technologies in research field of intelligent vehicle. Experiment platform visual guidance intelligent vehicle JLUIV-5 is establishedby Jilin University Intelligent Vehicle Group firstly. The system structure and assistant navigation control system and different image identify algorithms to recognize preview path and stops for variable illuminations are introduced. The dynamic response equation of steering control system was got by system identification experiment. By combined with the preview kinematics model and two-degree steering dynamic model of vehicle the steering kalman filter mathematics model based on preview kinematics for intelligent vehicle was obtained. And observer is designed by applying steady Kalman filter theory. The simulation and experiment results carry out in Jilin University Nanling Campus and Culture Center of Jilin Province show that the image identify algorithms and steady Kalmanstate observer designed by the proposed method has good adaptability for time-varying and parameters uncertain it can satisfy intelligent vehicle trace the path reliably during outdoor experiment. 2008 IEEE.

Dynamical chiral symmetry breaking and phase transition of cuprate superconductors in QED(3) 期刊论文 OAI收割
HIGH ENERGY PHYSICS AND NUCLEAR PHYSICS-CHINESE EDITION, 2007, 卷号: 31, 页码: 209-218
作者: Liang Xiao-Feng; Chen Huan; Chang Lei; Liu Yu-Xin

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收藏 | 浏览/下载：19/0 | 提交时间：2018/05/31

dynamical chiral symmetry breaking QED(3) Dyson-Schwinger equation phase structure and phase transition of cuprate superconductor d-wave superconductivity antiferromahnet