中国科学院机构知识库网格系统: 检索

On multistep Rayleigh quotient iterations for Hermitian eigenvalue problems 期刊论文 OAI收割
COMPUTERS & MATHEMATICS WITH APPLICATIONS, 2019, 卷号: 77, 期号: 9, 页码: 2396-2406
作者: Bai, Zhong-Zhi; Miao, Cun-Qiang; Jian, Shuai

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收藏 | 浏览/下载：51/0 | 提交时间：2020/01/10

Hermitian eigenvalue problem Rayleigh quotient iteration Multistep modification Inexact solve Preconditioning

Electrically responsive ultrafiltration polyaniline membrane to solve fouling under applied potential 期刊论文 OAI收割
JOURNAL OF MEMBRANE SCIENCE, 2019, 卷号: 572, 页码: 442-452
作者: Xu, Li Li; Xu, Yan; Liu, Lie; Wang, Kun Peng; Patterson, Darrell Alec

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收藏 | 浏览/下载：14/0 | 提交时间：2020/10/21

Electrically responsive membrane Polyaniline Solve fouling Electrical tuneability Electrically conductive membrane

Reentry guidance based on parametric optimization (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Mechatronics and Control Engineering, ICMCE 2012, November 29, 2012 - November 30, 2012, Guangzhou, China
作者: Li D.

收藏 | 浏览/下载：163/0 | 提交时间：2013/03/25

This paper presents a parametric optimization approach to solve reentry guidance. Due to the various constraints imposed on the trajectory original guidance problem can be converted into an optimal control problem with a merit function to be minimized. Direct implementation of method of variation and is too complex to get a reasonable result while a numerical parametric optimization approach is feasible and efficient if we choose appropriate control variables as the optimization parameters and effective optimization algorithm. A simulation of the approach is performed to show its validity on reentry guidance problem: as the value of merit function converges to acceptable threshold all constraints are hold. (2013) Trans Tech Publications Switzerland.

Lightweight design of large scale theodolite's turntable based on topology optimization of continuum structure (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Optoelectronics and Microelectronics, ICOM 2012, August 23, 2012 - August 25, 2012, Changchun, China
作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y.

收藏 | 浏览/下载：29/0 | 提交时间：2013/03/25

In order to solve the problem that the weight of large scale theodolite's casting or steel plate welded structure is too heavy lightweight design of large scale turntable based on topology optimization of continuum structure is investigated. Topology optimization could have better optimization efficiency because it can provide the optimized distribution of material and gain optimized structure in conceptual design phase of the structural design. In order to obtain lightweight and high stiffness structure a truss turntable based on topology optimization of continuum structure is presented and the validity of this lightweight structure is examined by finite element analysis. Comparing to the traditional welding steel turntable the lightweight turntable without changing the static displacement can lose 386.48 kg(lightweight ratio is 26.7%) and its first-order natural frequency raises from 167.02Hz to 173.71Hz. Meanwhile in other aspects this turntable also has better performance than traditional structure. 2012 IEEE.

A new algorithm for solving the best-fit sphere of optical aspherical surface (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Advances in Materials and Manufacturing, ICAMMP 2011, December 16, 2011 - December 18, 2011, Guilin, China
作者: Lin J.; Lu M.

收藏 | 浏览/下载：40/0 | 提交时间：2013/03/25

To solve the best-fit sphere (BFS) accurately is one of the technological keys for the generating and testing of optical aspherical surfaces. This paper presents a new algorithm for solving the BFS of aspherical surfaces to suppress some deficiencies in the existing BFS algorithms. In the proposed approach it is not only suitable for the conic surface a BFS is constructed but also for higher order aspheres. The obtained asphericity and material removal function is more suitable for the machining and test. (2012) Trans Tech Publications which passes through both sides of endpoints in the section o -?xy of the aspherical surfaces Switzerland. the center of the BFS is shifted along the x-axis and its radius of curvature is automatically computed. The variable step size method is proposed to speed up the convergence of the iteration. Through numerically solving the BFS of conic and cubic surface the advantages of the proposed approach are verified. The results show that the proposed approach is of rapid convergence and high accuracy

Accuracy synthesis of a 3-RPS parallel robot based on manufacturing costs (EI CONFERENCE) 会议论文 OAI收割
31st Chinese Control Conference, CCC 2012, July 25, 2012 - July 27, 2012, Hefei, China
Yao T.-K.; Xi Z.; Feng Z.; Zhang L.-M.; Yong W.

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

Pose accuracy is an important issue for parallel robot being used as mirror supporting system of telescope. One challenging topic is the accuracy synthesis which deals with the optimal design of the manufacturing and assembling tolerances of each component under the given pose accuracy. First the error model of the 3-RPS parallel robot is built based on total derivation of the kinematic equations. And the error variable of each spherical or rotate joint can be expressed as a single boundary error parameter but not three independent position parameters. Then the accuracy synthesis model is formulated taking the manufacturing costs as the optimization objective and the accuracy requirements as the constraint condition. Finally the genetic algorithm is used to solve the optimization problem and a simulation example is given. The results show that the accuracy synthesis method based on manufacturing costs can satisfy the need of pose accuracy and is better for engineering application than the method based on error sensitivity. 2012 Chinese Assoc of Automati.

Design of the real-time autofocusing system for collimator with long focus length and large aperture (EI CONFERENCE) 会议论文 OAI收割
2011 International Academic Conference on Numbers, Intelligence, Manufacturing Technology and Machinery Automation, MAMT 2011, December 24, 2011 - December 25, 2011, Wuhan, China
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：42/0 | 提交时间：2013/03/25

Large aperture collimator which has been widely used for calibrating and testing various optical devices plays an essential role in correlative laboratories. As being the basic testing and calibration equipment the large aperture collimator's accuracy should be much higher than the device under testing in order to ensure the accuracy of the measurement. However the process of adjusting the collimator is extremely complicated due to the collimator's large aperture and long focal length. So it is difficult to ensure the measurement's quality and easy to cause the system being vulnerable to the surrounding environment. One of the most common problems is defocus. In order to solve the problem above this issue presents a new type of autocollimator autofocusing system which uses pentaprism instead of using large-aperture plane mirror semiconductor lasers as light source and CCD sensor as receiver. The system is smaller lighter and more convenient when using. The computer simulation shows that the autofocusing system's resolution could reach the accuracy of 40m. If we use the relevant algorithms to execute the sub-pixel scanning the resolution could reach the accuracy of 10m. It shows that the system could satisfy the required testing precision of testing large aperture optical device.

Transitional compensation algorithm for correcting non-uniformity of LED display image (EI CONFERENCE) 会议论文 OAI收割
2012 2nd International Conference on Materials Science and Information Technology, MSIT 2012, August 24, 2012 - August 26, 2012, Xi'an, Shaan, China
Su W.-x.; Chen Y.-s.

收藏 | 浏览/下载：33/0 | 提交时间：2013/03/25

In order to solve the problem of high non-uniformity of LED display images which is caused by the edges of LED display panel during module splicing transitional compensation algorithm is proposed by improving the existed correction technique named the correction technique based on CCD. First introduce the three development stages of the LED display panel. Then the realization progress of the transitional compensation algorithm is described in detail after elaborating the principle of transitional compensation. Finally the algorithm is emplaned in a LED video control system to control the LED display panel whose display area is 1280960 and which is spliced by 3020 LED modules whose size are 6432. Experimental results show that this algorithm is able to reduce non-uniformity of LED display images from 29.3% before correcting to 0.95%. (2012) Trans Tech Publications Switzerland.

Research on satellite platform vibration compensation technology for space optical communication (EI CONFERENCE) 会议论文 OAI收割
2012 International Meeting on Opto-Electronics Engineering and Materials Research, OEMR 2012, July 27, 2012 - July 29, 2012, Shenyang, Liaoning, China
Han C.; Li X.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

The piezo-electric steering control system is used to compensate the vibration of satellite platform. The mathematical model of piezo-electric steering system is built. The adaptive controller based on improved LMS filter algorithm is designed according to this system characteristic. The adaptive delay filter is designed to solve slow convergence speed problem of traditional algorithm. Meanwhile the adaptive delay filter can also compensate phase delay of control circuit. The adaptive deviation filter is introduced and it effectively compensates the vibration deviation which is low frequency and high amplitude. The experimental results show that the remained errors are rad which meets space optical communication requirement and proves that this control scheme is valid and feasible. (2012) Trans Tech Publications Switzerland.

Simulation test research of using the Ritchey-Common method for the detection of large flat mirror (EI CONFERENCE) 会议论文 OAI收割
2012 International Conference on Frontiers of Advanced Materials and Engineering Technology, FAMET 2012, January 4, 2012 - January 5, 2012, Xiamen, China
作者: Zhang X.; Zhang X.; Zhang X.

收藏 | 浏览/下载：17/0 | 提交时间：2013/03/25

In the detection of large flat mirror the Ritchey-Common test can achieve high accuracy measurement. A method which expands the compressed images due to Ritchey Angle and rotates the plane under test is presented achieve two sets of influence functions through this we can built two equations according to two different angular positions we can solve the equations by least squares method. Then through fitting the coefficients we can get the flat errors this paper describe the simulation test of the method in order to prove the feasibility and reliability of this method. (2012) Trans Tech Publications.