中国科学院机构知识库网格系统: 检索

浏览/检索结果: 共8条，第1-8条

帮助

条数/页：排序方式：
	Influence of non-dimensional strength parameters on the seismic stability of cracked slopes 期刊论文 OAI收割 JOURNAL OF MOUNTAIN SCIENCE, 2019, 卷号: 16, 期号: 1, 页码: 153-167 作者: Zhao Lian-heng; Cheng Xiao; Li De-jian; Zhang Ying-bin \| 收藏 \| 浏览/下载：39/0 \| 提交时间：2020/11/02 Cracked slopes Upper bound limit analysis (UBLA) Generalized nonlinear failure criterion Pseudo-static method Displacement-based method
	Design of stable image platform on airborne camera (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Advanced Design and Manufacturing Engineering, ADME 2011, September 16, 2011 - September 18, 2011, Guangzhou, China 作者: Yang L.; Yang L. 收藏 \| 浏览/下载：19/0 \| 提交时间：2013/03/25 Modulation transfer function resulting from random vibration was analyzed. To conclude that the effect of angular displacement was the major factor. Allowable MTF degradation was represented and 34dB reduction was achieved at frequency of 100HZ. With the help of MSC.ADAMS simulation software and convert allowable MTF degradation into stable system design parameters simulated curve proves correct for isolator which can guide perfect design for stabilization system. Based on the spatial mechanism and translational principle of parallelogram and the irrotational displacement mechanism was tested by optical method an irrotational displacement isolator was developed. It can meet the requirements of irrotational displacement and damp. An instance was given coupled angle is less than 8? it can satisfy the demand of aerial imaging. (2011) Trans Tech Publications.
	Method of improving the accuracy of image motion measurement for panoramic aerial cameras (EI CONFERENCE) 会议论文 OAI收割 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology, April 26, 2010 - April 29, 2010, Dalian, China 作者: Jia P. 收藏 \| 浏览/下载：29/0 \| 提交时间：2013/03/25 To improve the accuracy of image motion measurement for panoramic aerial cameras the paper proposed a method of real-time image motion measurement based on 2D spatial correlation. An auxiliary area CCD is positioned paralleled to the main linear TDI CCD in the focal plane of the camera. For every frame of the image sequence taken by the auxiliary CCD a prediction on the displacement of the current image in the flight direction is made based on the forward image motion velocity. The current and the reference images are combined together for 2D-correlation which products an image motion vector. By decomposing the vector both the forward and pendulum-swing image motions can be determined. The demanding computational requirements for the real-time 2D-correlation are covered by a joint transform optical correlator. Simulation test results show that the accuracy is improved and the measurement error is within 0.2 pixels for input images with SNR=1 dB. 2010 Copyright SPIE - The International Society for Optical Engineering.
	Optimal design of strap-down inertial navigation support under random loads (EI CONFERENCE) 会议论文 OAI收割 2010 IEEE International Conference on Information and Automation, ICIA 2010, June 20, 2010 - June 23, 2010, Harbin, Heilongjiang, China 作者: Li M. 收藏 \| 浏览/下载：33/0 \| 提交时间：2013/03/25 In order to realize miniaturization and light weight of the strap-down inertial navigation system and then to make sure that it works well under random loads optimal design is applied to the strap-down inertial navigation support with the methods of topology optimization and size optimization. Firstly based on the installation requirement of devices and connection requirement of the support and the carrier the initial structure of the support is designed. Topology optimization with FEA software ANSYS is adopted on the initial structure to get the basic one. Then 5 critical sizes are chosen as design variables and the support structure is optimized by means of size optimization to reach light weight with satisfying the requirement of dynamic stiffness. Finally random vibration analysis is applied to the initial structure. In the mean time random vibration test is carried out to qualify the analysis method. After the qualification a random vibration analysis is applied to the optimized support structure to get the rms of displacement response and acceleration response of the support to validate whether the optimized structure is appropriate. The results indicate that the dynamic stiffness of the optimized support structure satisfies the design requirements and its weight is lighter 49.38% than that of the initial one. This research can be a reference to the structure design of supports under random loads and the result has been applied to the development and manufacture of a prototype aerocraft. 2010 IEEE.
	Configuring an electrostatic membrane reflector with potentials exerted on distributed electrodes (EI CONFERENCE) 会议论文 OAI收割 2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009, August 9, 2009 - August 12, 2009, Changchun, China 作者: Zhang P.; Shi G. 收藏 \| 浏览/下载：24/0 \| 提交时间：2013/03/25 Electrostatic membrane reflector (EMR) is very promised for optical quality application with the merits of utra-lightweight and flexible. Configuring a circular membrane reflector with electrostatic potentials exerted on distributed electrodes can approximatively produce a parabolic shape. A 300mm EMR (made from polyimide) stretched by distributed electrodes below is designed and the number of concentric electrodes needed for membrane shape forming is analysed. First based on an analytical solution of Poisson's equation determine the membrane control matrix by finding influence functions of 3 concentric electrodes and 6 control points on membrane surface in order to compute the needed voltages exerted on the distributed electrodes by the method of least-squares fitting. Then the final shape solved by finite element analysis with ANSYS is contrasted with the paraboloid and deviates greatly when the central displacement of membrane is beyond 2.5mm but in this range increasing the number of electrodes and control points will get a better shape. The corresponding errors are analyzed and the control method is concluded. Only using the integrated method of analytical computation numerical analysis and experiment the membrane shape of certain central displacement can be exactly predicted and controlled. 2009 IEEE.
	Target track system design based on circular projection (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China Song H.-J.; Zhu M.; Hu S.; Shen M.-L. 收藏 \| 浏览/下载：26/0 \| 提交时间：2013/03/25 Template matching is the process of searching the present and the location of a reference image or an object in a scene image. Template matching is a classical problem in a scene analysis: given a reference image of an object decide whether that object exists in a scene image under analysis and find its location if it does. The template matching process involves cross-correlating the template with the scene image and computing a measure of similarity between them to determine the displacement. The conventional matching method used the spatial cross-correlation process which is computationally expensive. Some algorithms are proposed for this speed problem such as pyramid algorithm but it still can't reach the real-time for bigger model image. Moreover the cross-correlation algorithm can't be effective when the object in the image is rotated. Therefore the conventional algorithms can't be used for practical purpose. In this paper an algorithm for a rotation invariant template matching method based on different value circular projection target tracking algorithm is proposed. This algorithm projects the model image as circular and gets the radius and the sum of the same radius pixel value. The sum of the same radius pixel value is invariable for the same image and the any rotated angle image. Therefore this algorithm has the rotation invariant property. In order to improve the matching speed and get the illumination invariance the different value method is combined with circular projection algorithm. This method computes the different value between model image radius pixel sum and the scene image radius pixel sum so that it gets the matching result. The pyramid algorithm also is been applied in order to improve the matching speed. The high speed hardware system also is been design in order to meet the real time requirement of target tracking system. The results show that this system has the good rotate invariance and real-time property.
	Displacement estimation by the phase-shiftings of fourier transform in present white noise (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China 作者: Wu Y.-H. 收藏 \| 浏览/下载：33/0 \| 提交时间：2013/03/25 Displacement estimation is a fundamental problem in Real-time video image processing. It can be typically approached by theories based on features in spatial domain. This paper presents an algorithm which improves the theory for estimating the moving object's displacement in spatial domain by its Fourier transform frequency spectrum. Because of the characters of Fourier transform the result is based on all the features in the image. Utilizing shift theorem of Fourier transform and auto-registration the algorithm employs the phase spectrum difference in polar coordinate of two frame images sequence with the moving target1 2. The method needn't transform frequency spectrum to spatial domain after calculation comparing with the traditional algorithm which has to search Direc peak and it reduces processing time. Since the technique proposed uses all the image information including all the white noise in the image especially and it's hard to overcome the aliasing from noises but the technique can be an effective way to analyze the result in little white noise by the different characters between high and low frequency bands. It can give the displacement of moving target within 1 pixel of accuracy. Experimental evidence of this performance is presented and the mathematical reasons behind these characteristics are explained in depth. It is proved that the algorithm is fast and simple and can be used in image tracking and video image processing.
	Optoelectronic non-contact measuring method for the taper of a bore (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Devices and Instruments, August 21, 2005 - August 26, 2005, Changchun, China 作者: Zhang G.; Zhang G.; Zhang G.; Yang L.; Yang L. 收藏 \| 浏览/下载：40/0 \| 提交时间：2013/03/25 Based on laser optical triangulation displacement and grating displacement inspecting principle optoelectronic non-contact inspecting method and inspecting system for the taper of small-calibre bore are presented. In this paper the constitute and overall structure of the system are described. Then the taper inspecting method and principle of the bore are discussed and theoretically analyzed and also the corresponding mathematics model is established. As inner diameter measurement is an important parameter for the taper of small-bore an inner diameter laser non-contact measuring method is presented based on the structure characteristic of the taper of small-calibre bore which adopted optoelectronic probe sensitive device (PSD) and laser optical triangulation inspecting principle. And then the laser probe inner diameter measuring system is designed based them. Moreover the measuring principle the project of optical system of this measuring system are illuminated in detail in this article. The accuracy of inspecting system is verified by experiment. The results showed that the measuring error of inspecting system is superior to 0.005 and the inspecting repetition is superior to 0.003. It indicates that the system can fulfill the inspecting accuracy demand for inspecting the taper of the small-calibre bore and the inspecting method is applicable.