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Chinese Academy of Sciences Institutional Repositories Grid

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	Affine object recognition and affine parameters estimation based on covariant matrix (EI CONFERENCE) 会议论文 OAI收割 2008 International Symposium on Information Science and Engineering, ISISE 2008, December 20, 2008 - December 22, 2008, Shanghai, China 作者: Wang Y.; Wang Y.; Wang Y.; Wang Y.; Wang Y. 收藏 \| 浏览/下载：148/0 \| 提交时间：2013/03/25 A new method of affine object recognition and affine parameters estimation is presented. For a real-time image and a group of templates in addition firstly on the basis of correct recognition we segment the object regions in them and compute their covariant matrices. Secondly it can estimate affine parameters exactly normalize the ellipse regions defined by covariant matrices to circle regions to get rotational invariants and the estimated error is within 3%. 2008 IEEE. and compute the similarity function value between rotational invariants of real-time image and every template respectively. Then compare the values with threshold set in advance if more than one value is larger than threshold take the corresponding templates as candidates and compute affine matrix between real-time image and every candidate. Finally transform the realtime image with every affine matrix and match the result with corresponding candidate by classical matching methods. Experimental results show that the presented method is robust to illumination with low computational complexity and it can realize recognition of different affine objects
	Application of photoresist melting method to the fabrication of holographic grating (EI CONFERENCE) 会议论文 OAI收割 ICO20: Optical Devices and Instruments, August 21, 2005 - August 26, 2005, Changchun, China 作者: Li W.; Tang Y.; Yu H.; Gao J.; Li W. 收藏 \| 浏览/下载：64/0 \| 提交时间：2013/03/25 A new technique of reducing surface roughness of photoresist grating is presented. In this paper photoresist melting method which is low-cost short-period and easy realization is presented. In addition the influence of photoresist melting on the groove profile of the photoresist grating is investigated. Experimental results show that the surface roughness reduces due to surface tension when developed photoresist is heated to be melting state by this method. In experiment when the melted photoresist grating is etched by ion beam the surface relief grating possessing preferable groove profile is obtained on K9 glass substrate then the surface is evaporated by aluminum using vacuum evaporation holographic grating with preferable groove profile is successively fabricated.
	Recent progress on asphere manufacturing and testing at CIOM (EI CONFERENCE) 会议论文 OAI收割 Advanced Optical Manufacturing and Testing Technology 2000, November 1, 2000 - November 3, 2000, Chengdu, China 作者: Zhang X.; Yu J.; Zhang X.; Zhang X. 收藏 \| 浏览/下载：22/0 \| 提交时间：2013/03/25 The manufacturing procedure of a 500 mm in diameter f/2 hyperbolic primary mirror based on Computer-Controlled Polishing is introduced in detail. The mirror was finally polished to the shape accuracy of 13 nm rms and the surface roughness of 2 nm Ra. Testing methods and data analysis for different stages ranging from grinding to polishing are discussed. Some critical factors affecting the efficiency and accuracy of the grinding/polishing procedure are summarized. In addition the preliminary work to make large off-axis asphere mirrors is presented. The difficulties in polishing and testing for both circular aperture and rectangular aperture mirrors are previewed and a possible solution is given. To control the geometrical parameters such as radius of curvature and conic constant a new profiler has been built and it has proven very useful to improve the grinding efficiency. Finally the manufacturing of small aspheres using deterministic grinding tool is also introduced. The fine grinding procedure of LOH's asphere grinding machine is presented.