中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
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Globalisation, cost competitiveness and international trade: The evolution of the Italian textile and clothing industries and the growth of trade with China SCI/SSCI论文  OAI收割
2016
作者:  
Dunford M.;  Dunford, R.;  Barbu, M.;  Liu, W. D.
  |  收藏  |  浏览/下载:27/0  |  提交时间:2017/11/09
Globalisation, cost competitiveness and international trade: The evolution of the Italian textile and clothing industries and the growth of trade with China SCI/SSCI论文  OAI收割
2016
作者:  
Dunford M.;  Dunford, R.;  Barbu, M.;  Liu, W. D.;  Xie, J.
收藏  |  浏览/下载:38/0  |  提交时间:2016/12/16
Geography, trade and regional development: the role of wage costs, exchange rates and currency/capital movements SCI/SSCI论文  OAI收割
2014
Dunford M.; Liu W. D.; Liu Z. G.; Yeung G.
收藏  |  浏览/下载:40/0  |  提交时间:2014/12/24
Geography, trade and regional development: the role of wage costs, exchange rates and currency/capital movements 期刊论文  OAI收割
Journal of Economic Geography, 2014, 卷号: 14, 期号: 6, 页码: 1175-1197
作者:  
Dunford M.;  Liu W. D.;  Liu Z. G.;  Yeung G.
  |  收藏  |  浏览/下载:18/0  |  提交时间:2014/12/24
Gimbal displacement error analysis on an electro-optical seeker (EI CONFERENCE) 会议论文  OAI收割
Optical Design and Testing IV, October 18, 2010 - October 20, 2010, Beijing, China
作者:  
Zhang X.;  Zhang X.;  Zhang X.
收藏  |  浏览/下载:32/0  |  提交时间:2013/03/25
It is essential to analyze the gimbal displacement errors for a seeker due to the importance for cueing of targets and tracking for the final approach. Otherwise  for a seeker electro-driven with a concentric glass dome  the large errors will decrease the picking  pointing  and tracking precision rooted from the displacement errors existing between the rotation center of the optical system and the gimbal. And the gimbaled camera system displacement errors are never eliminated but reduced due to the geometric errors consists of geometric tolerances of gimbal structure  manufacture  installation and vibration coming from working environment. In this paper  the gimbal displacement errors in an electro-optically stabilized platform resulting from geometric errors and environment errors were analyzed and shown in detail. The mathematical modal of the gimbal displacement errors created based on multi-body dynamics demonstrated the connection between the gimbal displacement errors and the stabilized platform. Taking a visible light image seeker as a case  the diameter is 120mm  and the geometric tolerances came from the values of primary design and the vibration data came from the environmental vibration test on the pitch-yaw seeker  and at the same time  the errors resulting from installation were considered too. Based on calculating  the maximum gimbal displacement error will reach to 0.2mm for pitching angle smaller than 40 and yawing angle smaller than 60. However  the critical parts have been found out according to the probability theory and the reliability analysis successfully used in the paper  and finally  the maximum gimbal displacement error reduced to 0.1mm  which is acceptable corresponding to the picking  pointing and tracking precision for an optical imaging seeker. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Design and image restoration research of a cubic-phase-plate system (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, April 26, 2010 - April 29, 2010, Dalian, China
作者:  
Zhang J.;  Zhang J.;  Zhang J.;  Shi G.;  Zhang X.
收藏  |  浏览/下载:25/0  |  提交时间:2013/03/25
Wave-front coding technology is a novel jointly optical and digital imaging technology which can greatly extend the depth of focus of optical systems. The image restoration process is an important part of wave-front coding technology. Using wave-front coding makes the modulation transfer function(MTF) values of the optical systems change little over a range of several times the depth of focus  which means the system MTF is quite insensitive to defocus  and there is no zero in the passband. So we can design a single filter for the restoration of images in different defocus positions. However  it's hard to avoid noise during image acquisition and transmission processes. These noises will be amplified in the image restoration  especially in the high frequency part when the MTF drop is relatively low. The restoration process significantly reduces the system signal to noise ratio this way. Aimed at the problem of noise amplification  a new algorithm was proposed which incorporated wavelet denoising into the iterative steps of Lucy-Richardson algorithm. Better restoration results were obtained through the new algorithm  effectively solving the noise amplification problem of original LR algorithm. Two sets of identical triplet imaging systems were designed  in one of which the cubic-phase-plate was added. Imaging experiments of the manufactured systems were carried  and the images of a traditional system and a wave-front coded system before and after decoding were compared. The results show that the designed wave-front coded system can extend the depth of focus by 40 times compared with the traditional system while maintaining the light flux and the image plane resolution. 2010 Copyright SPIE - The International Society for Optical Engineering.