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	The design problems of one kind of chaotic one-way hash function (EI CONFERENCE) 会议论文 OAI收割 2012 4th International Conference on Multimedia and Security, MINES 2012, November 2, 2012 - November 4, 2012, Nanjing, Jiangsu, China Li P.; Zhang M.; Shi J. 收藏 \| 浏览/下载：26/0 \| 提交时间：2013/03/25 The construction method of one kind of one-way hash function based on 1-D Logistic map is analyzed. The design problem and some collision problems are pointed out. By using the dictionary attack the collision probability of the arithmetic realized with signal floating point numbers is 2-23 and the collision probability of the arithmetic realized with double floating point numbers is 2-55. The reasons for these design problems are discussed and some key problems are pointed out which should be taken care of while constructing one-way hash function based on a digital chaotic map. 2012 IEEE.
	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：30/0 \| 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.
	Modulation transfer function measurement of sampled imaging systems in field test (EI CONFERENCE) 会议论文 OAI收割 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China 作者: Yang L.; Zhang J.; Zhang J.; Zhang J.; Wang J. 收藏 \| 浏览/下载：34/0 \| 提交时间：2013/03/25 A digital mirror device (DMD) based light projector was developed as the target generator in modulation transfer function (MTF) measurement. In order to overcome the sampling-scene phase effect in MTF measurement of sampled imaging systems a method using random targets is introduced to yield a phase-averaged MTF. The main potential problem of implementing this method is the fact that the stationary assumption of the random targets may be vitiated in practical measurement especially in field test due to the ill condition. We provide an efficient model-independent way of analyzing and isolating the spectral contents arising from these additional contributions to MTF measurement. Algorithms with adaptive parameter selection were also developed for spectral estimation of the test image in order to overcome the challenge brought by the size limit of the test matrices for one certain field of view derived from the isoplantic region. The MTF measurement of a CCD video imager is used to demonstrate the measurement technique and illustrate the benefits over other methods. In order to validate the results comparisons have been made between MTF measurements of imager implemented using this method and bar target direct measurements. 2010 Copyright SPIE - The International Society for Optical Engineering.
	A framework for real-valued cipher systems 期刊论文 OAI收割 JOURNAL OF SYSTEMS SCIENCE & COMPLEXITY, 2007, 卷号: 20, 期号: 4, 页码: 486-491 作者: Zhang, Zhaozhi; Jiang, Nan \| 收藏 \| 浏览/下载：17/0 \| 提交时间：2018/07/30 computational complexity theory digital one-way function general one-way function real-valued cipher system