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浏览/检索结果: 共5条，第1-5条 帮助 已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择发表日期升序发表日期降序提交时间升序提交时间降序题名升序题名降序作者升序作者降序 Blockchain data privacy access control based on searchable attribute encryption 期刊论文 Computers, Materials and Continua, 2021, 卷号: 66, 期号: 1, 页码: 871-884 作者:  Feng, Tao;  Pei, Hongmei;  Ma, Rong;  Tian, Youliang;  Feng, Xiaoqin 收藏  |  浏览/下载：12/0  |  提交时间：2020/12/18 Access control  Blockchain  Predictive analytics  Privacy by designAccess structure  Authorized users  Data privacy protections  Exposure problem  Hierarchical attributes  Prediction model  Searchable encryptions  Transaction information   ID-based Data Integrity Auditing Scheme from RSA with Resisting Key Exposure 会议论文 10th International Conference on Provable Security (ProvSec), Nanjing, PEOPLES R CHINA, 2016-11-10 作者:  Zhang, Jianhong;  Li, Pengyan;  Sun, Zhibin;  Mao, Jian 收藏  |  浏览/下载：5/0  |  提交时间：2019/12/30 ID-based auditing protocol  The RSA problem  Security proof  Efficiency analysis  Key exposure  Forward security   Method of auto multi-exposure for high dynamic range imaging (EI CONFERENCE) 会议论文 2010 International Conference on Computer, Mechatronics, Control and Electronic Engineering, CMCE 2010, August 24, 2010 - August 26, 2010, Changchun, China Piao Y.; Xu W. 收藏  |  浏览/下载：12/0  |  提交时间：2013/03/25 This paper proposes a method for calculating the multi-exposure times fast and accurately when the scene has a high dynamic range  minimizing the pictures needed to take and improving the dynamic range of the CCD system. The proposed method first measures the camera's response function referring [10]. After that the median value of the output picture is adjusted to be in the middle range of the system output by changing the exposure time. It can be inferred from the histogram of the current picture whether it's a high dynamic range scene by calculating the number of pixels under exposed and over exposed. Once again the under and over exposed pixels are adjusted to be in the middle according to the camera's response function. Finally different exposed pictures (2 or 3) are fused together by Gaussian function and the dynamic range is compressed by y correction. Experimental results on UNIQ-UM400 analog camera and a digital acquisition system show that the algorithm works well and solve the problem of low dynamic range of CCD camera. 2010 IEEE.   The study of mapping relation of aeroplane complex motion and image movement and compensation technique (EI CONFERENCE) 会议论文 2010 International Conference on Computer Application and System Modeling, ICCASM 2010, October 22, 2010 - October 24, 2010, Shanxi, Taiyuan, China Wei Z.; Wang Y.-Y.; Xue W.-Q.; Dai M. 收藏  |  浏览/下载：17/0  |  提交时间：2013/03/25 In order to solve the problem of image blurring due to the image motion which results from the aircraft's motion  attitude changes  and the relative motion of the camera and aircraft firstly  we install linear displacement transducer on the four shock absorbers. By analyzing the displacement values  the geometrical relationship between the camera and the aircraft is acquired  then relative motion amount between the object and the aircraft is obtained according to the motion and attitude changes. After that  making use of geometrical relationship  we can calculate the displacement variation of pixels within the camera exposure time. Thereafter  taking consider variable motion and non-linear motion as uniform motion in a straight line at the moment of imaging  then the model of the blurring image can be established according to the displacement variation of pixels within the camera exposure time  and fuzzy point spread function in the two-dimensional movement is built. By using Wiener filtering method with the optimal window  the image blurring is eliminated in aerial imaging system. Practice proved that this method can effectively eliminate the image blurring in the aerial imaging system. 2010 IEEE.   Micro-motion exposure method based on PZT piezoelectric ceramics (EI CONFERENCE) 会议论文 International Symposium on Photoelectronic Detection and Imaging 2009: Material and Device Technology for Sensors, June 17, 2009 - June 19, 2009, Beijing, China Sun W.-J.; Zhang M.-H.; Meng Z. 收藏  |  浏览/下载：91/0  |  提交时间：2013/03/25 There mainly is laser digital photofinishing technique and digital photofinishing technique based on LCD consisting of TFT and LCOS in the digital photofinishing field at the present time. The former have a good many merit such as wide color gamut  high processing rate  large output size and high brightness  but his cost is very high  his maintain technique being comparatively complex  that result in difficult use for people. The utilization ratio of the latter is low because of lower resolution and lower aperture ratio for LCD  but the digital photofinishing based on LCD have lower cost and higher utilization ration  being suitable for people's current standard of living. Considering above mentioned problem  a micro-motion exposure method based on PZT piezoelectric ceramics used in digital image photofinishing is presented. The two-dimension micro-motion exposure system consisting of PZT piezoelectric ceramics  LCD panel  polarizing film and spring strip is designed. By means of PZT piezoelectric ceramics the LCD panel is removed about the one half of the pixel size of the LCD panel for four times from the original place  at the same time imaging system is exposed four times at the printing paper. The software is used to control the time synchronization  the exposure time and motion range of the LCD panel. The system has advantages such as shorter response time than 0.1seconds  lesser motion error than 0.01 microns  high stability and repeatability. Experimental results show that the proposed micro-motion exposure method improve the picture brightness and enlarge output size  at the meantime reducing the cost of the system. 2009 SPIE.