2012
2012
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Record 49 of
Title:Theoretical Analysis on scanning spectral filter based on the bi-refraction electro-optical interferometer for pulse contrast improvement in femtosecond laser
Author(s):Ma, Zairu(1,2); Sui, Zhan(3); Feng, Guoying(2); Sun, Nianchun(2); Wang, Yishan(4); Zhang, Bin(2); Chen, Jianguo(2)Source: Optics Communications Volume: 285 Issue: 12 DOI: 10.1016/j.optcom.2012.02.018 Published: June 1, 2012Abstract:A spectral scanning filter method to improve the pulse contrast in the femtosecond chains is proposed, which is made using of the character that the instantaneous frequency varies with the time approximately linearly for the chirped pulse in the time-frequency domain. A spectral scanning filter based on the bi-refraction electro-optical interferometer is proposed and analyzed. The spectral scanning filter for reducing the ASE intensity is analyzed in the time-frequency domain by using the Short-Time Fourier Transformation method. The results show that the pulse contrast can be improved by two orders, and the transmission efficiency of the chirped pulse can exceed 85% when the synchronizing time jitter ranges from - 50 ps to 50 ps adopting the cascaded filter method. The great advantage of this novel nonlinear spectral filter technology fits the high energy and high peak intensity femtosecond chains for it filters the ASE in the near field in temporal domain. ? 2012 Elsevier B.V. All rights reserved.Accession Number: 20121714957859 -
Record 50 of
Title:Realization of NURBS for cranium in a laser sintering machine
Author(s):Zhuang, Jingyu(1,2); Liu, Defu(1); Gao, Chengde(1,2); Hu, Huanlong(1); Wang, Li(3); Shuai, Cijun(1,2); Peng, Shuping(4)Source: Advanced Materials Research Volume: 421 Issue: DOI: 10.4028/www.scientific.net/AMR.421.570 Published: 2012Abstract:It is an issue in the application of Non-Uniform Rational B-Spline (NURBS) how to achieve the characteristic parameters based on a given curve. In this work, the parameterization method of accumulated chord length is used to construct the knot vector. The tangent vector is chosen as the boundary condition. The characteristic parameters are calculated according to the key points and corresponding weights of a given curve. An example of NURBS interpolation for cranium is realized using the characteristic parameters obtained with Rhino software in a selective laser sintering (SLS) machine. The results show that the practical sintering curve is coincident with the given curve.Accession Number: 20115214641959 -
Record 51 of
Title:Research of experimentation data kinematics positioning of GPS
Author(s):Duan, Yingni(1); Zhang, Haifeng(2)Source: 2012 2nd International Conference on Remote Sensing, Environment and Transportation Engineering, RSETE 2012 - Proceedings Volume: Issue: DOI: 10.1109/RSETE.2012.6260686 Published: 2012Abstract:Aiming at solving the probloms such as the quantity of experimentation data, the rapid rate of data, artificial and inefficiency judge data in the process of gps equipment of Weapons Positioning error computation, this paper designs a set of positioning data acquisition and processing system. Based on medium-long baseline GPS kinematic positioning model and the theory of classic fading Kalman filter, a modified fading factor vector is proposed. Different widths of sliding windows are used toobtain a series of parallel filters. The weight factor of covariance is decided by the residuals of every filter. The modified fading Kalman filter is more effective and sensitive than classic Kalman filter. Various experiments are made to test the performance of this method. The results show the precision of long-baseline GPS kinematic positioning is improved. This system implements Positioning data acquisition, displaying, Positioning accuracy calculating and the original data storage, which improves experimenting process. ? 2012 IEEE.Accession Number: 20124015480998 -
Record 52 of
Title:Design of miniature camera lens including diffractive optical elements
Author(s):Yu, Dengqun(1); Cao, Jianzhong(1); Zhang, Jian(1); Yan, Aqi(1); Guo, Huinan(1)Source: Proceedings of the 2012 4th International Symposium on Information Science and Engineering, ISISE 2012 Volume: Issue: DOI: 10.1109/ISISE.2012.97 Published: 2012Abstract:To meet the demand for miniature camera lens, in this paper, there designed a new type of miniature plastic lens, which is made up of three lenses. The second surface of the first lens is designed as a diffractive surface. The diffractive lens is used to eliminate aberration. There has investigated the primary aberration about the systems expressed by PWC. The function relation among P∞, W∞, C∞, and the diffractive lens structure have been established. These three lens materials are 'PMMAO', 'P-CARBO' and 'PMMAO'. The F-number is 2. 4 and FOV is 50°. The overall length of this optical system is 6.52mm. The MTF at 250lp/mm is higher than 0. 3. ? 2012 IEEE.Accession Number: 20132016337987 -
Record 53 of
Title:Image encryption based on the random rotation operation in the fractional Fourier transform domains
Author(s):Liu, Zhengjun(1,2); Li, She(3); Yang, Meng(1); Liu, Wanyu(1); Liu, Shutian(4)Source: Optics and Lasers in Engineering Volume: 50 Issue: 10 DOI: 10.1016/j.optlaseng.2012.05.021 Published: October 2012Abstract:A kind of image encryption scheme is presented by using a rotation operation being regarded as the scrambling scheme of the pixels. The rotation operation is composed of rotation center, radii and angle. For the data of phase and amplitude of complex number, the rotation operation is performed with random controlling parameters iteratively. The parameters are random and serve as the key of this encryption method. Subsequently, the fractional Fourier transform is introduced to alter the values of image pixel. The process mentioned above will be achieved many times for enhancing the security of the proposed algorithm. Numerical simulation is given to demonstrate the validity and performance of the image hiding procedure. ? 2012 Elsevier Ltd. All rights reserved.Accession Number: 20122715199320 -
Record 54 of
Title:Registration algorithm of panchromatic and multi-spectral images based on SIFT and RANSAC
Author(s):Li, Ailing(1); Zhang, Boheng(1)Source: 2012 Symposium on Photonics and Optoelectronics, SOPO 2012 Volume: Issue: DOI: 10.1109/SOPO.2012.6271096 Published: 2012Abstract:Image registration is widely used in remote sensing, medical imaging, computer vision etc. In this paper , in the area of panchromatic and multi-spectral fusion, we propose a fast automatic image registration based on SIFT and RANSAC.And the experiment results using this automatic remote sensing registration method based on SIFT and RANSAC indicate that the method is more distinctive and robust, which results in a higher matching performance and a better matching efficiency. ? 2012 IEEE.Accession Number: 20124315589399 -
Record 55 of
Title:Camera design in ultra-low temperature vessel
Author(s):Li, Wu(1); Cao, Jian-Zhong(1); Yan, A-Qi(1); Wu, Deng-Shan(1); Zhang, Zhao-Hui(1); Zhang, Hai-Feng(1); Zhu, Qing(1); Dong, Sen(1); Zhang, Jian(1)Source: Proceedings - 2012 International Conference on Computer Science and Information Processing, CSIP 2012 Volume: Issue: DOI: 10.1109/CSIP.2012.6308868 Published: 2012Abstract:According to special application, surveillance camera working in the ultra-low temperature and high pressure vessel is designed. By request of optics and electronics system on temperature, research focus on the design from selection of the structure material, thermal insulation, the adaptability of optical system in the ultra-low temperature and high pressure environment. Finally, It is confirmed that opto-Mechanical structure with double layers thermal insulation of PIPA and ITO optical window have benefit on thermal insulation for the camera working in this ultra-low temperature(196°C) and high pressure(0.5MPa) environment. All the opto-Mechanical material which may be contact with ultra-low high pressure liquid can also be consistent with liquid. ? 2012 IEEE.Accession Number: 20124615663836 -
Record 56 of
Title:The 8-bit parallel CRC-32 research and implementation in USB 3.0
Author(s):Wu, Ying(1); Qiu, Yuehong(1)Source: Proceedings - 2012 International Conference on Computer Science and Service System, CSSS 2012 Volume: Issue: DOI: 10.1109/CSSS.2012.273 Published: 2012Abstract:This thesis proposed 8-bit parallel CRC-32 in order to meet the high throughput of USB3.0. The highest speed of USB3.0 reaches 5G bps. Firstly, we researched the Data Packet structure and the principles of the CRC-32 in the USB3.0 Specification. Secondly, deduced the equation of the 8-bit input data and the CRC-32. Finally, implemented the CRC-32 coding and decoding by the verilog HDL, verified the correctness of the design. The 8-bit parallel CRC-32 can process 8 bits every clock cycle. ? 2012 IEEE.Accession Number: 20130615981673 -
Record 57 of
Title:Real-time auto-focus system design based on climbing algorithm and its FPGA implementation
Author(s):Zhang, Haifeng(1); Zhang, Zhaohui(1); Yang, Hongtao(1); Wu, Li(1); Tang, Linao(1); Zhu, Qing(1); Dong, Sen(1); Qin, Maoyuan(1); Lei, Yangjie(1)Source: Proceedings of the 2012 8th International Conference on Computational Intelligence and Security, CIS 2012 Volume: Issue: DOI: 10.1109/CIS.2012.81 Published: 2012Abstract:In real-time imaging applications, the auto-focus algorithm and hardware structure must be adapted to the limited resources for fast and accurate real-time auto-focusing. In this paper, to obtain more precision, a new clarity evaluation function base on image's edge energy is proposed. Then, we present the corresponding FPGA hardware implementation which has simple structure. Additionally, utilizing the prior knowledge during the climbing process, a new climbing algorithm for the auto-focus which has the random start point is proposed. The experiment results show the proposed auto-focus algorithm can reduce the steps during the climbing and accelerate the auto-focus speed simultaneously. ? 2012 IEEE.Accession Number: 20130716023290 -
Record 58 of
Title:Constant current chopping subdivision driver of stepper motor applied in harsh environment
Author(s):Dong, Qiang(1); Li, Yan(1); Tian, Ye(1); Wang, Xianhong(1)Source: 2012 IEEE 5th International Conference on Advanced Computational Intelligence, ICACI 2012 Volume: Issue: DOI: 10.1109/ICACI.2012.6463332 Published: 2012Abstract:According to the special requirements of aerospace electronic products, this paper gives a designation of constant current subdivision driver of step motor based on the FPGA. In this design, the subdivision of the Sine/Cosine waveform is used to control current waveform, while the comparison of the feedback current and control current implements the function of constant current control. The design has some advantages such as stable output torque, low noise and vibration at low speed, short time in positioning and small possibility of losing step. ? 2012 IEEE.Accession Number: 20131116105449 -
Record 59 of
Title:Image encryption algorithm based on the random local phase encoding in gyrator transform domains
Author(s):Liu, Zhengjun(1,2); Yang, Meng(1); Liu, Wei(4); Li, She(3); Gong, Min(1); Liu, Wanyu(1); Liu, Shutian(4)Source: Optics Communications Volume: 285 Issue: 19 DOI: 10.1016/j.optcom.2012.05.061 Published: September 1, 2012Abstract:A random local phase encoding method is presented for encrypting a secret image. Some random polygons are introduced to control the local regions of random phase encoding. The data located in the random polygon is encoded by random phase encoding. The random phase data is the main key in this encryption method. The different random phases calculated by using a monotonous function are employed. The random data defining random polygon serves as an additional key for enhancing the security of the image encryption scheme. Numerical simulations are given for demonstrating the performance of the proposed encryption approach. ? 2012 Elsevier B.V. All rights reserved.Accession Number: 20123015268990 -
Record 60 of
Title:Detection of sudden pedestrian crossings for driving assistance systems
Author(s):Xu, Yanwu(1); Xu, Dong(1); Lin, Stephen(2); Han, Tony X.(3); Cao, Xianbin(4); Li, Xuelong(5)Source: IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics Volume: 42 Issue: 3 DOI: 10.1109/TSMCB.2011.2175726 Published: 2012Abstract:In this paper, we study the problem of detecting sudden pedestrian crossings to assist drivers in avoiding accidents. This application has two major requirements: to detect crossing pedestrians as early as possible just as they enter the view of the car-mounted camera and to maintain a false alarm rate as low as possible for practical purposes. Although many current sliding-window-based approaches using various features and classification algorithms have been proposed for image-/video-based pedestrian detection, their performance in terms of accuracy and processing speed falls far short of practical application requirements. To address this problem, we propose a three-level coarse-to-fine video-based framework that detects partially visible pedestrians just as they enter the camera view, with low false alarm rate and high speed. The framework is tested on a new collection of high-resolution videos captured from a moving vehicle and yields a performance better than that of state-of-the-art pedestrian detection while running at a frame rate of 55 fps. ? 2012 IEEE.Accession Number: 20122115046909