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SAR image despeckling based on edge detection and nonsubsampled second generation bandelets

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Journal of Systems Engineering and Electronics 2009年第3期20卷 519-526页

作者： Zhang Wenge~(1,2),Liu Fang~(1,2),Jiao Licheng~(2,3)& Gao Xinbo~(2,3) 1.School of Computer Science and Technology,xidian univ.,Xi’an 710071,P.R.China 2.Key Lab.of Intelligent Perception and Image Understanding of Ministry of Education of China,Xi’an 710071,P.R.China 3.Inst,of Intelligent Information Processing,xidian univ.,Xi’an 710071,P.R.China School of Computer Science and Technology Xidian Univ. Xi'an 710071 P. R. China Key Lab. of Intelligent Perception and Image Understanding of Ministry of Education of China Xi'an 710071 P. R. China Key Lab. of Intelligent Perception and Image Understanding of Ministry of Education of China Xi'an 710071 P. R. China Inst. of Intelligent Information Processing Xidian Univ. Xi'an 710071 P. R. China

To preserve the sharp features and details of the synthetic aperture radar （SAR） image effectively when despeckling, a despeckling algorithm with edge detection in nonsubsampled second generation bandelet transform （NSBT） domain is proposed. First, the Canny operator is utilized to detect and remove edges from the SAR image. Then the NSBT which has an optimal approximation to the edges of images and a hard thresholding rule are used to approximate the details while despeckling the edge-removed image. Finally, the removed edges are added to the reconstructed image. As the edges axe detected and protected, and the NSBT is used, the proposed algorithm reaches the state-of-the-art effect which realizes both despeckling and preserving edges and details simultaneously. Experimental results show that both the subjective visual effect and the mainly objective performance indexes of the proposed algorithm outperform that of both Bayesian wavelet shrinkage with edge detection and Bayesian least square-Gaussian scale mixture （BLS-GSM）.

关键词： computer image processing synthetic aperture radar speckle edge detection nonsubsampled second generation bandelet transform Canny operator threshold shrinkage.

Study on Isomerous CAD Model Exchange Based on Feature

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武汉理工大学学报 2006年第S2期28卷 497-501页

作者： SHAO Xiaodong CHEN Feng XU Chenguang (School of Mechano-electronic Engineering,xidian univ.,Xi’an 710071,China School of Mechano-electronic Engineering Xidian Univ.Xi'an 710071China

A model-exchange method based on feature between isomerous CAD systems is put forward in this *** this method,CAD model information is accessed at both feature and geometry levels and converted according to standard feature opera- *** feature information including feature tree,dimensions and constraints,which will be lost in traditional data conver- sion,as well as geometry are converted completely from source CAD system to destination *** the transferred model can be edit- ed through feature operation,which cannot be implemented by general model-exchange interface.

关键词： interface model exchange feature isomerous CAD standard

PERFORMANCE ANALYSIS OF PULSE COMPRESSION USING PHASE-CODED SIGNALS FOR SPARSE-ARRAY SYNTHETIC IMPULSE AND APERTURE RADAR

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Journal of Electronics(China) 1998年第4期15卷 332-338页

作者： Chen Baixiao Zhang Shouhong(Key Laboratory for Radar Signal Processing, xidian univ., Xi’an 710071)

Sparse-array Synthetic Impulse and Aperture Radar (SIAR) can isotropically radiate by employing multiple frequencies (synthetic pulse) and multiple antennas (synthetic antenna). According to Ambiguity Function(AF), its range resolution depends only on bandwidth of transmitted signals, however, the distance grating lobes emerge when increasing the time-bandwidth product of transmitted signals. The performance of pulse compression is analyzed with the transmitted signals modulated by phase-coded sequences. It is seen that greater ratio of pulse compression and suppression of range sidelobe in SIAR can be obtained, and its effective range and range resolution is increased as well.

关键词： Sparse array Synthetic impulse and aperture radar Phase-coded Pulse compression

A NEW ANONYMITY CONTROLLED E-CASH SCHEME

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Journal of Electronics(China) 2002年第4期19卷 369-374页

作者： Zhang Fangguo Wang Changjie Wang Yumin (Key Lab. on ISN, xidian univ., Xi’an, 710071) Key Lab. on ISN Xidian Univ. Xi'an 710071

E-cash is a type of very important electronic payment systems. The complete anonymity of E-cash can be used for criminal activities, so E-cash should be anonymity ***, Elliptic Curve Cryptography(ECC) has been regard as the mainstream of current public cryptography . In this paper, a new anonymity controlled E-cash scheme based on ECC for the first time and using a new technology-one-time key pairs digital signature is designed, and its security and efficiency are analyzed. In our scheme, the coin tracing and owner tracing can be implemented.

关键词： E-cash Anonymity control One-time key pairs digital signature ECC

A NEW INITIALIZATION METHOD OF CLUSTER CENTERS

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Journal of Electronics(China) 1999年第4期16卷 320-326页

作者： Pei Jihong Fan Jiulun Xie Weixin(School of Electronic Engineering, xidian univ., Xi’an 710071) (President Office, Shen-Zhen univ., Shenzhen 518060)

The problem of parameters selection for potential function used to initialize cluster centers is discussed, and two formulas are given for determining these parameters. Then a new potential function to initialize cluster centers is also given which is computational effective. Finally, a set of compared experiments is presented to show the effectiveness of the proposed methods.

关键词： Clustering Initialization Potential function Nonlinear optimal

DIRECTION-OF-ARRIVAL ESTIMATION BY CONTINUATION METHOD

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Journal of Electronics(China) 1999年第2期16卷 159-164页

作者： Li Youming Xu Chen Ren Chunli(Dept. Appl. Math., xidian univ., Xi’an 710071)(Dept. of Software, Shenzhen univ., Shenzhen 518060)

In this paper, the subspace fitting models for direction-of-arrival (DOA) estimation is analyzed, an effective algorithmic approach is given. As the initialization value is so critical to the global convergence, the continuation theory is also used to develop a new framework which solves the initialization problem powerfully. Some numerical evidence will be given to show that the performance of the new algorithm is very promising.

关键词： DOA estimation Matrix function differentiation Continuation Homotopy

基于模糊Lyapunov-Krasovskii函数的模糊系统的鲁棒H_∞控制

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系统工程与电子技术 2009年第2期31卷 424-427页

作者：张果李俊民西安电子科技大学理学院陕西西安710071

针对公共Lyapunov-krasovskii函数(LKF)方法判断离散时滞模糊系统鲁棒稳定性的保守性,构造了模糊LKF,并给出了系统鲁棒稳定的充分条件。应用并行分布补偿算法(PDC),设计了全局鲁棒稳定的模糊控制器。多个附加矩阵变量的引入,使控制器可... 详细信息

针对公共Lyapunov-krasovskii函数(LKF)方法判断离散时滞模糊系统鲁棒稳定性的保守性,构造了模糊LKF,并给出了系统鲁棒稳定的充分条件。应用并行分布补偿算法(PDC),设计了全局鲁棒稳定的模糊控制器。多个附加矩阵变量的引入,使控制器可以通过求解一系列线性矩阵不等式(LMI)获得。最后,通过一个仿真例子验证了方法的有效性。

关键词：离散时滞T-S模糊系统模糊Lyapunov—krasovskii函数鲁棒控制线性矩阵不等式

A NEW METHOD FOR SOLVING MSDE BASED ON WAVELET NEURAL NETWORKS

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Journal of Electronics(China) 1998年第3期15卷 215-220页

作者： Shui Penglang Bao Zheng Jiao Licheng (Key Lab. for Radar Signal Processing, xidian univ., Xi’an 710071)

In this paper, a new method to solve multiscale difference equation(MSDE) with the M-band wavelet neural networks is proposed. It is shown that the method has many advantages over the existing methods and enlarges the... 详细信息

关键词： Wavelet neural networks Multiscale difference equation M-band orthogonalwavelet basis

基于L-Wigner分布的多径ESM信号估计

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系统工程与电子技术 2009年第11期31卷 2618-2621页

作者：李林姬红兵西安电子科技大学电子工程学院陕西西安710071

针对电子支援测量(electronic support measurement,ESM)信号存在多径干扰,从而影响信号特征提取以及雷达辐射源识别的问题,提出了一种基于L-Wigner分布的多径信号估计方法。首先分析了多径ESM信号模型和时频域匹配滤波算法,接着研究了L... 详细信息

针对电子支援测量(electronic support measurement,ESM)信号存在多径干扰,从而影响信号特征提取以及雷达辐射源识别的问题,提出了一种基于L-Wigner分布的多径信号估计方法。首先分析了多径ESM信号模型和时频域匹配滤波算法,接着研究了L-Wigner分布对于多分量高阶频率调制信号的分辨性能,根据自身项和交叉项的不同特点,提出采用L-Wigner分布对多径信号进行估计。该方法计算简单,保证了估计结果具有较高的分辨性能。仿真实验结果证明了方法的正确性和有效性。

关键词：电子支援测量多径信号估计 L-Wigner分布时频分布