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Your search keyword '"Zhu, Shengqi"' showing total 18 results
Start Over Author "Zhu, Shengqi" Publisher elsevier b.v.
18 results on '"Zhu, Shengqi"'

14. A new Doppler ambiguity resolution technique for SAR data based on SPECAN processing

Author

Zhu, Shengqi, Liao, Guisheng, Tao, Haihong, Qu, Yi, and Zhou, Zhengguang

Subjects
*SYNTHETIC aperture radar, *DOPPLER effect, *DATA analysis, *RADON transforms, *LINEAR systems, *IMAGE analysis, *CONTRAST effect, *ANTENNAS (Electronics)
Abstract

Abstract: In this paper, we describe an approach for Doppler ambiguity resolution. This approach adopts the fact that unwrapped Doppler centroid is a linear function of range frequency for a given antenna squint angle. On this basis, an alternative azimuth compression method is addressed and performed in range frequency domain to accumulate target energy in the azimuth direction. The resulting trajectories behave as some straight lines with the average slope proportional to absolute Doppler centroid. This slope can be well estimated by image-contrast methods. Theoretical analysis and real measured SAR data show that the proposed approach works well in high- and relatively low-contrast scenes. [Copyright &y& Elsevier]

Published
2011
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15. Subpixel edge location method proposed to improve the performance of optical fiber spherical coupling probe during dimensional measurement of micro-cavities with high aspect ratio.

Author

Cui, Jiwen, Feng, Kunpeng, Zhu, Shengqi, Zhang, Yue, and Tan, Jiubin

Subjects
*OPTICAL fibers, *MOLECULAR probes, *ASPECT ratio (Images), *PERFORMANCE evaluation, *PIXELS, *DIMENSIONAL analysis
Abstract

Highlights: [•] SCP is applied to measure the dimension of micro-cavity with high aspect ratio. [•] Location method based on OJFMs is proposed to improve the performance of SCP. [•] Improved SCP is experimentally tested by measuring a blind micro-hole. [ABSTRACT FROM AUTHOR]

Published
2014
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16. Analysis of range dependence of clutter spectrum in bistatic STAP

Author

Qu, Yi, Liao, Guisheng, Zhu, Shengqi, and Liu, Xiangyang

Subjects
*BISTATIC radar, *ELECTRIC waves, *DOPPLER radar, *ADAPTIVE signal processing, *GEOMETRIC analysis, *SIMULATION methods & models
Abstract

Abstract: The range dependence of clutter spectrum is influenced by both the orientation of the receiver array axis and bistatic geometry. In order to mitigate the range dependence, there is a strong requirement of finding out the relationship between the Doppler frequency and the look direction of targets relative to the receiver array. The paper presents the analytical expressions of the clutter Doppler frequency and range for four types of bistatic radar system (the side looking and forward looking arrays with the vertical and horizontal baselines). According to these expressions the clutter spectrum can be compensated by the Doppler warping method. Analysis and simulations show that the clutter Doppler frequency trajectories exhibit a group of lines with different slopes for the side looking array with the vertical baseline, of which the clutter spectrum has a small dispersion in the main beam; the side looking array with the horizontal baseline has a wide clutter spectrum region in the main beam; there is a non-linear relation between Doppler and range for the forward looking array with the vertical or horizontal baseline wherein the Doppler frequency spread mainly depends on the orientation of the receiver array axis relative to the aircraft velocity vector; Doppler warping can mitigate the range-dependence effect on space-time adaptive signal processing (STAP) in four types of bistatic radars. [Copyright &y& Elsevier]

Published
2010
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17. Evolutionary algorithm with multiobjective optimization technique for solving nonlinear equation systems.

Author

Gao, Weifeng, Luo, Yuting, Xu, Jingwei, and Zhu, Shengqi

Subjects
*EVOLUTIONARY algorithms, *MATHEMATICAL optimization, *NONLINEAR systems, *ALGORITHMS, *DIFFERENTIAL evolution
Abstract

The challenge of solving nonlinear equation systems is how to locate multiple optimal solutions simultaneously in a single run. To address this issue, this paper proposes a novel algorithm by combining a diversity indicator, multi-objective optimization technique, and clustering technique. Firstly, a diversity indicator is designed to maintain the diversity of the population. Then, a K-means clustering-based selection strategy is introduced to locate the promising solutions. Finally, the local search is used to accelerate the convergence of population. The experimental results on 30 nonlinear equation systems show that the proposed algorithm is better than six state-of-the-art algorithms in terms of convergence rate and success rate. [ABSTRACT FROM AUTHOR]

Published
2020
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18. An enhanced multi-objective evolutionary optimization algorithm with inverse model.

Author

Zhang, Zhechen, Liu, Sanyang, Gao, Weifeng, Xu, Jingwei, and Zhu, Shengqi

Subjects
*EVOLUTIONARY algorithms, *PROCESS optimization, *GAUSSIAN processes
Abstract

Multi-objective evolutionary algorithm based on the inverse model (IM-MOEA) is a popular method to solve multi-objective optimization problems (MOPs). However, IM-MOEA has some drawbacks such as low accuracy and difficulty in dealing with MOPs with irregular PFs. To address these issues, adaptive reference vector mechanism and nonrandom grouping strategy are employed in IM-MOEA, which enhances the reliability of the inverse model. In addition, a modified selection mechanism is used to choose candidate solutions. Further, an enhanced IM-MOEA with adaptive reference vectors and nonrandom grouping (AN-IMMOEA) is proposed in this paper. The experimental results on 27 MOPs indicate that the proposed method has a better performance than other MOEAs. [ABSTRACT FROM AUTHOR]

Published
2020
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