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Your search keyword '"Zhang, Laixian"' showing total 92 results
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92 results on '"Zhang, Laixian"'

1. Research on Academic Evaluation Methods of Self study Exams from the Perspective of Military Vocational Education in the New Era

Author

Li, Rong, Zheng, Haijing, Guo, Huichao, Zhang, Laixian, Striełkowski, Wadim, Editor-in-Chief, Black, Jessica M., Series Editor, Butterfield, Stephen A., Series Editor, Chang, Chi-Cheng, Series Editor, Cheng, Jiuqing, Series Editor, Dumanig, Francisco Perlas, Series Editor, Al-Mabuk, Radhi, Series Editor, Scheper-Hughes, Nancy, Series Editor, Urban, Mathias, Series Editor, Webb, Stephen, Series Editor, Zhu, Shoutong, editor, Baldini, Andrea L., editor, Hong, Yongming, editor, Xu, Zhihua, editor, and Syed Mohammed, Sharifah Faizah, editor

Published
2024
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4. Research on Student's T-Distribution Point Cloud Registration Algorithm Based on Local Features.

Author

Sun, Houpeng, Li, Yingchun, Guo, Huichao, Luan, Chenglong, Zhang, Laixian, Zheng, Haijing, and Fan, Youchen

Subjects
DISTRIBUTION (Probability theory), POINT cloud, RANDOM noise theory, URBAN planning, REMOTE sensing
Abstract

LiDAR offers a wide range of uses in autonomous driving, remote sensing, urban planning, and other areas. The laser 3D point cloud acquired by LiDAR typically encounters issues during registration, including laser speckle noise, Gaussian noise, data loss, and data disorder. This work suggests a novel Student's t-distribution point cloud registration algorithm based on the local features of point clouds to address these issues. The approach uses Student's t-distribution mixture model (SMM) to generate the probability distribution of point cloud registration, which can accurately describe the data distribution, in order to tackle the problem of the missing laser 3D point cloud data and data disorder. Owing to the disparity in the point cloud registration task, a full-rank covariance matrix is built based on the local features of the point cloud during the objective function design process. The combined penalty of point-to-point and point-to-plane distance is then added to the objective function adaptively. Simultaneously, by analyzing the imaging characteristics of LiDAR, according to the influence of the laser waveform and detector on the LiDAR imaging, the composite weight coefficient is added to improve the pertinence of the algorithm. Based on the public dataset and the laser 3D point cloud dataset acquired in the laboratory, the experimental findings demonstrate that the proposed algorithm has high practicability and dependability and outperforms the five comparison algorithms in terms of accuracy and robustness. [ABSTRACT FROM AUTHOR]

Published
2024
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5. Research on Polarization Modulation of Electro-Optical Crystals for 3D Imaging Reconstruction.

Author

Sun, Houpeng, Li, Yingchun, Guo, Huichao, Luan, Chenglong, Zhang, Laixian, Zheng, Haijing, and Fan, Youchen

Subjects
THREE-dimensional imaging, STANDARD deviations, IMAGING systems, IMAGE reconstruction, TIME series analysis
Abstract

A method for enhancing the resolution of 3D imaging reconstruction by employing the polarization modulation of electro-optical crystals is proposed. This technique utilizes two polarizers oriented perpendicular to each other along with an electro-optical modulation crystal to achieve high repetition frequency and narrow pulse width gating. By varying the modulation time series of the electro-optical crystal, three-dimensional gray images of the laser at different distances are acquired, and the three-dimensional information of the target is reconstructed using the range energy recovery algorithm. This 3D imaging system can be implemented with large area detectors, independent of the an Intensified Charge-Coupled Device (ICCD) manufacturing process, resulting in improved lateral resolution. Experimental results demonstrate that when imaging a target at the distance of 20 m, the lateral resolution within the region of interest is 2560 × 2160, with a root mean square error of 3.2 cm. [ABSTRACT FROM AUTHOR]

Published
2024
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22. Single-source double heterodyne coherent detection high-speed moving target

Author

Zhao Yanzhong, Jianying Ren, Zhang Laixian, and Sun Huayan

Subjects
Physics, Acoustics, Bandwidth (signal processing), Detector, Low frequency, Laser, law.invention, symbols.namesake, Data acquisition, law, symbols, Dual frequency, Heterodyne detection, Doppler effect
Abstract

A novel single-source double-heterodyne coherent detection high-speed moving target is presented. Under a limited detector bandwidth condition, the method inherits the characteristics of dual frequency laser coherent detection and transforms the Doppler shift of a high-speed moving target to low frequency using the beat frequency difference method. Compared with the traditional heterodyne detection system, the maximum speed detectable range of the system is greatly increased. The double-heterodyne mixing process is deduced, and the relationship between the beat frequency, detector bandwidth, and maximum detectable speed of the system is obtained through analysis. Thus, the beat frequency can be dynamically adjusted for the system to adapt to different measurement environments. Different signal components and speed information extraction methods of detectors under different motion speeds are analyzed. The feasibility of the method is verified through simulation. Moreover, the data acquisition is minimal, and the system has good real-time performance.

Published
2019

23. Range-gated laser active imaging controlling system based on ARM&FPGA architecture

Author

Guo Huichao, Sun Huayan, and Zhang Laixian

Subjects
Computer science, business.industry, Laser, Visual control, law.invention, Set (abstract data type), Range (mathematics), Mode (computer interface), law, Fpga architecture, User interface, Field-programmable gate array, business, Computer hardware
Abstract

A range-gated laser active imaging controlling system based on ARM+FPGA architecture was designed. In the system, a visual control program was programmed based on ARM to enable users to set control parameters, work mode and watch the result image in time; a high precision synchronous control board based on FPGA was designed to synchronize the semiconductor pulse laser, ICCD camera and other modules precisely. Control parameters and result were exchanged between ARM and FPGA in time. Experiment was done using this system to get target plates’ range-gated images in door, 5ns image gate was achieved. The experimental results show that the system designed has many advantages such as having friendly user interface, integrity function and low-power.

Published
2019

24. Research on the method of detecting high-speed moving target with single-source dual-frequency laser coherence

Author

Zhao Yanzhong, Jianying Ren, Zhang Laixian, and Sun Huayan

Subjects
Response Frequency, Small data, Dynamic range, Computer science, Acoustics, Detector, Laser, law.invention, symbols.namesake, law, symbols, Cutoff, Doppler effect, Coherence (physics)
Abstract

This paper presents a method of detecting high-speed moving targets with single light source and dual frequency laser coherence.Due to the influence of cutoff response frequency of detector, the dynamic range of velocity measurement in traditional single-frequency coherent detection system is limited, and the velocity measurement of high-speed moving target cannot be realized. In this paper, six signal components are generated by four-light coherent mixing, one of which is the difference between the fixed frequency shift and the doppler frequency shift. The simulation verifies the feasibility of the method proposed in this paper, which has the characteristics of small data collection, large dynamic range, high precision and good real-time performance of the system, and improves the theoretical guidance of the method for further high-speed target detection research.

Published
2019

43. Laser-Echo-Power Distribution Model of Large-Field Cat-Eye Lens and Characteristics Analysis

Author

张来线 Zhang Laixian, 段帅军 Duan Shuaijun, 樊桂花 Fan Gui-hua, and 刘瑞丰 Liu Ruifeng

Subjects
Physics, Field (physics), business.industry, Echo (computing), Laser, Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, law.invention, Power (physics), Optics, law, Distribution model, Eye lens, business
Published
2019

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