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Your search keyword '"Wei, Jingbo"' showing total 45 results
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45 results on '"Wei, Jingbo"'

19. Despeckling SAR Images With Log-Yeo–Johnson Transformation and Conditional Diffusion Models

Author

Ma, Yaobin, Ke, Peng, Aghababaei, Hossein, Chang, Ling, and Wei, Jingbo

Abstract

Satellite images of synthetic aperture radar (SAR) sensors are contaminated by speckles from the coherent imaging mechanism. Although removing or mitigating speckle has been a critical issue for SAR applications, effective reduction continues to be a significant challenge for existing methods when preserving the intricate structures within SAR images. To address this issue, this work proposes a novel conditional diffusion model for SAR despeckling (DiffusionSAR). The new method explicitly learns data distributions by forward diffusion toward multiplicative gamma noise. The logarithmic and Yeo–Johnson (log-Yeo–Johnson) transformation are harnessed in preprocessing for fine-tuning or hybrid training. A prolonging steps technique is suggested in fine-tuning to match the preprocessing. A new synthetic dataset is designed for satellite SAR despeckling. The proposed method is compared with eight state-of-the-art methods using both synthetic and real-world SAR satellite images. The qualitative and quantitative evaluations confirm the effectiveness of the proposed method in structural preservation as well as noise reduction. A fine-tuning experiment using stacked multitemporal data shows the necessity of tine-tuning training in bridging the domain gap when trained with synthetic data and tested with real-world SAR data.

Published
2024
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30. UAV Image Stitching With Transformer and Small Grid Reformation.

Author

Cui, Zhiyuan, Tang, Rongxin, and Wei, Jingbo

Abstract

Due to parallax and inadequate key points, it is difficult to stitch unmanned aerial vehicle (UAV) images that are not rich in structure, which is addressed in this letter. Global matching is judged along with local similarity by a trained transformer, which provides the possibility of finding plenty of key points in low-feature regions. A new point matching constraint is designed based on the scores from the transformer. Line protection and distortion resistance are also used in local correction to alleviate global aberrations. The experiment shows that our method outperforms four state-of-the-art algorithms significantly, which reduces the position error by half in stitching inconspicuous features, such as woodland, bare land, and river. [ABSTRACT FROM AUTHOR]

Published
2023
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42. A Systemic Insight into Exohedral Actinides and Endohedral Borospherenes: An&B m and An@B n (An=U, Np, Pu; m = 28, 32, 34, 36, 38, 40; n = 36, 38, 40).

Author

Li, Peng, Wei, Jingbo, Wei, Hao, Wang, Kerong, Wu, Jizhou, Li, Yuqing, Liu, Wenliang, Fu, Yongming, Xie, Feng, and Ma, Jie

Subjects
*CHEMICAL bonds, *ACTINIDE elements, *ELECTRONIC excitation, *DENSITY functional theory, *CHARGE transfer, *TOPOLOGICAL property
Abstract

A series of exohedral actinide borospherenes, An&Bm, and endohedral borospherenes, An@Bn (An=U, Np, Pu; m = 28, 32, 34, 36, 38, 40; n = 36, 38, 40), have been characterized by density functional theory calculations. The electronic structures, chemical bond topological properties and spectra have been systematically investigated. It was found that An@Bn is more stable than An&Bn in terms of structure and energy, and UB36 in an aqueous solution is the most stable molecular in this research. The IR and UV-vis spectra of An&Bm and An@Bn are computationally predicted to facilitate further experimental investigations. Charge-transfer spectroscopy decomposes the total UV-Vis absorption curve into the contributions of different excitation features, allowing insight into what form of electronic excitation the UV–Vis absorption peak is from the perspective of charge transfer between the An atoms and borospherenes. [ABSTRACT FROM AUTHOR]

Published
2022
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44. A novel permanent magnet bias hybrid thrust magnetic bearing with extremely simple structure for high-speed rotating machinery.

Author

Wang, Haoze, Wu, Zhigang, Liu, Kun, Wei, Jingbo, and Hu, Hongjing

Abstract

This paper presents a novel permanent magnet (PM) bias hybrid thrust magnetic bearing (HTMB), which can be used to replace the traditional thrust magnetic bearings (TMBs) for high-speed rotating machinery. By adding two PM rings and by reducing the number of the control coils by half, this HTMB eliminates the bias current, reduces the number of amplifiers, and minimizes the magnetic bearing's structure complexity and power consumption. The analytical modelling method of the HTMB is presented in this paper. Mathematical models for calculating the magnetic force capacity and the stiffnesses of this bearing are derived as simplified formulae, which can be used for the design, analysis, and control of this bearing. Electromechanical characteristics of the HTMB are analyzed, which is compared to the traditional TMB to demonstrate the advantages of the HTMB. The prototype of the HTMB is designed, analyzed, and fabricated, whereas, the 2-D FEM is used to verify the design and the analytical model. Finally, an experimental setup is constructed and tested. The analytical and experimental results indicate that the proposed novel topology of this HTMB is feasible and the presented analytical model is accurate. [ABSTRACT FROM AUTHOR]

Published
2022
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