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Precise and efficient Chinese license plate recognition in the real monitoring scene of intelligent transportation system

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The Journal of China Universities of Posts and Telecommunications 2022年第3期29卷 1-14页

作者： jia wei Gong Chao School of Computer Science and Information Engineering Hefei University of TechnologyHefei 230009China

In this paper, the performance of you only look once(YOLO) series detectors on Chinese license plate recognition(LPR) in the real intelligent transportation system(ITS) monitoring scene is investigated. Specially, a precise and efficient automatic license plate recognition(ALPR) system based on the YOLOv4 detector is proposed. The proposed ALPR system contains three stages including vehicle detection, license plate detection(LPD) and LPR. In vehicle detection stage, YOLOv4 detector is directly applied. In LPD stage, YOLOv4-tiny detector is exploited. In the last stage, the YOLOv4-tiny detector with attention mechanism for LPR is proposed to use. In addition, a large Chinese license plate dataset containing 10 500 images collected from all 31 provinces in the Chinese mainland is created. This Chinese license plate dataset is named Hefei University of Technology license plate version 1(HFUT-LP v1). Particularly, HFUT-LP v1 dataset is collected in the real ITS monitoring scene. In order to compare the performance of different object detection algorithms for ALPR, a variety of object detection algorithms are used to make a comprehensive performance evaluation. Experimental results show that the proposed ALPR system achieves very high accuracy and has very fast processing speed, which is suitable for real-time LPR.

关键词： license plate detection(LPD) license plate recognition(LPR) YOLOv4-tiny detector attention mechanism intelligent transportation

Effects of congenital ptosis on the refractive development of eye and vision in children

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International Journal of Ophthalmology(English edition) 2020年第11期13卷 1788-1793页

作者： Xiao-Yu Zeng jia-Xing Wang Xiao-Li Qi Xue-Han Qian nan wei Tianjin Medical University Eye Institute Tianjin Medical University Eye HospitalCollege of Optometry and OphthalmologyTianjin Medical UniversityTianjin 300384China Department of Ophthalmology Emory University School of MedicineAtlantaGeorgia 30322USA

AIM:To investigate the influence of unilateral congenital ptosis on the development of the eye and vision in ***:In this prospective observational study,41 patients with unilateral congenital ptosis were enrolled(age range 3-15y).The blepharoptosis was divided into 3 subgroups according to the margin reflex distance-1(MRD-1),including mild group(MRD-1>2 mm),moderate group(0

关键词： unilateral congenital ptosis axial length AL/CR ratio amblyopia

Enhance the Performance of Directional Feature-based Palmprint Recognition by Directional Response Stability Measurement

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Machine Intelligence Research 2024年第3期21卷 597-614页

作者： Haitao Wang wei jia School of Computer Science and Information Engineering Hefei University of TechnologyHefei230009China

Palmprint recognition is an emerging biometrics technology that has attracted increasing attention in recent years. Many palmprint recognition methods have been proposed, including traditional methods and deep learning-based methods. Among the traditional methods, the methods based on directional features are mainstream because they have high recognition rates and are robust to illumination changes and small noises. However, to date, in these methods, the stability of the palmprint directional response has not been deeply studied. In this paper, we analyse the problem of directional response instability in palmprint recognition methods based on directional feature. We then propose a novel palmprint directional response stability measurement (DRSM) to judge the stability of the directional feature of each pixel. After filtering the palmprint image with the filter bank, we design DRSM according to the relationship between the maximum response value and other response values for each pixel. Using DRSM, we can judge those pixels with unstable directional response and use a specially designed encoding mode related to a specific method. We insert the DRSM mechanism into seven classical methods based on directional feature, and conduct many experiments on six public palmprint databases. The experimental results show that the DRSM mechanism can effectively improve the performance of these methods. In the field of palmprint recognition, this work is the first in-depth study on the stability of the palmprint directional response, so this paper has strong reference value for research on palmprint recognition methods based on directional features.

关键词： Biometrics palmprint recognition directional response stability directional coding-based methods directional feature

Rapid changes in the near-bottom temperature of the bottom aquaculture area around the Zhangzi Island in summer

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Acta Oceanologica Sinica 2020年第5期39卷 46-54页

作者： Xueliang nan Hao wei Renfu Fan wei Yang School of Marine Science and Technology Tianjin UniversityTianjin 300072China

Rapid changes in the near-bottom water temperature are important environmental factors that can significantly affect the growth and development of species in the bottom *** object of this research is to investigate the mechanism causing these rapid changes within a bottom culture area near the Zhangzi *** hydrographic transects observations in the North Yellow Sea(NYS)suggest that our mooring station is very close to the tidal mixing *** horizontal advection of the tidal front has induced the observed tidal change of bottom temperature at the mooring *** of the mooring near-bottom temperature and current measurements show that the angle between the tidal current horizontal advection and the swing of the tidal front is crucial in determining the variation trend of *** the angle equals 90°,the horizontal tidal current advects along the isotherms so the temperature remains the *** the angle is between 0°and 90°,the seawater moves from deep water to the warmer coastal zone and the temperature *** contrast,the horizontal tidal advection moves the coastal warm water to the mooring station and the water temperature increases when the angle is between 90°and 180°.The amplitude of the temperature change is proportional to the magnitude of the horizontal temperature gradient and the tidal excursion in the direction of the temperature *** study may facilitate the choice of culture area in order to have a good aquaculture production.

关键词： near-bottom temperature horizontal advection tidal mixing front bottom culture area Zhangzi Island

Challenges and strategies for ultrafast aqueous zinc-ion batteries

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Rare Metals 2021年第2期40卷 309-328页

作者： Qiao-nan Zhu Zhen-Ya Wang jia-wei Wang Xiao-Yu Liu Dan Yang Li-wei Cheng Meng-Yao Tang Yu Qin Hua Wang School of Chemistry Beihang UniversityBeijing100191China College of Applied Science and Technology Beijing Union UniversityBeijing100012China Faculty of Science Engineering and TechnologySwinburne University of TechnologyHawthorn3122VICAustralia Institute of Chemistry Henan Academy of SciencesZhengzhou450002China

With the rising demand for fast-charging technology in electric vehicles and portable devices,significant efforts have been devoted to the development of the highrate *** numerous candidates,rechargeable aqueous zinc-ion batteries(ZlBs)are a promising option due to its high theoretical capacity,low redox potential of zinc metal anode and inherent high ionic conductivity of aqueous *** the strong electrostatic interaction between Zn^(2+)and host generally leads to sluggish electrode kinetics,many strategies have been proposed to enhance fast(dis)charging ***,we review the state-of-the-art ultrafast aqueous ZIBs and focus on the rational electrode-designing strategies,such as crystal structure engineering,nanostructuring and morphology controlling,conductive materials introducing and organic molecule *** research directions and future perspectives are also proposed in this review.

关键词： Aqueous zinc-ion battery Cathode materials Energy density Energy storage Rate capacity Ultrafast

Reaction dynamics of proton-rich nuclei at energies around the Coulomb barrier:the cases of^(7)Be,^(8)B,and^(17)F

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Nuclear Science and Techniques 2024年第12期35卷 239-254页

作者： Tian‑Peng Luo Lei Yang Cheng‑jian Lin nan‑Ru Ma Pei‑wei Wen Hui‑Ming jia Feng Yang China Institute of Atomic Energy Beijing 102413China

The exploration of reaction dynamics,particularly the breakup and fusion mechanisms of proton drip-line nuclei at energies around the Coulomb barrier,is crucial in the feld of nuclear *** study reviews experimental investigations on the reactions induced by proton-rich nuclei,^(7)Be,^(8)B,and^(17)F,including elastic scattering and direct and fusion reactions at the near-barrier *** particular,we briefy introduce complete kinematic measurements of^(8)B+^(120)Sn and^(17)F+^(58)Ni at the energies of *** reaction dynamics are observed for proton-rich nuclei compared with neutron-rich nuclei.

关键词： Proton-rich nuclei Energies around the Coulomb barrier Elastic scattering Breakup reactions Fusion reactions

Design for structural flexibility using connected morphable components based topology optimization

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Science China(Technological Sciences) 2016年第6期59卷 839-851页

作者： DENG jia Dong CHEN wei Department of Mechanical Engineering Northwestern University

In topology optimization of structures considering flexibility, degenerated optimal solutions, such as hinges, gray areas and disconnected structures may appear. In this paper, built upon the newly developed morphable component based topology optimization approach, a novel representation using connected morphable components(CMC) and a linkage scheme are proposed to prevent degenerating designs and to ensure structure integrity. A lower bound condition of the thickness of each component is also incorporated to completely remove the smallest components in an optimal configuration. Designs of flexible structures, such as compliant mechanism design, maximum compliance structure design, and design of low-frequency resonating micro devices are studied to validate the proposed methodology. Our work demonstrates that the new methodology can successfully prevent degeneration solutions and possesses other advantages, such as minimum member size control in topology optimization of flexible structures.

关键词： topology optimization connected component degenerated designs

Heuristic algorithm based on the principle of minimum total potential energy(HAPE):a new algorithm for nesting problems

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第11期12卷 860-872页

作者： Xiao LIU jia-wei YE School of Civil and Transportation Engineering South China University of Technology Guangzhou 510640 China

We present a new algorithm for nesting *** equally spaced points are set on a sheet,and a piece is moved to one of the points and rotated by an *** the point and the rotation angle constitute the packing attitude of the *** propose a new algorithm named HAPE(Heuristic Algorithm based on the principle of minimum total Potential Energy) to find the optimal packing attitude at which the piece has the lowest center of *** addition,a new technique for polygon overlap testing is proposed which avoids the time-consuming calculation of no-fit-polygon(NFP).The detailed implementation of HAPE is presented and two computational experiments are *** first experiment is based on a real industrial problem and the second on 11 published benchmark *** a hill-climbing(HC) search method,the proposed algorithm performs well in comparison with other published solutions.

关键词： Packing Cutting Nesting Irregular Heuristic algorithm Minimum total potential energy

TRPIV investigation of space-time correlation in turbulent flows over flat and wavy walls

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Acta Mechanica Sinica 2014年第4期30卷 468-479页

作者： wei Wang Xin-Lei Guan nan jiang Department of Mechanics Tianjin University Tianjin Key Laboratory of Modern Engineering Mechanics The State Key Laboratory of Nonlinear Mechanics Institute of Mechanics Chinese Academy of Sciences

The present experimental work is devoted to in- vestigate a new space-time correlation model for the turbulent boundary layer over a flat and a wavy walls. A turbulent boundary layer flow at Reo = 2460 is measured by tomographic time-resolved particle image velocimetry （Tomo-TRPIV）. The space-time correlations of instantaneous streamwise fluctuation velocity are calculated at 3 different wall-normal locations in logarithmic layer. It is found that the scales of coherent structure increase with moving far away from the wall. The growth of scales is a manifestation of the growth of prevalent coherent structures in the turbulent boundary layer like hairpin vortex or hairpin packets when they lift up. The resulting contours of the space-time correlation exhibit elliptic-like shapes rather than straight lines. It is suggested that, instead of Taylor hypothesis, the elliptic model of the space-time correlation is valid for the wallbounded turbulent flow over either a flat wall or a wavy wall. The elliptic iso-correlation curves have a uniform preferred orientation whose slope is determined by the convection velocity. The convection velocity derived from the space-time correlation represents the velocity at which the large-scale eddies carry small-scale eddies. The sweep velocity rep- resents the distortions of the small-scale eddies and is intimately associated with the fluctuation velocity in the logarithmic layer of turbulent boundary layers. The nondimensionalized correlation curves confirm that the elliptic model is more proper for approximating the space-time correlation than Taylor hypothesis, because the latter can not embody the small-scale motions which have non-negligible distortions. A second flow over a wavy wall is also recorded using TRPIV. Due to the combined effect of shear layers and the adverse pressure gradient, the space-time correlation does not show an elliptic-like shape at some specific heights over the wavy wall, but in the outer region of the wav

关键词： Tomographic particle image velocimetry Tur-bulent boundary layer Wavy wall Space-time correlation Taylor hypothesis Elliptic model