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STUDY ON RECTANGULAR WAVEGUIDE GRATING SLOW-WAVE STRUCTURE WITH COSINE-SHAPED GROOVES

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Journal of Electronics(China) 2007年第3期24卷 384-389页

作者： Lu Zhigang Wei Yanyu Gong yubin wu Zhoumiao Wang Wenxiang School of Physical Electronics University of Electronic Science and Technology of China Chengdu 510054 China

This paper focuses on a new rectangular waveguide grating Slow-Wave Structure (SWS) with cosine-shaped grooves and studies the propagation characteristics of the wave in the SWS. By using the approximate field-matching conditions,the dispersion equation and the coupling impedance of this circuit are obtained. The dispersion curves and coupling impedances of the fundamental wave are calculated and the influences of the various geometrical dimensions are discussed. The results show that the bandwidth of the cosine-shaped groove SWS is much wider than that of rectangular-shaped groove one. And reducing the groove width can broaden the frequency-band and decrease the phase-velocity,while increment of the groove-depth can also decrease phase-velocity. For above cases,the coupling impedance is more than 16Ω. The present analysis will be helpful on further study and design of the RF systems used in millimeter wave Traveling Wave Tube (TWT).

关键词： Traveling Wave Tub (TWT) Rectangular waveguide grating Cosine-shaped groove Dispersion equation Coupling impedance

Robot visual guide with Fourier-Mellin based visual tracking

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Frontiers of Optoelectronics 2019年第4期12卷 413-421页

作者： Chao PENG Danhua CAO yubin wu Qun YANG School of Optical and Electronic Information Huazhong University of Science and TechnologyWuhan 430074China

Robot vision guide is an important research area in industrial automation,and image-based target pose estimation is one of the most challenging *** focus on target pose estimation and present a solution based on the binocular stereo vision in this *** improve the robustness and speed of pose estimation,we propose a novel visual tracking algorithm based on Fourier-Mellin transform to extract the target *** evaluate the proposed tracking algorithm on online tracking benchmark-50(OTB-50)and the results show that it outperforms other lightweight trackers,especially when the target is rotated or *** final experiment proves that the improved pose estimation approach can achieve a position accuracy of 1.84 mm and a speed of 7 FPS(frames per second).Besides,this approach is robust to the variances of illumination and can work well in the range of 250-700 lux.

关键词： robot visual guide target pose estimation stereo vision visual tracking Fourier-Mellin transform(FMT)

Defect detection on button surfaces with the weighted least-squares model

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Frontiers of Optoelectronics 2017年第2期10卷 151-159页

作者： Yu HAN yubin wu Danhua CAO Peng YUN School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China

Defect detection assurance on production lines machine-vision-based surface is important in quality This paper presents a fast defect detection method using the weighted least-squares model. We assume that an inspection image can be regarded as a combination of a defect-free template image and a residual image. The defect-free template image is generated from training samples adaptively, and the residual image is the result of the subtraction between each inspection image and corresponding defect-free template image. In the weighted least-squares model, the residual error near the edge is suppressed to reduce the false alarms caused by spatial misalignment. Experiment results on different types of buttons show that the proposed method is robust to illumination vibration and rotation deviation and produces results that are better than those of two other methods.

关键词： machine vision surface defect detection.weighted least-squares model

Improved accuracy of superpixel segmentation by region merging method

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Frontiers of Optoelectronics 2016年第4期9卷 633-639页

作者： Song ZHU Danhua CAO yubin wu Shixiong JIANG School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China

Superpixel as an important pre-processing technique has been successfully used in many vision applications. In this paper, we proposed a region merging method to improve superpixel segmentation accuracy with low computational cost. We first segmented the image into many accurate small regions, and then progressively agglomerated them until the desired region number was reached. The region merging weight was derived from a novel energy function, which encourages the superpixel with color consistency and similar size. Experimental results on the Berkeley BSDS500 data set showed that our region merging method can significantly improve the accuracy of superpixel segmentation. Moreover, the region merging method only need 50ms to process a 481x321 image on a single Intel i3 CPU at 2.5 GHz.

关键词： image processing image segmentation super-pixels region merging

Co-production of hydrogen, oxygen, and electricity via an integrated solar-driven system with decoupled water electrolyzer and Na-Zn ion battery

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Journal of Energy Chemistry 2025年第1期100卷 621-627页

作者： Fei Lv Longjie Liu Jiazhe wu Pengfei Wang Lixia Pan Dengwei Jing yubin Chen International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University

Combining water electrolysis and rechargeable battery technologies into a single system holds great promise for the co-production of hydrogen （H2） and ***,the design and development of such systems is still in its ***,an integrated hydrogen-oxygen （O2）-electricity co-production system featuring a bipolar membrane-assisted decoupled electrolyzer and a Na-Zn ion battery was established with sodium nickelhexacyanoferrate （NaNiHCF） and Zn2+/Zn as dual redox *** decoupled electrolyzer enables to produce H2and O2in different time and space with almost 100%Faradaic efficiency at 100 mA ***,the charged NaNiHCF and Zn electrodes after the electrolysis processes formed a Na-Zn ion battery,which can generate electricity with an average cell voltage of 1.75 V at 10 m A *** connecting Si photovoltaics with the modular electrochemical device,a well-matched solar driven system was built to convert the intermittent solar energy into hydrogen and electric energy with a solar to hydrogen-electricity efficiency of 16.7%,demonstrating the flexible storage and conversion of renewables.

关键词： Hydrogen Electricity Decoupled water electrolyzer Na-Zn ion battery Solar energy

Lens distortion correction based on one chessboard pattern image

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Frontiers of Optoelectronics 2015年第3期8卷 319-328页

作者： yubin wu Shixiong JIANG Zhenkun XU Song ZHU Danhua CAO School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan 430074 China

This paper proposes a detection method of chessboard comer to correct camera distortions -including radial distortion, decentering distortion and prism distor- tion. This proposed method could achieve high comer detection rate. Then we used iterative procedure to optimize distortion parameter to minimize distortion residual. In this method, first, non-distortion points are evaluated by four points near image center; secondly, Levenberg-Marquardt nonlinear optimization algorithm was adopted to calculate distortion parameters, and then to correct image by these parameters; thirdly, we calculated comer points on the corrected image, and repeated previous two steps until distortion parameters converge. Results showed the proposed method by iterative procedure can make the impact of slight distortion around image center negligible and the average of distortion residual of one line is almost 0.3 pixels.

关键词： computer vision camera distortion distortion correction comer detection

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直立式混凝土落地声屏障振动放大效应

振动．测试与诊断 2024年第2期44卷 337-344,412,413页

作者：刘必灯宋瑞祥邬玉斌吴琼吴瑞北京市科学技术研究院城市安全与环境科学研究所北京100054

以普速铁路路侧落地安装直立式混凝土声屏障为研究对象,利用原位试验方法研究了列车运行下屏障板水平及竖向加速度时程和频谱特征,结合悬臂板理论模态分析了屏障板相对其基础的振动放大效应及机理。结果表明,钢轨-轨枕-道床-声屏障基础... 详细信息

以普速铁路路侧落地安装直立式混凝土声屏障为研究对象,利用原位试验方法研究了列车运行下屏障板水平及竖向加速度时程和频谱特征,结合悬臂板理论模态分析了屏障板相对其基础的振动放大效应及机理。结果表明,钢轨-轨枕-道床-声屏障基础振动递减,屏障板较其基础加速度平均放大2倍,振级平均增大6 dB,道床和基础竖向振动卓越频率为63.5 Hz,水平向放大显著频段为6~8 Hz和40~50 Hz,竖向放大显著频率为63.5 Hz和160 Hz。理论模态分析显示,屏障板水平向前2阶自振频率为7 Hz和46 Hz,竖向1阶自振频率为170 Hz,说明水平放大效应与其前2阶自振频率相关,竖向放大效应与其1阶自振频率和基础激励频率相关。将屏障板振动响应估算简化为地基土-声屏障动力相互作用耦合振动模型,以考虑其受地基激励强迫振动和自由振动双重影响是合理可行的。

关键词：落地声屏障振动放大效应地基土-声屏障动力相互作用加速度时程和频谱特征原位试验普速铁路

鲍德里亚和马克思的异曲同工之处：读鲍德里亚的《消费社会》

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社会 2013年第5期33卷 230-241页

作者：吴玉彬上海大学社会学院

长期以来，无论是纵欲还是节俭，消费都被认为是私人的活动。在日常生活中，人们一般在消耗、消灭、毁灭和浪费等意义上理解消费，消费因此被妖魔化和污名化，学界也曾对其漠不关心，甚至认为“消费是对文化的腐蚀”（Miller，1995），... 详细信息

长期以来，无论是纵欲还是节俭，消费都被认为是私人的活动。在日常生活中，人们一般在消耗、消灭、毁灭和浪费等意义上理解消费，消费因此被妖魔化和污名化，学界也曾对其漠不关心，甚至认为“消费是对文化的腐蚀”（Miller，1995），但学术的思想和创新此时却从这些稀松平常、细微琐碎的消费领域等方面获致进展，近些年消费文化研究以及消费社会学和消费人类学领域的异军突起即为一个证明，其中关于鲍德里亚消费思想的研究尤其受到关注。对于鲍德里亚的思想，尽管已经有了一些讨论和分析，但仍然值得重新梳理、探讨和评估。

关键词：《消费社会》鲍德里亚异曲同工马克思文化研究消费社会学人的活动日常生活

Reentry Tracking Control of Hypersonic Glider Based on Legendre Pseudospectral Method

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Reentry Tracking Control of Hypersonic Glider Based on Legen...