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Optical scrambler using WGM micro-bottle cavity

Chinese Optics Letters 2023年第6期21卷 6-10页

作者：常朋发王晨蒋涛王龙生赵彤高华贾志伟郭园园王云才王安帮 Key Laboratory of Advanced Transducers&Intelligent Control Systems Ministry of Education and Shanxi ProvinceCollege of Physics&Optoelectronic EngineeringTaiyuan University of TechnologyTaiyuan 030024China Guangdong Provincial Key Laboratory of Photonics Information Technology School of Information EngineeringGuangdong University of TechnologyGuangzhou 510006China

An optical scrambler using a whispering-gallery-mode[WGM]micro-bottle cavity to scramble a complex optical signal to generate an uncorrelated output is *** experimentally demonstrated this micro-cavity scrambler by using chaotic laser light as the incident signal and studied the influence of the coupling *** achieved full scrambling with a low cross correlation of 0.028 between the output and the *** indicate that the scrambling effect originates from the interference among numerous WGMs in the bottle *** is believed that the micro-bottle cavity with an efficient scrambling function can become a promising candidate for encryption.

关键词： scrambler encryption whispering gallery mode micro-bottle cavity secure communication

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Nonlinear Dynamic Behavior and Vibration Mechanism of a Large Range Rotating Elastic Beam Under Parallel Misalignment Constraints 10

Nonlinear Dynamic Behavior and Vibration Mechanism of a Larg...

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10th International Conference on Advances in Machinery, Material Science and Engineering Application, MMSE 2024

作者： Zhao, Lei Xu, Meiye Zhai, Ran Jiao, Likuan Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China School of Mechanic Engineering Tianjin University of Technology Tianjin300384 China

ISBN: (纸本)9781643685465

Large rotating flexible machines are prone to vibration at high speeds, which is a difficult engineering problem. In this study, we have deeply explored its nonlinear dynamic behavior and vibration mechanism, especially considering the effect of parallel misalignment. Through mathematical modeling and MATLAB simulations, we found that the rotational speed and the amount of misalignment are the key parameters affecting the stability of the system. The results show that the rotational speed and parallel misalignment are the sensitive parameters of the system. When the amount of misalignment is 0.002 mm, with the increase of rotational speed, the elastic beam exhibits nonlinear M-type vibration, doubly periodic and chaotic behaviors, which show high-frequency abrupt excitation;when the angular speed is 50 rad/s, with the increase of the amount of misalignment from 0.001 mm to 0.1 mm, the system exhibits the transformation of doubly periodic, chaotic and proposed periodic motions, and the characteristics of intermittent vibration are significant. These results provide an important theoretical basis for suppressing its nonlinear vibration. © 2024 The Authors.

关键词： Rotating machinery

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Nonreciprocity of energy transfer in a nonlinear asymmetric oscillator system with various vibration states

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Applied Mathematics and Mechanics(English Edition) 2023年第5期44卷 727-744页

作者： Jian’en CHEN Jianling LI Minghui YAO Jun LIU Jianhua ZHANG Min SUN Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China School of Aeronautics and Astronautics Tiangong UniversityTianjin 300387China Agricultural Information Institute of Chinese Academy of Agricultural Sciences Key Laboratory of Agricultural Big DataMinistry of Agriculture and Rural AffairsBeijing 100081China School of Science Tianjin Chengjian UniversityTianjin 300384China

The nonreciprocity of energy transfer is constructed in a nonlinear asymmetric oscillator system that comprises two nonlinear oscillators with different parameters placed between two identical linear *** slow-flow equation of the system is derived by the complexification-averaging *** semi-analytical solutions to this equation are obtained by the least squares method,which are compared with the numerical solutions obtained by the Runge-Kutta *** distribution of the average energy in the system is studied under periodic and chaotic vibration states,and the energy transfer along two opposite directions is *** effect of the excitation amplitude on the nonreciprocity of the system producing the periodic responses is analyzed,where a three-stage energy transfer phenomenon is *** the first stage,the energy transfer along the two opposite directions is approximately equal,whereas in the second stage,the asymmetric energy transfer is *** energy transfer is also asymmetric in the third stage,but the direction is reversed compared with the second ***,the excitation amplitude for exciting the bifurcation also shows an asymmetric *** vibrations are generated around the resonant frequency,irrespective of which linear oscillator is *** excitation threshold of these chaotic vibrations is dependent on the linear oscillator that is being *** addition,the difference between the energy transfer in the two opposite directions is used to further analyze the nonreciprocity in the *** results show that the nonreciprocity significantly depends on the excitation frequency and the excitation amplitude.

关键词： nonreciprocity strong nonlinearity energy transfer chaotic vibration higher branch of response

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Small-Target Infrastructure Detection with Spatial Tracking and Multi-Level Feature Extraction of Railway Track Scenes

Small-Target Infrastructure Detection with Spatial Tracking ...

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2024 International Conference on intelligent Communication, Sensing and Electromagnetics, ICSE 2024

作者： Du, Heng Cang, Huaiming Bai, Yiwen Wang, Xinyi Beijing Elephant Technology Co. Ltd Beijing China School of Transportation Science and Engineering Beihang University Beijing102206 China State Key Lab of Intelligent Transportation System Beijing100191 China School of Mechanical Engineering Tianjin University of Technology Tianjin Key Laboratory for Advanced Mechanical System Design and Intelligent Control Tianjin China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin300384 China

ISBN: (纸本)9798350354935

In the field of railway transportation, with the continuous improvement of train running speed and the continuous increase of operating mileage, it becomes particularly important to ensure the safety and integrity of small-Target infrastructure along the railway train. Although many small-Target detection methods have been proposed, the research on small-Target infrastructure detection along rail trains is very rare. To solve this problem, this paper proposes a small-Target infrastructure detection network with spatial tracking and multi-level feature extraction based on Yolov8n. The experimental results show that ST-YOLO has a 3.6% mAP improvement on the OSDaR23 dataset compared to the baseline Yolov8n, and shows significant advantages over other state-of-The-Art methods. © 2024 IEEE.

关键词： Railroads

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Multi-objective optimization of heat sink with multi-cross-ribbed-fins for a motor controller

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Journal of Engineering and Applied Science 2022年第1期69卷 1-21页

作者： Zhang, Chao Chen, Liang Tong, Zhiting Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

A novel multi-cross-ribbed-fin layout was proposed to supersede the original smooth fin to fulfill the lightweight requirement of the air-cooled heat sink for the electrical vehicle motor controller. The thermal design with multi-cross-ribbed-fins was optimized using the multi-objective optimization method to minimize the chip’s temperature rise and the weight of the heat sink simultaneously. The design variables are the number of multi-cross-ribbed-fins ranging from 12 to 24, the number of cross ribs on either side varying from 1 to 4, and cross rib height in the region of 1.00–2.50mm. The standard k-Ε turbulence model was validated compared to the experimental data for the original heat sink with smooth fins. The Pareto front solution set was obtained by performing the mixed-level orthogonal design procedure with the numerical simulations, constructing the surrogated-based model with backpropagation neural net training, and implementing the genetic algorithm. The numerical results showed that the recommended optimal designs have the multi-cross-ribbed-fin number of 17–19, the number of cross ribs of 2–3, and a cross rib height of 2.13–2.50mm. The maximum decreases in the temperature rise and weight are 7.63% and 9.45%, respectively. For verifying the superiority of current optimal designs, one of the optimal designs of the heat sink, which yields comparative temperature rise of the chip but reduced weight, was selected to be experimentally tested and compared with the data for the original heat sink. © 2022, The Author(s).

关键词： Genetic algorithms

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An accurate pose measurement method of workpiece based on rapid extraction of local feature points

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Optoelectronics Letters 2022年第6期18卷 372-377页

作者： ZHANG Jiangtao QIAO Zhifeng WANG Shihao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin 300384China

Ceramic sanitary products with complex curved surfaces are generally fragile and difficult to *** the industrial robot is utilized to realize the automatic grinding of such products,the precise positioning of the product is required *** this paper,an accurate pose measurement system for complex curved surface parts is designed by point cloud registration *** order to improve the stability of the system,this paper combines the advantages of normal vector features and fast point feature histogram(FPFH)features,and proposes a point cloud registration algorithm based on the rapid extraction of local feature *** results verify that the improved algorithm has improved both efficiency and accuracy,and the system can effectively achieve accurate positioning of products.

关键词： robot system curved

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Simultaneously realizing thermal and electromagnetic cloaking by multi-physical null medium

arXiv

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arXiv 2023年

作者： Liu, Yichao Ma, Xiaomin Chao, Kun Sun, Fei Chen, Zihao Shan, Jinyuan Chen, Hanchuan Zhao, Gang Chen, Shaojie Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China

Simultaneously manipulating multiple physical fields plays an important role in the increasingly complex integrated systems, aerospace equipment, biochemical productions, etc. For on-chip systems with high integration level (e.g., electronic/photonic chips and radio-frequency/microwave circuits), where both electromagnetic information/energy transporting and heat dissipation/recovery need to be considered, the precise and efficient control of the propagation of electromagnetic waves and heat fluxes simultaneously is particularly important. In this study, we propose a graphical designing method based on thermal-electromagnetic null medium to simultaneously control the propagation of electromagnetic waves and thermal fields according to the pre-designed paths. A thermal-electromagnetic cloak, which can create a cloaking effect on both electromagnetic waves and thermal fields simultaneously, is designed by thermal-electromagnetic surface transformation and verified by both numerical simulations and experimental measurements. The thermal-electromagnetic surface transformation proposed in this study provides a new methodology for simultaneous controlling on electromagnetic and temperature fields, which can be used to realize a series of novel thermal-electromagnetic devices such as thermal-electromagnetic shifter, splitter, bender, multiplexer and mode converter. The designed thermal-electromagnetic cloak opens up new ways to create a concealed region where any object within it does not create any disturbance to the external electromagnetic waves and temperature fields simultaneously, which may have significant applications in improving thermal-electromagnetic compatibility problem, protecting of thermal-electromagnetic sensitive components, and improving efficiency of energy usage for complex on-chip systems. Copyright © 2023, The Authors. All rights reserved.

关键词： Electromagnetic waves

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A calibration method of external parameters of 2D laser in rotary 3D scanning

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Optoelectronics Letters 2022年第12期18卷 730-736页

作者： WANG Shihao QIAO Zhifeng HUANG Jiahao Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical EngineeringTianjin University of TechnologyTianjin300384China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of TechnologyTianjin300384China

Aiming at the problem of external parameter calibration in the combined rotating three-dimensional(3D) scanning process of laser radar and turntable, a fast 3D data scanning and accurate equipment calibration method suitable for industrial application scenarios is proposed. The coordinates of the center of the circle in the laser radar coordinate system are obtained by fitting the coordinates of the center of the circle with the scanning arc. Through the standard size and rotation angle of the target ball, the coordinates of the ball center in the turntable coordinate system are obtained. The rotation parameter R and the translation parameter T of the minimum value of the data set conversion error function in the two coordinate systems are calculated. The experimental results show that the error between the converted data and the actual data is within 0.1 mm, which meets the actual work requirements. This calibration method has the advantages of high accuracy and strong robustness.

关键词： coordinate rotation parameter

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Research on workflow recognition for liver rupture repair surgery

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Mathematical Biosciences and Engineering 2024年第2期21卷 1844-1856页

作者： Men, Yutao Zhao, Zixian Chen, Wei Wu, Hang Zhang, Guang Luo, Feng Yu, Ming Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China Medical Support Technology Research Department Systems Engineering Institute Academy of Military Sciences People’s Liberation Army Tianjin300161 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology Tianjin300384 China

Liver rupture repair surgery serves as one tool to treat liver rupture, especially beneficial for cases of mild liver rupture hemorrhage. Liver rupture can catalyze critical conditions such as hemorrhage and shock. Surgical workflow recognition in liver rupture repair surgery videos presents a significant task aimed at reducing surgical mistakes and enhancing the quality of surgeries conducted by surgeons. A liver rupture repair simulation surgical dataset is proposed in this paper which consists of 45 videos collaboratively completed by nine surgeons. Furthermore, an end-to-end SA-RLNet, a self attention-based recurrent convolutional neural network, is introduced in this paper. The self-attention mechanism is used to automatically identify the importance of input features in various instances and associate the relationships between input features. The accuracy of the surgical phase classification of the SA-RLNet approach is 90.6%. The present study demonstrates that the SA-RLNet approach shows strong generalization capabilities on the dataset. SA-RLNet has proved to be advantageous in capturing subtle variations between surgical phases. The application of surgical workflow recognition has promising feasibility in liver rupture repair surgery. ©2024 the Author(s), licensee AIMS Press. This is an open access article distributed under the terms of the Creative Commons.

关键词： Image classification

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Feature Pyramid Network Based on Skip Connect for Vehicle Prediction 2

Feature Pyramid Network Based on Skip Connect for Vehicle Pr...

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2nd International Conference on Robotics, Automation and intelligent control, ICRAIC 2022

作者： Li, Peixin Liu, Jiaqi Yang, Lu Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control School of Mechanical Engineering Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Tianjin University of Technology China

The trajectory prediction of the target vehicle can improve the perception ability of autonomous driving vehicles in the open world environment and is an essential technology for realizing high-level fully automatic driving. The traditional vehicle trajectory prediction model based on image input is sensitive to the image style of the dataset and has weak generalization ability. The prediction model based on intermediate features can overcome the problem of different dataset styles. However, there are relatively few explorations on building models based on intermediate semantic features. Inspired by the feature pyramid in image processing, this paper proposes an FPSP (Feature Pyramid network based on Skip connect for vehicle Prediction) network. By adding the pyramid feature branch, the original network is improved. The initial coarse information is hierarchically introduced into corresponding abstract high-dimensional features. Experiments on the KITTI dataset prove that FPSP achieves considerable improvement with only a slight increase in time consumption. © Published under licence by IOP Publishing Ltd.

关键词： Forecasting

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