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arXiv 2020年

作者： Jia, Peng Liu, Qiang Sun, Yongyang College of Physics and Optoelectronics Taiyuan University of Technology Taiyuan030024 China Key Laboratory of Advanced Transducers and Intelligent Control Systems Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan030024 China

Wide field small aperture telescopes are widely used for optical transient observations. Detection and classification of astronomical targets in observed images are the most important and basic step. In this paper, we propose an astronomical targets detection and classification framework based on deep neural networks. Our framework adopts the concept of the Faster R-CNN and uses a modified Resnet50 as backbone network and a Feature Pyramid Network to extract features from images of different astronomical targets. To increase the generalization ability of our framework, we use both simulated and real observation images to train the neural network. After training, the neural network could detect and classify astronomical targets automatically. We test the performance of our framework with simulated data and find that our framework has almost the same detection ability as that of the traditional method for bright and isolated sources and our framework has 2 times better detection ability for dim targets, albeit all celestial objects detected by the traditional method can be classified correctly. We also use our framework to process real observation data and find that our framework can improve 25% detection ability than that of the traditional method when the threshold of our framework is 0.6. Rapid discovery of transient targets is quite important and we further propose to install our framework in embedded devices such as the Nvidia Jetson Xavier to achieve real-time astronomical targets detection and classification abilities. Copyright © 2020, The Authors. All rights reserved.

关键词： Deep neural networks

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A threshold segmentation method for non-uniform illumination image based on brightness equalization 2

A threshold segmentation method for non-uniform illumination...

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2019 2nd International Conference on advanced Materials, intelligent Manufacturing and Automation, AMIMA 2019

作者： Guo, Hui Chen, Peng Huang, Shun Hu, Cong Zhang, Lijun School of Automation China University of Geosciences Wuhan430074 China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex System Wuhan430074 China

In the process of image acquisition, non-uniform illumination images are common due to poor lighting, surface reflection, or a combination of these two factors. In order to improve the quality of image segmentation, an image threshold segmentation method is proposed for non-uniform illumination images. First, the brightness of different regions in the image is compensated to make the brightness background of the whole image consistent. Second, the gradation histogram of the processed image is obtained and simulated into Gaussian distribution curve, then the inflection points of the curve are calculated. Finally, the two inflection points are set as thresholds to segment the image after brightness equalization. This method eliminates the influence of non-uniform illumination to a certain extent and gets a better segmentation effect. Experiments were carried out on images containing several different types of non-uniform illumination. The results demonstrate that the proposed method outperforms the compared enhancement algorithms in threshold segmentation. © Published under licence by IOP Publishing Ltd.

关键词： Luminance

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Image retrieval based on convolutional neural network and linear discriminate analysis 2

Image retrieval based on convolutional neural network and li...

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2019 2nd International Conference on advanced Materials, intelligent Manufacturing and Automation, AMIMA 2019

作者： Xia, Wei Hu, Cong Cheng, Xianghui Chen, Peng Jin, Xing School of Automation China University of Geosciences Wuhan430074 China Hubei Key Laboratory of Advanced Control and Intelligent Automation for Complex System Wuhan430074 China

Image retrieval is a hot research topic in the field of computer vision image processing, and the user queries the image database for similar images and produces a list of recommendations. The paper firstly sets forth the research status of image retrieval, then the convolution neural network is briefly introduced. Due to the traditional image retrieval and recommendation system use manual extraction of image features is relatively cumbersome, and the retrieval accuracy is not high research status, the paper proposes an image retrieval method based on the improved convolutional neural network and linear discriminate analysis. Caltech256 and CIFAR-10 datasets were trained using the model in this paper, experimental, results show that the proposed method can effectively improve the performance of retrieval. © Published under licence by IOP Publishing Ltd.

关键词： Search engines

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Advancing energy absorption in additively manufactured meta-plates through machine learning-driven inverse design

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Thin-Walled Structures 2025年 215卷

作者： Qingyuan Liu Liang Mou Lan Zhang Shuai Yuan Haiyang Peng Jinguo Ge Yunze Yang Yuhong Long Hualin Fan Guangxi Key Laboratory of Manufacturing System & Advanced Manufacturing Technology School of Mechanical and Electrical Engineering Guilin University of Electronic Technology Jinji road Guilin Guangxi 541004 China Research Center of Lightweight Structures and Intelligent Manufacturing State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and Astronautics Nanjing 210016 China

Transportation safety systems (e.g., automotive crash boxes, train front-end energy absorption structures) require energy absorbers to simultaneously control energy absorption ( EA ), peak crushing force or stress ( PCF , PCS ), mean crushing force or stress ( MCF , MCS ), and undulation of load carrying ( ULC ). This study proposed meta-plates, characterized by stacking layers, twisting angles, and wall thicknesses. An additive manufacturing constrained machine learning and genetic algorithm (ML-GA) co-design framework was designed to optimize the crashworthiness performances. Finite element (FE) simulations incorporating nonlinear material models and contact algorithms, combined with Latin hypercube sampling, efficiently explored 10.7% of the design space, capturing nonlinear large deformations under quasi-static compression up to 50% strain. 600 independent samples were calculated to evaluate the performance of the ML model, which achieved 96.0% prediction accuracy ( R 2 score). At a given target relative density ( ρ ∗ ) ranging from 4% to 14%, the optimized meta-plates demonstrated 80%–200% higher MCS compared to benchmark shell/plate lattices at equivalent ρ ∗ . The meta-plates also exhibited directional crushing behavior with crushing force efficiency ( CFE ) around 1.0. Experimental validations show < 6% deviation from predictions also witnessed the high MCS , low PCS , and nearly free from stress fluctuation for meta-plates with 8%, 10%, and 14% ρ ∗ values. This methodology enables rapid design of lightweight energy absorbers with tunable deformation modes and extremely high material efficiency, providing a paradigm shift from trial-and-error approaches to intelligent crashworthy structure development.

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Design of deep-water omnidirectional spirit level

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Journal of Measurement Science and Instrumentation 2021年第4期12卷 472-478页

作者： ZHAO Lianyu LI Shuo ZHAO Xiaolei LI Maolin CHEN Jinyu WANG Chenglin Tianjin Key Laboratory of Advanced Mechatronic System Design and Intelligent Control National Demonstration Center of Experimental Mechanical and Electrical Engineering EducationSchool of Mechanical EngineeringTianjin University of TechnologyTianjin 300384China Offshore Oil Engineering Co. Ltd.Tianjin 300461China

Attitude adjustment is a key link in the installation process of underwater facilities in deep *** solve this problem,an omnidirectional spirit level for deep water was *** sealing principle of the spirit level and the principle of deep-water pressure resistance are analyzed,and the threaded connection strength is *** mechanical simulation verifies that the spirit level can withstand the pressure of 2000 m water depth,and the water pressure test is carried out for 30 min in a 20 MPa hyperbaric *** the experiment is completed,the appearance of the spirit level is intact and there is no *** experiment results show that the deep-water omnidirectional spirit level can be used in the deep sea within 2000 m.

关键词： deep water omnidirectional spirit level attitude adjustment pressure test underwater pressure

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Chaos generation by a hybrid integrated chaotic semiconductor laser

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Chinese Physics B 2018年第5期27卷 122-130页

作者： Ming-Jiang Zhang Ya-Nan Niu Tong Zhao Jian-Zhong Zhang Yi Liu Yu-Hang Xu Jie Meng Yun-Cai Wang An-Bang Wang Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceTaiyuan University of TechnologyTaiyuan 030024China Institute of Optoelectronic Engineering College of Physics&OptoelectronicsTaiyuan University of TechnologyTaiyuan 030024China

We design a hybrid integrated chaotic semiconductor laser with short-cavity optical *** can be assembled in a commercial butterfly shell with just three *** of them is coated by a transflective film to provide the optical feedback for chaos generation while insuring regular laser *** prove the feasibility of the chaos generation in this compact structure and provide critical external parameters for the fabrication by theoretical *** than the usual changeless internal parameters used in previous simulation research,we extract the real parameters of the chip by ***,the maps of the largest Lyapunov exponent with varying bias current and feedback intensity Kap demonstrate the dynamic characteristics under different external-cavity *** laser chip has its own optimal external cavity length(L)and feedback intensity(Kap)to generate chaos because of the different internal *** have acquired two ranges of optimal parameters(L=4 mm,0.12〈Kap〈0.2 and L=5 mm,0.07〈Kap〈0.12)for two different chips.

关键词： chaotic dynamic characteristics integrated chaotic semiconductor laser short-cavity optical feedback extraction of internal parameters

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controllable optical bistability in a three-mode optomechanical system with a membrane resonator

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Chinese Physics B 2018年第7期27卷 382-387页

作者： Jiakai Yan Xiaofei Zhu Bin Chen Department of Physics College of Physics and OptoelectronicsTaiyuan University of TechnologyTaiyuan 030024Chin Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi ProvinceTaiyuan 030024China

We study the optical bistability （OB） in a three-mode cavity optomechanical system, where an oscillating membrane of perfect reflection is inserted between two fixed mirrors of partial transmission. By investigating the behavior of steady state solutions, we find that the left and right cavities will exhibit the bistable behavior simultaneously in this optomechanical system by adjusting the left and right coupling fields. In addition, one can control the OB threshold and the width of the OB curve via adjusting the coupling strength, the detuning, and the decay rate. Moreover, we further illustrate the OB appearing in the cavity by the effective potential as a function of the position.

关键词： optical bistability oscillating membrane optomechanical system

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RETRACTED ARTICLE:Thermal,mechanical,and tribological properties of sodium-montmorillonite-nanoparticle-reinforced polyethersulfone and polytetrafluoroethylene ternary composites

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Friction 2022年第7期10卷 1134-1134页

作者： Shicheng YAN Yahong XUE Yahui HU Shoujun WANG 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 College of Mechanical Engineering Tianjin University of TechnologyTianjin 300384China

The Editor-in-Chief has retracted this article[1]because a large number of figures as well significant parts of the text overlap with the 2017 *** by Zhen Zuo[2].All authors agree to this retraction.[1]Yan S C,Xue Y H,Hu Y H,Wang S ***,mechanical,and tribological properties of sodium-montmorillonite-nanoparticlereinforced polyethersulfone and polytetrafluoroethylene ternary ***(2020).https://***/10.1007/s40544-019-0343-x.[2]Zuo *** on tribological property and friction interface interaction of PES/PTFE ***.D ***(China):Yanshan University,2017.

关键词： friction Friction tribological

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Stability Enhancement of BOTDR Strain Sensing system by Using SOA-Based-Gain-Switched Modulation

Stability Enhancement of BOTDR Strain Sensing System by Usin...

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Optoelectronics Global Conference (OGC)

作者： Changshuo Liang Zeyu Ji Zheng Fang Qing Bai Yu Wang Xin Liu Baoquan Jin Key Laboratory of Advanced Transducers and Intelligent Control Systems Ministry of Education Taiyuan University of Technology Taiyuan China State Key Laboratory of Coal and CBM Co-mining Shanxi Jincheng Anthracite Mine Group Co. Ltd. Jincheng China

ISBN: (数字)9781728198606

ISBN: (纸本)9781728198613

Stable extinction ratio (ER) of the probe pulse is crucial to the measurement stability of Brillouin Optical Time-Domain Reflectometry (BOTDR). In this paper, a dynamic and continuous ER measurement scheme is proposed to evaluate the ER stability. Besides, a modified optical pulse modulation scheme based on gain switch is proposed to replace the conventional electric-optic modulation (EOM), aiming at enhancing the stability of BOTDR strain sensing system. The gain switch utilizes semiconductor optical amplifier (SOA) to generate probe pulse with the higher and more stable ER. Experiment results in 4 hours show the improvement of the ER stability with the proposed gain-switched modulation, which further improves the stability of BOTDR strain sensing system.

关键词： Modulation Erbium Optical switches Optical fibers Optical fiber sensors Optical variables measurement Optical pulses

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GPR detection of underground void based on low-rank and sparse representation 17

GPR detection of underground void based on low-rank and spar...

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17th International Conference on Ground Penetrating Radar, GPR 2018

作者： Liu, Li Han, Yinping Li, Jingxia Xu, Hang Wang, Bingjie Key Laboratory of Advanced Transducers and Intelligent Control System Ministry of Education and Shanxi Province Taiyuan University of Technology Taiyuan China

ISBN: (纸本)9781538657775

Underground void detection is important due to its effects on subsidence higher risk. Ground penetrating radar (GPR) is a nondestructive geophysical electromagnetic method and has been widely used in underground void detection or cavities locator. However, because of heavy clutter conditions, the void response is usually obscured. In this paper, an imaging-followed-removal algorithm based on low-rank and sparse representation is presented to suppress the clutter and obtain the void geometrical properties. The proposed algorithm firstly focus the sparsity of the raw data using Frequency-Wavenumber migration imaging method, and then removal the clutter by the robust principle component analysis (RPCA) method. Simulation results of air-filled void, air-water-filled void, and void with pipeline in its side show that our proposed algorithm can remove the dutter efficiently and then the void information can be easily obtained, which is beneficial to further identification. © 2018 IEEE.

关键词： Ground penetrating radar systems

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