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9th Symposium on Novel Photoelectronic Detection Technology and Applications

作者： Hu, Xiaobo Hu, Xiaomin State Key Laboratory of Modern Optical Instrumentation College of Optical Science and Engineering Zhejiang University Hangzhou310027 China Shaoxing Rail Transit Shaoxing312000 China

ISBN: (纸本)9781510664432

Endoscopic imaging is an important tool for living detection, and it provides first-hand information for pathological diagnosis, such as digestive tract and respiratory tract disease. However, the imaging quality of endoscopic images faces many challenges due to the particularity of human internal environment. For example, water vapor and blood stains will block the lens, and unstable movements of the endoscope equipment will cause serious jitter of the field of view. In addition, the imaging range of the endoscope is limited, and the jitter often caused the problem of target loss. Based on the above problems, the algorithm on target segmentation and tracking of medical endoscopic images is proposed to assist doctors in real-time analysis, and extract accurate information in the harsh observation environment. Target Segmentation and tracking are two important tasks in computer vision. Most tracking algorithms use target detection to ensure real-time performance, however, the combination of segmentation and tracking is conducive to improving the identification accuracy. In addition, most segmentation and tracking focus on the real scenarios, the related datasets include DAVIS (Densely-Annotated Video Segmentation), OTB (Online Objective Tracking Benchmark) and VOT (Visual Object Tracking). However, the endoscope images are quite different due to the small detection range and difficult control of the viewing angle. Inspire by SAT (state-Aware Tracker), AlexNet is used to perform the tracking task to ensure real-time tracking, and excessive receptive field and random sampling are introduced to adapt to the characteristic of fast speed and irregular direction of target movements in the endoscope scene. In addition, this paper uses the training enhancement of the first-frame deformation to simulate the process of target appearance. VOT and DAVIS are used for pre-training, and the Hyper Kvasir dataset, which is the dataset on endoscopic polyp, is used for semi-supervised

关键词： Endoscopy

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High Impedance Faults Identification Method of Traction Power Supply System Based on Continuous Wavelet Transform and CNN Under New Energy Access

High Impedance Faults Identification Method of Traction Powe...

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International Conference of Electrical, Electronic and Networked Energy Systems, EENES 2024

作者： Kang, Jinli Fu, Qincui Xu, Huadeng Xiong, Changwu State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong University Nanchang330013 China School of Electrical and Automation Engineering East China Jiaotong University Nanchang330013 China

ISBN: (纸本)9789819618637

The fault patterns of the traction power supply system under new energy access are becoming increasingly complex and diverse. Furthermore, the characteristics of high impedance fault nonlinear faults are weak, and traditional protection methods often result in misjudgement or omission of judgement. In light of these challenges, this paper proposes a method of identifying high-impedance faults of the traction network based on continuous wavelet transform and convolutional neural network. By constructing signal samples of high impedance faults and other transient disturbances in the traction network, applying the continuous wavelet transform to transform the signals into two-dimensional time-frequency diagrams, and inputting them into a convolutional neural network, the identification of high-impedance faults and other transient disturbances is achieved. The experimental results demonstrate that the recognition accuracy of the method presented in this paper reaches 95%, exhibiting high recognition accuracy and anti-interference ability. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Wavelet transforms

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Theoretical research on gas seepage in the formations surrounding bedded gas storage salt cavern

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Petroleum Science 2022年第4期19卷 1766-1778页

作者： Xiang-Sheng Chen Yin-Ping Li Ya-Long Jiang Yuan-Xi Liu Tao Zhang State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang 330013Jiangxi China State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071 HubeiChina University of Chinese Academy of Sciences Beijing 100049China

When constructing salt cavern gas or petroleum storage in lacustrine sedimentary salt formations rich in mudstone interlayers, the influence of the sealing performance of interlayers and salt-mud interface on the storage tightness should be considered adequately. In order to reveal the gas seepage in deep formations surrounding bedded salt cavern underground storage, a leakage analysis model was established based on the characteristics of a low dip angle and the interbedded structure of bedded rock salt. The gas seepage governing equations for one-dimensional and plane radial flow were derived and solved. A gas seepage simulation experiment was conducted to demonstrate the accuracy and reliability of the theoretical calculation results. The error of the seepage range was approximately 6.70%, which is acceptable. The analysis and calculation results indicate that the motion equation of gas in deep formations satisfies a non-Darcy's law with a threshold pressure gradient and slippage effect. The sufficient condition for the gas flow to stop is that the pressure gradient is equal to the threshold pressure *** relationship between the leakage range and operating time is a positive power function, that is, the leakage range gradually increases with time and eventually stabilizes. As the seepage range increases, the seepage pressure decreases sharply during the early stage, and then decreases gradually until the flow *** the research results with engineering applications, three quantitative evaluation indexes named the maximum admissible leakage range, leakage volume and leakage rate are proposed for the tightness evaluation of gas storage salt cavern during their operating stage. These indexes can be used directly in actual engineering applications and can be compared with the key design parameters stipulated in the relevant specifications. This work is expected to provide theoretical and technical support for the gas loss and tightness evaluation of

关键词： Gas storage salt cavern Seepage Tightness Non-Darcy's law Leakage

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Research on Traction Optimization Control Strategy for 10,000-Ton Heavy Haul Trains 19th

Research on Traction Optimization Control Strategy for 10,00...

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19th Annual Conference of China Electrotechnical Society, ACCES 2024

作者： Zhang, Kunpeng Tang, Junjie Yang, Hui School of Electrical and Automation Engineering East China Jiaotong University Nanchang330013 China Jiangxi Provincial Key Laboratory of Advanced Control and Optimization Nanchang330013 China State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure Jiangxi Nanchang330013 China

ISBN: (纸本)9789819613823

Aiming at the problems of difficult control of electric traction equipment for heavy haul trains and low accuracy of control models, a distributed fuzzy sliding mode optimization control strategy for heavy haul trains based on a predictive compensation model is proposed. Firstly, based on the complex road condition information of heavy haul railways, a longitudinal dynamics model of heavy haul trains is established. Then, a long short-term memory neural network (LSTM) optimized by the Northern Goshawk Optimization (NGO) algorithm is used to predict and compensate the uncertain terms in the model. At the same time, a variable universe fuzzy algorithm (VUF) is used to improve the fast terminal sliding mode controller (FTSM). Finally, the improved controller is combined with the air braking strategy to jointly control the corrected model. The simulation results based on the heavy haul train operation simulation platform and real operation data show that the proposed method can effectively improve the handling stability and safety of 10,000-ton heavy haul trains. © Beijing Paike Culture Commu. Co., Ltd. 2025.

关键词： Traction control

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Investigation on microstructures and properties of semi-solid Al_(80)Mg_(5)Li_(5)Zn_(5)Cu_(5)light-weight high-entropy alloy during isothermal heat treatment process

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China Foundry 2022年第6期19卷 519-527页

作者： Yong Hu Yuan-yuan Liu Long-zhi Zhao Yan-chuan Tang Hai-tao Jiao De-jia Liu State Key Laboratory of Performance Monitoring Protecting of Rail Transit Infrastructure East China Jiaotong UniversityNanchang 330013China School of Materials Science and Engineering East China Jiaotong UniversityNanchang 330013China

The Al_(80)Mg_(5)Li_(5)Zn_(5)Cu_(5)light-weight high-entropy alloy with globular microstructure was fabricated by isothermal heat *** effects of isothermal temperatures and holding times on the semi-solid microstructure evolution were *** results indicate that,with increase of the isothermal temperature,the average grain size increases and the spheroidization time *** prolongation of holding time,the shape factor increases firstly and then decreases,and the average grain size decreases at first and then increases when the isothermal temperature is below 520°C,however it increases gradually at 540℃.The optimal semi-solid microstructure is obtained at 520℃ for 30 min,whose shape factor and average grain size are 0.90 and 56.4μm,*** with as-cast Al_(80)Mg_(5)Li_(5)Zn_(5)Cu_(5) light-weight high-entropy alloy,the compressive strength and plasticity of semi-solid Al_(80)Mg_(5)Li_(5)Zn_(5)Cu_(5) light-weight high-entropy alloy are increased by 36%and 108%,*** formation of semi-solid microstructures includes three stages:melting separation,spheroidization,and coarsening *** sluggish diffusion effect of Al_(80)Mg_(5)Li_(5)Zn_(5)Cu_(5) light-weight high-entropy alloy leads to a low coarsening rate,resulting in slow grain growth.

关键词： light-weight high-entropy alloy semi-solid isothermal heat treatment microstructure

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Ultraviolet photodetector of TiO2 film in different phase on various substrates

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Ceramics International 2025年第13期51卷 17190-17199页

作者： Qi, Jiawei Wu, Yanxia Zhang, Caili Yu, Shengwang Wang, Yongsheng Liu, Ying Hei, Hongjun College of Materials Science and Engineering Taiyuan University of Technology Taiyuan030024 China Lanzhou Institute of Chemical Physics Chinese Academy of Sciences Lanzhou730000 China Instrumental Analysis Center Taiyuan University of Technology Taiyuan034000 China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu610031 China

TiO2 films were gained via annealed Ti films prepared by radio frequency (RF) magnetron sputtering with different sputtering power on various substrates, including Si, quartz glass and diamond. TiO2 films with different phases were obtained by adjusting the sputtering power of Ti target. The results showed that TiO2 films transferred from the anatase phase to the mixed phase then to the rutile phase with increasing sputtering power from 100 W to 300 W. The average transmittance of the samples in the visible light band exceeded 70 % and the adjustable Eg range of the prepared TiO2 film was 3.15–3.21 eV. Specially, the TiO2-based metal-semiconductor-metal (MSM) ultraviolet (UV) photodetector with the film prepared at 100 W (S1) on Si substrate exhibited the better photoelectric performance at 20 V bias, with photo-to-dark current ratio (PDCR), responsivity (R), external quantum efficiency (EQE), and specific detectivity (D∗) of 1.9 × 103, 75.9 mA/W, 15.9 % and 2.3 × 1011 Jones, respectively. Meanwhile, the performance of UV photodetectors with diamond substrate was almost better than that of Si substrate except for S1 due to wide band gap, high carrier mobility and high thermal conductivity of diamond. The performance of S1 on Si substrate was better than diamond substrate owing to the thermal expansion coefficient between anatase TiO2 and Si was closer to that between it and diamond. In addition, when Ti was deposited on Si (111) at room temperature, a strong chemical bond (Ti-Si) was formed between Ti and Si, so that Ti was more uniformly covered on the surface of Si (111) than on the surface of diamond. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Nanocrystals

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Study on Noise Distribution of Square Cylinder Flow Based on Aerodynamic Sound Source Identification 7th

Study on Noise Distribution of Square Cylinder Flow Based on...

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7th China Aeronautical Science and Technology Conference, CASTC 2024

作者： Li, Muxiao Wang, Fuchuan Zhang, Ping Liu, Chang Han, Jian Wu, En Co. Ltd. Chengdu610092 China School of Mechanical Engineering Southwest Jiaotong University Chengdu610031 China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu610031 China

ISBN: (纸本)9789819797707

In this paper, the unsteady flow field around the square bar is calculated with the IDDES (Improved delayed detached eddy simulation) model, according to the problem of aerodynamic noise generated by flow going by a square cylinder in the field of aviation. Due to the acoustic analogy integration solution of FW-H equation, the characterization methods of dipole and quadru-pole source intensity are established. Based on this, the distribution characteristics of the near field aerodynamic sound source around the square cylinder are obtained and the formation mechanism of the aerodynamic sound source is further studied by analyzing the unsteady flow field. The results show that the dipole sources are mainly distributed on the upper and lower surfaces of the square cylinder, which is related to the pressure fluctuation caused by the separated vortex formed at the front edge of the square cylinder flapping the upper and lower surfaces of the square cylinder;the di-rectivity of far-field noise generated by dipole source is also explained from the perspective of sound source distribution. The quadrupole sources are mainly distributed in the separation zone near the upper, lower and leeward surfaces of the square cylinder, which is related to the velocity fluctuation in the separation zone. The component along the flow direction of Lighthill stress tensor corresponds to the largest sound source intensity. © Chinese Society of Aeronautics and Astronautics 2025.

关键词： Unsteady flow

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Vibration Characteristics of High-Speed Train Axle Box Bearing with Raceway Defects Considering Track Irregularity 6th

Vibration Characteristics of High-Speed Train Axle Box Beari...

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6th International Conference on Electrical engineering and Information Technologies for rail Transportation, EITRT 2023

作者： Yin, Zhonghui Wang, Zhiwei Zhang, Weihua School of Mechanical Engineering Xihua University Chengdu610039 China School of Mechanical Engineering Southwest Jiaotong University Chengdu610031 China State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong University Chengdu610031 China

ISBN: (纸本)9789819993185

Axle box bearing (ABB) of a high-speed train transmits the loads and motions between the wheelset and bogie, which is essential to the operation. The ABBs may experience raceway defects during long-term operation, which threatens the running safety. The vibration signal of ABB is widely used to the condition monitoring, while it is often limited by the noise in operation. To reveal the vibration features of raceway defects, a vehicle-track longitudinal-vertical coupled dynamics model considering ABBs is established. The bearing nonlinear frictions and contact stiffness, wheel-rail interactions, and track irregularity are comprehensively considered. In the model, the raceway defect is performed by displacement excitation function. Compared to the classical bearing models, the proposed model can simulate the bearing vibration characteristics more accurately. On the basis, the vibration characteristics of ABB with raceway defects are revealed and discussed at different running speeds. Besides, the statistical indicators are used to evaluate the vibration features. © 2024, Beijing Paike Culture Commu. Co., Ltd.

关键词： Defects

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Linear active disturbance rejection control of heavy-haul train operation based on an interval type-2 fuzzy logic system model

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Transportation Safety and Environment 2022年第4期4卷 130-139页

作者： Yating Fu Wenxuan Rao Hui Yang State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure Nanchang 330013JiangxiChina School of Electrical and Automation Engineering East China Jiaotong UniversityNanchang 330013JiangxiChina

The heavy-haul train(HHT)has large capacity and high efficiency,which represents the level of freight and makes the amelioration of control performance a trend in various *** the model reliability and increasing the anti-disturbance ability of the operation controller are two main ways to improve the operation control accuracy of ***,to describe the large nonlinear system more precisely,an interval type-2 fuzzy logic system(IT2FLS)is introduced to obtain a dynamic ***,a linear active disturbance rejection controller(LADRC)is designed to achieve precise operational *** addition,the‘bandwidth method’is combinedwith the sparrowsearch algorithm(SSA)to solve the difficulty of controller parameters ***,the stability analysis of the closed-loop control system is *** simulation experiments are conducted based on data collected from HXD1 locomotives driven by excellent *** show that the speed tracking error is no more than 0.5 km/h,and demonstrate that the proposed method significantly improves the operational performance of HHTs.

关键词： Heavy-haul train operational control IT2FLS LADRC sparrow search algorithm

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key Factors Identification for the Energy Efficiency of Metro System Based on DEMATEL-ISM 1

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2nd International Conference on Information Control, Electrical engineering and rail transit, ICEERT 2022

作者： Zhang, Chen Chen Xiao, Xue Mei Wang, Yan Hui School of Mechanical and Automotive Engineering Xiamen University of Technology Xiamen361024 China State Key Laboratory of Rail Transit Control and Safety Beijing Jiaotong University Beijing100044 China

ISBN: (数字)9789819964314

ISBN: (纸本)9789819964307

A quantitative analysis method for identifying key factors influencing the energy efficiency of the metro system based on DEMATEL-ISM was proposed in response to the complex internal relationship of key factors. To be specific, a system of factors influencing the energy efficiency was established in terms of vehicles, operation organizations, and electromechanical equipment, with a focus on analysing the interactive relationship between the influencing factors. On this basis, a DEMATEL-ISM model method system was put forward to analyse the importance of various factors using the centrality and cause degree of the influencing factors. Moreover, a multi-level hierarchical model for the factors influencing the energy efficiency was also built. Finally, the set composed of key factors of energy efficiency of the metro system was determined, providing theoretical support for the energy-saving optimization and system plan and design. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Energy efficiency

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