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14th International Conference on Reliability, Maintainability and Safety, ICRMS 2023

作者： Zhou, Weixuan Lv, Chuan Geng, Jie Jin, Yuxue Zhang, Miao Gao, Zhuoying School of Reliability and Systems Engineering Beihang University Beijing China State Key Laboratory of Virtual Reality Technology and System Beihang University Beijing China Key Laboratory of Reliability and Environmental Engineering Beihang University Beijing China

ISBN: (纸本)9798350329988

Recent research in the process of equipment state evolution emphasizes the comprehensive consideration of the event process. However, the process does not consider the self-recovery capability of equipment in detail. In view of this problem, a detailed explanation of the self-recovery characteristics is given. Subsequently, a self-recovery model for equipment is established. Furthermore, the degradation process considering self-recovery is established. Finally, a numerical analysis is carried out to give the degradation process curve with self-recovery characteristics. The result shows that the degradation process can reflect the state evolution process more comprehensively for the equipment with self-recovery capability. © 2023 IEEE.

关键词： Degradation process Gamma process Self-recovery Shock process

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A Distributed Photovoltaics Ordering Grid-Connected Method for Analyzing Voltage Impact in Radial Distribution Networks

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Energy Engineering 2024年第10期121卷 2937-2959页

作者： Cuiping Li Kunqi Gao Can Chen Junhui Li Xiaoxiao Wang Yinchi Shao Xingxu Zhu Key Laboratory of Modern Power System Simulation and Control&Renewable Energy Technology Ministry of Education(Northeast Electric Power University)Jilin132012China State Grid Jibei Electric Power Co. Ltd.Electric Power Research InstituteBeijing100045China

In recent years,distributed photovoltaics(DPV)has ushered in a good development situation due to the advantages of pollution-free power generation,full utilization of the ground or roof of the installation site,and balancing a large number of loads ***,under the background of a large-scale DPV grid-connected to the county distribution network,an effective analysis method is needed to analyze its impact on the voltage of the distribution network in the early development stage of ***,a DPV orderly grid-connected method based on photovoltaics grid-connected order degree(PGOD)is *** method aims to orderly analyze the change of voltage in the distribution network when large-scale DPV will be ***,based on the voltagemagnitude sensitivity(VMS)index of the photovoltaics permitted grid-connected node and the acceptance of grid-connected node(AoGCN)index of other nodes in the network,thePGODindex is constructed to determine the photovoltaics permitted grid-connected node of the current photovoltaics grid-connected state ***,a photovoltaics orderly grid-connected model with a continuous updating state is constructed to obtain an orderly DPV grid-connected *** simulation results illustrate that the photovoltaics grid-connected order determined by this method based on PGOD can effectively analyze the voltage impact of large-scale photovoltaics grid-connected,and explore the internal factors and characteristics of the impact.

关键词： Radial distribution network distributed photovoltaics photovoltaics grid-connected order degree electrical distance photovoltaics action area

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A review of structures,verification,and calibration technologies of space robotic systems for on-orbit servicing

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Science China(Technological Sciences) 2021年第3期64卷 462-480页

作者： DING XiLun WANG YeCong WANG YaoBing XU Kun Robotics Institute Beihang UniversityBeijing 100191China Beijing Institute of Spacecraft System Engineering Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and ApplicationsBeijing 100094China

Recently,with the rapid development of aerospace technology,an increasing number of spacecraft is being launched into ***,the demands for on-orbit servicing(OOS)missions are rapidly *** robotics is one of the most promising approaches for various OOS missions;thus,research on space robotics technologies for OOS has attracted increased attention from space agencies and universities *** this paper,we review the structures,ground verification,and onorbit kinematics calibration technologies of space robotic systems for ***,we systematically summarize the development of space robotic systems and OOS programs based on space ***,according to the structures and applications,these systems are divided into three categories:large space manipulators,humanoid space robots,and small space *** to the capture mechanisms adopted,the end-effectors are systematically ***,the ground verification facilities used to simulate a microgravity environment are summarized and ***,the on-orbit kinematics calibration technologies are discussed and analyzed compared with the kinematics calibration technologies of industrial manipulators with regard to four ***,the development trends of the structures,verification,and calibration technologies are discussed to extend this review work.

关键词： space robotic system on-orbit servicing large space manipulator humanoid space robot verification kinematics calibration

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Application research of time-slot task synchronization method based on timestamp counter polling in electromagnetic transient real-time simulation 6

Application research of time-slot task synchronization metho...

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6th International Conference on Information Science, Electrical, and Automation Engineering, ISEAE 2024

作者： Guo, Qi Lu, Yuanhong Guo, Tianyu Zhang, Jie Huang, Libin Tu, Liang Guo, Zhilong Xu, Dehuai Guo, Chuang State Key Laboratory of HVDC Electric Power Research Institute China Southern Power Grid Guangzhou China Guangdong Provincial Key Laboratory of Intelligent Operation and Control for New Energy Power System Guangzhou China CSG Key Laboratory for Power System Simulation Electric Power Research Institute China Southern Power Grid Guangzhou China Dawning Network Technology Corp. Ltd. Wuhan China

ISBN: (纸本)9781510682924

In the practical application of electromagnetic transient real-time simulation computing platform, due to the large amount of calculation and long calculation time of electromagnetic transient simulation calculation, in order to improve the calculation speed and accuracy, it is usually necessary to use multiple CPU cores for parallel calculation at the same time, and ensure that each task synchronization and coordination among the computing cores. So, it is of great significance to select an appropriate task synchronization method for the realization of the electromagnetic transient real-time simulation computing platform. The paper puts forward a kind of based on TSC (Time Stamp Counter) Time Stamp Counter polling Time slot task synchronization method, this method supports high precision Time synchronization and coordination between different tasks, and can adapt to the transmission and efficient processing of large amounts of data. The test results prove that this method can avoid the overhead and delay of a large number of interrupts and thread switching, improve the efficiency, stability and predictability of task execution, and meet the performance requirements of the task synchronization method based on the centralized tightly coupled electromagnetic transient real-time simulation prototype. © 2024 SPIE.

关键词： Electromagnetic transients

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An improved GNSS ambiguity best integer equivariant estimation method with Laplacian distribution for urban low-cost RTK positioning

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Satellite Navigation 2024年第1期5卷 109-124页

作者： Ying Liu Wanke Liu Xiaohong Zhang Yantao Liang Xianlu Tao Liye Ma School of Geodesy and Geomatics Hubei Luojia LaboratoryWuhan University129 Luoyu RoadWuhan430079HubeiChina Chinese Antarctic Center of Surveying and Mapping Wuhan University129 Luoyu RoadWuhan430079HubeiChina School of Instrument Science and Engineering Southeast UniversityNanjingJiangsuChina The 54 Research Institute of China Electronics Technology Group CorporationShijiazhuang050081HebeiChina State Key Laboratory of Satellite Navigation System and Equipment Technology Shijiazhuang050081HebeiChina

The integer least squares(ILS)estimation is commonly used for carrier phase ambiguity resolution(AR).More recently,the best integer equivariant(BIE)estimation has also attracted an attention for complex application scenarios,which exhibits higher reliability by a weighted fusion of integer ***,traditional BIE estimation with Gaussian distribution(GBIE)faces challenges in fully utilizing the advantages of BIE for urban low-cost positioning,mainly due to the presence of outliers and unmodeled *** this end,an improved BIE estimation method with Laplacian distribution(LBIE)is proposed,and several key issues are discussed,including the weight function of LBIE,determination of the candidates included based on the OIA test,and derivation of the variance of LBIE solutions for reliability *** results show that the proposed LBIE method has the positioning accuracy similar to the BIE using multivariate t-distribution(TBIE),and significantly outperforms the ILS-PAR and GBIE *** an urban expressway test with a Huawei Mate40 smartphone,the LBIE method has positioning errors of less than 0.5 m in three directions and obtains over 50%improvements compared to the ILS-PAR and GBIE *** an urban canyon test with a low-cost receiver STA8100 produced by STMicroelectronics,the positioning accuracy of LBIE in three directions is 0.112 m,0.107 m,and 0.252 m,respectively,with improvements of 17.6%,27.2%,and 26.1%compared to GBIE,and 23.3%,28.2%,and 30.6%compared to ***,its computational time increases by 30–40%compared to ILS-PAR and is approximately half of that using TBIE.

关键词： Ambiguity resolution Best integer equivariant estimation Laplacian distribution Urban environments Low-cost GNSS receivers Real-time kinematic

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Measurement-based Path Loss Prediction and Analysis in Water Scenarios

Measurement-based Path Loss Prediction and Analysis in Water...

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2024 IEEE International Conference on Computational Electromagnetics, ICCEM 2024

作者： Li, Hanpeng Chen, Xiaomin Li, Hangang Ma, Jian Ye, Xuchao Song, Lixin Zhang, Taotao Zhong, Weizhi Zhu, Qiuming Nanjing University of Aeronautics and Astronautics College of Electronic and Information Engineering Nanjing211106 China Aviation Key Laboratory of Science and Technology On Aero Electromechanical System Integration Nanjing211106 China State Key Lab. of Complex Electromagnetic Environment Effects On Electronics and Information System Luoyang471003 China

ISBN: (纸本)9798350383317

Unmanned aerial vehicles (UAVs) have enabled the unmanned management of water areas. Path loss (PL) serves as a critical factor that affects the UAV communication quality. In this work, a PL model for UAV channel in water scenarios is proposed, aiming to explore the multidimensional relationship between transceiver distance, carrier frequency, UAV height, and PL by constructing an Artificial Neural Network (ANN). Moreover, channel measurements are conducted in a river area, and the obtained data are analyzed using the proposed ANN model as well as the close-in (CI) model. The analysis results demonstrates that the PL increases initially and then declines as the UAV height increases. The proposed ANN model has higher prediction accuracy than the classic empirical model, and can achieve precise prediction of the PL in water scenarios. © 2024 IEEE.

关键词： Neural networks

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Flexible and electrically robust graphene-based nanocomposite paper with hierarchical microstructures for multifunctional wearable devices

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Nano Materials Science 2023年第3期5卷 319-328页

作者： Zhen-Hua Tang Wei-Bin Zhu Jun-Zhang Chen Yuan-Qing Li Pei Huang Kin Liao Shao-Yun Fu College of Aerospace Engineering Chongqing UniversityChongqing400044China State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqing400044China Aerospace Engineering Khalifa UniversityAbu Dhabi127788United Arab Emirates

Multifunctional and flexible wearable devices play a crucial role in a wide range of applications,such as heath monitoring,intelligent skins,and human-machine *** flexible and conductive materials for multifunctional wearable devices with low-cost and high efficiency methods are highly ***,a conductive graphene/microsphere/bamboo fiber(GMB)nanocomposite paper with hierarchical surface microstructures is successfully fabricated through a simple vacuum-assisted filtration followed by thermo-foaming *** as-prepared microstructured GMB nanocomposite paper exhibits not only a high volume electrical conductivity of~45 S/m but also an excellent electrical stability(i.e.,relative changes in resistance are less than 3%under stretching,folding,and compressing loadings)due to its unique structure *** this microstructured nanocomposite paper as active sensing layer,microstructured pressure sensors with a high sensitivity(-4 kPa^(-1)),a wide sensing range(0–5 kPa),and a rapid response time(about 140 ms)are *** addition,benefitting from the outstanding electrical stability and mechanical flexibility,the microstructured nanocomposite paper is further demonstrated as a low-voltage Joule heating *** surface temperature of the microstructured nanocomposite paper rapidly reaches over 80℃ when applying a relatively low voltage of 7 V,indicating its potential in human thermotherapy and thermal management.

关键词： Graphene Bamboo fibers Microspheres Pressure sensors Joule heating devices

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Study on wear mechanism of small ball-end grinding wheel and surface integrity of complex component under high-speed machining condition

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Wear 2025年 570卷

作者： Qin, Biao Liu, Henan Cheng, Jian Tian, Jinchuan Sun, Jiangang Chen, Mingjun School of Mechatronics Engineering Harbin Institute of Technology Heilongjiang Harbin150001 China State Key Laboratory of Robotics and System Harbin Institute of Technology Heilongjiang Harbin150001 China Zhengzhou Research Institute Harbin Institute of Technology Zhengzhou450000 China

The small ball-end fine diamond grinding wheel is well-suited for machining complex components with small curved surface structures, demonstrating high-precision and high-quality machining capabilities. By increasing the speed of the workpiece, the issue of poor grinding performance caused by the small diameter of the ball-end grinding wheel can be effectively overcome. However, this strategy inevitably increases wheel wear and affects surface integrity. To address these challenges, this paper systematically investigates the grinding characteristics of the small ball-end grinding wheel. First, grinding experiments were performed to investigate the influence of workpiece speed, feed rate, and grinding depth on the material removal rate, wheel wear, and surface integrity. Then, the wear mechanism of the grinding wheel was analyzed. The wear modes of the grinding wheel at high workpiece speeds include metal adhesive wear and abrasive grain fracture, which enhance the self-sharpening of the grinding wheel while accelerating its wear. Furthermore, the surface morphology creation mechanism of fused silica under different material removal modes was revealed. Moreover, the correlation between material removal rate and surface roughness caused by wheel wear was revealed. A high-speed grinding strategy was subsequently proposed based on the relationship between the grinding characteristics and grinding parameters of the small ball-end grinding wheel under various grinding conditions. Finally, the feasibility of this grinding strategy was validated through its application to the machining of the complex curved fused silica hemispherical resonator (HSR). Experimental results indicate that under the high workpiece speed condition, the best surface roughness of HSR decreases from 90.5 nm to 62.2 nm, while the maximum grinding wheel wear increases from 9.7 μm to 11.5 μm, with minimal impact on surface integrity. Therefore, the high-speed grinding strategy proposed in this study ho

关键词： Fused silica

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Time-series variation and attribution analysis of downward shortwave radiation over the Yunnan-Kweichow plateau from 1984 to 2018

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International Journal of Digital Earth 2023年第1期16卷 337-354页

作者： Lijia Cheng Bo-Hui Tang Zhiwei He Zhitao Fu Menghua Li Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunmingPeople’s Republic of China State Key Laboratory of Resources and Environment Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijingPeople’s Republic of China

The downward shortwave radiation(DSR)is a key input parameter for land surface models and climate *** on the daily averaged Global Land Surface Satellite downward shortwave radiation(GLASS-DSR)dataset over the Yunnan-Kweichow Plateau(YKP)from 1984 to 2018,this paper analyzes variation trend and breakpoints of *** results show that:annual averaged DSR decreases at a decreasing rate of-1.84 W·m^(-2)·decade^(-1) over the YKP from 1984 to 2018;the overall distribution of interannual averaged DSR shows higher in the mid-west,and gradually decreasing from west to northeast over the YKP;the estimated averaged DSR is larger in spring than in summer due to the influence of the monsoon;monthly averaged DSR reaches its maximum in May and its minimum in December;breakpoints are found in the seasonal and trend components of daily averaged *** driving factors are examined for their effects on DSR variation,including annual average temperature,precipitation,10 m wind speed,aerosol optical thickness(AOT),total cloud cover,elevation,slope,aspect,longitude,latitude,and climate *** to thefindings,AOT predominates in the spatio-temporal distribution of DSR over the *** study will contribute to studies related to climate change and highland radiation.

关键词： Yunnan-Kweichow plateau downward shortwave radiation time-series analysis breakpoints detection attribution analysis

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Phenomenological Modeling of Deformation-Induced Martensite Transformation Kinetics in Austenitic Stainless Steels

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Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science 2024年第1期55卷 73-92页

作者： Zhang, Wen Zheng, Qide Gu, Nan Zhuang, Xincun Zhao, Zhen Institute of Forming Technology and Equipment School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai200030 China State Key Laboratory of Mechanical System and Vibration Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures Shanghai Jiao Tong University Shanghai200240 China National Engineering Research Center of Die & Mold CAD Shanghai Jiao Tong University Shanghai200030 China

The aim of this study is to predict the kinetics of deformation-induced martensite transformation (DIMT) by proposing a novel model considering the effects of three loading characteristics: temperature, strain rate, and stress state. Experiments including hot compression, tension, notched tension, and shear tests using 304 stainless steel plate were carried out to investigate the transformation kinetics. After a decoupling analysis was conducted on the effects of the three characteristics, particularly the temperature and strain rate effects under high strain rate loading conditions, three kinetic sub-models were established individually for each effect, and the proposed model was developed by multiplying the three kinetic sub-models. A stepwise fitting method was proposed for the calibration of material constants to replace complex iterative optimization algorithms and improve the certainty of the values of the material constants. The proposed model was further validated using the experimental data of various austenitic stainless steels obtained from previous studies. Result shows the model revealed satisfactory accuracy in predicting the DIMT behavior in material experiment. After compiling the model into a USDFLD subroutine, simulation of a heat-assisted fine-blanking process was conducted in ABAQUS, giving a reasonable prediction of martensite content of the blanking parts. © 2023, The Minerals, Metals & Materials Society and ASM International.

关键词： Austenitic stainless steel

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