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Information Communication Technologies Conference (ICTC)

作者： Benchu Zhang Zaiyue Yang School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen China Shenzhen Key Laboratory of Control Theory and Intelligent Systems and the School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen China

ISBN: (数字)9798350373523

ISBN: (纸本)9798350373530

Since the Low Earth Orbit (LEO) satellite communication system has the advantages of low latency, global coverage, and rapid reconstruction, it has become the main networking method of satellite networks [1]. Routing is the basis for realizing satellite communications. Because the complexity of the shortest path algorithm basically determines the computational complexity of the routing algorithm, the shortest path algorithm is the core of the routing problem. This paper attempts to use the laws of LEO satellite network topology to calculate the shortest path between the source satellite and the destination satellite. First, we derive the function of inter-satellite link (ISL) length with time and establish the geometric model of the satellite network. Then, on the basis of this model, we establish the shortest path algorithm between source-destination pairs (SD pairs) - the symmetric geometry algorithm (SGA). In addition, in order to ensure the optimality of the path, we extend the applicable scene of the model from the two-dimensional plane to the three-dimensional sphere. The simulation test results show that compared with the traditional Dijkstra’s algorithm, SGA can greatly improve the calculation speed of the shortest path while ensuring the optimality of the path.

关键词： Geometry Solid modeling Satellites Network topology Geometric modeling Low earth orbit satellites Routing

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Characteristic Analysis of a Cylindrical Linear Motor for Drive Mechanism

Characteristic Analysis of a Cylindrical Linear Motor for Dr...

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International Conference on Electrical Machines and systems (ICEMS)

作者： Xu Niu Tianda Yu Lu Zhang He Zhang School of Electrical Engineering Harbin Institute of Technology Harbin China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China

The control rod drive mechanism (CRDM) is a critical device in nuclear plants. This paper proposes a kind of CRDM applying the cylindrical linear induction motor (CLIM). First, the structure and the working principle are introduced. Second, the finite-element method (FEM) is applied to analyze the electromagnetic characteristics of CRDM. The lifting force variation curves with different electromagnetic and structural parameters are obtained. Third, the thermal analysis is carried out by FEM. The steady-state thermal distribution and temperature of each component of CRDM are obtained. All the above results show that the proposed CRDM can meet the design criteria and such functions as rising, falling, and holding still.

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Research on the Remaining Useful Life Prediction Model of Complex Equipment

Research on the Remaining Useful Life Prediction Model of Co...

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Artificial Intelligence and Intelligent Manufacturing (AIIM), International Symposium on

作者： Lei Tang Yifei Tang Junhao Zhang Mengjuan Liu Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu China School of Information and Software Engineering University of Electronic Science and Technology of China Chengdu China Glasgow College University of Electronic Science and Technology of China Chengdu China

ISBN: (数字)9798331541729

ISBN: (纸本)9798331541736

With the rapid advancement of artificial intelligence technology, the development of intelligent manufacturing has become an inevitable trend. Utilizing AI technology to ensure the safe operation of factories is a crucial aspect of smart factories. In particular, research focused on fault diagnosis and remaining useful life (RUL) prediction models based on machine learning has garnered significant attention from both academia and industry. This paper explores RUL prediction models for complex equipment, introduces four representative models, and analyzes their performance using two benchmark datasets, C-MAPSS and N-CMAPSS. Finally, the paper discusses the future research and application trends of artificial intelligence technology in complex equipment operation and maintenance.

关键词： Fault diagnosis Training Analytical models Machine learning Predictive models Market research Production facilities Maintenance Monitoring Smart manufacturing

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design approach of contingency point return trajectory for manned lunar missions based on homotopy continuation 3

Design approach of contingency point return trajectory for m...

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2024 3rd International Conference on Aerospace, Aerodynamics and Mechatronics Engineering, AAME 2024

作者： Lu, Lin Li, Haiyang Dong, Tianshan Zhu, Binyu College of Aerospace Science and Engineering National University of Defense Technology Changsha410073 China Hunan Key Laboratory of Intelligent Planning and Simulation for Aerospace Missions Changsha410073 China Beijing Institute of Spacecraft System Engineering Beijing100094 China

In terms of the requirement of contingency return during the circumlunar flight phase in manned lunar missions, this article presents a contingency point return trajectory design approach. In consideration of the point return constraint, an initial value estimate model is proposed. A nonlinear programming problem is constructed and solved by adopting an improved differential evolution algorithm with good global search ability. On the basis of the initial value estimate, homotopy continuation is used to gradually approximate and obtain the high-fidelity solution. The simulation results indicate that the design approach can effectively calculate a contingency point return trajectory with good convergence. © Published under licence by IOP Publishing Ltd.

关键词： Lunar missions

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Probability distribution based resource management for multitenant cloud clusters

Probability distribution based resource management for multi...

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作者： Zhou, Jun Feng, Dan Wang, Fang Future Network Research Center Purple Mountain Laboratories Nanjing China School of Computer Huazhong University of Science and Technology Wuhan China Key Laboratory of Information Storage System Wuhan National Laboratory for Optoelectronics Wuhan China

Accurate resource allocation and colocating jobs are effective ways to increase resource utilization and reduce costs in modern datacenters. The main challenges are fluctuations in resource consumption and interference among colocated jobs. Therefore, we propose a resource management schema based on the probability distributions of resource consumption and completion time for multitenant cloud clusters. First, we found that the characteristics of the task can be well described by the probability distribution of resource consumption and completion time, and the probability distribution function can be obtained by Gaussian fitting. Second, we propose a probability distribution based resource allocation (PDRA) strategy for batch jobs. Third, we design a tail latency aware allocation (TLAA) strategy to use transient resources efficiently while ensuring tail latency requirements. Finally, we design a cost-effective resource revocation (CERR) strategy to revoke transient resources with minimal eviction costs. Experimental results demonstrate the efficiency of our resource management. Our resource allocation strategies (PDRA and TLAA) can effectively improve resource utilization and reduce job completion time. CERR can reduce the impact of resource revocation on batch jobs and perform better than existing resource revocation strategies. © 2021 John Wiley & Sons Ltd.

关键词： Resource allocation

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Study of aerodynamic and inertial forces of a experimental and numerical methods

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Chinese Journal of Aeronautics 2022年第6期35卷 63-76页

作者： Xiaowu YANG Bifeng SONG Wenqing YANG Dong XUE Yang PEI Xinyu LANG School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical UniversityXi’an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057China

The force-generation mechanism of a dovelike flapping-wing micro air vehicle was studied by numerical simulation and *** obtain the real deformation pattern of the flapping wing,the digital image correlation technology was used to measure the dynamic deformation of the *** dynamic deformation data were subsequently interpolated and embedded into the CFD solver to account for the aeroelastic *** dynamic deformation data were further used to calculate the inertial forces by regarding the wing as a system of particles to take into account the wing *** temporal variation of the forces produced by the flapping wing was measured by a miniature load *** numerical results provide more flow details of the unsteady aerodynamics of the flapping wing in terms of vortex formation and *** calculated results of the inertial forces are analyzed and compared with the CFD results which represent the aerodynamic *** addition,the total forces,i.e.,the sum of the CFD result and inertial result,are compared with the experimental results,and an overall good agreement is obtained.

关键词： Aerodynamic force CFD Digital image correlation Flapping-wing micro air vehicles Inertial force

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Research on Identification Strategy of Fault-Sensitive Frequency for Planetary Gearboxes

Research on Identification Strategy of Fault-Sensitive Frequ...

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TEPEN International Workshop on Fault Diagnostics and Prognostics, TEPEN-IWFDP 2024

作者： Xie, Ruitong Zhang, Mian Chen, Jiwei Zhu, Songsong Wang, Zhiyuan Zhao, Mengxiong Xiang, Hongbiao Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechanical System Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Binshuixidao 391 Xiqing District Tianjin300384 China State Key Laboratory of Water Resources Engineering and Management Wuhan University Wuhan430072 China

ISBN: (纸本)9783031694820

Planetary gearboxes find extensive application in wind power generation, aerospace, industrial production and other fields. Harsh operational conditions and prolonged periods of continuous work often lead to various gear damages. Therefore, it is important to continuously monitor the health status of planetary gearboxes. However, the fault-sensitive frequencies of planetary gearboxes used in the existing signal models and fault diagnosis indicators are calculated theoretically or searched artificially. In response to this, this paper proposes a strategy for identifying fault-sensitive frequencies in planetary gearboxes intelligently by combining spectral amplitude analysis with three models: Random Forest (RF), Support Vector Machine (SVM) and Deep Neural Network (DNN). Experiments are carried out to verify the effectiveness and superiority of the proposed strategy. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Deep neural networks

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An Order Demodulation Analysis Method for Planetary Gearboxes

An Order Demodulation Analysis Method for Planetary Gearboxe...

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TEPEN International Workshop on Fault Diagnostics and Prognostics, TEPEN-IWFDP 2024

作者： Chen, Jiwei Xie, Ruitong Zhu, Songsong Zhao, Mengxiong Wang, Zhiyuan Zhang, Mian Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechanical System Tianjin University of Technology Tianjin300384 China National Demonstration Center for Experimental Mechanical and Electrical Engineering Education Binshuixidao 391 Xiqing District Tianjin300384 China State Key Laboratory of Water Resources Engineering and Management Wuhan University Wuhan430072 China

ISBN: (纸本)9783031694820

In addressing challenges such as the speed change of planetary gearbox (PG) during operation and the complexity in extracting fault features, an order demodulation analysis method based on order tracking (OT) and variational mode decomposition (VMD) is proposed. Non-stationary time domain signals are transformed into relatively stable angular domain signals through angular resampling. The intrinsic mode function (IMF) is obtained by demodulation of the angular multi-component signal using the VMD method. The instantaneous order of a proper IMF is calculated via Hilbert Transform. The sensitive single component is selected by matching the meshing order and the central order of the instantaneous order. Finally, the amplitude of the characteristic order components extracted from the instantaneous order spectrum was used as features and Support Vector Machine (SVM) was employed for the classification of four different conditions in the sun gear. Comparing the results of the proposed method with Deep Neural Networks (DNN) and Convolutional Neural Networks (CNN), the experimental results demonstrate the effectiveness of the proposed method in diagnosing PGs under non-stationary conditions. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Epicyclic gears

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Optimized Moderator design and Analysis of a Pin-Type Supercritical Carbon Dioxide reactor Based on reactor Monte Carlo Code

Optimized Moderator Design and Analysis of a Pin-Type Superc...

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作者： Zhao, Xingyu Liu, Minyun Cui, Rongyi Huang, Shanfang Wang, Kan Lu, Chuan Department of Engineering Physics Tsinghua University Beijing100084 China Department of Engineering Physics Tsinghua University Beijing100084 China China Nuclear Power Engineering Co. Ltd. Beijing100840 China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of China Chengdu610213 China

This study analyzed an yttrium hydride (YH2) moderated supercritical carbon dioxide cooled reactor loaded with pin-type, beryllium oxide diluted oxide fuel elements to reduce the critical enrichment. The impact of the YH2 on the coolant void reactivity was studied along with a moderator zoning scheme to flatten the radial power distribution. The YH2 was added as hexagonal moderating rods at the center of the fuel assemblies. The core was modeled using the continuous-energy reactor Monte Carlo code (RMC) with the on-the-fly cross sections treatment. The results showed that the YH2 moderator increased the thermal fission and reduced the critical enrichment of the core with the same diluent volume fraction by more than 30%. The YH2 moderator significantly softened the neutron energy spectrum and reduced the neutron leakage upon core voiding, resulting in both a weaker positive spectral reactivity feedback and a weaker negative leakage reactivity feedback during core depressurization. For an UO2-loaded core, the YH2 gave a lower negative coolant void reactivity, while for a mixed oxide fuel (MOX)-loaded core with diluent volume fractions smaller than 35%, the spectral feedback was more important and the YH2 strongly reduced the positive coolant void reactivity to less than $1. Arranging the YH2 in the peripheral assemblies reduced the radial power peaking factor to 1.319. The study shows that the YH2 moderator can reduce the critical enrichment, make the core less sensitive to voiding, and can flatten the radial power distribution of a single-enrichment core through moderator zoning. [DOI: 10.1115/1.4056772] © 2023 American Society of Mechanical Engineers (ASME). All rights reserved.

关键词： Carbon dioxide

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Optically transparent Millimeter-Wave metasurface for frequency-spatial multiplexed holographic imaging 12

Optically transparent Millimeter-Wave metasurface for freque...

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12th IEEE Asia-Pacific Conference on Antennas and Propagation, APCAP 2024

作者： Zhang, Zhiyun Zhang, Guang Zhou, Yulong Li, Sijia Tian, Jianghao Guo, Zexu Cao, Xiangyu Air Force Engineering University Information and Navigation College Xi'an710077 China Shaanxi Changling Electronic Technology Co. Ltd. Baoji721006 China Pla Naval University of Engineering National Key Laboratory of Science and Technology on Vessel Integrated Power System Wuhan430033 China

ISBN: (纸本)9798350351019

Restricted by the physical properties of materials, most traditional electromagnetic (EM) metasurfaces cannot achieve transparent stealth in visible spectrum. Although some metasurfaces for holography have been designed, there is no standard method for evaluating the advancement of wavefront manipulation, metasurface design, and algorithms. Here, a novel full space control the complex amplitude of a metasurface with optical transparency (OT) is presented in the millimeter-wave (mmWave) band. Through frequency-multiplexing, two distinct holographic images 'HOLO' and 'GRAM' with high quality are designed, achieving signal-to-noise ratios (SNR) of 14.6 dB and 14.4 dB, respectively. The 64 × 64 bi-layered metasurface is composed of glass and PET substrates and three silver mesh layers. By changing the opening size and rotating angle of split rings, phase and amplitude modulations are simultaneously and independently realized at 26.6 GHz and 44.0 GHz. © 2024 IEEE.

关键词： Microwave holography

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