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Computer Information science and Artificial Intelligence (CISAI), International Conference on

作者： Ronghuan Yu Shenhao An Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China

ISBN: (纸本)9781665406932

The space-ground integrated network is one of the important information infrastructures of the country in the future. In order to display its network structure in all directions and from multiple angles, a multi-view visualization interactive analysis method is proposed. First introduces the relevant basic technology, and then constructs the network dynamic model, which is mainly divided into three parts: link visibility analysis, relative motion analysis and visualization model construction. Finally, the digital earth technology is based on a unified coordinate system and data source. Establish a multi-dimensional view on it and provide a variety of interactive operations. Experimental results show that this method can more comprehensively show the structure of the space-ground integrated network, and help users understand its evolutionary law.

关键词： Earth Solid modeling Analytical models Visualization Information science Three-dimensional displays Soft sensors

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A DQN-based hyperheuristic algorithm for emergency scheduling of Earth observation satellites

A DQN-based hyperheuristic algorithm for emergency schedulin...

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International Conference on Electronics, Communications and Information technology (CECIT)

作者： Zheng Liu Wei Xiong Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China

ISBN: (纸本)9781665437585

With the surge of emergency task demand, large-scale Earth observation satellite emergency scheduling has become a practical problem which is urgent to be solved. In view of this situation, this paper analyzes the constrains and conflict relationship in this problem, and proposes a DQN-based hyperheuristic algorithm. The algorithm includes encoding and decoding, deep Q-network and several low-level heuristic operators. A Markov decision model of this problem is established and 7 low-level heuristic operators are designed according the feature of this problem. After training, DQN behaves well when selecting operators for the scheduling scheme. Finally, several groups of comparative experiments verify the algorithm's ability in solving large-scale satellite emergency scheduling problems.

关键词： Training Earth Satellites Heuristic algorithms Markov processes Scheduling Information and communication technology

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Answer Extraction with Graph Attention Network for Knowledge Graph Question Answering

Answer Extraction with Graph Attention Network for Knowledge...

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International Conference on Computer and Communications (ICCC)

作者： Jie Zhang Zhongmin Pei Wei Xiong Zhangkai Luo Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China

ISBN: (数字)9781728186351

ISBN: (纸本)9781728186368

In the knowledge graph question answering, the graph neural network can be used to encode the subgraph nodes related to the question entity to select the correct answer node. However, existing researches mainly focus on the modalities for the node encoding with graph neural network, ignoring that different types of subgraphs have different requirements for encoding information. To overcome the problem, this paper divides the subgraph into two types: the searching graph and the extending graph. Then we propose an answer extraction method with graph attention network for the searching graph, which can weight the information of neighbor nodes with different attention instead of the average. The hierarchical attention is also introduced to integrate question information into the subgraph node embedding to obtain the node presentation with question dependency. The accuracy of 48.2% is achieved on the CommonsenseQA dataset, which is much higher than the random guess (20%). In addition, the accuracy of the simplified model with no hierarchical attention decreases by 3.5%, which indicates the hierarchical attention mechanism can improve the predictive performance of the proposed model.

关键词： Computational modeling Predictive models Knowledge discovery Search problems Graph neural networks Encoding Task analysis

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Research on Multi-Satellite Mission Planning Based on Improved Genetic Algorithm

Research on Multi-Satellite Mission Planning Based on Improv...

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Computer science and Management technology (ICCSMT), International Conference on

作者： Yang Yang Desheng Liu Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China

For the multi-satellite mission planning problem, a multi-satellite mission planning model is constructed by considering the constraints of satellite’s visibility window to the target, attitude transition, storage and energy consumption, and an improved genetic algorithm is proposed to solve the model. The algorithm adopts the real number coding method to improve the solution efficiency, introduces the adaptive mechanism and the elite retention strategy, which improves the problems that the genetic algorithm is easy to fall into local optimum and converge early. The effectiveness of the improved genetic algorithm for solving multi-star mission planning is verified through simulation case analysis, and it is compared and analyzed with the standard genetic algorithm. The results show that the well genetic algorithm can achieve faster convergence and better planning results, and has better adaptability to large-scale mission planning problems.

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Indoor visual navigation system based on paired-landmark for small UAVs

Indoor visual navigation system based on paired-landmark for...

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IEEE International Conference on Robotics and Biomimetics

作者： Tianmiao Wang Yicheng Zhang Chaolei Wang Jianhong Liang Han Gao Miao Liu Qinpu Guan Anqi Sun BeiHang University Beijing China Science and Technology on Special System Simulation Laboratory Beijing Simulation Center Beijing China Beihang University Beijing CN

ISBN: (纸本)9781479973989

This paper has presented an implementation of visual based non-GNSS navigation method for small VTOL (Vertically Taking-off and Landing) UAV (Unmanned Aerial Vehicle). A novel method of constructing landmarks is described in detail. It uses a pair of landmarks instead of the general landmark which usually is a single geometry or coding image. The paired-landmark method inherits general landmark methods' advantages of low-cost, high-efficiency and the ability of absolute positioning. And it also solves the problem of requiring too much different characteristic landmarks when handling large area navigation. The paired-landmark method has been verified by a real parameter simulation environment. Real flight experiment is also carried out to test the effectiveness and performance of the paired-landmark navigation method. It can be concluded that, besides achieved the expected positioning precision, the proposed system also reduced the consumption of calculation and memory space.

关键词： Cameras Aircraft Aircraft navigation Visualization Atmospheric modeling Estimation

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A Microservices Oriented Edge Computing Framework for LVC simulation in the IoT Era

A Microservices Oriented Edge Computing Framework for LVC Si...

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2019第十一届计算机建模与仿真国际会议

作者： Wenxin Sun Yanlong Zhai Tianhong Bao Muhammad Mudassar Jun Shen Kai Yang School of Computer Science Beijing Institute of Technology School of Computing & Information Technology University of Wollongong Science and Technology on Special System Simulation Laboratory Beijing Simulation Center

Modeling and simulation are essential methods to better understand a complex system in the real world. Many simulation systems have strong demand for involving physical devices or equipment in the system to improve the fidelity. But most of the current cloud based simulation systems are designed for equipment with adequate resources and suffering from high latency for their centralized communication. Edge computing is getting much attention as a new paradigm for distributed systems involving heterogeneous devices and requiring real-time communication. However, edge computing is still in its initial stage and there is no consensus on the edge framework and implementation. To the best of our knowledge, no detailed studies have explored the edge-side simulation and modeling. In this paper, we study and design an edge-side simulation framework, which exploits light-weight microservices architecture to build scalable and real-time LVC(Live, Virtual and Constructive) simulations. Specifically, the application model is designed to illustrate how LVC simulation integrates with edge computing and cloud computing. The autonomous negotiation service and time synchronization services are discussed in details. Though it is a preliminary edge computing framework for LVC simulation, no similar research has been conducted for modeling and simulation using edge computing.

关键词： Edge-side simulation microservices LVC simulation IoT

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Key Techniques on Unified Identity Authentication in OpenMBEE Integration

Key Techniques on Unified Identity Authentication in OpenMBE...

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IEEE International Conference on Electronics and Communication Engineering (ICECE)

作者： Junjie Xue Junhua Zhou Guoqiang Shi Chaoqun Feng Penghua Liu Hongyan Quan Beijing Complex Product Advanced Manufacturing Engineering Research Center Beijing Simulation Center Beijing China State Key Laboratory of Intelligent Manufacturing System Technology Beijing Institute of Electronic System Engineering Beijing China Beijing Simulation Center Science and Technology on Space System Simulation Laboratory Beijing China School of Computer Science and Technology East China Normal University Shanghai China

ISBN: (纸本)9781728188577

In order to make full use of the concept of model-based systems engineering (MBSE) and the collaborative design capability of the open model-based engineering environment (OpenMBEE) in establishing complex product development platform, we propose an effective method to solve the problem of unified identity authentication in OpenMBEE integration. The proposed method is based on the Model View Controller(MVC) architecture in OpenMBEE, which has the characteristics strong plasticity and can be benefit for expanding the function in the controller layer. In our research, we make full use of the Software Development Kit (SDK) of OpenMBEE to expand the existing functions in the controller layer, and increase the function of communicating with the application development platform, then realize the function of sharing user authentication information between the development platform and OpenMBEE. After expansion, the system includes three modules, including the Front-end Service Module(FSM), MQ based Information Receiving Service Module(IFRSM), and the OpenMBEE Backend Server Module(BSM). The effectiveness of the proposed strategies is verified by some practical instances, which verifies that our study can provide an effective design idea for the identity authentication in OpenMBEE integration.

关键词： Analytical models Databases Authentication Computer architecture Control systems Data models Software

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Impedance Modeling and Stability Analysis of a Three-phase Three-level NPC Inverter Connected to the Grid

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CSEE Journal of Power and Energy systems 2020年第2期6卷 270-278页

作者： Bo Zhang Xiong Du Jingbo Zhao Jiapei Zhou Xiaoming Zou State Key Laboratory of Power Transmission Equipment&System Security and New Technology(Chongqing University) Shapingba DistrictChongqing 400044China Power System Technology Center Electric Power Research Institute of State GridJiangsu Electric Power Co.Ltd.Jiangsu 320115China HVDC Simulation Center Department of HVDC technologyGlobal Energy Interconnection Research InstituteBeijing 102209China

The interaction between grid-connected inverters and the grid may cause stability issues,and compromise the reliable operation of the *** study investigates the stability of a three-level neutral point clamped(NPC)inverter connected to the grid using impedance-based *** the impedance model of a three-phase three-level NPC inverter has not yet been reported,this study fills the literature gap by analyzing the influence of three-level DC-side neutral point control on the impedance *** fully considering the DC bus dynamics and DC voltage control loop,and the current loop and phase-locked loop(PLL),the admittance model of a three-phase three-level NPC inverter is established and verified by ***,in the stability analysis of a threelevel NPC inverter grid-connected system,the frequency coupling introduced by the PLL and DC bus dynamics is included with the help of an established admittance *** stability of the grid-connected system under different grid short circuit ratios(SCR)and operating power levels is analyzed according to the Nyquist stability *** experimental results revealed that the established impedance model of the three-phase three-level NPC inverter can properly represent the stability of this system.

关键词： Grid-connected inverter neutral point control stability three-level

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The missing base molecules in atmospheric acid-base nucleation

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National science Review 2022年第10期9卷 196-208页

作者： Runlong Cai Rujing Yin Chao Yan Dongsen Yang Chenjuan Deng Lubna Dada Juha Kangasluoma Jenni Kontkanen Roope Halonen Yan Ma Xiuhui Zhang Pauli Paasonen Tuukka Pet?j? Veli-Matti Kerminen Yongchun Liu Federico Bianchi Jun Zheng Lin Wang Jiming Hao James N.Smith Neil M. Donahue Markku Kulmala Douglas R.Worsnop Jingkun Jiang State Key Joint Laboratory of Environment Simulation and Pollution Control School of Environment Tsinghua University Institute for Atmospheric and Earth System Research/Physics Faculty of Science University of Helsinki Aerosol and Haze Laboratory Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Collaborative Innovation Center of Atmospheric Environment and Equipment Technology Nanjing University of Information Science and Technology Laboratory of Atmospheric Chemistry Paul Scherrer Institute Center for Joint Quantum Studies and Department of Physics School of Science Tianjin University Key Laboratory of Cluster Science Ministry of Education of China School of Chemistry and Chemical Engineering Beijing Institute of Technology Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3) Department of Environmental Science and Engineering Fudan University Chemistry Department University of California Center for Atmospheric Particle Studies Carnegie Mellon University Department of Chemistry Carnegie Mellon University Aerodyne Research Inc.

Transformation of low-volatility gaseous precursors to new particles affects aerosol number concentration,cloud formation and hence the *** clustering of acid and base molecules is a major mechanism driving fast nucleation and initial growth of new particles in the ***,the acid-base cluster composition,measured using state-of-the-art mass spectrometers,cannot explain the measured high formation rate of new *** we present strong evidence for the existence of base molecules such as amines in the smallest atmospheric sulfuric acid clusters prior to their detection by mass *** demonstrate that forming（H2SO4）1（amine）1is the rate-limiting step in atmospheric H2SO4-amine nucleation and the uptake of（H2SO4）1（amine）1is a major pathway for the initial growth of *** proposed mechanism is very consistent with measured new particle formation in urban beijing,in which dimethylamine is the key base for H2SO4nucleation while other bases such as ammonia may contribute to the growth of larger *** findings further underline the fact that strong amines,even at low concentrations and when undetected in the smallest clusters,can be crucial to particle formation in the planetary boundary layer.

关键词： new particle formation acid-base nucleation aerosol polluted urban environment

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The Analysis and Compensation of Elastic Unbalance Torque of the Three-axis Air-bearing Simulator 5

The Analysis and Compensation of Elastic Unbalance Torque of...

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2021 5th International Conference on Electrical, Automation and Mechanical Engineering, EAME 2021

作者： Li, Zhanxin Cao, Zizhen Duan, Wenjie Du, Yikang Liu, Haiteng Tianjin Institute of Aerospace Mechanical and Electrical Equipment Tianjin China Tianjin Key Laboratory of Microgravity Environment Simulation Technology Tianjin China Beijing Institute of Control Engineering Beijing China Science and Technology on Space Intelligent Control Laboratory Beijing China

The most important interfering torque of a three-axis air-bearing simulator is the displacement of the center of mass in the gravity field caused by structural elasticity. In order to characterize the torque, a mathematical model of the interference moment was established. Based on the model, it is suggested that the vertical stiffness and horizontal stiffness of the structure should be equal as far as possible during the structural design, and the elastic unbalance moment can be compensated by the vertical offset of the center of mass of the air floating platform relative to the rotation center after the initial attitude leveling. ABAQUS was used to build a simulation model of the air floating platform, and the changes of the structure's centroid before and after the gravitational field was applied were extracted by software to simulate the centroid deviation caused by the elastic deformation of the structure, which was used as the characterization to conduct discrete optimization of the structure. The optimal structural parameters were obtained. Then the disturbance torque curve and the corresponding initial centroid offset after initial centroid compensation were calculated by mathematical model. The results are of positive guiding significance to the design of three-axis air-bearing simulator. © 2021 Institute of Physics Publishing. All rights reserved.

关键词： Torque

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