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SSRN 2024年

作者： Song, Feilong Wu, Yun Yang, Xingkui Zhou, Jianping Xu, Shida Kang, Jinhui Wang, Jiaojiao National.Key Lab of Aerospace Power System and Plasma Technology Air Force Engineering University Xi’an710038 China Institute of Aeroengine Xi’an Jiaotong University Xi’an710049 China Beijing Aeronautical Technology Research Center Beijing100071 China Key Laboratory of Complex Aviation Simulation System Beijing100076 China

The suppression of pressure feedback and the control for detonation wave operating mode play a key role in improving the stagnation pressure gain of RDC. In this study, a unique Tesla RDC, in which Tesla pneumatic valve is introduced into the inlet structure and combustion chamber, has been tested compared with traditional configuration (RP-3 kerosene as fuel) at a flow rate of 1kg/s under the outlet throat to air inlet area ratio of 3. It is observed that the application of Tesla valve effectively controls the propagation direction of detonation wave and rotates clockwise as expected. At the same time, the percentage of pressure fluctuation to the static pressure in plenum decreases as a whole, and the lowest is only 4.2%. The maximum pressure gain obtained by equivalent available pressure method in all operating conditions is -26.1%. In addition, there is a linear relationship between thrust and air plenum pressure (Pt2), and when the Pt2 increases, the percentage of thrust to the required for the theoretical pressure gain of 0 increases gradually, up to 60.8% at the equivalence ratio of 0.65 and Pt2 of 2.47atm. It is predicted that a higher stagnation pressure gain will be achieved by carrying out a larger flow rate of 2.5kg/s and increasing Pt2 to 6.1atm. This work provides a new idea for RDC feedback suppression and mode control, and demonstrates the potential advantages of Tesla valve in RDC. © 2024, The Authors. All rights reserved.

关键词： Detonation

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Effectiveness Evaluation of Reconnaissance Satellite system based on Analytic Hierarchy Process and Cloud Model 5

Effectiveness Evaluation of Reconnaissance Satellite System ...

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5th IEEE Information technology, Networking, Electronic and Automation Control Conference, ITNEC 2021

作者： Han, Chi Xiong, Wei Xiong, Minghui Liu, Zhen Liu, Wenwen Yu, Xiaolan Jian, Ping Space Engineering University Aerospace Information Institute Beijing China Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing China

ISBN: (纸本)9781665415989

Considering the complexity of effectiveness evaluation index of reconnaissance satellite system (RSS), the cloud model theory and AHP method are combined. A fuzzy evaluation method of combat effectiveness based on cloud model is proposed. A multi-layer evaluation index system is constructed through the AHP method, and the weight of each level index is calculated. Combining the multi-dimensional cloud model with the AHP method, a quantitative fuzzy evaluation method for qualitative indicators and quantitative data is designed, and the qualitative evaluation results are obtained. The experimental results show that the proposed evaluation method can effectively realize the fuzzy quantitative evaluation under the complex evaluation index system with good performance in terms of calculation accuracy and fuzziness. © 2021 IEEE.

关键词： Analytic hierarchy process

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AEROACOUSTIC INVESTIGATION OF GRID TURBULENCE INTERACTING WITH ROTORS 29

AEROACOUSTIC INVESTIGATION OF GRID TURBULENCE INTERACTING WI...

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29th International Congress on Sound and Vibration, ICSV 2023

作者： Wu, Han Chen, Wangqiao Zhang, Xin Zhong, Siyang Huang, Xun Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong Department of Aeronautical and Aviation Engineering The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong State Key Laboratory for Turbulence and Complex System Department of Aeronautics and Astronautics College of Engineering Peking University Beijing China

ISBN: (纸本)9788011034238

The aerodynamic noise of rotors is an environmental constraint in the operation of multi-rotor powered urban air mobility (UAM) vehicles. It is essential to study the rotor noise in turbulent flows that are common in practical flights. In this work, a benchmarking turbulence grid is installed in the jet exit of an open-jet anechoic wind tunnel to generate turbulent flows. The grid-generated turbulence is characterized by the hot-wire anemometry at several downstream locations of the grid. The hot-wire results show that the turbulence intensity decays with the streamwise locations, following a power law of -5/7. The power spectral properties of the grid turbulence are also assessed, indicating a good agreement with the von Kármán turbulence spectrum. Then, the aerodynamic force and noise of a high-speed rotating rotor with a diameter of 217 mm are measured in both clean and turbulent flows. Force measurements show that the thrust and torque coefficients decrease with the advance ratio J, and the coefficient curves collapse well for all the rotational speeds. The rotor induces more torque and power under the grid turbulence. The noise measurements show that the broadband noise above 1,000 Hz can be significantly increased by turbulence, and a difference of more than 10 dB can be observed at J = 0.84. The noise directivity indicates that turbulence interaction noise is more significant at the rotor upstream. The turbulence interaction noise of rotors can impose a significant noise source to surroundings, the physics of which needs to be further investigated for noise reductions of future UAM vehicles. © 2023 Proceedings of the International Congress on Sound and Vibration. All rights reserved.

关键词： Turbulence

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Erratum to: Depth estimation using an improved stereo network (Frontiers of Information technology & Electronic Engineering, (2022), 23, 5, (777-789), 10.1631/FITEE.2000676)

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Frontiers of Information technology and Electronic Engineering 2023年 1-1页

作者： Xu, Wanpeng Zou, Ling Wu, Lingda Qi, Yue Qian, Zhaoyong Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing101416 China Peng Cheng Laboratory Shenzhen518055 China Digital Media School Beijing Film Academy Beijing100088 China

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Answer Extraction with Graph Attention Network for Knowledge Graph Question Answering 6

Answer Extraction with Graph Attention Network for Knowledge...

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6th IEEE International Conference on Computer and Communications, ICCC 2020

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

ISBN: (纸本)9781728186351

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. © 2020 IEEE.

关键词： Knowledge graph

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VRHD: An Interactive Visualization Method for Hyperspectral Data Based on Volume Rendering 5

VRHD: An Interactive Visualization Method for Hyperspectral ...

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5th IEEE International Conference on Signal and Image Processing, ICSIP 2020

作者： Hao, Hongxing Yu, Ronghuan Hu, Huaquan Fan, Youchen Space Engineering University Science and Technology on Complex Electronic System Simulation Laboratory Beijing China

ISBN: (数字)9781728168968

ISBN: (纸本)9781728168968

As the development of data visualization technology, it becomes more and more convenient to commit data analyzing and mining in some research areas. Data visualization paves the way to understand the abstract numbers in an intuitive manner. This paper focuses on the hyperspectral data analysis by visualization. We research the ray casting based volume data rendering method and propose the method termed Volume Rendering of Hyperspectral Data(VRHD) to visualize the hyperspectral data. The triple control elements including color, transparency and visual district are proposed to do the data analysis and solve the overlapping problem in cubic data visualization by traditional screen. The results prove that the proposed algorithm can help the data user or analyzer to grasp the character of the data such as noise distribution in an integral view. © 2020 IEEE.

关键词： Remote sensing

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A Rapid Evaluation Method of Radar Tracking Accuracy 4

A Rapid Evaluation Method of Radar Tracking Accuracy

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4th International Conference on Electronic Information technology and Computer Engineering, EITCE 2020

作者： Zhao, Zhongwen Zhang, Xu Li, Guodong Science and Technology on Complex Electronics System Simulation Laboratory Space Engineering University Beijing China

ISBN: (纸本)9781450387811

In order to solve the problem that the accuracy evaluation method based on error grouping is complex and can only be applied to post-processing, a fast judgment analysis method of radar tracking accuracy is proposed. This method decouples the two main processes of accuracy evaluation, namely error estimation and error statistics, and achieves fast analysis of radar tracking accuracy through real-Time estimation of local accuracy and fast statistics of average accuracy of whole track. At the same time, this method avoids the discrimination of abnormal errors by applying robust median and median absolute difference estimation, further simplifies the error estimation process, so that it is more suitable for real-Time data analysis. © 2020 ACM.

关键词： Tracking radar

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Research on the information system architecture design framework and reference resources of American Army

Research on the information System architecture design frame...

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作者： Jian Ping Space Engineering University Science and Technology on Complex Electronic System Simulation Laboratory

The concept of architecture is put forward by the US Army, which refers to the composition structure of the system and its mutual relationship, as well as the principles and guidelines guiding the design and development of the system. Architecture design technology and its reference resources have important theoretical and technical support for the top-level design of information *** on the analysis of architecture technology and function, this paper systematically studies the connotation and development history of the architecture design framework of the US army, and sorts out the main reference resources of the architecture design of the US army, such as the common joint task list, information system interoperability level model, joint technology architecture. It provides useful reference for the theoretical and technical research of information system top-level design.

关键词： Information system Architecture design DODAF(Department of Defense Architecture Framework) Top-level design Reference resources

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

With the surge of emergency task demand,largescale Earth observation satellite emergency scheduling has become a practical problem which is urgent to be *** view of this situation,this paper analyzes the constrains and conflict relationship in this problem,and proposes a DQNbased hyperheuristic *** 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 *** training,DQN behaves well when selecting operators for the scheduling ***,several groups of comparative experiments verify the algorithm's ability in solving large-scale satellite emergency scheduling problems.

关键词： DQN hyperheuristic EOS emergency scheduling

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A Region Preference-based Optimization Algorithm for Satellite Mission Planning Problem

A Region Preference-based Optimization Algorithm for Satelli...

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作者： Minghui Xiong Wei Xiong Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University

For the earth observation satellite mission planning problem, objectives such as observed target quantity, observation profit, energy consumption, image quality should be considered simultaneously, which is a many-objective optimization problem. Classical optimization-based mission planning algorithms obtain a set of non-dominated solutions in the entire search space, while only a single satisfy final plan is desired by decision maker. In this paper, a five-objective optimization model for satellite mission planning problem is constructed, then a region preference-based evolutionary algorithm, HMOEA-T, is applied to obtain the desired solutions. The decision makers describe the preference on each objective in target region form, then the algorithm guides a more detailed search within the preference region rather than the entire Pareto front. Comparative studies with preference-based methods(T-NSGA-III) and classical methods(NSGA-III) are conducted. We have exemplified the proposed method manage to obtain the solutions satisfying the mission planning preference and achieve better performance in convergence and diversity.

关键词： Optimization algorithm Preference articulation Satellite mission planning Many-objective optimization model

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