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10th IEEE Jubilee International Symposium on Applied Machine Intelligence and Informatics, SAMI 2012

作者： Du, Runle Liu, Jiaqi Wang, Yonghai National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

ISBN: (纸本)9781457701979

During its flight, Spacecrafts need to maneuver its attitude across a number of predefined positions. The order to traverse these attitudes is a combinational optimization problem. In this article, fuel cost is estimated by analyzing the angular momentum change during attitude transitions. Based on this estimation, an optimization algorithm for both fuel-cost and maneuver-time oriented path planner is introduced. Simulation result demonstrated the effectiveness of proposed approach. © 2012 IEEE.

关键词： Attitude control

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Effects of discharge types on plasma collisional absorption of electromagnetic waves

Effects of discharge types on plasma collisional absorption ...

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International Workshop on Metamaterials

作者： Runhui Wu Shengjun Zhang Jiaqi Liu Aimin Ren Gang Meng Wei Liang Xuemei Liu National Key Laboratory of Science and Technology on test physics & numerical mathematical Beijing China

In this paper, the collisional absorption mechanism of electromagnetic wave in plasma of different types is studied with numerical methods. The collision frequency and electromagnetic wave which is made by RF discharge in the obturator or DC discharge around the opening space. The computation models are founded for calculating the absorption by the plasma. The FDTD method is presented for simulating the collisional absorption of electromagnetic wave power for one-dimensional homogeneous/inhomogeneous plasma. The emulational results illustrate that there are two conclusions: 1) the homogeneous plasma which is produced by RF discharge in the obturator on collisional absorption of electromagnetic wave can absorb the energy of electromagnetic wave effectively in the finite bandwidth; 2) the inhomogeneous plasma which is produced by DC discharge around the opening space can absorb the energy of electromagnetic wave availably both in the wide bandwidth and from low-frequency to high-frequency.

关键词： Plasmas Discharges (electric) Absorption Radio frequency Nonhomogeneous media Electromagnetic scattering Attenuation

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FSS design research for improving the wide-band stealth performance of radar absorbing materials

FSS design research for improving the wide-band stealth perf...

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International Workshop on Metamaterials

作者： Wang Ming-liang Zhang Sheng-jun Liu Jia-qi Liang Wei Liu Xue-mei X. W. Liang National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematical Beijing China

The frequency selective surface (FSS) is designed to improve the wide-band stealth performance of radar absorbing materials (RAM) at the frequency range from 2GHz to 12GHz. The FSS element structure is designed for thin RAM coating, and the electromagnetic wave reflectivity performance of RAM containing FSS is analyzed by using the numerical simulation. The influence of FSS design parameters on the reflectivity of RAM is researched, and the FSS design parameters include the element geometry parameter, the length of the array periods, and the permittivity of substrate material. The research results show that the three absorbing wide-bands can appear and that the reflectivity is lower than -10dB, so the wide-band stealth performance of RAM containing FSS can be improved at the frequency range from 2GHz to 12GHz.

关键词： Frequency selective surfaces Random access memory Reflectivity Resonant frequency Arrays Substrates

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Attitude maneuver path optimization for small scale spacescraft

Attitude maneuver path optimization for small scale spacescr...

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International Symposium on Applied Machine Intelligence and Informatics (SAMI)

作者： Runle Du Jiaqi Liu Yonghai Wang Test Physics and Numerical Mathematics National Key Laboratory of Science and Technology Beijing China

关键词： Attitude control Fuels Space vehicles Path planning Switches Optimization Heuristic algorithms

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Effective Observing Area based evaluating method for formation design

Effective Observing Area based evaluating method for formati...

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IEEE AESS European Conference on Satellite Telecommunications (ESTEL)

作者： Runle Du Jiaqi Liu Yonghai Wang Yizhong Fang Gang Meng National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China

When multiple flying vehicles collaborate in locating a target, their formation design is an important factor to the error of location. Based on the analyses of contribution that formation design made to the location error, Effective Observing Area is defined as a criterion to assess formation design. An evaluation method for formation design is then proposed in this paper, which can serve as a guide in further formation design. Digital simulation results have proved the effectiveness and correct of this concept.

关键词： Vectors Target tracking Algorithm design and analysis Space vehicles Extraterrestrial measurements

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The role of single loading dielectric layer on properties of frequency selective surfaces

The role of single loading dielectric layer on properties of...

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International Workshop on Metamaterials

作者： S. J. Zhang J. Q. Liu M. L. Wang W. M. Ms W. Liang X. M. Liu X. C. Hou National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Aerospace Science & Industry Defense Technology R & T Center

Frequency selective surfaces (FSS) have attracted researchers from many subjects for decades for its tempting applications such as for radome radar cross section (RCS) reduction, sub-reflector, ***. Many studies was focused on different type FSS, such as unit shape, dielectric loading, layers of FSS. And it is of popular consideration that double dielectric loading on both sides of FSS be an ideal configuration. In this paper, the type of single side loading, which is more similar to the practical configuration, was studied with the numerical method. And it is found that both the thickness of thick loading layer and the constant of the thin substrate play key roles to the properties of FSS.

关键词： Frequency selective surfaces Dielectrics Substrates Loading Load modeling Frequency modulation Equivalent circuits

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Double-stage Metamodel and Its Application in Aerodynamic Design Optimization

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Chinese Journal of Aeronautics 2011年第5期24卷 568-576页

作者： ZHANG Dehu GAO Zhenghong HUANG Likeng WANG Mingliang National Key Laboratory of Science and Technology on Aerodynamic Design and Research Northwestern Polytechnical University Xi＇an 710072 China National Key Laboratory of Science and Technology on Test Physics ＆ Numerical Mathematical Beijing 100076 China

Constructing metamodel with global high-fidelity in design space is significant in engineering design. In this paper, a double-stage metamodel （DSM） which integrates advantages of both interpolation metamodel and regression metamodel is constructed. It takes regression model as the first stage to fit overall distribution of the original model, and then interpolation model of regression model approximation error is used as the second stage to improve accuracy. Under the same conditions and with the same samples, DSM expresses higher fidelity and represents physical characteristics of original model better. Besides, in order to validate DSM characteristics, three examples including Ackley function, airfoil aerodynamic analysis and wing aerodynamic analysis are investigated, In the end, airfoil and wing aerodynamic design optimizations using genetic algorithm are presented to verify the engineering applicability of DSM.

关键词： optimization genetic algorithm double-stage metamodel Kriging BP neural network Latin hypercube Parsecmethod

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Study on reflection selective structure on near infrared

Study on reflection selective structure on near infrared

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International Conference on Electronics and Optoelectronics

作者： Li, Yizhou Wang, Daorong Liu, Jiaqi Li, Hongjie Zhao, Juyan National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematical Beijing China

ISBN: (纸本)9781612842738

The paper bring forward a design of multilayer structure which has a high reflectivity for 1.82μm laser beam and a high absorptivity for 1.48μm laser beam. The experiment reveal that the absorptivity of the film reach to 95% at incidence angle from 0 to 40 for 1.48μm laser beam and has a high reflectivity for 1.82μm high power laser at incidence angle of 30o at laser power density above 500w/cm2. © 2011 IEEE.

关键词： Reflection

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Nonlinear control algorithm for smooth transition in large-angle attitude maneuver

Nonlinear control algorithm for smooth transition in large-a...

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2011 International Conference on Recent Advancements in Electrical, Electronics and Control Engineering, IConRAEeCE'11

作者： Du, Runle Liu, Jiaqi Wang, Yonghai Meng, Gang Mu, Chenyang National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics China

ISBN: (纸本)9781457721472

Large-angle attitude maneuver is common during the mission of spacecrafts, such as aligning to star to calibrate navigation system. Published works on attitude tracking always focus on optimizing the time and fuel cost, neglecting the smoothness requirement and angular speed limitations. In this paper, a nonlinear control algorithm is prompted for smooth transition in large-angle attitude maneuver. A nonlinear filter is added to the attitude feedback control loop, to carry out angular speed control in large-angle maneuvers. Simulation results demonstrated the effectiveness and reliability of proposed approach. © 2011 IEEE.

关键词： Navigation systems

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In-material measurement technique for brittle materials subjected to shock loading

In-material measurement technique for brittle materials subj...

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2011 International Conference on Electronic and Mechanical Engineering and Information technology, EMEIT 2011

作者： Xu, Songlin Liu, Yonggui Zheng, Hang Wang, Daorong CAS Key Laboratory for Mechanical Behavior and Design of Materials University of Science and Technology of China Hefei Anhui 230026 China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing 100076 China

ISBN: (纸本)9781612840857

Two kinds of magnetic gauges, including electromagnetic particle velocity (EMV) gauge and a combined gauge composed of EMV gauge and electromagnetic (EM) stress gauge, are introduced to investigate the dynamic damage of brittle materials subjected to shock loading. The former is now used for the measurements of non-magnetic materials under pressure-shear impact loading. The latter one can be used in normal plate impact, and the experimental results with this gauge could be self-proofed. The preliminarily experimental results show that these techniques are satisfactory. © 2011 IEEE.

关键词： Gages

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