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

作者： Jiang, Zhiye Zheng, Pei Qiu, Yuwei Zhu, Hailiang Ding, Chenyu Wei, Gao National Key Laboratory of Science and Technology on Test Physics Numerical Mathematics Beijing China School of Electronics and Information Northwestern Polytechnical University Xi'an Shaanxi China

ISBN: (纸本)9781728186351

Research on mechanically beam-steering of horn antenna using non-uniform meta-surface is presented in this paper. After optimizing the layout of quasi-I-shaped unit cell, we designed a flexible bi-layer meta-surface that can bring a main beam deflection of 40°. When the meta-surface is sliding along the long side of horn antenna, the main beam can be steered accordingly in a range of ±40°. A mechanically radiation reconfigurable antenna is thus achieved by a simple structure. Sliding of the meta-surface relative to the horn can be realized by a motor-driven conveyor belt when the prototype is fabricated in the following research. © 2020 IEEE.

关键词： Horn antennas

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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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Source-Configured Microwave Plasmonic Vortices Based on Single Meta-Particle

Source-Configured Microwave Plasmonic Vortices Based on Sing...

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2023 International Applied Computational Electromagnetics Society Symposium, ACES-China 2023

作者： Kong, Xianglin Zhao, Lei Shen, Xiaopeng Xu, Yinfang School of Information and Control Engineering China School of Materials Science and Physics China University Mining and Technology Xuzhou China National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing China

ISBN: (纸本)9781733509657

In this paper, generation of plasmonic vortices with tunable topologic charges is proposed in the microwave regime. Tunable vortices with topologic charges of 0, +1 and -1 can be configured by illuminating incident plane waves with linearly polarization (LP), left-circularly polarization (LHCP) and right-circularly polarization (RHCP) on a single meta-particle, respectively. A spiral meta-particle operating at 2.94 GHz is designed, fabricated and measured to demonstrate the source-configured characteristics. The results showed that simulation and test are consistent with the theoretical ones. © 2023 Applied Computational Electromagnetics Society (ACES).

关键词： Vortex flow

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Unified OSTBC-based communication scheme for cooperative space vehicles

Unified OSTBC-based communication scheme for cooperative spa...

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IET International Radar Conference 2018, IRC 2018

作者： Geng, Jian Liu, Hongyan Jin, Wen Yan, Xinfeng Xu, Jin Beijing Institute of Space Long March Vehicle Beijing China National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics China

In many spatial cooperative vehicle networks, omni-directional communication is preferred due to its flexibility for networking. In the recent studies, space time code was shown to be an effective approach for improving the performance of the omni-directional communication between space vehicles. This paper studies the unified scheme for the orthogonal space time block code-based transmission between two space vehicles equipped with different numbers of antennas. It is obtained that at most six passive antennas and four RF chains are enough for the typical use. In the proposed scheme, the receiver can perform a unified detection procedure regardless of the actual number of the transmit antennas, which facilitates the practical application. Simulation results validate the proposed scheme in terms of the cumulative distribution function of the received signal-to-noise ratios. © 2019 Institution of Engineering and technology. All rights reserved.

关键词： Space time codes

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Real-Time Path Planning based on the Lock Loss Model

Real-Time Path Planning based on the Lock Loss Model

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2022 International Applied Computational Electromagnetics Society Symposium, ACES-China 2022

作者： Luo, Xun Liu, Li Liu, Xin National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematical Beijing China China Academy of Launch Vehicle Technology Beijing China

ISBN: (纸本)9781665452366

A new method of aircraft low altitude penetration is proposed with temporal constraints that allow periods of high observability interspersed with periods of low observability. The aircraft's RCS character is simplified into the 'bow-tie' distribution, then the aircraft can dynamically adjust its yaw angle to minimize the risk from the radars. According to the modified Lock Loss model and the TWS(Track While Scan) radar work flow, and real-time evaluating model on the original path, a fast real-time path planning method is present on the situation that unexpected threats occur. An example of real-time path planning is given. © 2022 IEEE.

关键词： Locks (fasteners)

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Research on networking communication technology based on small spacecraft 67

Research on networking communication technology based on sma...

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67th International Astronautical Congress, IAC 2016

作者： Peng, Qin Yang, Cao Lu, Gao Zhiye, Jiang Jinliang, Bai National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics China Academy of Launch Vehicle Technology No. 1 Nan Da Hong Men Road Beijing China

Small spacecrafts have many advantages such as distribution area controllable, flexible, easy networking and co-optimal allocation of resources. The distributed collaborative networking technology can make several small spacecrafts to co-ordinate and work together as a whole. The technology has good prospects in the aerospace field and has obtained wide attention, for it can achieve communication transmission, space exploration, decision-making tasks and other functions. This paper proposes a collaborative networking solution based on small spacecraft, focusing on the research of key technologies such as networking method, communication protocols, synchronous communication and interference. This paper designed a collaborative network communication system solution, developed a prototype and verified the feasibility of the solution through simulation analysis and prototype testing. This paper also suggested the ideas and methods to improve future collaborative network communication system. Copyright © 2016 by the International Astronautical Federation (IAF). All rights reserved.

关键词： Spacecraft

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Measurement and Analysis of Si3N4 Particles by Infrared Spectrum 3

Measurement and Analysis of Si3N4 Particles by Infrared Spec...

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3rd International Computing Imaging Conference, CITA 2023

作者： Wang, Xiaoli Li, Yanan Wei, Sai Li, Xinghua Yu, Han Aerospace Research Institute of Materials & Processing Technology Beijing China Beijing University of Technology Beijing China National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing China

ISBN: (纸本)9781510671409

In this paper, the principle of Attenuated Total Reflection (ATR) is used to test and study the silicon nitride particle samples, and the influence of particle size, shape and crystal phase on its infrared spectral performance is emphatically analyzed. It is found that the larger the particle size of Si3N4 is, the more its extinction peak moves to the long wave. The smaller the particle size is, the lower the extreme value of infrared transmission in the characteristic spectrum segment is. For Si3N4 particles of the same scale, spherical like particles can obtain lower infrared transmittance, while cylindrical like ones show a wider range of infrared absorption bands. Under the same shape and similar scale, α Phase Si3N4 particles have better infrared absorption than β Phase. © 2023 SPIE.

关键词： Fourier transform infrared spectroscopy

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Motion Prediction for Target Tracking with Bearing-only Measurement 41

Motion Prediction for Target Tracking with Bearing-only Meas...

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第41届中国控制会议

作者： Cuicui Jiang Yizhong Fang Qinglei Hu School of Automation Science and Electrical Engineering Beihang University National Key Laboratory of Science and Technology on Test Physics & Numerical Mathematics Beijing Institute of Space Long March Vehicle Beihang Hangzhou Innovation Institute Yuhang

ISBN: (数字)9789887581536

ISBN: (纸本)9781665482561

Target tracking with bearing-only measurement plays an important role for autonomous guidance and control ***,in some no-bearing measurement cases,the target motion should be predicted based on the available history *** this end,this paper compares two typical nonlinear Kalman filter techniques with the bearing measurement to firstly estimate the target state and ***,several Sigma points are chosen around the state by combining the unscented transform with the ***,for a long prediction time,the Sigma points are fed into the kinematic model to recursively obtain the target ***,the statistical properties are concluded from the Sigma points predictions,including the state mean and *** is shown that the covariance can provide an uncertainty region analysis for the target ***,the numerical simulation is given to validate the effectiveness of the proposed motion prediction approach.

关键词： Bearing-only Kalman Filter Unscented Transform Motion Prediction

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Deep representation method for radar emitter signal using wavelet packets decomposition

Deep representation method for radar emitter signal using wa...

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IET International Radar Conference 2018, IRC 2018

作者： Cao, Yang Bai, Jin Liang Li, Hongbo Zhao, Jian Liu, Shuo Gao, Zhiyong National Key Laboratory of Science and Technology on Test Physics and Numerical Mathematics Beijing China School of Electronics and Information Engineering Harbin Institute of Technology Harbin China

Signal representation is to transform the intercepted original signal into feature parameters, which is the basis for the electronic reconnaissance system to analyse and identify a radar. The traditional method is to manually design a limited number of features with prior knowledge, which can only achieve the desired results in specific applications. Therefore, it is necessary to study signal representation methods that are more adaptable, reasonable, and effective. This study proposes a feature-level design scheme that extracts multi-level signal feature parameters to obtain deep essential feature representations, which is consistent with deep-learning frameworks. Through the decomposition through wavelet packet transform (WPT), the best sub-band tree structure of the signal can be obtained, and the depth representation of the signal can be well achieved, which can meet requirements of time-frequency analysis automatically. Here, Symlets wavelet packet decomposition (WPD) is used as an example to implement multi-layer signal feature representation. The combination of characteristic parameters at different levels can reflect the different information contained in different radar signals. The simulation results show that the method can effectively identify the modulation mode of radar signals and enhance the information mining ability from radar signals. © 2019 Institution of Engineering and technology. All rights reserved.

关键词： Radar

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Localized Heating and Dynamics of the Solar Corona due to a Symbiosis of Waves and Reconnection

arXiv

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arXiv 2025年

作者： Srivastava, A.K. Mondal, Sripan Priest, Eric R. Mishra, Sudheer K. Pontin, David I. Kwon, R.Y. Yuan, Ding Murawski, K. Asai, Ayumi Varanasi221005 India Mathematics Institute St Andrews University St AndrewsKY16 9SS United Kingdom Astronomical Observatory Kyoto University Sakyo Kyoto606-8502 Japan School of Information and Physical Sciences University of Newcastle Australia Korea Astronomy and Space Science Institute Daejeon34055 Korea Republic of Shenzhen Key Laboratory of Numerical Prediction for Space Storm Institute of Space Science and Applied Technology Harbin Institute of Technology Guangdong Shenzhen China Institute of Physics University of Maria Curie-Sklodowska Pl. M. Curie-Sklodowskiej 5 Lublin20-031 Poland

The Sun’s outer atmosphere, the corona, is maintained at mega-Kelvin temperatures and fills the heliosphere with a supersonic outflowing wind. The dissipation of magnetic waves and direct electric currents are likely to be the most significant processes for heating the corona, but a lively debate exists on their relative roles. Here, we suggest that the two are often intrinsically linked, since magnetic waves may trigger current dissipation, and impulsive reconnection can launch magnetic waves. We present a study of the first of these processes by using a 2D physics-based numerical simulation using the Adaptive Mesh Refined (AMR) Versatile Advection Code (VAC). Magnetic waves such as fast magnetoacoustic waves are often observed to propagate in the large-scale corona and interact with local magnetic structures. The present numerical simulations show how the propagation of magnetic disturbances towards a null point or separator can lead to the accumulation of the electric currents. Lorentz forces can laterally push and vertically stretch the magnetic fields, forming a current sheet with a strong magnetic-field gradient. The magnetic field lines then break and reconnect, and so contribute towards coronal heating. numerical results are presented that support these ideas and support the concept of a symbiosis between waves and reconnection in heating the solar corona. Copyright © 2025, The Authors. All rights reserved.

关键词： Lorentz force

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