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arXiv 2025年

作者： Wen, Shiming Zhang, Bo Xu, Shuangjing Sun, Yan Mai, Xiaofeng Zhang, Jingdong Cui, Lang Li, Xiaofeng Todt, Helge Yan, Xi Jiang, Pengfei Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Rd. Xuhui Shanghai200030 China Xinjiang Astronomical Observatory Chinese Academy of Sciences 150 Science 1-Street Urumqi Xinjiang830011 China Yuquan Rd. Shijingshan Beijing100049 China Korea Astronomy and Space Science Institute 776 Daedeok-daero Yuseong-gu Daejeon34055 Korea Republic of A20 Datun Road Chaoyang District Beijing100101 China Xinjiang Key Laboratory of Radio Astrophysics 150 Science 1-Street Xinjiang Urumqi830011 China School of Computer Science and Information Engineering Changzhou Institute of Technology Jiangsu Changzhou213032 China Institut für Physik und Astronomie Universität Potsdam Karl-Liebknecht-Str. 24/25 PotsdamD-14476 Germany

We report the first measurement of the orbital period of a long-period colliding-wind binary (CWB) system WR 146, derived by tracing the rotational morphology of its wind-colliding region (WCR) and the relative orientation of the two binary components. This result is based on our imaging observations using the Very Long Baseline Array (VLBA) and the European Very Long Baseline Interferometry (VLBI) Network (EVN), combined with archival data from VLBA, EVN, the Very Large Array (VLA), the enhanced Multi-Element radio-Linked Interferometer Network (eMERLIN) arrays, and optical images from the Hubble Space Telescope (HST). We evaluated two methods for determining the binary’s orbital period based on the images of the WCR: (I) fitting the shock cone of the WCR and (II) stacking images using the cross-correlation function. Using these techniques, we find orbital period estimates of 810+120−90 years from method I and 1120+540−270 years from method II, both of which support a long orbital period of approximately 1,000 years. Furthermore, we analyzed archival spectral data of WR 146 to estimate the stellar wind velocities of the binary components, finding no significant orbital phase lag between the binary orientation and the WCR rotation. We also estimate the range of the binary’s mass using the currently measured parameters. © 2025, CC BY-NC-SA.

关键词： Space telescopes

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Energy Consumption Optimal Design of Power Grid Inspection Trajectory for UAV Mobile Edge Computing Node

Energy Consumption Optimal Design of Power Grid Inspection T...

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Power and Electrical engineering (ACPEE), 5th Asia Conference on

作者： Yu Zhang Junfeng Li Litong Zhang Na Zhao Wei Tang Rui Wang Ke Xiong Institute of Economics and Energy Supply and Demand State Grid Energy Research Institute Co. Ltd. Beijing China State Grid Corporation of China Beijing China Network and Information Security Research Center Research Institute of China United Network Communication Co. Ltd. Beijing China School of Telecommunications Engineering Beijing Polytechnic Beijing China School of Automatic Control Engineering Liaoning Radio and TV University Shenyang China School of Computer and Information Technology Beijing Jiaotong University Beijing China

The inspection of transmission equipment by UAV has become an indispensable daily operation and maintenance method for overhead transmission lines. The passive sensors installed on the power transmission equipment needs to complete all its data calculation tasks within a given period of time, and needs to store a certain amount of energy to maintain its normal operation afterwards. During the inspection work, the UAV provides energy for the sensor device, and calculates the data uploaded by the sensor device, and returns the result to the sensor after the calculation is completed. Aiming at the problem of limited UAV energy and short working time, this paper proposes a optimization problem through joint optimization of UAV trajectory, sensor data unloading, sensor wireless energy transmission and other factors. According to convex optimization theory, this optimization problem can be solved based on successive convex approximation (SCA) theory. Compared with the benchmark algorithm, the UAV obtained by the optimization plan in this paper has the lowest flight energy consumption, and as time increases, the advantages of the optimization plan in this paper become more obvious. The algorithm proposed in this paper effectively reduces the energy consumption of the UAV during the execution of the mission and improves the efficiency of the UAV inspection.

关键词： Energy consumption Computational modeling Wireless power transfer Inspection Approximation algorithms Sensors Trajectory

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Wireless Avionics Intra-Communications: A Survey of Benefits, Challenges, and Solutions

arXiv

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arXiv 2020年

作者： Park, Pangun Marco, Piergiuseppe Di Nah, Junghyo Fischione, Carlo Department of Radio and Information Communications Engineering Chungnam National University Korea Republic of Department of Information Engineering Computer Science and Mathematics University of L’Aquila Italy Department of Electrical Engineering Chungnam National University Korea Republic of Department of Network and Systems Engineering School of Engineering KTH Royal Institute of Technology Sweden

In the aeronautics industry, wireless avionics intra-communications have a tremendous potential to improve efficiency and flexibility while reducing the weight, fuel consumption, and maintenance costs over traditional wired avionics systems. This survey starts with an overview of the major benefits and opportunities in the deployment of wireless technologies for critical applications of an aircraft. The current state-of-art is presented in terms of system classifications based on data rate demands and transceiver installation locations. We then discuss major technical challenges in the design and realization of the envisioned aircraft applications. Although wireless avionics intra-communication has aspects and requirements similar to mission-critical applications of industrial automation, it also has specific issues such as complex structures, operations, and safety of the aircraft that make this area of research self-standing and challenging. To support the critical operations of an aircraft, existing wireless standards for mission-critical industrial applications are briefly discussed to investigate the applicability of the current solutions. Specifically, IEEE 802.15.4-based protocols and Bluetooth are discussed for low data rate applications, whereas IEEE 802.11-based standards are considered for high data rate applications. Eventually, we propose fundamental schemes in terms of network architecture, protocol, and resource management to support the critical avionics applications and discuss the research directions in this emerging area. Copyright © 2020, The Authors. All rights reserved.

关键词： Real time systems

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Model-based safety analysis for an aviation software specification

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International Journal of Performability engineering 2020年第2期16卷 238-254页

作者： Hu, Jun Chen, Shuo Chen, Defeng Kang, Jiexiang Wang, Hui College of Computer Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing211106 China Department of Software China National Aeronautic Radio Electronics Research Institute Shanghai200233 China Collaborative Innovation Center of Novel Software Technology and Industrialization Nanjing210007 China School of Mechanical Engineering Hefei University of Technology Hefei230601 China

Model-based safety analysis (MBSA) is a kind of safety analysis technology that combines system fault models with formal analysis methods. In this paper, a real flight guidance subsystem (FGS) in aviation domain is studied, and an example of safety modeling and formal analysis of high-level software requirement specification is given. A framework of model transformation is established, which can transform a high-level FGS software requirement model described by Requirement State Machine Language (RSML-e) into a formal NuSMV model. Then, according to the real system requirements and engineering experience, the relevant failure modes and the safety properties that need to be verified are designed. Finally, formal safety analysis and verification based on NuSMV are implemented in a platform xSAP. This case study shows that the MBSA method can be used effectively for the safety analysis of the real aviation system. © 2020 Totem Publisher, Inc.

关键词： Requirements engineering

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Robust beamforming design for covert communications

arXiv

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arXiv 2021年

作者： Ma, Shuai Zhang, Yunqi Li, Hang Lu, Songtao Al-Dhahir, Naofal Zhang, Sha Li, Shiyin School of Information and Control Engineering China University of Mining and Technology Xuzhou221116 China National Mobile Communications Research Laboratory Southeast University Nanjing210096 China Shenzhen Research Institute of Big Data Shenzhen Guangdong518172 China IBM Thomas J. Watson Research Center Yorktown HeightsNY10598 United States Electrical and Computer Engineering Department University of Texas at Dallas DallasTX75080 United States Shenzhen Institute of Radio Testing and Tech Shenzhen518000 China

In this paper, we consider a common unicast beamforming network where Alice utilizes the communication to Carol as a cover and covertly transmits a message to Bob without being recognized by Willie. We investigate the beamformer design of Alice to maximize the covert rate to Bob when Alice has either perfect or imperfect knowledge about Willie’s channel state information (WCSI). For the perfect WCSI case, the problem is formulated under the perfect covert constraint, and we develop a covert beamformer by applying semidefinite relaxation and the bisection method. Then, to reduce the computational complexity, we further propose a zero-forcing beamformer design with a single iteration processing. For the case of the imperfect WCSI, the robust beamformer is developed based on a relaxation and restriction approach by utilizing the property of Kullback-Leibler divergence. Furthermore, we derive the optimal decision threshold of Willie, and analyze the false alarm and the missed detection probabilities in this case. Finally, the performance of the proposed beamformer designs is evaluated through numerical experiments. © 2021, CC BY.

关键词： Channel state information

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Galaxy clusters at z ∼ 1 imaged by ALMA with the Sunyaev–Zel’dovich effect

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Publications of the Astronomical Society of Japan 2023年第2期75卷 311-337页

作者： Kitayama, Tetsu Ueda, Shutaro Okabe, Nobuhiro Akahori, Takuya Hilton, Matt Hughes, John P. Ichinohe, Yuto Kohno, Kotaro Komatsu, Eiichiro Lin, Yen-Ting Miyatake, Hironao Oguri, Masamune Sifón, Cristóbal Takakuwa, Shigehisa Takizawa, Motokazu Tsutsumi, Takahiro van Marrewijk, Joshiwa Wollack, Edward J. Department of Physics Toho University 2-2-1 Miyama Chiba Funabashi274-8510 Japan No. 1 Section 4 Roosevelt Road Taipei10617 Taiwan Institute of Astronomy National Tsing Hua University Hsinchu30013 Taiwan Department of Physics Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Astrophysical Science Center Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Core Research for Energetic Universe Department of Physics Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Physics Program Graduate School of Advanced Science and Engineering Hiroshima University 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima739-8526 Japan Mizusawa VLBI observatory National Astronomical Observatory of Japan 2-21-1 Osawa Mitaka Tokyo181-8588 Japan Operation Division SKA Observatory Jodrell Bank Lower Withington MacclesfieldSK11 9DL United Kingdom Astrophysics Research Centre University of KwaZulu-Natal Westville Campus Durban4041 South Africa School of Mathematics Statistics & Computer Science University of KwaZulu-Natal Westville Campus Durban4041 South Africa Wits Centre for Astrophysics School of Physics University of the Witwatersrand Private Bag 3 Johannesburg2050 South Africa Department of Physics and Astronomy Rutgers The State University of New Jersey PiscatawayNJ08854-8019 United States Department of Physics Rikkyo University 3-34-1 Nishi-Ikebukuro Toshima-ku Tokyo171-8501 Japan Institute of Astronomy School of Science The University of Tokyo 2-21-1 Osawa Mitaka Tokyo181-0015 Japan Research Center for the Early Universe School of Science The University of Tokyo 7-3-1 Hongo Bunkyo Tokyo113-0033 Japan Max-Planck-Institut für Astrophysik Karl-Schwarzschild Str. 1 GarchingD-85741 Germany The University of Tokyo Institutes for Advanced Study The University of Tokyo 5-1-5 Kashiwanoha Chiba Kashiwa277-8583 Japan Nagoya University Furo-cho Chikusa-

We present high angular resolution measurements of the thermal Sunyaev–Zel’dovich effect (SZE) toward two galaxy clusters, RCS J2319+0038 at z = 0.9 and HSC J0947−0119 at z = 1.1, by the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 3. They are supplemented with available Chandra X-ray data, optical data taken by Hyper Suprime-Cam on Subaru, and millimeter-wave SZE data from the Atacama Cosmology Telescope. Taking into account departures from spherical symmetry, we have reconstructed non-parametrically the inner pressure profile of two clusters as well as electron temperature and density profiles for RCS J2319+0038. This is one of the first such measurements for an individual cluster at z 0.9. We find that the inner pressure profile of both clusters is much shallower than that of local cool-core clusters. Our results consistently suggest that RCS J2319+0038 hosts a weak cool core, where radiative cooling is less significant than in local cool cores. On the other hand, HSC J0947−0119 exhibits an even shallower pressure profile than RCS J2319+0038 and is more likely to be a non-cool-core cluster. The SZE centroid position is offset by more than 140 h−170 kpc from the peaks of galaxy distribution in HSC J0947−0119, suggesting a stronger influence of mergers in this cluster. We conclude that these distant clusters are at a very early stage of developing the cool cores typically found in clusters at lower redshifts. © The Author(s) 2023. Published by Oxford University Press on behalf of the Astronomical Society of Japan.

关键词： Millimeter waves

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Erratum to: Several Articles in JETP Letters

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JETP Letters 2022年第8期116卷 589-591页

作者： Godunov, S. I. Karkaryan, E. K. Novikov, V. A. Rozanov, A. N. Vysotsky, M. I. Zhemchugov, E. V. Inogamov, N. A. Perov, E. A. Zhakhovsky, V. V. Shepelev, V. V. Petrov, Yu. V. Fortova, S. V. Tarasenko, S. V. Shavrov, V. G. Valeev, B. Yu. Toksumakov, A. N. Kvashnin, D. G. Chernozatonskii, L. A. Makarov, A. S. Kretova, M. A. Afonin, G. V. Qiao, J. C. Glezer, A. M. Kobelev, N. P. Khonik, V. A. Klumov, B. A. Magadeev, E. B. Vakhitov, R. M. Tamm Department of Theoretical Physics Lebedev Physical Institute Russian Academy of Sciences Moscow Russia Alikhanov Institute for Theoretical and Experimental Physics National Research Center Kurchatov Institute Moscow Russia Centre de Physique des Particules de Marseille CPPM Aix-Marseille Universite CNRS/IN2P3 Marseille France Landau Institute for Theoretical Physics Russian Academy of Sciences Chernogolovka Russia Joint Institute for High Temperatures Russian Academy of Sciences Moscow Russia All-Russia Research Institute of Automatics Moscow Russia Institute for Computer Aided Design Russian Academy of Sciences Moscow Russia Moscow Institute of Physics and Technology (National Research University) Dolgoprudnyi Russia Dоnetsk Institute for Physics and Engineering Donetsk Ukraine Kotelnikov Institute of Radio Engineering and Electronics Russian Academy of Sciences Moscow Russia Emanuel Institute of Biochemical Physics Russian Academy of Sciences Moscow Russia Scientific School on Chemistry and Technology of Polymer Materials Plekhanov Russian University of Economics Moscow Russia Voronezh State Pedagogical University Voronezh Russia School of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University Xi’an People’s Republic of China National University of Science and Technology MISiS Moscow Russia Institute of Solid State Physics Russian Academy of Sciences Chernogolovka Russia Bashkir State University Ufa Russia

An Erratum to this paper has been published: https://***/10.1134/S0021364022340021

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The Modified Traditional Motion Compensation Method in Video Compression Applications

The Modified Traditional Motion Compensation Method in Video...

引用

International Conference on engineering and Telecommunication (EnT)

作者： Alexander V. Dvorkovich Gennady Yu. Gryzov Dam Trong Nam Viktor P. Dvorkovich MIPT-School of Radio Engineering and Computer Technology Moscow Institute of Physics and Technology Moscow Russian Federation Multimedia Systems and Technology Lab Moscow Institute of Physics and Technology Moscow Russian Federation

ISBN: (数字)9781728135649

ISBN: (纸本)9781728135656

This paper is dedicated to the research and development of the modified traditional motion compensation method. The paper proposes a new motion compensation method with the use of approximation functions with additional parameters. For applying the considered approximation functions in the considered wavelet-based video codec Dirac, the subtasks associated with the accuracy and the transmission method of additional parameters have been solved. Based on the processing results of different video with the approximation functions studied, the best suitable function has been chosen. Compared with the traditional motion compensation method, the usage of the proposed method in the considered video codec can reduce bitrate up to 20% for good reconstruction quality PSNR = 40 dB and up to 33.5% for excellent quality PSNR = 42 dB for frame splitting case 16×16. In the case of block size 32×32, the proposed method can reduce bitrate from 3% to 35% for quality PSNR = 40 dB and from 2% to 40% for quality PSNR = 42 dB.

关键词： Motion compensation Video codecs Cost function Bit rate Motion estimation Physics Brightness

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Solder joint image adaptive block compressive sensing with convex optimisation and Gini index

Solder joint image adaptive block compressive sensing with c...

引用

7th International Symposium on Test Automation and Instrumentation, ISTAI 2018

作者： Zhao, Huihuang Wang, Yaonan Zheng, Jinhua Qiao, Zhijun Zhang, Yun Department of Computer Science and Technology College of Computer Science and Technology Hengyang Normal University Hengyang Hunan China Hunan Provincial Key Laboratory of Intelligent Information Processing and Application Hengyang China Department of Electrical and Engineering College of Electrical and Information Engineering Hunan University Changsha China School of Mathematical and Statistical Sciences University of Texas Rio Grande ValleyTX United States Institute of Radio and TV Technology Communication University of Zhejiang Hangzhou310018 China

This study aims to improve the performance in solder joint image compression and reconstruction. A novel adaptive block compressive sensing with convex optimisation and Gini index (Ad_BCSGB_Gini) methodology for solder joint image compression and reconstruction is proposed. At first, the image is split into square blocks and each block is resized into a row which consists of a new image. Then, the new image is transformed into a sparse signal by an orthogonal basis matrix, and the image reconstruction is handled as a convex optimisation problem. Moreover, a gradient-based method which has fast computational speed is used to reconstruct image. There is a control factor which controls a norm l1 in the optimisation problem. To achieve the best performance, at last, the proposed method adaptively selects the best result by comparing Gini index of the reconstruction results based on different control factor values. Experimental results with different methods indicate that the Ad_BCSGB_Gini method is able to achieve the best performance in quantisation comparison than several classical algorithms, and Ad_BCSGB_Gini has a good robustness. © 2019 Institution of engineering and technology. All rights reserved.

关键词： Convex optimization

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On More than Two Decades of Celestial Reference Frame VLBI Observations in the Deep South: IVS-CRDS (1995-2021)

arXiv

引用

arXiv 2023年

作者： Weston, S. de Witt, A. Krásná, Hana Le Bail, Karine Hardin, Sara Gordon, David Fengchun, Shu Fey, Alan Schartner, Matthias Basu, Sayan Titov, Oleg Behrend, Dirk Jacobs, Christopher S. Hankey, Warren Salguero, Federico Reynolds, John E. School of Engineering Computer and Mathematical Sciences Faculty of Design and Creative Technologies Auckland University of Technology New Zealand The South African Radio Astronomy Observatory South Africa Department für Geodäsie und Geoinformation Wiedner Hauptstraße 8 WienA-1040 Austria NVI Inc. NASA Goddard Space Flight Center Code 61A GreenbeltMD20771 United States Chalmers University of Technology Onsala Space Observatory Onsala439 92 Sweden U.S. Naval Observatory WashingtonDC20392 United States Shanghai Astronomical Observatory Chinese Academy of Sciences 80 Nandan Road Shanghai200030 China ETH Zürich Institute of Geodesy and Photogrammetry Zurich Switzerland Geoscience Australia PO Box 378 CanberraACT2601 Australia Jet Propulsion Laboratory California Institute of Technology 4800 Oak Grove Dr. PasadenaCA United States University of Tasmania Hobart Australia National Scientific and Technical Research Council CONICET Argentina CSIRO Space and Astronomy Australia Telescope National Facility P.O. Box 76 EppingNSW1710 Australia

The International VLBI Service for Geodesy & Astrometry (IVS) regularly provides high-quality data to produce Earth Orientation Parameters (EOP), and for the maintenance and realization of the International Terrestrial and Celestial Reference Frames, ITRF and ICRF. The first iteration of the celestial reference frame (CRF) at radio wavelengths, the ICRF1, was adopted by the International Astronomical Union (IAU) in 1997 to replace the FK5 optical frame. Soon after, the IVS began official operations and in 2009 there was a significant increase in data sufficient to warrant a second iteration of the CRF, ICRF2. The most recent ICRF3, was adopted by the IAU in 2018. However, due to the geographic distribution of observing stations being concentrated in the Northern hemisphere, CRFs are generally weaker in the South due to there being fewer Southern Hemisphere observations. To increase the Southern Hemisphere observations, and the density, precision of the sources, a series of deep South observing sessions was initiated in 1995. This initiative in 2004 became the IVS Celestial Reference Frame Deep South (IVS-CRDS) observing program. This paper covers the evolution of the CRDS observing program for the period 1995 to 2021, details the data products and results, and concludes with a summary of upcoming improvements to this ongoing project. © 2023, CC BY.

关键词： Geodesy

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