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A Comprehensive Classification and Analysis of Geomagnetic Storms Over Solar Cycle 24

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Research in Astronomy and Astrophysics 2024年第8期24卷 77-86页

作者： Raja Adibah Raja Halim Shah Nurul Shazana Abdul Hamid Mardina Abdullah Adlyka Annuar Idahwati Sarudin Zahira Mohd Radzi Akimasa Yoshikawa Department of Applied Physics Faculty of Science and TechnologyUniversiti Kebangsaan Malaysia space Science Centre (ANGKASA) Institute of Climate ChangeUniversiti Kebangsaan Malaysia Department of Electrical Electronic and Systems EngineeringFaculty of Engineering and Built EnvironmentUniversiti Kebangsaan Malaysia School of Physics Universiti Sains Malaysia Malaysian space Agency (MYSA) International Research Center for space and Planetary Environmental Science (i-SPES) Kyushu University

A geomagnetic storm is a global disturbance of Earth?s magnetosphere,occurring as a result of the interaction with magnetic plasma ejected from the *** considerable research,a comprehensive classification of storms for a complete solar cycle has not yet been fully developed,as most previous studies have been limited to specific storm *** study,therefore,attempted to present complete statistics for solar cycle 24,detailing the occurrence of geomagnetic storm events and classifying them by type of intensity (moderate,intense,and severe),type of complete interval (normal or complex),duration of the recovery phase (rapid or long),and the number of steps in the storm?s *** analysis was applied to data from ground-based magnetometers,which measured the Dst index as provided by the World Data Center for Geomagnetism,Kyoto,*** study identified 211 storm events,comprising moderate (177 events),intense (33 events),and severe (1 event) *** 36%of ICMEs and 23%of CIRs are found to be geoeffective,which caused geomagnetic *** to four-step development of geomagnetic storms was exhibited during the main phase for this solar *** showed the geomagnetic storms developed one or more steps in the main phase,which were probably related to the driver that triggered the geomagnetic storms.A case study was additionally conducted to observe the variations of the ionospheric disturbance dynamo (Ddyn) phenomenon that resulted from the geomagnetic storm event of 2015July *** attenuation of the Ddyn in the equatorial region was analyzed using the H component of geomagnetic field data from stations in the Asian sector (Malaysia and India).The variations in the Ddyn signatures were observed at both stations,with the TIR station (India) showing higher intensity than the LKW station (Malaysia).

关键词： (Sun:) solar-terrestrial relations (Sun:) sunspots Sun: activity Sun: coronal mass ejections (CMEs)

Assessment of corrected time-step method for nominal ionospheric gradient calculation: A comparative analysis with spatial approaches

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Earth and Planetary Physics 2024年第4期8卷 641-649页

作者： Slamet Supriadi Prayitno Abadi Susumu Saito Harry Bangkit Dwiko Unggul Prabowo Adi Purwono Ginaldi Ari Nugroho Research Center for Smart Mechatronics National Research and Innovation Agency(BRIN)BandungIndonesia Research Center for Climate and Atmosphere BRINBandungIndonesia School of Electrical Engineering Telkom UniversityKab.BandungIndonesia Electronic navigation Research Institute National Institute of MaritimePort and Aviation TechnologyTokyoJapan Research Center for space BRINBandungIndonesia

The effect of ionospheric delay on the ground-based augmentation system under normal conditions can be mitigated by determining the value of the nominal ionospheric gradient(σvig).The nominal ionospheric gradient is generally obtained from Continuously Operating Reference Stations data by using the spatial single-difference method(mixed-pair,station-pair,or satellite-pair)or the temporal single-difference method(time-step).The time-step method uses only a single receiver,but it still contains ionospheric temporal *** introduce a corrected time-step method using a fixed-ionospheric pierce point from the geostationary equatorial orbit satellite and test it through simulations based on the global ionospheric *** also investigate the effect of satellite paths on the corrected time-step method in the region of the equator,which tends to be in a more north–south direction and to have less coverage for the east–west ionospheric *** study also addresses the limitations of temporal variation correction coverage and recommends using only the correction from *** processes are developed under simulations because observational data are still difficult to *** findings demonstrate that the corrected time-step method yieldsσvig values consistent with other approaches.

关键词： ground-based augmentation system nominal ionospheric gradient time-step correction global ionospheric model

A novel fractional case study of nonlinear dynamics via analytical approach

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Applied Mathematics(A Journal of Chinese Universities) 2024年第2期39卷 276-290页

作者： Hassan Khan Adnan Khan Rasool Shah Dumitru Baleanu Department of Mathematics Abdul Wali khan UniversityMardan 23200Pakistan Department of Mathematics Faculty of Arts and SciencesCankaya UniversityAnkara 06530Turkey Institute of space Sciences Magurele-BucharestRomania

The present work describes the fractional view analysis of Newell-Whitehead-Segal equations,using an innovative *** work is carried with the help of the Caputo operator of fractional *** analytical solutions of some numerical examples are presented to confirm the reliability of the proposed *** derived results are very consistent with the actual solutions to the problems.A graphical representation has been done for the solution of the problems at various fractional-order ***,the solution in series form has the desired rate of convergence and provides the closed-form *** is noted that the procedure can be modified in other directions for fractional order problems.

关键词： Homotopy Perturbation method Shehu transform Newell-Whitehead-Segel Equation Caputo operator

Improving the spaceborne GNSS-R altimetric precision based on the novel multilayer feedforward neural network weighted joint prediction model

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Defence Technology（防务技术） 2024年第2期32卷 271-284页

作者： Yiwen Zhang Wei Zheng Zongqiang Liu Qian Xuesen Laboratory of space Technology China Academy of Space TechnologyBeijing 100094China China Academy of Aerospace Science and Innovation Beijing 100176China State Key Laboratory of space-Ground Integrated Information Technology Beijing Institute of Satellite Information EngineeringBeijing 100194China

Global navigation satellite system-reflection(GNSS-R)sea surface altimetry based on satellite constellation platforms has become a new research direction and inevitable trend,which can meet the altimetric precision at the global scale required for underwater *** present,there are still research gaps for GNSS-R altimetry under this mode,and its altimetric capability cannot be specifically ***,GNSS-R satellite constellations that meet the global altimetry needs to be ***,the matching precision prediction model needs to be established to quantitatively predict the GNSS-R constellation altimetric ***,the GNSS-R constellations altimetric precision under different configuration parameters is calculated,and the mechanism of the influence of orbital altitude,orbital inclination,number of satellites and simulation period on the precision is analyzed,and a new multilayer feedforward neural network weighted joint prediction model is ***,the fit of the prediction model is verified and the performance capability of the model is tested by calculating the R2 value of the model as 0.9972 and the root mean square error(RMSE)as 0.0022,which indicates that the prediction capability of the model is ***,using the novel multilayer feedforward neural network weighted joint prediction model,and considering the research results and realistic costs,it is proposed that when the constellation is set to an orbital altitude of 500 km,orbital inclination of 75and the number of satellites is 6,the altimetry precision can reach 0.0732 m within one year simulation period,which can meet the requirements of underwater navigation precision,and thus can provide a reference basis for subsequent research on spaceborne GNSS-R sea surface altimetry.

关键词： GNSS-R satellite constellations Sea surface altimetric precision Underwater navigation Multilayer feedforward neural network

Multi-path navigation method using solar panel-reflected solar oscillations for Earth satellites

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Science China(Information Sciences) 2024年第7期67卷 327-328页

作者： Yuqing YANG Haonan YANG Xiaolin NING Weiren WU Jiancheng FANG School of Instrument Science & Opto-electronics Engineering Beihang University Lunar Exploration and space Program Center China National Space Administration

Several autonomous navigation methods have been studied to reduce reliance on the ground stations. Geomagnetic navigation, gravity gradient navigation, and celestial navigation using optical sensors are typical autonomous navigation methods. Geomagnetic and gravity gradient navigation have low navigation accuracy (1301 m [1] and 235 m [2], respectively) due to the poor accuracy of the geomagnetic and gravity gradient maps.

关键词： Solar panels

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Fault diagnosis method of link control system for gravitational wave detection

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Journal of Systems Engineering and Electronics 2024年第4期35卷 922-931页

作者： GAO Ai XU Shengnan ZHAO Zichen SHANG Haibin XU Rui School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China Key Laboratory of Autonomous navigation and Control for Deep space Exploration Ministry of Industry and Information TechnologyBeijing 100081China Key Laboratory of Dynamics and Control of Flight Vehicle Ministry of EducationBeijing 100081China

To maintain the stability of the inter-satellite link for gravitational wave detection,an intelligent learning monitoring and fast warning method of the inter-satellite link control system failure is *** from the traditional fault diagnosis optimization algorithms,the fault intelligent learning method pro-posed in this paper is able to quickly identify the faults of inter-satellite link control system despite the existence of strong cou-pling *** constructing a two-layer learning network,the method enables efficient joint diagnosis of fault areas and fault *** simulation results show that the average identification time of the system fault area and fault parameters is 0.27 s,and the fault diagnosis efficiency is improved by 99.8%compared with the traditional algorithm.

关键词： large scale multi-satellite formation gravitational wave detection laser link monitoring fault diagnosis deep learning

Improving path planning efficiency for underwater gravity-aided navigation based on a new depth sorting fast search algorithm

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Defence Technology（防务技术） 2024年第2期32卷 285-296页

作者： Xiaocong Zhou Wei Zheng Zhaowei Li Panlong Wu Yongjin Sun School of Automation Nanjing University of Science and TechnologyNanjing210094China China Academy of Aerospace Science and Innovation Beijing100176China Qian Xuesen Laboratory of space Technology China Academy of Space TechnologyBeijing100094China School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin150001China

This study focuses on the improvement of path planning efficiency for underwater gravity-aided ***,a Depth Sorting Fast Search(DSFS)algorithm was proposed to improve the planning speed of the Quick Rapidly-exploring Random Trees*(Q-RRT*)algorithm.A cost inequality relationship between an ancestor and its descendants was derived,and the ancestors were filtered ***,the underwater gravity-aided navigation path planning system was designed based on the DSFS algorithm,taking into account the fitness,safety,and asymptotic optimality of the routes,according to the gravity suitability distribution of the navigation ***,experimental comparisons of the computing performance of the ChooseParent procedure,the Rewire procedure,and the combination of the two procedures for Q-RRT*and DSFS were conducted under the same planning environment and parameter conditions,*** results showed that the computational efficiency of the DSFS algorithm was improved by about 1.2 times compared with the Q-RRT*algorithm while ensuring correct computational results.

关键词： Depth Sorting Fast Search algorithm Underwater gravity-aided navigation Path planning efficiency Quick Rapidly-exploring Random Trees*(QRRT*)

DiriNet:An Estimation Network for Spectral Response Function and Point Spread Function

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Journal of Beijing Institute of Technology 2024年第4期33卷 287-297页

作者： Ting Hu Siyuan Cheng Chang Liu Beijing Key Laboratory of Computa-tional Intelligence and Intelligent System Faculty of Infor-mation TechnologyBeijing University of TechnologyBei-jing 100124China space Star Technology Co. LtdBeijing 100086China Research Institute of Intelligent Wire-less Communication Network Technology Faculty of Infor-mation TechnologyBeijing University of TechnologyBei-jing 100124China.

Hyper-and multi-spectral image fusion is an important technology to produce hyper-spectral and hyper-resolution images,which always depends on the spectral response function andthe point spread ***,few works have been payed on the estimation of the two degra-dation *** learn the two functions from image pairs to be fused,we propose a Dirichletnetwork,where both functions are properly ***,the spatial response function isconstrained with positivity,while the Dirichlet distribution along with a total variation is imposedon the point spread *** the best of our knowledge,the neural network and the Dirichlet regularization are exclusively investigated,for the first time,to estimate the degradation *** image degradation and fusion experiments demonstrate the effectiveness and superiority of theproposed Dirichlet network.

关键词： Dirichlet network point spread function spectral response function hyper-spectralimage multi-spectral image

On Multi-Granulation Rough Sets with Its Applications

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Computers, Materials & Continua 2024年第4期79卷 1025-1038页

作者： Radwan Abu-Gdairi R.Mareay M.Badr Department of Mathematics Faculty of ScienceZarqa UniversityZarqa13132Jordan Department of Mathematics Faculty of ScienceKafrelsheikh UniversityKafrelsheikh33516Egypt Department of Mathematics Faculty of ScienceNew Valley UniversityEl Kharga72713Egypt

Recently,much interest has been given tomulti-granulation rough sets (MGRS), and various types ofMGRSmodelshave been developed from different viewpoints. In this paper, we introduce two techniques for the classificationof MGRS. Firstly, we generate multi-topologies from multi-relations defined in the universe. Hence, a novelapproximation space is established by leveraging the underlying topological structure. The characteristics of thenewly proposed approximation space are *** introduce an algorithmfor the reduction ***, a new approach for the classification ofMGRS based on neighborhood concepts is introduced. Finally, areal-life application from medical records is introduced via our approach to the classification of MGRS.

关键词： Multi-granulation rough sets data classifications information systems interior operators closure operators approximation structures