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Use of GIS technology and cellular automata for modeling multiple socio-economic scenarios of regional spatial development and inter-regional cooperation

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Geo-Spatial Information Science 2023年第1期26卷 71-93页

作者： Igor Musikhin Alexander Karpik department of Photogrammetry and Remote Sensing Siberian State University of Geosystems and TechnologiesNovosibirskRussia department of space and physical geodesy Siberian State University of Geosystems and TechnologiesNovosibirskRussia

The advancement of effective spatial planning to support sustainable development and interregional cooperation has become an issue of serious concern for regional *** planning research helps to identify economic clusters and analyze their changing spatial patterns,which is important for understanding regional economic space dynamics and poten-tial inter-regional *** support decision-makers in the development of efficient plans of spatial development encompassing the identification of the best-suited territories,a combined Geographic Information System(GIS)based approach to interpret qualitatively expressed multiple socio-economic scenarios in quantitative map-based terms of graded suitability,and a formalized approach to the socio-economic evaluation of the territory is *** on GIS technology coupled with integrated cellular automata decision analysis techniques,the study provides a method that performs socio-economic assessment of the study area according to the generated scenarios of regional spatial and socio-economic *** proposed method is applied to Primorsky and Khabarovsk Krais,located in the Russian Far ***-economic scenarios of spatial development initiated by investors and regional authorities were assessed and *** generated socio-economic scenar-ios illustrate how the unified set of spatial and socio-economic variables can be linked and used to gain insights into inter-regional socio-economic and spatial *** application results demonstrate the advantage of the proposed method in identifying the best-suited unit areas for targeted regional development.

关键词： Geographic Information System(GIS) spatial development socioeconomic scenarios interregional cooperation open source software Cellular Automata(CA)

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Exact Computation of the Topology and Geometric Invariants of the Voronoi Diagram of Spheres in 3D

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Journal of Computer Science & Technology 2013年第2期28卷 255-266页

作者： Franois Anton Darka Mioc Marcelo Santos Research Division of geodesy National Space Institute Technical University of Denmark department of geodesy and Geomatics Engineering University of New Brunswick

In this paper, we are addressing the exact the Voronoi diagram of spheres using Wu＇s algorithm. computation of the Delaunay graph （or quasi-triangulation） and Our main contributions are first a methodology for automated derivation of invariants of the Delaunay empty circumsphere predicate for spheres and the Voronoi vertex of four spheres, then the application of this methodology to get all geometrical invariants that intervene in this problem and the exact computation of the Delaunay graph and the Voronoi diagram of spheres. To the best of our knowledge, there does not exist a comprehensive treatment of the exact computation with geometrical invariants of the Delaunay graph and the Voronoi diagram of spheres. Starting from the system of equations defining the zero-dimensional algebraic set of the problem, we are applying Wu＇s algorithm to transform the initial system into an equivalent Wu characteristic （triangular） set. In the corresponding system of algebraic equations, in each polynomial （except the first one）, the variable with higher order from the preceding polynomial has been eliminated （by pseudo-remainder computations） and the last polynomial we obtain is a polynomial of a single variable. By regrouping all the formal coefficients for each monomial in each polynomial, we get polynomials that are invariants for the given problem. We rewrite the original system by replacing the invariant polynomials by new formal coefficients. We repeat the process until all the algebraic relationships （syzygies） between the invariants have been found by applying Wu＇s algorithm on the invariants. Finally, we present an incremental algorithm for the construction of Voronoi diagrams and Delaunay graphs of spheres in 3D and its application to geodesy.

关键词： Voronoi diagram of spheres Delaunay graph of spheres Wu's method invariant characteristic set

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Simulation of the Internal Wave of a Subsurface Vehicle in a Two-Layer Stratified Fluid

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Journal of Ocean University of China 2020年第6期19卷 1255-1264页

作者： AKBARNEJAD BAIE Mohammad PIROOZNIA Mahmood AKBARINASAB Mohammad department of physical Oceanography Science and Research BranchIslamic Azad UniversityTehran ***Iran department of geodesy K.N.Toosi University of TechnologyTehran ***Iran department of physical Oceanography University of MazandaranBabol ***Iran

Internal waves are one of the various phenomena that occur at sea,and they affect acoustic equipment and sea density measurement *** this study,internal waves are simulated using computational fluid dynamics method in the presence of a submarine in a pre-stratified *** scenarios were implemented by Froude number changes and submersible velocity by using the Navier-Stokes k-εturbulence *** indicate that the realizable k-εturbulence model gives better results than the RNG k-εmodel and the internal waves flow in this model are well represented,which increases the wavelength of the internal waves by increasing the Froude number and floating velocity,while the internal angle of the Kelvin waves is *** also observe that increasing the floating velocity causes the turbulent velocity contours to increase due to the drag coefficient and its relationship with the Reynolds *** Reynolds number increases with the increasing velocity of the float *** results indicate the efficiency of this method in the discovery of subsurface objects.

关键词： internal waves numerical simulation computational fluid dynamics turbulence models

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A Comparative study on generalized Manev potential and Newtonian potential in perturbed restricted four-body problem

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Applied Mathematics(A Journal of Chinese Universities) 2023年第1期38卷 44-57页

作者： Jagadish Singh Omale Solomon Okpanachi department of Mathematics Faculty of Physical SciencesAhmadu Bello UniversityZariaNigeria department of Engineering and space Systems National Space Research and Development Agency(NASRDA)Obasanjo Space CentreAbujaNigeria

The motion of a test particle within the context of the restricted four-body problem(R4BP)driven by a new kind of potential,called the generalized Manev potential,with perturbations in the Coriolis and centrifugal forces is considered in this *** system possesses eight libration points which were distributed on its plane of motion in different manner from those of the usual Newtonian *** the case of the perturbed R4BP under Newtonian potential,where two of these librations are stable,all of them are unstable in linear sense under Manev *** found that a gradual perturbation in the centrifugal force causes the trajectories of motion to drift inward but the Coriolis force was proven to have no effect on the location of the libration points of the *** first order Lyapunov characteristic exponents,the dynamical behavior of the system is found *** experimented with a high velocity stellar system(82 ***)to establish the applicability of the model in astrophysics.

关键词： generalized Manev potential Coriolis force centrifugal force stability chaotic 82 G.Eridani

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Impact of radiation pressure and circumstellar dust on motion of a test particle in Manev’s field

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Astrodynamics 2021年第2期5卷 77-89页

作者： Jagadish Singh Solomon Okpanachi Omale Lawrence O.Inumoh Felix Ale department of Mathematics Faculty of Physical SciencesAhmadu Bello UniversityZariaNigeria Engineering and space Systems department National Space Research and Development Agency(NASRDA)Obasanjo Space CentreAbujaNigeria

In this paper,we present a study on the impact of radiation pressure and circumstellar dust on the motion of a test particle in the framework of the restricted four-body problem under the Manev’s *** show that the distribution of equilibrium points on the plane of motion is slightly different from that of the classical Newtonian *** the aid of the Lyapunov characteristic exponents,we show that the system is sensitive to changes in initial conditions;hence,the orbit of the system is found to be chaotic in the phase space for the given initial ***,a numerical application of this model to a stellar system(Gliese 667C)is considered,which validates the dependence of the equilibrium points on the mass *** show that the non-collinear equilibrium points of this stellar system are distributed symmetrically about the x-axis,and five of them are linearly *** basins of attraction of the system show that the equilibrium points have irregular boundaries,and we use the energy integral and the Manev parameter to illustrate the zero-velocity curves showing the permissible region of motion of the test particle with respect to the Jacobi constant.

关键词： Manev potential circumstellar dust Lyapunov characteristic exponents(LCEs) stability chaos basins of attraction

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Flux emergence in the solar active region NOAA 11158: the evolution of net current

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Research in Astronomy and Astrophysics 2015年第9期15卷 1547-1558页

作者： Panditi Vemareddy Parameswaran Venkatakrishnan Solipuram Karthikreddy Indian Institute of Astrophysics Udaipur Solar Observatory Physical Research Laboratory department of Earth and space Sciences Indian Institute of Space Science and Technology

We present a detailed investigation of the evolution of observed net vertical current using a time series of vector magnetograms of the active region （AR） NOAA 11158 obtained from the Helioseismic and Magnetic Imager. We also discuss the relation of net current to the observed eruptive events. The AR evolved from the βγ to βγδ3 configuration over a period of six days. The AR had two sub-regions of activity with opposite chirality： one dominated by sunspot rotation producing a strong CME, and the other showing large shear motions producing a strong flare. The net current in each polarity over the CME producing sub-region increased to a maximum and then decreased when the sunspots were separated. The time profile of net current in this sub-region followed the time profile of the rotation rate of the south-polarity sunspot in the same sub-region. The net current in the flaring sub-region showed a sudden increase at the time of the strong flare and remained unchanged until the end of the observation, while the sunspots maintained their close proximity. The systematic evo- lution of the observed net current is seen to follow the time evolution of total length of strongly sheared polarity inversion lines in both of the sub-regions. The observed photospheric net current could be explained as an inevitable product of the emergence of a twisted flux rope, from a higher pressure confinement below the photosphere into the lower pressure environment of the photosphere.

关键词： Sun:active regions -- magnetic fields -- activity -- coronal mass ejec-tions -- non-potentiality -- electric current

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ETH-GQS: An estimation of geoid-to-quasigeoid separation over Ethiopia

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geodesy and Geodynamics 2022年第1期13卷 31-37页

作者： Ephrem Y.Belay Walyeldeen Godah Malgorzata Szelachowska Robert Tenzer Ethiopian space Science and Technology Institute Addis Ababa Ethiopia Centre of geodesy and Geodynamics Institute of Geodesy and Cartography(IGiK)WarsawPoland department of Land Surveying and Geo-Informatics Hong Kong Polytechnic UniversityHong KongChina

The determination of accurate orthometric or normal heights remains one of the main challenges for the geodetic community in *** heights are required for geodetic and geodynamic scientific research as well as for extensive engineering *** main objective of this study is to estimate the geoid-to-quasi geoid separation(GQS)in Ethiopia(ETH-GQS).Such separation would be required for the conversion between geoid and quasigeoid models,which is mandatory for the determination of accurate geodetic heights in mountain *** airborne free-air gravity anomalies and the topo-graphic information retrieved from the SRTM3(Shuttle Radar Topography Mission of a spatial resolution 3 arc-second)digital elevation model were used to compute the ETH-GQS model according to the Sjoberg's strict formula for the geoid-to-quasigeoid *** ETH-GQS was then validated using GNSS-levelling data as well as geoid heights determined from different Global Geopotential Models(GGMs),namely the EGM2008,EIGEN-6C4 and *** results reveal that the standard deviation of differences between the geoid heights obtained from the EIGEN-6C4 model and the geometric geoid heights obtained from GNSS-levelling data were improved by~75%(***~24 to~6 cm)when considering GQS values obtained from the ETH-GQS.

关键词： Geoid-to-quasigeoid separation GNSS-Levelling Ethiopian vertical control network Orthometric and normal heights Airborne gravity data

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Investigation of the Co-seismic Gravity Field Variations Caused by the 2004 Sumatra-Andaman Earthquake Using Monthly GRACE Data

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Journal of Earth Science 2011年第2期22卷 280-291页

作者：李进申文斌 department of Geophysics School of Geodesy and GeomaticsWuhan University Key Laboratory of Geodynamic geodesy Chinese Academy of Sciences department of Geophysics School of Geodesy and Geomatics/Key Laboratory of Geospace Environment and GeodesyWuhan University State Key Laboratory of Information Engineering in Surveying Mapping and Remote Sensing

Gravity Recovery and Climate Experiment（GRACE） observations have been used to de-tect the co-seismic and post-seismic gravity field variations due to the Mw=9.3 Sumatra-Andaman earthquake that occurred on December 26,*** article focuses on investigating some gravita-tional effects caused by this huge *** computed the geoid height changes,the equivalent water height（EWH） changes,and the gravity changes using the GRACE Level-2 monthly spherical harmonic（SH） solutions released by University of Texas Center for space Research（UTCSR）.The GRACE results agree well with the prediction by a dislocation model and are consistent with the results obtained by some previous *** particular,we calculated the three components of the gravity gradient variations and found that they can recover the seismic-related signature more sensitively due to a certain degree of amplification of the signals.A positive-negative-positive mode predominates in the spatial distribution of the horizontal components of the gravity gradient variations,which is possibly attributed to the anomalies in the crustal density distribution caused by the uplift-subduction effect of the dip-slip ***,the latitude components of the gravity gradient changes show strong suppression of the north-south stripes,which is due to the along-orbit measurements of the two GRACE *** conclude that the posi-tive-negative-positive mode in latitude gravity gradient changes would be a more sensitive fea-ture to detect the deformations of some major dip-slip earthquakes by GRACE data.

关键词： satellite geodesy time-variablegravity gravity gradient change dislocation model Sumatra-Andaman earthquake.

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Precise orbit determination for LEO satellites:single-receiver ambiguity resolution using GREAT products

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Geo-Spatial Information Science 2022年第1期25卷 63-73页

作者： Xingxing Li Yujie Qin Keke Zhang Jiaqi Wu Wei Zhang Qian Zhang Hongmin Zhang School of geodesy and Geomatics Wuhan UniversityWuhanHubeiChina department of geodesy and Remote Sensing of the German Research Centre for Geosciences(GFZ) PotsdamGermany

In recent years,the large Low Earth Orbit(LEO)constellations have become a hot topic due to their great potential to improve the Global Navigation Satellite Systems(GNSS)positioning *** of the important focus is how to obtain the accurate and reliable orbits for these constellations with dozens of LEO *** GNSS-based Precise Orbit Determination(POD)will be exclusively performed to achieve this goal,where the Integer Ambiguity Resolution(IAR)plays a key role in acquiring high-quality *** this study,we present a comprehensive analysis of the benefit of the single-receiver IAR in LEO POD and discuss its implication for the future LEO *** perform ambiguity-fixed LEO POD for four typical missions,including Gravity Recovery and Climate Experiment(GRACE)Follow-On(GRACE-FO),Swarm,Jason-3 and Sentinel-3,using the Uncalibrated Phase Delay(UPD)products generated by our GREAT(GNSS+REsearch,Application and Teaching)*** results show that the ambiguity fixing processing can significantly improve the accuracy of LEO *** are negligible differences between our UPD-based ambiguity-fixed orbits and those based on the Observable Signal Bias(OSB)and Integer Recovery Clock(IRC)products,indicating the good-quality of UPD products we *** to the float solution,the fixed solution presents a better consistency with the external precise science orbits and the largest accuracy improvement of 5 mm is achieved for GRACE-FO ***,the benefit can be observed in laser ranging residuals as well,with a Standard Deviation(STD)reduction of 3–4 mm on average for the fixed *** from the absolute orbits,the relative accuracy of the space baseline is also improved by 20–30%in the fixed *** result demonstrates the superior performance of the ambiguity-fixed LEO POD,which appears as a particularly promising technique for POD of future LEO constellations.

关键词： Precise orbit determination single-receiver ambiguity resolution onboard GPS observation LEO

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Collision effects on propagation characteristics of electromagnetic waves in a sub-wavelength plasma slab of partially ionized dense plasmas

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Plasma Science and Technology 2018年第1期20卷 101-107页

作者：李博文王志斌聂秋月王晓钢孔繁荣王振宇 department of Physics Harbin Institute of Technology Laboratory for space Environment and physical Sciences Harbin Institute of Technology School of Electrical Engineering and Automation Harbin Institute of Technology

Intensive collisions between electrons and neutral particles in partially ionized plasmas generated in atmospheric/sub-atmospheric pressure environments can sufficiently affect the propagation characteristics of electromagnetic waves, particularly in the sub-wavelength regime. To investigate the collisional effect in such plasmas, we introduce a simplified plasma slab model with a thickness on the order of the wavelength of the incident electromagnetic wave. The scattering matrix method （SMM） is applied to solve the wave equation in the plasma slab with significant nonuniformity. Results show that the collisions between the electrons and the neutral particles, as well as the incident angle and the plasma thickness, can disturb the transmission and reduce reflection significantly.

关键词： plasmasonic sheath electromagnetic wave scattering matrix method

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