Collision detection is an important component in simulation applications which are based on virtual geographic information system(VGIS).In this paper,an effective collision detection algorithm for multiple objects in ...Collision detection is an important component in simulation applications which are based on virtual geographic information system(VGIS).In this paper,an effective collision detection algorithm for multiple objects in VGIS,VGISCOLLIDE,is presented.The algorithm firstly integrates existing quadtree,which is the global hierarchical structure of VGIS,with axis-aligned bounding box of object to perform the broad-phase of collision detection.After that,exact collision detection between two objects which have passed the broad-phase of collision detection is performed.The algorithm makes no assumption about input primitives or object’s motion and is directly applicable to all triangulated models.It can be applicable to both rigid and deformable objects without preprocessing.The performance of the algorithm has been demonstrated in several environments consisting of a high number of objects with hundreds of thousands of triangles.展开更多
With the proposition of the Digital Earth(DE)concept,Virtual Geographic Information System(VGIS)has started to play the role of a Digital Earth prototype system.Many core problems involved in VGIS,such as out-of-core ...With the proposition of the Digital Earth(DE)concept,Virtual Geographic Information System(VGIS)has started to play the role of a Digital Earth prototype system.Many core problems involved in VGIS,such as out-of-core management and interactive rendering of very large scale terrain and image data,have been well studied in the past decades.However,the jitter problem,a common problem in VGIS that often causes annoying visual artefacts and deteriorates the output image quality,draws little attention.In this paper,after an intensive analysis of the jitter problem,a comprehensive framework is proposed to address such a problem while accounting for the characteristics of different data types in VGIS,such as terrain or ocean mesh data,vector data and 3-D model data.Specifically,this framework provides an improved dynamic local coordinate system(DLCS)method for terrain or ocean mesh data.For vector data,the framework provides a simple and effective multiple local coordinate systems(MLCS)method.The framework provides a MLCS method for 3-D model data making full use of the existing local coordinate system of the model.The advantages of the proposed methods over current approaches are analysed and highlighted through case studies involving large GIS datasets.展开更多
In recent years,Volunteered Geographic Information(VGI)has emerged as a crucial source of mapping data,contributed by users through crowdsourcing platforms such as OpenStreetMap.This paper presents a novel approach th...In recent years,Volunteered Geographic Information(VGI)has emerged as a crucial source of mapping data,contributed by users through crowdsourcing platforms such as OpenStreetMap.This paper presents a novel approach that Integrates Large Language Models(LLMs)into a fully automated mapping workflow,utilizing VGI data.The process leverages Prompt Engineering,which involves designing and optimizing input instructions to ensure the LLM produces desired mapping outputs.By constructing precise and detailed prompts,LLM agents are able to accurately interpret mapping requirements,and autonomously extract,analyze,and process VGI geospatial data.They dynamically interact with mapping tools to automate the entire mapping process—from data acquisition to map generation.This approach significantly streamlines the creation of high-quality mapping outputs,reducing the time and resources typically required for such tasks.Moreover,the system lowers the barrier for non-expert users,enabling them to generate accurate maps without extensive technical expertise.Through various case studies,we demonstrate the LLM application across different mapping scenarios,highlighting its potential to enhance the efficiency,accuracy,and accessibility of map production.The results suggest that LLM-powered mapping systems can not only optimize VGI data processing but also expand the usability of ubiquitous mapping across diverse fields,including urban planning and infrastructure development.展开更多
Assessing regional economic development is key for advancing towards the Sustainable Development Goals and ensuring sustainable societal progress.Traditional evaluation methods focus on basic economic metrics like pop...Assessing regional economic development is key for advancing towards the Sustainable Development Goals and ensuring sustainable societal progress.Traditional evaluation methods focus on basic economic metrics like population and capital,which may not fully reflect the complexities of economic activities.Nighttime light(NTL)has been validated as an alternative indicator for regional economic development,yet limitations persist in its evaluation.This study integrates OpenStreetMap(OSM)data and NTL data,providing a novel data integration approach for evaluating economic development.The study uses mainland of China as a case,applying ordinary least squares(OLS)and geographically weighted regression(GWR)to evaluate OSM and NTL data across provincial,municipal,and county levels.It compares OSM,NTL,and their combined use,providing key empirical insights for enhancing data fusion models.The study results reveal:(1)NTL data is more accurate for provincial-level economic activity,while OSM data excels at the county level.(2)GWR demonstrates superior capability over OLS in revealing the spatial dynamics of economic development across scales.(3)Through the integration of both datasets,it is observed that,compared to single-data modeling,the performance is enhanced at the city scale and county scale.The study demonstrates that combining OSM and NTL data effectively assesses economic development in both developed and underdeveloped areas at provincial,municipal,and county levels.The study offers a straightforward and efficient approach to data integration.The findings offer new research perspectives and scientific support for sustainable regional economic growth,particularly valuable in data-scarce,underdeveloped areas.展开更多
基金supported by a Grant from the National High Technology Research and Development Program of China(863 Programme)(No.2009AA12Z331).
文摘Collision detection is an important component in simulation applications which are based on virtual geographic information system(VGIS).In this paper,an effective collision detection algorithm for multiple objects in VGIS,VGISCOLLIDE,is presented.The algorithm firstly integrates existing quadtree,which is the global hierarchical structure of VGIS,with axis-aligned bounding box of object to perform the broad-phase of collision detection.After that,exact collision detection between two objects which have passed the broad-phase of collision detection is performed.The algorithm makes no assumption about input primitives or object’s motion and is directly applicable to all triangulated models.It can be applicable to both rigid and deformable objects without preprocessing.The performance of the algorithm has been demonstrated in several environments consisting of a high number of objects with hundreds of thousands of triangles.
基金by the National High Technology Research and Development Program of China(863 Program)(No.2009AA12Z331)and the National Natural Science Foundation of China(No.60972052)supported by the Young Researcher Grant of National Astronomical Observatories,Chinese Academy of Sciences.
文摘With the proposition of the Digital Earth(DE)concept,Virtual Geographic Information System(VGIS)has started to play the role of a Digital Earth prototype system.Many core problems involved in VGIS,such as out-of-core management and interactive rendering of very large scale terrain and image data,have been well studied in the past decades.However,the jitter problem,a common problem in VGIS that often causes annoying visual artefacts and deteriorates the output image quality,draws little attention.In this paper,after an intensive analysis of the jitter problem,a comprehensive framework is proposed to address such a problem while accounting for the characteristics of different data types in VGIS,such as terrain or ocean mesh data,vector data and 3-D model data.Specifically,this framework provides an improved dynamic local coordinate system(DLCS)method for terrain or ocean mesh data.For vector data,the framework provides a simple and effective multiple local coordinate systems(MLCS)method.The framework provides a MLCS method for 3-D model data making full use of the existing local coordinate system of the model.The advantages of the proposed methods over current approaches are analysed and highlighted through case studies involving large GIS datasets.
基金National Natural Science Foundation of china(No.42371446)Natural Science Foundatiorof Hubei Province(No.2024AFD412)Fundamental Research Funds for National Universities,China University of Geosciences(Wuhan)(No.2024XLA17).
文摘In recent years,Volunteered Geographic Information(VGI)has emerged as a crucial source of mapping data,contributed by users through crowdsourcing platforms such as OpenStreetMap.This paper presents a novel approach that Integrates Large Language Models(LLMs)into a fully automated mapping workflow,utilizing VGI data.The process leverages Prompt Engineering,which involves designing and optimizing input instructions to ensure the LLM produces desired mapping outputs.By constructing precise and detailed prompts,LLM agents are able to accurately interpret mapping requirements,and autonomously extract,analyze,and process VGI geospatial data.They dynamically interact with mapping tools to automate the entire mapping process—from data acquisition to map generation.This approach significantly streamlines the creation of high-quality mapping outputs,reducing the time and resources typically required for such tasks.Moreover,the system lowers the barrier for non-expert users,enabling them to generate accurate maps without extensive technical expertise.Through various case studies,we demonstrate the LLM application across different mapping scenarios,highlighting its potential to enhance the efficiency,accuracy,and accessibility of map production.The results suggest that LLM-powered mapping systems can not only optimize VGI data processing but also expand the usability of ubiquitous mapping across diverse fields,including urban planning and infrastructure development.
基金funded by The Third Comprehensive Scientific Investigation in Xinjiang(Grant No.2021xjkk1001)Program of National Social Science Foundation of China(Grant No.22BJL061)+1 种基金Major Project of Xinjiang Social Science Foundation(Grant No.21AZD008)The National Natural Science Foundation of China(Grant No.41461035).
文摘Assessing regional economic development is key for advancing towards the Sustainable Development Goals and ensuring sustainable societal progress.Traditional evaluation methods focus on basic economic metrics like population and capital,which may not fully reflect the complexities of economic activities.Nighttime light(NTL)has been validated as an alternative indicator for regional economic development,yet limitations persist in its evaluation.This study integrates OpenStreetMap(OSM)data and NTL data,providing a novel data integration approach for evaluating economic development.The study uses mainland of China as a case,applying ordinary least squares(OLS)and geographically weighted regression(GWR)to evaluate OSM and NTL data across provincial,municipal,and county levels.It compares OSM,NTL,and their combined use,providing key empirical insights for enhancing data fusion models.The study results reveal:(1)NTL data is more accurate for provincial-level economic activity,while OSM data excels at the county level.(2)GWR demonstrates superior capability over OLS in revealing the spatial dynamics of economic development across scales.(3)Through the integration of both datasets,it is observed that,compared to single-data modeling,the performance is enhanced at the city scale and county scale.The study demonstrates that combining OSM and NTL data effectively assesses economic development in both developed and underdeveloped areas at provincial,municipal,and county levels.The study offers a straightforward and efficient approach to data integration.The findings offer new research perspectives and scientific support for sustainable regional economic growth,particularly valuable in data-scarce,underdeveloped areas.
