Traditional geographic information system models for map representation use superposition of layers to model physical reality,neglecting the integrity of the environment and limiting the ability to express interaction...Traditional geographic information system models for map representation use superposition of layers to model physical reality,neglecting the integrity of the environment and limiting the ability to express interactions between features in complex phenomenon.This results in limitations regarding dynamic simulation and geographic causality reasoning.In this paper,we extend the framework of the geographic scene by formalizing the relationship between geographic processes and events to construct a dynamic data model:the process-event-centred dynamic data model.The key element of this data model is relationships between processes,events,and states of the natural or man-made phenomenon of interest.The identified relationships can be translated into a network of hierarchical,developmental,and causal graphs and realized in the Neo4j graph database.The implementation in the graph database supports spatio-temporal reasoning in geographic scenes and achieves an organizational framework for simulating spatio-temporal dynamics and complex calculations.The example of a 2019 mega-typhoon process is used to demonstrate the introduced process-event-centred model and its implementation in the graph database.A series of queries to the graph database show the capabilities of the data model for spatial reasoning and dynamic modeling.展开更多
A novel approach is introduced for the detection of the location and direction of traffic congestion using GPS data from taxis.This approach uses a dynamic model that conceptualizes events,processes,and states.The sta...A novel approach is introduced for the detection of the location and direction of traffic congestion using GPS data from taxis.This approach uses a dynamic model that conceptualizes events,processes,and states.The states are the locations of the taxis,the processes are the motion of taxis,and the events are congestion.The model is implemented as a graph database,which represents the relationships between states,events,processes,and things(such as points of interest and road grid).Algorithms for constructing and updating the relationships and taxi behaviors dynamic retrieval method in Neo4j are presented and are used to demonstrate the capabilities in dynamic expression and reasoning.An implementation of Shanghai in 2015finally demonstrated the ability of congestion direction detection and the cause searching of traffic congestion.展开更多
Interpreting spatial data to derive information is a core task in the field of Geographic Information Science and Technology.A logical step following the collection of data in online repositories is to provide geoproc...Interpreting spatial data to derive information is a core task in the field of Geographic Information Science and Technology.A logical step following the collection of data in online repositories is to provide geoprocessing technology for analysing data online.Online geoprocessing technology can be employed for providing a specified set of tools in a theme-specific platform,documenting a model or workflow and making it widely available,automating recurring tasks or offering simple tools to a large user group.This systematic analysis of literature evaluates how much available online geoprocessing tools are being used for answering questions in specific application contexts.An initial set of articles is derived from a keyword-based search in the database Scopus.This set of articles is manually filtered to identify applications of online geoprocessing tools.The analysis of application-related articles shows that virtually all applications require further development of tools.Experts outside the spatial information science field are still underrepresented regarding the use of this technology.The required adaptation of technology for user tasks is identified as major barrier for the wide use of online geoprocessing.Further research needs to assess user tasks and how online geoprocessing can provide the required functions in a useroriented manner.展开更多
Online geoprocessing,the provision and the use of spatial analysis functionality on the Web,is a powerful technological approach to fully realise the vision of a Digital Earth.The Digital Earth objectives include the ...Online geoprocessing,the provision and the use of spatial analysis functionality on the Web,is a powerful technological approach to fully realise the vision of a Digital Earth.The Digital Earth objectives include the integration of information across diverse domains in order to address environmental and societal challenges as well as the interactive and exploratory provision of information to a wide audience(Craglia et al.2008).展开更多
基金supported by National Natural Science Foundation of China[grant number 41631175,42077003].
文摘Traditional geographic information system models for map representation use superposition of layers to model physical reality,neglecting the integrity of the environment and limiting the ability to express interactions between features in complex phenomenon.This results in limitations regarding dynamic simulation and geographic causality reasoning.In this paper,we extend the framework of the geographic scene by formalizing the relationship between geographic processes and events to construct a dynamic data model:the process-event-centred dynamic data model.The key element of this data model is relationships between processes,events,and states of the natural or man-made phenomenon of interest.The identified relationships can be translated into a network of hierarchical,developmental,and causal graphs and realized in the Neo4j graph database.The implementation in the graph database supports spatio-temporal reasoning in geographic scenes and achieves an organizational framework for simulating spatio-temporal dynamics and complex calculations.The example of a 2019 mega-typhoon process is used to demonstrate the introduced process-event-centred model and its implementation in the graph database.A series of queries to the graph database show the capabilities of the data model for spatial reasoning and dynamic modeling.
基金supported by National Natural Science Foundation of China[grant number 42071364 and 41631175].
文摘A novel approach is introduced for the detection of the location and direction of traffic congestion using GPS data from taxis.This approach uses a dynamic model that conceptualizes events,processes,and states.The states are the locations of the taxis,the processes are the motion of taxis,and the events are congestion.The model is implemented as a graph database,which represents the relationships between states,events,processes,and things(such as points of interest and road grid).Algorithms for constructing and updating the relationships and taxi behaviors dynamic retrieval method in Neo4j are presented and are used to demonstrate the capabilities in dynamic expression and reasoning.An implementation of Shanghai in 2015finally demonstrated the ability of congestion direction detection and the cause searching of traffic congestion.
基金The author thanks anonymous reviewers and colleagues from the University of Salzburg for critical comments and feedback as well as the Department of Geoinformatics of the University of Salzburg for supporting the open access publication of this article.
文摘Interpreting spatial data to derive information is a core task in the field of Geographic Information Science and Technology.A logical step following the collection of data in online repositories is to provide geoprocessing technology for analysing data online.Online geoprocessing technology can be employed for providing a specified set of tools in a theme-specific platform,documenting a model or workflow and making it widely available,automating recurring tasks or offering simple tools to a large user group.This systematic analysis of literature evaluates how much available online geoprocessing tools are being used for answering questions in specific application contexts.An initial set of articles is derived from a keyword-based search in the database Scopus.This set of articles is manually filtered to identify applications of online geoprocessing tools.The analysis of application-related articles shows that virtually all applications require further development of tools.Experts outside the spatial information science field are still underrepresented regarding the use of this technology.The required adaptation of technology for user tasks is identified as major barrier for the wide use of online geoprocessing.Further research needs to assess user tasks and how online geoprocessing can provide the required functions in a useroriented manner.
文摘Online geoprocessing,the provision and the use of spatial analysis functionality on the Web,is a powerful technological approach to fully realise the vision of a Digital Earth.The Digital Earth objectives include the integration of information across diverse domains in order to address environmental and societal challenges as well as the interactive and exploratory provision of information to a wide audience(Craglia et al.2008).
