5,836 research outputs found

    Techniques for Statistical Data Visualization in GIS

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    This paper proposes an original solution to present statistical data using the facilities provided by the Geographical Information Systems, to improve the means of statistical data figure and distribution inside the territorial profile. The proposed solution allows to represent more statistical data sets, on the same map, using two different methods of data representation: using a color ramp to represent the territorial distribution of an aggregate indicator and a set of charts overlapped to represent the proportions of the variables that form the indicator. On the other hand, there is a way to represent statistical data using 3D cartograms. Thus, in GIS, the users can distinguish the intensity of the studied economic or social phenomenon because of the heights of the administrative units will be different.Geographical Information Systems, Spatial Visualization, ArcObjects, 2D and 3D Cartograms

    Advanced techniques for the storage and use of very large, heterogeneous spatial databases. The representation of geographic knowledge: Toward a universal framework

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    A new approach to building geographic data models that is based on the fundamental characteristics of the data is presented. An overall theoretical framework for representing geographic data is proposed. An example of utilizing this framework in a Geographic Information System (GIS) context by combining artificial intelligence techniques with recent developments in spatial data processing techniques is given. Elements of data representation discussed include hierarchical structure, separation of locational and conceptual views, and the ability to store knowledge at variable levels of completeness and precision

    Techniques for Statistical Data Visualization in GIS

    Get PDF
    This paper proposes an original solution to present statistical data using the facilities provided by the Geographical Information Systems, to improve the means of statistical data figure and distribution inside the territorial profile. The proposed solution allows to represent more statistical data sets, on the same map, using two different methods of data representation: using a color ramp to represent the territorial distribution of an aggregate indicator and a set of charts overlapped to represent the proportions of the variables that form the indicator. On the other hand, there is a way to represent statistical data using 3D cartograms. Thus, in GIS, the users can distinguish the intensity of the studied economic or social phenomenon because of the heights of the administrative units will be different

    Constrained tGAP for generalisation between scales: the case of Dutch topographic data

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    This article presents the results of integrating large- and medium-scale data into a unified data structure. This structure can be used as a single non-redundant representation for the input data, which can be queried at any arbitrary scale between the source scales. The solution is based on the constrained topological Generalized Area Partition (tGAP), which stores the results of a generalization process applied to the large-scale dataset, and is controlled by the objects of the medium-scale dataset, which act as constraints on the large-scale objects. The result contains the accurate geometry of the large-scale objects enriched with the generalization knowledge of the medium-scale data, stored as references in the constraint tGAP structure. The advantage of this constrained approach over the original tGAP is the higher quality of the aggregated maps. The idea was implemented with real topographic datasets from The Netherlands for the large- (1:1000) and medium-scale (1:10,000) data. The approach is expected to be equally valid for any categorical map and for other scales as well

    GIS Processing for Geocoding Described Collection Locations

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    Much useful data is currently not available for use in contemporary geographic information systems because location is provided as descriptive text and not in a recognized coordinate system format. This is particularly true for datasets with significant temporal depth such as museum collections. Development is just beginning on applications that automate the conversion of descriptive text based locations to geographic coordinate values. These applications are a type of geocoding or locator service and require functionality in two domains: natural language processing and geometric calculation. Natural language processing identifies the spatial semantics of the text describing a location and tags the individual text elements according to their spatially descriptive role. This is referred to as geoparsing. Once identified, these tagged text elements can be either converted directly to numeric values or used as pointers to geometric objects that represent geographic features identified in the description. These values and geometries can be employed in a series of functions to determine coordinates for the described location. This is referred to as geoprocessing. Selection of appropriate text elements from a location description and ancillary data as input is critical for successful geocoding. The traverse, one of many types of location description is selected for geocoding development. Specific text elements with spatial meaning are identified and incorporated into an XML format for use as geoprocessing input. Information associated with the location is added to the XML format to maintain database relations and geoprocessing error checking functionality. ESRI’s ArcGIS 8.3 is used as a development environment where geoprocessing functionality is tested for XML elements using ArcObjects and VBA forms

    Economic Geography and the Evolution of Networks

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    An evolutionary perspective on economic geography requires a dynamic understanding of change in networks. This paper explores theories of network evolution for their use in geography and develops the conceptual framework of geographical network trajectories. It specifically assesses how tie selection constitutes the evolutionary process of retention and variation in network structure and how geography affects these mechanisms. Finally, a typology of regional network formations is used to discuss opportunities for innovation in and across regions.evolution, network trajectory, evolutionary economic geography, social network analysis, innovation

    Context Mediation Demonstration of Counter-Terrorism Intelligence (CTI) Integration

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    Examination of intelligence failures prior to the 9/11/01 attacks made clear it that lack of effective information exchange among government agencies hindered the capability of identifying potential threats and preventing terrorist actions. A 2002 National Research Council study noted that “Although there are many private and public databases that contain information potentially relevant to counterterrorism programs, they lack the necessary context definitions (i.e., metadata) and access tools to enable interoperation with other databases and the extraction of meaningful and timely information.”[14] This report clearly recognized the importance of problems that the semantic data integration research community has been studying
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