212,900 research outputs found
Monitoring land use changes using geo-information : possibilities, methods and adapted techniques
Monitoring land use with geographical databases is widely used in decision-making. This report presents the possibilities, methods and adapted techniques using geo-information in monitoring land use changes. The municipality of Soest was chosen as study area and three national land use databases, viz. Top10Vector, CBS land use statistics and LGN, were used. The restrictions of geo-information for monitoring land use changes are indicated. New methods and adapted techniques improve the monitoring result considerably. Providers of geo-information, however, should coordinate on update frequencies, semantic content and spatial resolution to allow better possibilities of monitoring land use by combining data sets
Spatial database implementation of fuzzy region connection calculus for analysing the relationship of diseases
Analyzing huge amounts of spatial data plays an important role in many
emerging analysis and decision-making domains such as healthcare, urban
planning, agriculture and so on. For extracting meaningful knowledge from
geographical data, the relationships between spatial data objects need to be
analyzed. An important class of such relationships are topological relations
like the connectedness or overlap between regions. While real-world
geographical regions such as lakes or forests do not have exact boundaries and
are fuzzy, most of the existing analysis methods neglect this inherent feature
of topological relations. In this paper, we propose a method for handling the
topological relations in spatial databases based on fuzzy region connection
calculus (RCC). The proposed method is implemented in PostGIS spatial database
and evaluated in analyzing the relationship of diseases as an important
application domain. We also used our fuzzy RCC implementation for fuzzification
of the skyline operator in spatial databases. The results of the evaluation
show that our method provides a more realistic view of spatial relationships
and gives more flexibility to the data analyst to extract meaningful and
accurate results in comparison with the existing methods.Comment: ICEE201
Geospatial distribution and population substructure of subgroups of US ethnic minorities: implications for perpetuation of health disparities and paucity of precision medicine
Substructure due to familial-associated divisions exists in all large populations. Geographical heterogeneity in US ethnic minorities is a function of historical, social, political, and economic factors overlaying regional geographical biodiversity. Using geospatial, historical, demographic, genetic, and epidemiological databases, we identify 40 US microethnic isolates across the US, the âminorities within ethnic minoritiesâ and locate their geospatial distributions within the US. Key components of the environment relevant to health disparities are identified and elaborated in terms of their impact on genomics. US ethnic minority microethnic isolates often have distinct genetic and social histories from the US ethnic majority that put these isolates at a disadvantage in the quest for access to relevant, precision medicine because of the magnitude of imbedded (North Atlantic Euro-American) bias in the existing databases. However, these microethnic isolates are also at a disadvantage when simply aggregated with their nearest ethnic minority macroethnic group (e.g., generic African American). The use of geospatial and ethnographic analyses has the potential to accelerate the accurate identification of heretofore disadvantaged subgroups of ethnic minority groups, bringing them into the mainstream of genomic diversity studies and healthcare acces
Exploiting microvariation: How to make the best of your incomplete data
n this article we discuss the use of big corpuses or databases as a first step for qualitative analysis of linguistic data. We concentrate on ASIt, the Syntactic Atlas of Italy, and take into consideration the different types of dialectal data that can be collected from similar corpora and databases. We analyze all the methodological problems derived from the necessary compromise between the strict requirements imposed by a scientific inquiry and the management of big amounts of data. As a possible solution, we propose that the type of variation is per se a tool to derive meaningful generalizations. To implement this idea, we examine three different types of variation patterns that can be used in the study of morpho-syntax: the geographical distribution of properties (and their total or partial overlapping, or complementary distribution), the so-called leopard spots variation, and the lexical variation index, which can be used to determine the internal complexity of functional items
Using a GIS for Real Estate Market Analysis: The Problem of Spatially Aggregated Data
Many databases used for real estate market analysis are not available at the address level. For example, information on employment and unemployment may be available only for labor market areas; and Census data is typically tabulated for blocks or higher levels of spatial aggregation. A Geographic Information System (GIS) associates these spatially aggregated data with the geographical center of the area. This poses special problems when we use a GIS to evaluate linkages between supply and demand. This article presents some solutions to this problem; methods that are relatively easy to implement on a GIS are emphasized. A GIS can be used to calculate a theoretical average travel distance to the population in the geographical area. We propose ways to determine when these theoretical distances are inadequate approximations; and we provide alternatives for these situations.
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