207 research outputs found

    Methods to Measure Map Readability

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    Creation of maps in real-time web services introduces challenges concerning map readability. Therefore we must introduce analytical measures controlling the readability. The aim of this study is to develop and evaluate analytical readability measures with the help of user tests

    The stock-flow model of spatial data infrastructure development refined by fuzzy logic

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    The system dynamics technique has been demonstrated to be a proper method by which to model and simulate the development of spatial data infrastructures (SDI). An SDI is a collaborative effort to manage and share spatial data at different political and administrative levels. It is comprised of various dynamically interacting quantitative and qualitative (linguistic) variables. To incorporate linguistic variables and their joint effects in an SDI-development model more effectively, we suggest employing fuzzy logic. Not all fuzzy models are able to model the dynamic behavior of SDIs properly. Therefore, this paper aims to investigate different fuzzy models and their suitability for modeling SDIs. To that end, two inference and two defuzzification methods were used for the fuzzification of the joint effect of two variables in an existing SDI model. The results show that the Average–Average inference and Center of Area defuzzification can better model the dynamics of SDI development

    Automatic integration of spatial data in viewing services

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    Geoportals are increasingly used for searching viewing and downloading spatial data. This study concerns methods to improve the visual presentation in viewing services. When spatial data in a viewing service are taken from more than one source there are often syntactic semantic topological and geometrical conflicts that prevent maps being fully consistent. In this study we extend a standard view service with methods to solve these conflicts. The methods are based on: (1) semantic labels of data in basic services (2) a rule-base in the portal layer and (3) integration methods in the portal layer. To evaluate the methodology we use a case study for adding historical borders on top of a base-map. The results show that the borders are overlaid on top of the map without conflicts and that a consistent map is generated automatically as an output. The methodology can be generalized to add other types of data on top of a base-map

    Are associations between socio-economic characteristics and exposure to air pollution a question of study area size? An example from Scania, Sweden

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    BACKGROUND: Numerous studies have shown that exposure to air pollutants in the area of residence and the socio-economic status of an individual may be related. Therefore, when conducting an epidemiological study on the health effect of air pollution, socio-economy may act as a confounding factor. In this paper we examine to what extent socio-economic status and concentrations of NO(2 )in the county/region of Scania, southern Sweden, are associated and if such associations between these factors differ when studying them at county or city level. To perform this study we used high-resolution census data and modelled the annual exposure to NO(2 )using an emission database, a dispersion modelling program and a geographical information system (GIS). RESULTS: The results from this study confirm that socio-economic status and the levels of NO(2 )in the area of residence are associated in some cities. The associations vary considerably between cities within the same county (Scania). Even for cities of similar sizes and population bases the associations observed are different. Studying the cities together or separately yields contradictory results, especially when education is used as a socio-economic indicator. CONCLUSION: Four conclusions have been drawn from the results of this study. 1) Adjusting for socio-economy is important when investigating the health effects of air pollution. 2) The county of Scania seems to be heterogeneous regarding the association between air pollution and socio-economy. 3) The relationship between air pollution and socio-economy differs in the five cities included in our study, depending on whether they are analysed separately or together. It is therefore inadvisable to determine and analyse associations between socio-economy and exposure to air pollutants on county level. This study indicates that the size and choice of study area is of great importance. 4) The selection of socio-economic indices (in this study: country of birth and education level) is important

    Automated Enrichment of Routing Instructions

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    Commonly used navigation instructions are based on metric turn descriptions (e.g. “turn left onto Nienburger Straße in 100 m”). For the user it is easy to follow the route, but later it is typically hard to remember how s/he got there. Orientation is based on remarkable objects or locations called landmarks. They are then linked and combined to so-called survey knowledge in the psychological model of a cognitive map. Some of today’s navigation systems also contain landmarks – they are, however, only used at decision points of the route. The goal of this research is to enhance the user's own sense of orientation by enriching common routing instructions with relational hints to landmarks. First, potential landmark objects are defined, extracted from OpenStreetMap and assigned an importance weight. The landmarks are then used to enrich the given routes: In the enrichment process, the influence of the landmarks is modeled as a decline of the weight by distance. Afterwards the most influential landmark is selected for each route segment. The 9-Intersection-Model and an adapted Direction-RelationMatrix are the core methods that are used to analyse and determine the relations between the route and the chosen landmarks. The automatic description of relevant landmarks along a route is implemented as an interactive web-map. The main goal of this paper is the development of the system. Still, a first evaluation was conducted, in order to test the users’ ability of orientation after using enriched instructions compared to users using the classic ones

    Some strategic national initiatives for the Swedish education in the geodata field

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    This paper describes national cooperation in Sweden launched by its universities and authorities, aimed at improving geodata education. These initiatives have been focused upon providing common access to geodata, the production of teaching materials in Swedish and organizing annual meetings for teachers. We argue that this type of cooperation is vital to providing high quality education for a poorly recognized subject in a country with a relatively small population

    Some strategic national initiatives for the Swedish education in the geodata field

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    Ponencias, comunicaciones y pĂłsters presentados en el 17th AGILE Conference on Geographic Information Science "Connecting a Digital Europe through Location and Place", celebrado en la Universitat Jaume I del 3 al 6 de junio de 2014.This paper describes national cooperation in Sweden launched by its universities and authorities, aimed at improving geodata education. These initiatives have been focused upon providing common access to geodata, the production of teaching materials in Swedish and organizing annual meetings for teachers. We argue that this type of cooperation is vital to providing high quality education for a poorly recognized subject in a country with a relatively small population

    A Case Study of Simultaneous Generalisation

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