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Der krönende Abschluss eines UNIGIS MSc Studiums ist sicherlich die Master Thesis. Mit ihr belegen unsere MSc-AbsolventInnen, dass sie den akademischen Grad "Master of Science (Geographical Information Science & Systems)" zu Recht führen.  Im UNIGIS professional Studiengang muss keine Abschlussarbeit verfasst werden. Dennoch nehmen einige Studierende die Möglichkeit war, ein Geoinformatikprojekt durchzuführen und entsprechend zu dokumentieren.

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Stephanie Kirchmayr-Novak [01-2015]:

Bewertung der Datenqualität der OpenStreetMap als Datengrundlage für einen Verkehrsgraph mit Hilfe offener Daten und Software

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This work assesses the quality of a street traffic graph elaborated based on data of the OpenStreetMap (OSM) applying direct intrinsic methods. The use case defining the quality requirements of the task is calculating catchment areas of park-and-ride facilities in the Southern region of Vienna. The evaluation and the data used for the task are restricted to open data and open source software, respectively freeware. In order to gain more insight into the strengths and weaknesses of the data, the main intrinsic approach is complemented by an extrinsic evaluation for randomly selected sample areas, again using only freely available open data resources. After the discussion of quality parameters defined by ISO-Standard 19157:2011, the work presents the intrinsic and extrinsic evaluation methods heretofore applied to assess the data quality of the OpenStreetMap. Based on this knowledge, a user specific evaluation process is designed determining the quality requirements for each quality character intrinsically assessable. In total four quality characteristics are evaluated. These are the logical consistency, the completeness of objects and attributes, the thematic accuracy as well as the usability. No statements are made for positional accuracy and temporal quality. The results show, that the extraction of routable street traffic graphs based on OSM data is possible with Open Source and Freeware tools. The street traffic graph is logically consistent. The usability is ensured by a broad documentation of the OSM data as well as the software tools applied. The completeness of the objects conforms to the quality requirements set for a macroscopic street traffic graph: the main street network is represented and all settlement areas - i.e. inhabitants of the region - are connected to the graph. A visual control of the completeness of objects against the official and freely available transport infrastructure maps implies that the street network of the region is correctly represented. The assessment of the thematic accuracy shows that the street traffic graph holds plausible speed limits. It further reveals which settings should be adapted by the user during conversion of the OSM-data, in order to optimize the graph for the use-case. These adaptations include the adjustment of the default speed attribution for slip roads as well as the exclusion of "streets with least traffic relevance". Finally the implementation of the use-case illustrates, that the street traffic graph is adequate for calculating catchment areas with Voronoi-Polygons. Before using the graph for more detailed analysis, as for example the designation of distinct driving time isochrones, it is advised to further adapt the traffic graph. Particularly, delays for stops at traffic signals should be included into the calculation of driving times in order to display more reliable results, especially in urban areas. Traffic signals are included in the OSM data model, but the conversion program used does not consider them by default. The intrinsic evaluation of the street traffic graph is well applicable for the case of macroscopic traffic modelling and the selected use case. It does however not include the assessment of parameters like the accuracy of turn restrictions, one-way regulations or locally specific speed restrictions, which require the comparison to a reference traffic graph. These weaknesses are not of significant relevance for the use case, but have to be considered for small scale network analysis and routing applications.


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