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Auflistung nach Autor:in "Schenk, Franz"

1 - 6 von 6
  • Konferenzbeitrag
    Estimating the Number of Web Pages of the Environmental Administration in Germany
    (EnviroInfo Dessau 2012, Part 1: Core Application Areas, 2012) Schenk, Franz; Kruse, Fred
    The German environmental information portal PortalU 2 is an access point to a large number of information sources, all from public authorities. The user is offered a single point of entry for queries on a large variety of data with environmental relevance. In this respect, one of the most important tasks in the maintenance of the portal is to guarantee a high degree of relevance for all the different kinds of information sources. In addition to relevance, which often cannot be defined exactly, quantity of information is a measure that normaly can be obtained more easily. While this is generally true for highly structured information like records in a metadata catalogue or entities in database systems, it can be difficult when dealing with unstructured information sources like web pages. In this paper we show the obstacles that we encountered in our examinations on the size of our web page index and present how the information providers respectively contribute to the web page index of the environmental adminstration in Germany.
  • Konferenzbeitrag
    From Simple Dara Sources to a Complex Information System: Integrating Heterogeneous Data Models into an Information Infrastructure for the Puplic Administration
    (Integration of Environmental Information in Europe, 2010) Schenk, Franz; Kruse, Fred; Klenke, Martin
    Granting access to governmental data has become a matter of public interest since long. There are national and international regulations like the German environmental information act (UIG) or the European infrastructure for spatial information (INSPIRE). Both encourage governmental institutions to make information available to the public. Despite the fast-paced development in information technology many problems with data integration are far from being solved. The availability of distributed data demands for standardised procedures in service discovery and invocation, in data processing and integration. Although there are many efforts for a standardisation of web services and data exchange formats, on the level of the administrative institutions heterogeneous data structures and service interfaces are still the normal case. Hence, the complexity of granting access to environmental information in a uniform way with respect to the aforementioned regulations is very high. The German environmental information portal PortalU (www.portalu.de) is a publicly financed information infrastructure. It offers a single point of entry for all information with environmental relevance held by public authorities. Here, the key problem is not how to deliver the information or how to present the results of a query, but how to integrate the plethora of heterogeneous data sources. The aim is to allow for the integration of data in as many formats as possible and give access to all sources with a uniform query mechanism. The architecture of PortalU contributes to this situation with its flexible and extensible concept of specialised data source plug-ins. From the point of view of the query facility in PortalU, all information sources are treated uniformly as they all deliver their search results in the same way (the ranking of the results can be influenced, though). Data sources of very different structure can be connected, indexed and queried. The key component is the iBus, a communication broker that distributes queries to all connected data sources and collects, combines, and delivers the answers in return. One of the strong points in the architecture of PortalU is the wide range of data formats and the diversity of information systems that are supported.
  • Konferenzbeitrag
    Identifying Information with Environmental Relevance in Web Sites of the Public Administration Using Automatic Classification
    (Innovations in Sharing Environmental Observations and Information, 2011) Schenk, Franz; Meyerholt, Daniel
    Abstract The German environmental information portal PortalU is a publicly financed information infrastructure. It offers a single point of entry for searches on all kinds of information with environmental relevance held by public authorities. From the point of view of the query facility in PortalU, all information sources can be treated uniformly based on the common structure of the search results. One of the key problems in PortalU is how to ensure the relevance of data that is available in a distributed index structure. Whereas some data sources, e.g. metadata catalogues, typically contain only highly relevant material with respect to the content model of PortalU, other data sources like Web indexes tend to contain more heterogeneous material. In this paper we describe how automatic classification of Web pages can be used in order to provide information with a high degree of environmental relevance.
  • Konferenzbeitrag
    InGrid - The development of a metadata editor in the context of INSPIRE
    (Innovations in Sharing Environmental Observations and Information, 2011) Kruse, Fred; Schenk, Franz
    The software InGrid was developed for creation and operation of the German Environmental Portal, PortalU. Meanwhile it is not only be used to operate this central German portal but also in many German states, in the municipal sector, as research portal or in European projects. The software includes an integrated metadata catalogue the InGridCatalog, which offers among other things an OGC- and INSPIRE-compliant interface. The metadata are be maintained via the also integrated InGrid-Editor. This editor provides a usability optimised surface, which allows an OGC- and INSPIRE-compliant creation and maintenance of metadata. The data model as well as the surface of the editor has been made flexible, to support also future INSPIRE data specifications.
  • Konferenzbeitrag
    OpenSearch - Simple formats to share environmental information
    (Integration of Environmental Information in Europe, 2010) Klenke, Martin; Kruse, Fred; Schenk, Franz
    Data infrastructures and responsibilities of public authorities in Germany are still very heterogeneous. eGovernment initiatives to enhance technical and semantical interoperability between different data and information providers exist in some fields though, on the whole, public and private information systems for citizens and experts are still monolithic. Diverse data, formats, and information models are widely spread over all levels of public administration ranging from local authorities to federal states and government organisations. In the field of environmental information, new challenges for data publication and interchange arise from national and international regulations, particularly the EC Environmental Information Directive (2003/4/EC) and the EC INSPIRE directive (2007/2/EC). The former tempts with a very broad definition on what environmental information is and the public duties in terms of its publication. The latter challenges with very detailed obligations on how to set up a technical infrastructure to share digital spatial information, specifically environmental information. In Germany, PortalU and the technical infrastructure behind it is one approach to meet those challenges. A set of connectors, both open and proprietary, allow easy integration of web and data base contents in the PortalU information space. Open machine interfaces grant remote access to this information pool by external clients. For metadata, an OGC compliant catalog service (OGC 2007) provides access to environmental data described in catalogue systems. The interface is of particular importance in the INSPIRE context. However, the underlying data model is thick and complex and interoperability between different implementations of the ‘standard’ is still an issue in a technical as well as a semantical sense. OpenSearch defines a couple of simple formats which are well established in the web search community for the exchange of result sets. Through exclusive use of the http protocol, OpenSearch is robust and easily deployable even in restrictive security infrastructures. Recent PortalU software developments make use of OpenSearch technology. In our paper, we give a brief overview over the components and describe some first use cases.
  • Konferenzbeitrag
    Weiterentwicklungen von PortalU im Zeichen von INSPIRE: Pflege und Weitergabe von Metadaten
    (Informationsgewinnung und Datenaufbereitung für maritime Informationssysteme, 2011) Schenk, Franz
    The INSPIRE regulations have by now become national law in most of the member states of the European Union. In order to be fully compliant with these regulations, a metadata editor for the public administration has to deal with additional requirements. The kind and amount of efforts that are necessary in order to fulfil these requirements vary depending on the complexity and the background of the data model. In this paper we describe the challenges that PortalU faced when preparing the InGrid catalogue for full conformity with INSPIRE.