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Auflistung nach Autor:in "Lehfeldt, Rainer"

1 - 6 von 6
  • Konferenzbeitrag
    Automation of Metadata Repository Development with XML Schema
    (Environmental Communication in the Information Society - Proceedings of the 16th Conference, 2002) Kazakos, Wassilios; Valikov, Alexei; Schmidt, Andreas; Lehfeldt, Rainer
    Metadata standards have been discussed since years in the environmental domain. Although the community has agreed that metadata are important for information finding, an globally accepted standard is still missing. Different requirements in diverse environmental application domains, countries and organisations have led to a huge variety on metadata vocabularies and technologies. Even projects using existing standards tend to adjust them slightly to their own requirements. A consequence is that new metadata repositories are developed or adapted to the new meta data element sets over and over again. In this paper we present a novel approach for the automation of metadata repository development. As input the system requires only an XML Schema describing the metadata vocabulary. Based on this schema the user interface, database schema and the search, retrieval and upload mechanism are generated during a batch process. The user interface layout can be further controlled by templates. The system is developed for the NOKIS project and evaluated by generating a metadata repository for an adjusted ISO 19115 metadata element set.
  • Konferenzbeitrag
    Metadata Repositories in Governmental Information Systems for Coastal Regions in Germany
    (The Information Society and Enlargement of the European Union, 2003) Kazakos, Wassilios; Lehfeldt, Rainer; Michl, Christian; Heidmann, Carsten; Valikov, Alexei
  • Konferenzbeitrag
    NOKIS++ Informationsinfrastrukturen für Nord- und Ostseeküste
    (Workshop des Arbeitskreises „Umweltdatenbanken“ der Fachgruppe „Informatik im Umweltschutz“, 2005) Kazakos, Wassilios; Briesen, Marcus; Lehfeldt, Rainer; Reimers, Hans-Christian
  • Konferenzbeitrag
    Providing Access to Environmental Data in a SOA in NOKIS
    (Environmental Informatics and Industrial Ecology, 2008) Heidmann, Carsten; Sellerhoff, Frank; Lehfeldt, Rainer; Valikov, Aleksei; Kazakos, Wassilios
    NOKIS and NOKIS++ are two German R&D projects, which aim at the integration of distributed data from different sources provided in various formats. The authors describe a Service Oriented Architecture, which has been implemented for users from coastal zone management. The available data types are characterized and the categories of used services are explained, together with the relevant standards in their respective sectors of application. Examples of the implemented services are given and the instrument to combine the available services is introduced. The article finishes with a short comparison between a SOA and central approaches.
  • Konferenzbeitrag
    Sharing ISO 19115 Metadata in NOKIS – Experiences, Features, Perspectives
    (Sh@ring – EnviroInfo 2004, 2004) Kazakos, Wassilios; Valikov, Alexei; Lehfeldt, Rainer; Heidmann, Carsten
    NOKIS (North See and Baltic See Coastal Information System) main objective is to establish a metadata information system for the German North Sea and Baltic Sea coastal regions. Starting back in January 2001 it was one of the first metadata systems using an extended element set of ISO 19115. It became so far one of the most advanced suites for the Web-based management of large-scale environmental metadata. With this paper we would like to participate in the lively discussion about the use and the usefulness of ISO 19115 in the environmental domain by sharing our experiences. In addition we would like to present and discuss the newest features of the system, which we believe are interesting for most future metadata applications. First to mention a service for the transformation of geographic coordinates into different coordinate system. Secondly, our new extensible query mechanism which provides simple user interface to a flexible construction of complex queries. Finally, we will discuss our solution for relational Persistence for XML-based Metadata.
  • Konferenzbeitrag
    Using ISO 19115 Metadata and WebServices to Facilitate Data Access, Visualization and Processing
    (Informatics for Environmental Protection - Networking Environmental Information, 2005) Kazakos, Wassilios; Briesen, Marcus; Lehfeldt, Rainer; Reimers, Hans-Christian
    It is nowadays commonly accepted that metadata and metadata systems are useful and necessary for organizational and inter-organizational networking, information flow and retrieval. ISO 19115 and its XML-representation ISO 19139 have become de facto standard for metadata descriptions in the environmental community. Many initiatives are formed to establish a wide network of metadata repositories. They collect metadata about geographic and nongeographic information or create broker architectures and systems to allow retrieval through distributed repositories. We want go one step further and describe how we use Metadata to access, to process and to visualize data. The means to achieve this are Web services. In this paper we describe the general idea of our service oriented architecture for environmental information handling and show the advantages and possibilities of our comprehensive approach to wrap and bridge isolated applications through services. Special focus is put on the basic principles of the architecture and the workflow to support the users. To exemplify our approach and to show that environmental information handling goes beyond OGC-conformance, we focus on integrated coastal zone management (ICZM). The scenarios used throughout this paper reflect the new challenges addressed in the NOKIS++ project.