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Auflistung nach Autor:in "Krieger, Rolf"

1 - 7 von 7
  • Konferenzbeitrag
    Adaption von Information Retrieval-Verfahren zur automatisierten Produktsuche und -klassifikation
    (INFORMATIK 2003 – Innovative Informatikanwendungen, Band 2, Beiträge der 33. Jahrestagung der Gesellschaft für Informatik e.V. (GI), 2003) Naumann, Stefan; Krieger, Rolf; Kuhn, Norbert; Schürmann, Cordula; Sommer, Christian
    Die Suche nach Produkten über Merkmal/Wert-Paare in Datenbanken und im Internet ist ein wesentlicher Teil des elektronischen Beschaffungsprozesses. In diesem Beitrag wird ein Verfahren für die Suche in merkmalsbasierten Produktkatalogen vorgestellt. Das mehrstufige Verfahren adaptiert klassische Methoden aus dem Information Retrieval und der Fuzzy-Logik für diesen Suchvorgang. Ein Export der Suchergebnisse als XML-Produktkatalog unterstützt die Integration in bestehende Beschaffungsprozesse. Das Verfahren lässt sich auch zur automatischen Klassifikation vorhandener Produkte einsetzen.
  • Konferenzbeitrag
    Data Management for Performance Analysis of Renewable Power Generation Systems
    (Sh@ring – EnviroInfo 2004, 2004) Gemmel, Matthias; Krieger, Rolf; Naumann, Stefan; Hinzmann, Bruno
    In the area of renewable power generation the number of small power generation systems like photovoltaic plants or wind turbines has been increasing during the last years. In order to determine the electrical energy generated by the systems, to analyze their performance and reliability and to detect malfunctions at an early stage it is necessary to install and to operate a measurement and information system. One key component of such a system is a tool for managing the master and measurement data of renewable power generation systems that is described in this paper.
  • Konferenzbeitrag
    Environmental Data Catalogue: Implementation and Data Quality Issues
    (Informatics for Environmental Protection - Networking Environmental Information, 2005) Fischer-Stabel, Peter; Krieger, Rolf; Schäfer, Kerstin; Wannemacher, Stefan
    In Germany the environmental data catalogue was designed as a meta information system for retrieving environmental information held by public authorities. It is providing its user with information about who is having which information at what location. In this paper we discuss some issues concerning the implementation of the environmental data catalogue at public authorities and the management of data quality.
  • Konferenzbeitrag
    Functional and Technical Requirements for a Regional Environmental Information System
    (Environmental Informatics and Systems Research, 2007) Fischer-Stabel, Peter; Krieger, Rolf; Schäfer, Kerstin; Wannemacher, Stefan
    In the last decade public authorities have invested large amounts of money and time in metadata management projects in order to provide public access to environmental data held by them. Directive 2003/4/EC on public access to environmental information has enforced these activities. But most of the projects are initiated at a national or state level and are restricted to environmental data held by authorities at these levels. But Directive 2003/4/EC is also of importance for public authorities at a regional or local level. Therefore in this paper we discuss some central issues concerning the dissemination of environmental information at regional and local levels by means of Web-based information systems.
  • Konferenzbeitrag
    Integration of Sensor Data and their Presentation in Regional Environmental Information Systems and Mobile Applications
    (Innovations in Sharing Environmental Observations and Information, 2011) Beck, Marc; Hempe, Christian; Krieger, Rolf; Mut, Andreas; Schmitt, Bernhard
    During the last years, environmental observation and sensor networks have increasingly been built up for environmental monitoring. In Europe, most of these networks are managed by public authorities. Web-based information systems are used for the dissemination of collected sensor data about the environment. To date, it is very difficult to get information about sensors located in a specified area if different observation and sensor networks are to be considered. In this paper, we describe a prototype of an information system to solve this problem. Based on this system, we describe two applications, a regional environmental information system and a mobile application, providing a more comprehensive view on sensors in a specified area and their data.
  • Konferenzbeitrag
    Process Models and Software Components for Electronic Marketplaces of Used Products
    (Sh@ring – EnviroInfo 2004, 2004) Naumann, Stefan; Krieger, Rolf; Kuhn, Norbert
    Electronic marketplaces play an increasingly role in buying and selling products. Their importance can also be observed in the case of used products (Fichter 2003). Designing electronic marketplaces for used products in comparison to new products leads to some important additional requirements and problems that have to be considered. For instance, their specifications are often incomplete and inaccurate. This makes the search for products more difficult. In this paper, we first discuss these problems in more detail. Moreover, we describe algorithms, software components, and business processes for electronic marketplaces taking into account the special requirements of used products.
  • Konferenzbeitrag
    Web Usage Analysis for Assessing and Improving Metadata Quality
    (Managing Environmental Knowledge, 2006) Krieger, Rolf; Schöpflin-Reichmann, Elke; Sattler, Thomas; Schäfer, Kerstin
    Due to Directive 2003/4/EC on public access to environmental information public authorities have invested large amounts of money and time in metadata management projects. For instance, in Germany the Environmental Data Catalogue was designed as a Web-based meta information system for retrieving environmental information held by public authorities. The benefits of the system depend on the quality of the metadata provided. As well-known data quality is expressed in several dimensions, e.g. accessibility, completeness, relevancy, timeliness etc.. To guarantee a high metadata quality public authorities have to develop a long-term metadata management strategy concerning the Environmental Data Catalogue. At a tactical level this requires a continuous monitoring of the usage of the Environmental Data Catalogue. One attractive strategy for analyzing the usage of the system is the analysis of log files provided by the Environmental Data Catalogue. But to our knowledge only a few German authorities, e.g. the State Institute for Environment, Measurement and Nature Conservation Baden Württemberg, have started to analyse the UDK-log files continuously in a systematic way. The reasons are: (a) The UDK-software only provides rudimentary support for managing the logging process. (b) It is difficult to analyse the log files because there are no metrics and no tool for analyzing the application-specific log files of the Environmental Data Catalogue. Due to these facts in our contribution we present procedures, metrics and a tool for analysing the specific UDK-log files. The UDK Log-File-Analyser receives the daily log files as input, aggregates and analyses the data and provides a summary report, a weekly report, an error report and a search term evaluation report as result. The reports list several metrics (e.g. number of sessions and object views, list of most popular UDK-objects, list of most popular search terms etc.). The statistics are presented in tabular and graphical form. Using our tool we analysed the daily log files of the Environmental Data Catalogue of the German State of Baden-Württemberg from October 1st, 2003 to October 31st, 2004. Thereby we identified several data quality problems with respect to content and accessibility. To solve these problems, we derived several activities from our empirical study. For instance based on the search term evaluation report produced by our tool the most popular keywords can be identified. Assigning these keywords to relevant UDK-objects improves the accessibility of the data. In addition our tool provides a list of search terms for which the Environmental Data Catalogue has not delivered relevant objects. This list can help identify missing objects. Adding these objects improves the completeness of data. In summary, with our tool and metrics public authorities have instruments for guiding their meta data management and for improving metadata quality concerning the Environmental Data Catalogue. Moreover, our results show that web usage analysis is a promising way to gain insights into the environmental information demand of the public.