Now showing items 1-20 of 617

  • PROSET - A Language for Prototyping with Sets 

    Doberkat E; Franke W; Gutenbeil U; Hasselbring W; Lammers U; Pahl C (IEEE, 1992)
    We discuss the prototyping language PROSET(Prototyping with Sets) as a language for experimental and evolutionary prototyping, focusing its attention on algorithm design. Some of PROSET's features include generative ...
  • Evaluation of main memory join algorithms for joins with subset join predicates 

    Helmer, S; Moerkotte, G (Morgan Kaufmann Publishers, 1997)
    Current data models like the NF2 model and object-oriented models support set-valued attributes. Hence, it becomes possible to have join predicates based on set comparison. This paper introduces and evaluates two main ...
  • Diag-Join: An Opportunistic Join Algorithm for 1:N Relationships 

    Helmer, S; Westmann, T; Moerkotte, G (Morgan Kaufmann Publishers Inc., 1998)
    Time of creation is one of the predominant (often implicit) clustering strategies found not only in Data Warehouse systems: line items are created together with their corresponding order, objects are created together with ...
  • Modal Logics for Reasoning about Object-based Component Composition 

    Pahl C (British Computer Society, 2000)
    Component-oriented development of software supports the adaptability and maintainability of large systems, in particular if requirements change over time and parts of a system have to be modified or replaced. The software ...
  • Diagrammatic Acquisition of Functional Knowledge for Product Configuration Systems with the Unified Modeling Language 

    Felfernig, A; Zanker, M (Springer, 2000)
    Shorter product cycles, lower prices of products, and the production of goods that are tailored to the customers needs made knowledge based product configuration systems a great success of AI technology. However, configuration ...
  • Cooperating configuration agents supporting supply chain integration of customizable products 

    Felfernig A; Friedrich G; Jannach D; Zanker M (IEEE Computer Society, 2000)
    The integration of configuration systems for supporting the supply-chain management of configurable products and services is still an open research issue. Current configurator approaches are designed for solving local ...
  • Studies for optimization of data analysis queries for HEP using HERA-B commissioning data 

    Amaral, V; Moerkotte, G; Amorim, A; Helmer, S (Science Press NY Ltd., 2001)
    In this paper we present an overview of the ongoing studies to build up a framework that supports the analysis after the reprocessing phase. This framework aims to develop a standard data query language for the HEP community. ...
  • Indexing fuzzy data 

    Helmer, S (IFSA/NAFIPS, 2001)
    Providing efficient query processing in database systems is one step in gaining acceptance of such systems by end users. We propose several techniques for indexing fuzzy sets in databases to improve the query evaluation ...
  • Evaluation of usage patterns for web-based educational systems using web mining 

    Donnellan D; Pahl C (MCIL, 2001)
    Virtual courses often separate teacher and student physically from one another, resulting in less direct feedback. The evaluation of virtual courses and other computer-supported educational systems is therefore of major ...
  • Distributed configuring 

    Felfernig, A; Friedrich, G; Jannach, D; Zanker, M (Morgan Kaufmann, 2001)
    Shorter product cycles, lower prices, and the production of highly variant products tailored to the customer needs are the main reasons for the proceeding success of product configuration systems. However, today’s product ...
  • Formalising dynamic composition and evolution in Java systems 

    Pahl, C (ECOOP, 2001)
    A variety of Java constructs involve an idea of time dynamic establishment and closure of connections or the composition and customisation of components in order to guarantee reliability and maintainability in dynamic ...
  • Components, contracts, and connectors for the Unified Modelling Language UML 

    Pahl C (Springer, 2001)
    The lack of a component concept for the UML is widely ac- knowledged. Contracts between components can be the starting point for introducing components and component interconnections. Contracts between service providers ...
  • Observation and abstract behaviour in specification and implementation of state-based systems 

    Pahl C (British Computer Society, 2001)
    Classical algebraic specification is an accepted framework for specification. A criticism which applies is the fact that it is functional, not based on a notion of state as most software development and implementation ...
  • Interactivity and integration in virtual courses 

    Pahl C (IEEE, 2001)
    Web-based virtual courses focussing on content delivery only have turned out not to be as successful as expected, We will investigate reasons and suggest some remedies using our own virtual Database course for illustration. ...
  • Natix: A technology overview 

    Fiebig, T; Helmer, S; Kanne, CC; Moerkotte, G; Neumann, J; Schiele, R; Westmann, T (Springer, 2002)
    Several alternatives to manage large XML document collections exist, ranging from file systems over relational or other database systems to specifically tailored XML base management systems. In this paper we review Natix, ...
  • Optimized Translation of XPath into Algebraic Expressions Parameterized by Programs Containing Navigational Primitives 

    Helmer, S; Kanne, CC; Moerkotte, G (IEEE Computer Society, 2002)
    We propose a new approach for the efficient evaluation of XPath expressions. This is important, since XPath is not only used as a simple, stand-alone query language, but is also an essential ingredient of XQuery and XSLT. ...
  • A temporal description logic for reasoning over conceptual schemas and queries 

    Artale A; Franconi E (Springer, 2002)
    This paper introduces a new logical formalism, intended for temporal conceptual modelling, as a natural combination of the well-known description logic DLR and point-based linear temporal logic with Since and Until. We ...
  • The Semantics of Modal Predicate Logic I: Counterpart-Frames 

    Kracht, M; Kutz, O (World Scientific, 2002)
    We introduce a new semantics for modal predicate logic, with respect to which a rich class of first-order modal logics is complete, namely all normal first-order modal logics that are extensions of free quantified K. This ...
  • Connecting Abstract Description Systems 

    Kutz, O; Wolter, F; Zakharyaschev, M (Morgan Kaufmann, 2002)
  • An evaluation of scaffolding for virtual interactive tutorials 

    Pahl C (Association for the Advancement of Computers in Education, 2002)
    Scaffolding refers to a temporary support framework used during construction. Applied to teaching and learning it describes measures to support a learner to become confident and self-reliant in a subject. In a Web environment ...