Now showing items 21-40 of 542

    • A conceptual architecture for semantic web services development and deployment 

      Pahl C (Inderscience Publishers, 2005)
      Several extensions of the Web Services Framework (WSF) have been proposed. The combination with Semantic Web technologies introduces a notion of semantics, which can enhance scalability through automation. Service composition ...
    • Stream Integration Techniques for Grid Monitoring 

      Cooke A; Gray AJG; Nutt W (Springer, 2005)
      Grids are distributed systems that provide access to computational resources in a transparent fashion. Providing information about the status of the Grid itself is called Grid monitoring. As an approach to this problem, ...
    • Equivalences among Aggregate Queries with Negation 

      Cohen S; Nutt W; Sagiv Y (Association for Computing Machinery (ACM), 2005)
      Query equivalence is investigated for disjunctive aggregate queries with negated subgoals, constants and comparisons. A full characterization of equivalence is given for the aggregation functions count, max, sum, prod, ...
    • Strategies for Query Unnesting in XML databases 

      May N; Helmer S; Moerkotte G (Association for Computing Machinery (ACM), 2006)
    • Reasoning on temporal class diagrams: Undecidability results 

      Artale A (Springer Verlag (Germany), 2006)
      This paper introduces a temporal class diagram language useful to model temporal varying data. The atemporal portion of the language contains the core constructors available in both EER diagrams and UML class diagrams. The ...
    • Rewriting queries with arbitrary aggregation functions using views 

      Cohen S; Nutt W; Sagiv Y (Association for Computing Machinery (ACM), 2006)
      The problem of rewriting aggregate queries using views is studied for conjunctive queries with arbitrary aggregation functions and built-in predicates. Two types of queries over views are introduced for rewriting aggregate ...
    • Algebraic Translation and Optimization of (Nested) XPath Expressions 

      Brantner M; Kanne CC; Helmer S; Moerkotte G (IEEE, 2006)
      The XPath language incorporates powerful primitives for formulating queries containing nested subexpressions which are existentially or universally quantified. However, even the best published approaches for evaluating ...
    • A Change-based Approach to Software Evolution 

      Robbes R; Lanza M (2007)
      Software evolution research is limited by the amount of information available to researchers: Current version control tools do not store all the information generated by developers. They do not record every intermediate ...
    • Developing domain ontologies for course content 

      Boyce S; Pahl C (International Forum of Educational Technology & Society, 2007)
      Ontologies have the potential to play an important role in instructional design and the development of course content. They can be used to represent knowledge about content, supporting instructors in creating content or ...
    • An ontology for software component matching 

      Pahl C (Springer Verlag, 2007)
      Matching is a central activity in the discovery and assembly of reusable software components. We investigate how ontology technologies can be utilised to support software component development. We use description logics, ...
    • Evolving objects in temporal information systems 

      Artale A; Parent C; Spaccapietra S (Springer Verlag (Germany), 2007)
    • Deciding equivalences among conjunctive aggregate queries 

      Cohen S; Nutt W; Sagiv Y (Association for Computing Machinery, 2007)
      Equivalence of aggregate queries is investigated for the class of conjunctive queries with comparisons and the aggregate operators count, count-distinct, min, max, and sum. Essentially, this class contains unnested SQL ...
    • Semantic model-driven architecting of service-based software systems 

      Pahl C (Elsevier, 2007)
      Model-driven development is a software development framework that emphasises model-based abstraction and automated code generation. Service-based software architectures benefit in particular from semantic, ontology-based ...
    • Notes on Logics of Metric Spaces 

      Kutz O (Springer Verlag (Germany), 2007)
      In [14], we studied the computational behaviour of various first-order and modal languages interpreted in metric or weaker distance spaces. [13] gave an axiomatisation of an expressive and decidable metric logic. The main ...
    • Answering queries over incomplete data stream histories 

      Gray JG; Nutt W; Williams MH (Emerald, 2007)
      Purpose – Distributed data streams are an important topic of current research. In such a setting, data values will be missed, e.g. due to network errors. This paper aims to allow this incompleteness to be detected and ...
    • The influence of inertial loading on color gamut properties of a TFT LCD display 

      Grbec S; Tkalčič M; Diaci J (2008)
      The article presents the results of an experiment where a 7 in. TFT LCD display was exposed to harmonic vibration with acceleration amplitudes up to 200 m/s and frequency sweep in the range between 40 Hz and 1.5 kHz. The ...
    • Nearest-biclusters collaborative filtering based on constant and coherent values 

      Symeonidis P; Nanopoulos A; Papadopoulos A; Manolopoulos Y (2008)
      Collaborative Filtering (CF) Systems have been studied extensively for more than a decade to confront the "information overload" problem. Nearest-neighbor CF is based either on similarities between users or between items, ...
    • Providing justifications in recommender systems 

      Symeonidis P; Nanopoulos A; Manolopoulos Y (2008)
      Recommender systems are gaining widespread acceptance in e-commerce applications to confront the "information overload"problem. Providing justification to a recommendation gives credibility to a recommender system. Some ...
    • Collaborative recommender systems: Combining effectiveness and efficiency 

      Symeonidis P; Nanopoulos A; Papadopoulos A; Manolopoulos Y (2008)
      Recommender systems base their operation on past user ratings over a collection of items, for instance, books, CDs, etc. Collaborative filtering (CF) is a successful recommendation technique that confronts the "information ...
    • Content-driven design and architecture of E-learning applications 

      Pahl C (ACTA Press, 2008)
      E-learning applications combine content with learning technology systems to support the creation of content and its delivery to the learner. In the future, we can expect the distinction between learning content and its ...