Query Algebra Operations for Interval Probabilities

The groundswell for the `00s is imprecise probabilities. Whether the numbers represent the probable location of a GPS device at its next sounding, the inherent uncertainty of an individual expert\u27s probability prediction, or the range of values derived from the fusion of sensor data, probability intervals became an important way of representing uncertainty. However, until recently, there has been no robust support for storage and management of imprecise probabilities. In this paper, we define the semantics of traditional query algebra operations of selection, projection, Cartesian product and join, as well as an operation of conditionalization, specific to probabilistic databases. We provide efficient methods for computing the results of these operations and show how they conform to probability theory

Vergleich der Immunantwort nach konventioneller und laparoskopischer Sigmaresektion

This paper introduces the concept of a Parameterised Search System (PSS), which allows flexibility in user queries, and, more importantly, allows system engineers to easily define customised search strategies. Putting this idea into practise requires a carefully designed system architecture that supports a declarative abstraction language for the specification of search strategies. These specifications should stay as close as possible to the problem definition (i.e., the retrieval model to be used in the search application), abstracting away the details of the physical organisation of data and content. We show how extending an existing retrieval system with an abstraction mechanism based on array databases meets this requirement

The use of summaries in XML retrieval

Abstract. The availability of the logical structure of documents in contentoriented XML retrieval can be beneficial for users of XML retrieval systems. However, research into structured document retrieval has so far not systematically examined how structure can be used to facilitate the search process of users. We investigate how users of an XML retrieval system can be supported in their search process, if at all, through summarisation. To answer this question, an interactive information retrieval system was developed and a study using human searchers was conducted. The results show that searchers actively utilise the provided summaries, and that summary usage varied at different levels of the XML document structure. The results have implications for the design of interactive XML retrieval systems.