This paper analyses reported difficulties in spatial data retrieval from Internet portals, based on results from an empirical survey. The analysis reveals the problems which cause ...
In this paper, we develop a novel Web Usage Manipulation Language (WUML) which is a declarative language for manipulating Web log data. We assume that a set of trails formed by use...
Abstract. In this paper we present a novel approach for the predicative specification of user rights in the context of an object oriented use case driven development process. We e...
A general notion of bisimulation is studied for dynamical systems. An algebraic characterization of bisimulation together with an algorithm for computing the maximal bisimulation r...
We consider the problem of resource sharing when processing large numbers of continuous queries. We specifically address sliding-window aggregates over data streams, an important...