A calculus for generic, QoS-aware component composition

Software QoS properties, such as response time, availability, bandwidth requirement, memory usage, among many others, play a major role in the processes of selecting and composing software components. This paper extends a component calculus to deal, in an effective way, with them. The calculus models components as generalised Mealy machines, i.e., state-based entities interacting along their life time through well defined interfaces of observers and actions. QoS is introduced through an algebraic structure specifying the relevant QoS domain and how its values are composed under different disciplines. A major effect of introducing QoS-awareness is that a number of equivalences holding in the plain calculus become refinement laws. The paper also introduces a prototyper for the calculus developed as a ‘proof-of-concept’ implementation.FCT -Fuel Cell Technologies Program(FCOMP-01-0124-FEDER-020537

Collaborative and Usage-driven Evolution of Personal Ontologies

Large information repositories as digital libraries, online shops, etc. rely on a taxonomy of the objects under consideration to structure the vast contents and facilitate browsing and searching (e.g., ACM topic classification for computer science literature, Amazon product taxonomy, etc.). As in heterogenous communities users typically will use different parts of such an ontology with varying intensity, customization and personalization of the ontologies is desirable. Of particular interest for supporting users during the personalization are collaborative filtering systems which can produce personal recommendations by computing the similarity between own preferences and the one of other people. In this paper we adapt a collaborative filtering recommender system to assist users in the management and evolution of their personal ontology by providing detailed suggestions of ontology changes. Such a system has been implemented in the context of Bibster, a peer-to-peer based personal bibliography management tool. Finally, we report on an experiment with the Bibster community that shows the performance improvements over nonpersonalized recommendations

StateWebCharts: A Formal Description Technique Dedicated to Navigation Modelling of Web Applications

International audienceThis paper presents StateWebCharts (SWC), a formal description technique based on statecharts for describing navigation on web applications. This notation extends the classical statecharts notation by adding more necessary concepts such as an appropriate semantics for states and transitions in a Web context, including notions like dialog initiative control and client and server activities. As well as statecharts do, this formal description technique features a graphical representation thus making it easier to use for web designers and formal enough to allow to rigorously reason about properties of navigation models. In order to show the applicability of the notation, we show, in the paper, its use on two real-size web applications