<> "The repository administrator has not yet configured an RDF license."^^ . <> . . . "QoS Negotiation in Service Composition"^^ . "Service composition in Service Oriented Computing concerns not only integration of heterogeneous distributed applications but also dynamic selection of services. Quality of Service (QoS) plays a key role in service composition as services providing the same functionalities can be differentiated according to their QoS guarantees. At subscription time, a service requester and a provider may sign a contract recording the QoS of the supplied service. The cc-pi calculus has been introduced as a constraint-based model of QoS contracts. In this work we propose a variant of the cc-pi calculus in which the alternatives in a choice rather than being selected non-deterministically have a dynamic priority. Basically, a guard cj:πj in a choice is enabled if the constraint cj is entailed by the store of constraints and the prefix πj can be consumed. Moreover, the j-th branch can be selected not only if the corresponding guard cj:πj is enabled but also if cj is weaker than the constraints ci of the other enabled alternatives. We prove that our choice operator is more general than a choice operator with static priority. Finally, we exploit some examples to show that our prioritised calculus allows arbitrarily complex QoS negotiations and that a static form of priority is strictly less expressive than ours."^^ . "2011" . . "80" . "1" . . "Elsevier"^^ . . . "Journal of Logic and Algebraic Programming"^^ . . . "15678326" . . . . . . . . . . "Ugo"^^ . "Montanari"^^ . "Ugo Montanari"^^ . . "Maria Grazia"^^ . "Buscemi"^^ . "Maria Grazia Buscemi"^^ . . . . . "HTML Summary of #114 \n\nQoS Negotiation in Service Composition\n\n" . "text/html" . . . "QA75 Electronic computers. Computer science"@en . .