In this paper we generalize known workload decomposition results for Lévy queues with secondary jump inputs and queues with server vacations or service interruptions. Special cases are polling systems with either compound Poisson or more general Lévy inputs. Our main tools are new martingale results, which have been derived in a companion paper.

The negotiation of Service Level Agreements for composite web services is a very complex process. It involves the coordination of the negotiation process so that the end-to-end QoS requirements of the user request are satisfied while ensuring that the atomic QoS requirements are also simultaneously satisfied. This paper summarizes three decision-making mechanisms which support the process of Se...

The present paper considers an important problem related to the further development of the semantic Web service technology – the dynamic composition of semantic Web services. It is proposed an approach, in which the process of finding an appropriate service composition is guided by the algorithm for run-time decomposition of the user goal into sub-goals and discovering the existing services abl...

The number and size of information services available on the internet has been growing exponentially over the past few years. This growth has created an urgent need for information agents that act as brokers in the sense that they can autonomously search, gather, and integrate information on behalf of a user. To remain useful, such brokers will have to evolve throughout their lifetime to keep u...

The exponential growth in the number and size of information services available on the internet has created an urgent need for information agents which act as brokers in that they can autonomously search, gather and integrate information on behalf of a user. Moreover, the inherent volatility of the internet and the wide range of information processing tasks to be carried out, calls for a framew...

We consider a discrete-time Geo/G/1 retrial queue with starting failures in which all the arriving customers require a first essential service while only some of them ask for a second optional service. We study the Markov chain underlying the considered queueing system and its ergodicity condition. Explicit formulae for the stationary distribution and some performance measures of the system in ...

In a layered service-oriented enterprise architecture, business processes are supported by application services which are, in turn, supported by technological services. Service-orientation promotes the reuse and modular design of information systems. But achieving these design qualities requires the business processes of an organization to be consistently decomposed so that their supporting ser...

This experience paper describes the process of leveraging the NFV orchestration platform built in the EU FP7 project UNIFY to deploy a dynamic network service exemplified by an elastic router. Elasticity is realized by scaling dataplane resources as a function of traffic load. To achieve this, the service includes a custom scaling logic and monitoring capabilities. An automated monitoring frame...

Forest ecosystem services are fundamental for human life. To protect and increase forest ecosystem services, the driving factors underlying changes in forest ecosystem service values must be determined to properly implement forest resource management planning. This study examines the driving factors that affect changes in forest ecosystem service values by focusing on regional forest characteri...