Miroslav Zivkovic

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In this paper we consider the general problem of resource provisioning within cloud computing. We analyze the problem of how to allocate resources to different clients such that the service level agreements (SLAs) for all of these clients are met. A model with multiple service request classes generated by different clients is proposed to evaluate the(More)
Magnetic twisting cytometry probes mechanical properties of an adherent cell by applying a torque to a magnetic bead that is tightly bound to the cell surface. Here we have used a three-dimensional finite element model of cell deformation to compute the relationships between the applied torque and resulting bead rotation and lateral bead translation. From(More)
With the increasing number of mobile and wireless networks that are deployed, the handovers between these systems take place more often. In order to provide end-users with uninterrupted access to services, support for fast handover is essential. One of the prerequisites of a fast-handover is transparent end-user authentication. In this paper we address(More)
We investigate dynamic decision mechanisms for composite web services maximizing the expected revenue for the providers of composite services. A composite web service is represented by a (sequential) workflow, and for each task within this workflow, a number of service alternatives may be available. These alternatives offer the same functionality at(More)
In this paper we investigate sequential decision mechanisms for composite web services. After executing each sub-service within a sequential workflow, decisions are made whether to terminate or continue the execution of the workflow. These decisions are based on observed response times, expected rewards, and typical Service Level Agreement parameters such(More)
In this paper, we analyze overload control for composite web services in service oriented architectures by an orchestrating broker, and propose two practical access control rules which effectively mitigate the effects of severe overloads at some web services in the composite service. These two rules aim to keep overall web service performance (in terms of(More)
Rapid acquisition of accurate crosstalk estimates is a core requirement for effective precoding in digital subscriber line (DSL) systems. It is shown that signal-to-noise ratio (SNR) reports provided by customer premises equipment (CPE) can be used to perform this task by “tuning” the precoder, i.e., iterating alternate steps of estimation and precoder(More)
Service composition is one of the major approaches in service oriented architecture (SOA) based systems. Due to the inherent stochastic nature of services execution environment the issue of composite service quality assurance within SOA is a very challenging one. Such heterogeneous environment requires dynamic, run-time composition of services. We show how(More)
Due to the inherent stochastic nature of services execution environment within service oriented systems, a runtime adaptation of the given composition may be required. We address a runtime service adaptation mechanism based on conditional retries for the orchestrated web services. The conditional retry may be issued while a concrete service within(More)