Preemptive multi-tasking is a commonly used architecture for designing and implementing embedded real-time software. However, preemptive multi-tasking comes with its own costs. These costs include overheads due to preemptions and context-switches that result in waste of CPU bandwidth. Also, each task incurs a memory cost largely due to the need to maintain a separate stack for each task. These ...

This paper explains how DiffServ has been implemented in an IP network simulator using an asynchronous conservative parallel discrete event simulation (PDES) kernel. DiffServ provides Quality of Service (QoS) functionality for IP networks and is designed to provide greater scalability and lower overhead than previous IP based QoS schemes. The paper explains the DiffServ components that have bee...

Acknowledgement I would like to express my sincere acknowledgements to the Mälardalen University and East China University of Science and Technology for the precious chance they have provided to realize and complete my one year study here with my total satisfaction. Special appreciation goes to Dr. Radu Dobrin, Dr. Moris Behnam, Abhilash Thekkilakattil for giving me all the support that I neede...

In this paper, we compare the makespan of preemptive and i-preemptive schedules where only a limited number i of preemptions is allowed. The problem is to schedule n independent jobs on m identical processors that operate in parallel. The objective is to minimize the makespan, i.e., the completion time of the last job that finishes. We show that the ratio of the optimal ipreemptive schedule len...

For many queueing systems the server is not continuously available. Service interruptions may result from repair times after server failures, from planned maintenance periods or from periods during which customers from other queues are being served. These service interruptions cause an overall performance degradation which is most striking when interruptions can start while a customer is being ...

Many real-world embedded systems employ a preemptive scheduling policy in order to satisfy their realtime requirements. However, most System-Level Design Languages (SLDLs) which were proposed up to now, such as SpecC, do not explicitly support modeling of preemptions. This paper proposes techniques for modeling xed-priority preemptive multi-task systems in the SpecC SLDL. The modeling technique...

We analyze a discrete-time queueing system with server interruptions and a hybrid preemptive repeat interruption discipline. Such a discipline encapsulates both the preemptive repeat identical and the preemptive repeat different disciplines. By the introduction and analysis of so-called service completion times, we significantly reduce the complexity of the analysis. Our results include a.o. th...

This paper derives a preemptive equilibrium in strategic investment in alternative projects. The problem is formulated in a real options model with a multidimensional state variable that represents project-specific uncertainty. The proposed method enables us to evaluate the value of potential alternatives. The results not only extend previous studies with a one-dimensional state variable but al...