Emilia Rosti

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Multicast services and wireless interconnection networks are among the emerging technologies of the last decade. They drove the development of eecient one-to-many and many-to-many communication primitives and they raised the need for secure multicast services as well. On the other side, technology advances have made possible a wide spectrum of portable(More)
In this paper we systematically examine various performance issues involved in the coordinated allocation of processor and disk resources in large-scale parallel computer systems. Models are formulated to investigate the I/O and computation behavior of parallel programs and workloads, and to analyze parallel scheduling policies under such workloads. These(More)
In multiprocessor systems, a reasonable goal of the sched-uler is to keep all processors as busy as possible. One technique for doing this is to allocate all available processors to the jobs waiting for service. Techniques which allocate all available processors are known as work-conserving policies. In this paper, non-work-conserving policies are examined.(More)
ÐA fundamental understanding of the interplay between computation and I/O activities in parallel applications that manipulate huge amounts of data is critical to achieving good application performance, as well as correctly characterizing the workloads of large-scale high-performance parallel systems. In this paper, we present a formal model of the behavior(More)
In this paper, some peculiar properties of multi-class product-form closed queueing networks with two classes of customers are presented. In particular, we show that in a network with two stations there exists a combination of customer classes such that the stations are equally utilized regardless of the population size. Such an equiutilization point is(More)
Mobile ad hoc network is a wireless network without the support of network infrastructure. Security is one of the main challenge in ad hoc network due to dynamic topology and mobility of nodes. In this paper, we present a new composite key management scheme based on a combination of techniques such as hierarchical clustering, partially distributed key(More)