Raquel Vigolvino Lopes

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Elasticity is a key property to reduce the costs associated with running services in cloud systems that employ an infrastructure-as-a-service (IaaS) deployment model. However, to be able to exploit this property, users of IaaS systems need to be able to anticipate the short-term future demand of their own services, so that only the required infrastructure(More)
With the emergence of the cloud computing paradigm and the continuous search to reduce the cost of running Information Technology (IT) infrastructures, we are currently experiencing an important change in the way these infrastructures are assembled, configured and managed. In this research we consider the problem of managing a computing infrastructure whose(More)
The energy costs of running computer systems are a growing concern: for large data centers, recent estimates put these costs higher than the cost of hardware itself. As a consequence, energy efficiency has become a pervasive theme for designing, deploying, and operating computer systems. This paper evaluates the energy trade-offs brought by data(More)
The new ways of doing science, rooted on the unprecedented processing, communication and storage infrastructures that became available to scientists, are collectively called e-Science. Many research labs now need non-trivial computational power to run e-Science applications. Grid and voluntary computing are well-established solutions that cater to this(More)
Peer-to-peer (P2P) desktop grids have been proposed as an economical way to increase the processing capabilities of information technology (IT) infrastructures. In a P2P grid, a peer donates its idle resources to the other peers in the system, and, in exchange, can use the idle resources of other peers when its processing demand surpasses its local(More)
The authors report a case of ectopic cutaneous schistosomiasis in a 35 year-old female who presented clustered reddish macules and papules on the left buttock. The diagnosis was not suspected during clinical evaluation and required visualization of Schistosoma mansoni eggs on sections of tissue.
Capacity Planning is one of the activities developed by Information Technology departments over the years, it aims at estimating the amount of resources needed to offer a computing service. This activity contributes to achieving high Quality of Service levels and also to pursuing better economic results for companies. In the Cloud Computing context, one(More)
We consider the problem of managing a hybrid computing infrastructure whose processing elements are comprised of in-house dedicated machines, virtual machines acquired on-demand from a cloud computing provider through short-term reservation contracts, and virtual machines made available by the remote peers of a best-effort peer-to-peer (P2P) grid. Each of(More)
Cloud Computing has the purpose of providing computing services in different levels, from remote data storage and computing resources (Infrastructure as a Service - IaaS) to applications accessed through the Internet (Software as a Service - SaaS). From the perspective of an application provider, it is important to manage the capacity of the applications(More)