Stella C. S. Porto

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Most parallel jobs cannot be fully parallelized. In a homogeneous parallel machine | one in which all processors are identical | the serial fraction of the computation has to be executed at the speed of any of the identical processors, limiting the speedup that can be obtained due to parallelism. In a heterogeneous architecture, the sequential bottleneck(More)
Parallel programs may be represented as a set of interrelated sequential tasks. When multiproces-sors are used to execute such programs, the parallel portion of the application can be speeded up by an appropriate allocation of processors to the tasks of the application. Given a parallel application deened by a task precedence graph, the goal of task(More)
This paper presents parallelization strategies for a tabu search algorithm for the task scheduling problem on heterogeneous processors under task precedence constraints. Par-allelization relies exclusively on the decomposition of the solution space exploration. Four diierent parallel strategies are proposed and implemented on an asynchronous parallel(More)
This paper presents the solution quality analysis of a parallel tabu search algorithm for the task scheduling problem on heterogeneous processors under precedence constraints. We evaluate the achieved makespan reduction of diierent parallel applications relatively to the results obtained by the best greedy algorithm in the literature, as a function of(More)
Health sector reform in Brazil built the Unified Health System according to a dense body of administrative instruments for organizing decentralized service networks and institutionalizing a complex decision-making arena. This article focuses on the equity in health care services. Equity is defined as a principle governing distributive functions designed to(More)
We give a new formulation for the problem of task scheduling into unrelated processors under precedence constraints. This formulation has a polynomial number of variables and does not require that the processing times be integer valued. 1 Motivation Let T = ft 1 ; : : :; t n g be a set of partially ordered tasks and P = fp 1 ; : : :; p m g a set of(More)
The article analyzes the World Health Organization Report for 2000, with emphasis placed on the methodology used to analyze the indicators utilized to compare and classify the performance of the health systems of the 191 member countries. The Report's contribution was the compromise of monitoring the performance of the health systems of member countries,(More)