Arnaud Legrand

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The Computational Grid provides a promising platform for the eÆcient execution of parameter sweep applications over very large p arameter spaces. Sche duling such applications is challenging because target resour ces are heter ogene ous,because their load and availability varies dynamically, and because independent tasks may share common data les. In this p(More)
We presented the SimGrid simulation framework whose goal is to provide a generic evaluation tool for large-scale distributed computing. Its main components are: two APIs for researchers who study algorithm and need to prototype simulations quickly, and two for developers who can develop applications in the comfort of the simulated world before deploying(More)
Since the advent of distributed computer systems an active field of research has been the investigation of scheduling strategies for parallel applications. The common approach is to employ scheduling heuristics that approximate an optimal schedule. Unfortunately, it is not possible to obtain analytical results to compare and select appropriate heuristics(More)
Many applications in scientific and engineering domains are structured as large numbers of independent tasks with low granularity. These applications are thus amenable to straightforward parallelization, typically in master-worker fashion, provided that efficient scheduling strategies are available. Such applications have been called divisible-loads because(More)
The study of parallel and distributed applications and platforms, whether in the cluster, grid, peer-to-peer, volunteer, or cloud computing domain, often mandates empirical evaluation of proposed algorithmic and system solutions via simulation. Unlike direct experimentation via an application deployment on a real-world testbed, simulation enables fully(More)
We consider the problem of allocating a large number of independent, equal-sized tasks to a heterogeneous computing platform. We use a nonoriented graph to model the platform, where resources can have different speeds of computation and communication. Because the number of tasks is large, we focus on the question of determining the optimal steady state(More)
BACKGROUND Although recent reports suggest that supplementation with probiotics may enhance intestinal function in premature infants, the mechanisms are unclear, and questions remain regarding the safety and efficacy of probiotics in extremely low-birth-weight infants. OBJECTIVE The objective was to evaluate the efficacy of probiotics on the digestive(More)
In this paper, we consider the problem of allocating a large number of independent, equal-sized tasks to a heterogeneous ”grid” computing platform. We use a tree to model a grid, where resources can have different speeds of computation and communication, as well as different overlap capabilities. We define a base model, and show how to determine the maximum(More)