Browsing by Subject "Task interaction graph"

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Open Access
Exact algorithms for a task assignment problem
(World Scientific Publishing Company, 2009) Kaya, Kamer; Uçar, B.
We consider the following task assignment problem. Communicating tasks are to be assigned to heterogeneous processors interconnected with a heterogeneous network. The objective is to minimize the total sum of the execution and communication costs. The problem is NP-hard. We present an exact algorithm based on the well-known A* search. We report simulation results over a wide range of parameters where the largest solved instance contains about three hundred tasks to be assigned to eight processors. © World Scientific Publishing Company.
Open Access
Task assignment in heterogeneous computing systems
(Academic Press, 2006-01) Ucar, B.; Aykanat, Cevdet; Kaya, K.; Ikinci, M.
The problem of task assignment in heterogeneous computing systems has been studied for many years with many variations. We consider the version in which communicating tasks are to be assigned to heterogeneous processors with identical communication links to minimize the sum of the total execution and communication costs. Our contributions are three fold: a task clustering method which takes the execution times of the tasks into account; two metrics to determine the order in which tasks are assigned to the processors; a refinement heuristic which improves a given assignment. We use these three methods to obtain a family of task assignment algorithms including multilevel ones that apply clustering and refinement heuristics repeatedly. We have implemented eight existing algorithms to test the proposed methods. Our refinement algorithm improves the solutions of the existing algorithms by up to 15% and the proposed algorithms obtain better solutions than these refined solutions. © 2005 Elsevier Inc. All righs reserved.