Browsing by Author "Uçar, B."
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1.5D parallel sparse matrixvector multiply
Kayaaslan, E.; Aykanat, Cevdet; Uçar, B. (Society for Industrial and Applied Mathematics, 2018)There are three common parallel sparse matrixvector multiply algorithms: 1D rowparallel, 1D columnparallel, and 2D rowcolumnparallel. The 1D parallel algorithms offer the advantage of having only one communication ... 
Adapting iterativeimprovement heuristics for scheduling filesharing tasks on heterogeneous platforms
Kaya, Kamer; Uçar, B.; Aykanat, Cevdet (Springer, Berlin, Heidelberg, 2008)We consider the problem of scheduling an application on a computing system consisting of heterogeneous processors and one or more file repositories. The application consists of a large number of filesharing, otherwise ... 
Encapsulating multiple communicationcost metrics in partitioning sparse rectangular matrices for parallel matrixvector multiplies
Uçar, B.; Aykanat, Cevdet (SIAM, 2004)This paper addresses the problem of onedimensional partitioning of structurally unsymmetric square and rectangular sparse matrices for parallel matrixvector and matrixtransposevector multiplies. The objective is to ... 
Exact algorithms for a task assignment problem
Kaya, Kamer; Uçar, B. (World Scientific Publishing Company, 2009)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 ... 
Heuristics for scheduling filesharing tasks on heterogeneous systems with distributed repositories
Kaya, K.; Uçar, B.; Aykanat, Cevdet (Academic Press, 2007)We consider the problem of scheduling an application on a computing system consisting of heterogeneous processors and data repositories. The application consists of a large number of filesharing otherwise independent ... 
A matrix partitioning interface to PaToH in MATLAB
Uçar, B.; Çatalyürek, U. V.; Aykanat, Cevdet (Elsevier BV, 2010)We present the PaToH MATLAB Matrix Partitioning Interface. The interface provides support for hypergraphbased sparse matrix partitioning methods which are used for efficient parallelization of sparse matrixvector ... 
A message ordering problem in parallel programs
Uçar, B.; Aykanat, Cevdet (Springer, 2004)We consider a certain class of parallel program segments in which the order of messages sent affects the completion time. We give characterization of these parallel program segments and propose a solution to minimize the ... 
Minimizing communication cost in finegrain partitioning of sparse matrices
Uçar, B.; Aykanat, Cevdet (Springer, 2003)We show a twophase approach for minimizing various communicationcost metrics in finegrain partitioning of sparse matrices for parallel processing. In the first phase, we obtain a partitioning with the existing tools on ... 
Multilevel direct Kway hypergraph partitioning with multiple constraints and fixed vertices
Aykanat, Cevdet; Cambazoglu, B. B.; Uçar, B. (Academic Press, 200805)Kway hypergraph partitioning has an evergrowing use in parallelization of scientific computing applications. We claim that hypergraph partitioning with multiple constraints and fixed vertices should be implemented using ... 
Parallel frequent item set mining with selective item replication
Özkural E.; Uçar, B.; Aykanat, Cevdet (Institute of Electrical and Electronics Engineers, 2011)We introduce a transaction database distribution scheme that divides the frequent item set mining task in a topdown fashion. Our method operates on a graph where vertices correspond to frequent items and edges correspond ... 
Parallel image restoration using surrogate constraint methods
Uçar, B.; Aykanat, Cevdet; Pınar, M. Ç.; Malas, T. (Academic Press, 2007)When formulated as a system of linear inequalities, the image restoration problem yields huge, unstructured, sparse matrices even for images of small size. To solve the image restoration problem, we use the surrogate ... 
Partitioning sparse matrices for parallel preconditioned iterative methods
Uçar, B.; Aykanat, Cevdet (Society for Industrial and Applied Mathematics, 2007)This paper addresses the parallelization of the preconditioned iterative methods that use explicit preconditioners such as approximate inverses. Parallelizing a full step of these methods requires the coefficient and ... 
Revisiting hypergraph models for sparse matrix partitioning
Uçar, B.; Aykanat, Cevdet (Society for Industrial and Applied Mathematics, 2007)We provide an exposition of hypergraph models for parallelizing sparse matrixvector multiplies. Our aim is to emphasize the expressive power of hypergraph models. First, we set forth an elementary hypergraph model for the ...