Browsing by Author "Aykanat, Cevdet"
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Dataparallel web crawling models
Cambazoglu, B. B.; Turk, A.; Aykanat, Cevdet (Springer, 2004)The need to quickly locate, gather, and store the vast amount of material in the Web necessitates parallel computing. In this paper, we propose two models, based on multiconstraint graphpartitioning, for efficient ... 
Decomposing linear programs for parallel solution
Pınar, Ali; Çatalyürek Ümit V.; Aykanat, Cevdet; Pınar, Mustafa (Springer, 199508)Coarse grain parallelism inherent in the solution of Linear Programming (LP) problems with block angular constraint matrices has been exploited in recent research works. However, these approaches suffer from unscalability ... 
Direct volume rendering of unstructured grids
Berk, Hakan; Aykanat, Cevdet; Güdükbay, Uğur (Pergamon Press, 2003)This paper investigates three categories of algorithms for direct volume rendering of unstructured grids, which are imagespace, objectspace, and hybrid methods. We propose three new algorithms. Cell Projection algorithm, ... 
Document replication strategies for geographically distributed web search engines
Kayaaslan, E.; Cambazoglu, B. B.; Aykanat, Cevdet (Elsevier Ltd., 2013)Largescale web search engines are composed of multiple data centers that are geographically distant to each other. Typically, a user query is processed in a data center that is geographically close to the origin of the ... 
Effect of inverted index partitioning schemes on performance of query processing in parallel text retrieval systems
Cambazoğlu, B. Barla; Çatal, A.; Aykanat, Cevdet (Springer, 200611)Sharednothing, parallel text retrieval systems require an inverted index, representing a document collection, to be partitioned among a number of processors. In general, the index can be partitioned based on either the ... 
The effect of various sparsity structures on parallelism and algorithms to reveal those structures
Selvitopi, O.; Acer, S.; Manguoğlu, M.; Aykanat, Cevdet (Birkhauser, 2020)Structured sparse matrices can greatly benefit parallel numerical methods in terms of parallel performance and convergence. In this chapter, we present combinatorial models for obtaining several different sparse matrix ... 
An effective model to decompose linear programs for parallel solution
Pınar, Ali; Aykanat, Cevdet (Springer, 199608)Although inherent parallelism in the solution of block angulax Linear Programming (LP) problems has been exploited in many research works, the literature that addresses decomposing constraint matrices into block angular ... 
Efficient fast hartley transform algorithms for hypercubeconnected multicomputers
Aykanat, Cevdet; Derviş, A. (IEEE, 1995)Although fast Hartley transform (FHT) provides efficient spectral analysis of real discrete signals, the literature that addresses the parallelization of FHT is extremely rare. FHT is a real transformation and does not ... 
Efficient overlapped FFT algorithms for hypercubeconnected multicomputers
Aykanat, Cevdet; Dervis, A. (1994)In this work, we propose parallel FFT algorithms, for mediumtocoarse grain hypercubeconnected multicomputers, which are more elegant and efficient than the existing ones. The proposed algorithms achieve perfect loadbalance ... 
Efficient parallel spatial subdivision algorithm for objectbased parallel ray tracing
Aykanat, Cevdet; İşler, V.; Özgüç, B. (Pergamon Press, 1994)Parallel ray tracing of complex scenes on multicomputers requires the distribution of both computation and scene data to the processors. This is carried out during preprocessing and usually consumes too much time and memory. ... 
Efficient successor retrieval operations for aggregate query processing on clustered road networks
Demir, E.; Aykanat, Cevdet (Elsevier Inc., 2010)GetSuccessors (GS) which retrieves all successors of a junction is a kernel operation used to facilitate aggregate computations in road network queries. Efficient implementation of the GS operation is crucial since the ... 
Efficient vectorization of forward/backward substitutions in solving sparse linear equations
Aykanat, Cevdet; Özgü, Özlem; Güven, N. (IEEE, 1994)Vector processors have promised an enormous increase in computing speed for computationally intensive and timecritical power system problems which require the repeated solution of sparse linear equations. Due to short ... 
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 ... 
Energypricedriven query processing in multicenter web search engines
Kayaaslan, Enver; Cambazoglu, B. B.; Blanco, R.; Junqueira, F. P.; Aykanat, Cevdet (IEEE, 201107)Concurrently processing thousands of web queries, each with a response time under a fraction of a second, necessitates maintaining and operating massive data centers. For largescale web search engines, this translates ... 
Exploiting locality in sparse matrixmatrix multiplication on manycore rchitectures
Akbudak K.; Aykanat, Cevdet (IEEE Computer Society, 2017)Exploiting spatial and temporal localities is investigated for efficient rowbyrow parallelization of general sparse matrixmatrix multiplication (SpGEMM) operation of the form C=A,B on manycore architectures. Hypergraph ... 
A fast neuralnetwork algorithm for VLSI cell placement
Aykanat, Cevdet; Bultan, T.; Haritaoğlu, İ. (Pergamon Press, 1998)Cell placement is an important phase of current VLSI circuit design styles such as standard cell, gate array, and Field Programmable Gate Array (FPGA). Although nondeterministic algorithms such as Simulated Annealing (SA) ... 
Fast optimal load balancing algorithms for 1D partitioning
Pınar, A.; Aykanat, Cevdet (Academic Press, 2004)The onedimensional decomposition of nonuniform workload arrays with optimal load balancing is investigated. The problem has been studied in the literature as the "chainsonchains partitioning" problem. Despite the rich ... 
Fast sharedmemory streaming multilevel graph partitioning
Jafari, N.; Selvitopi, O.; Aykanat, Cevdet (Elsevier, 20200912)A fast parallel graph partitioner can benefit many applications by reducing data transfers. The online methods for partitioning graphs have to be fast and they often rely on simple onepass streaming algorithms, while the ... 
A faulttolerant hexagonal systolic array
Aykanat, Cevdet; Özgüner, F. (Elsevier, 1992) 
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 ...