• Title/Summary/Keyword: graph parallel algorithm

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Database Segment Distributing Algorithm using Graph Theory (그래프이론에 의한 데이터베이스 세그먼트 분산 알고리즘)

  • Kim, Joong Soo
    • Journal of Korea Multimedia Society
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    • v.22 no.2
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    • pp.225-230
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    • 2019
  • There are several methods which efficiencies of database are uprise. One of the well-known methods is that segments of database satisfying a query was rapidly accessed and processed. So if it is possible to search completely parallel multiple database segment types which satisfy a query, the response time of the query will be reduced. The matter of obtaining CPS(Completely Parallel Searchable) distribution without redundancy can be viewed as graph theoretic problem, and the operation of ring sum on the graph is used for CPS. In this paper, the parallel algorithm is proposed.

Automatic decomposition of unstructured meshes employing genetic algorithms for parallel FEM computations

  • Rama Mohan Rao, A.;Appa Rao, T.V.S.R.;Dattaguru, B.
    • Structural Engineering and Mechanics
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    • v.14 no.6
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    • pp.625-647
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    • 2002
  • Parallel execution of computational mechanics codes requires efficient mesh-partitioning techniques. These mesh-partitioning techniques divide the mesh into specified number of submeshes of approximately the same size and at the same time, minimise the interface nodes of the submeshes. This paper describes a new mesh partitioning technique, employing Genetic Algorithms. The proposed algorithm operates on the deduced graph (dual or nodal graph) of the given finite element mesh rather than directly on the mesh itself. The algorithm works by first constructing a coarse graph approximation using an automatic graph coarsening method. The coarse graph is partitioned and the results are interpolated onto the original graph to initialise an optimisation of the graph partition problem. In practice, hierarchy of (usually more than two) graphs are used to obtain the final graph partition. The proposed partitioning algorithm is applied to graphs derived from unstructured finite element meshes describing practical engineering problems and also several example graphs related to finite element meshes given in the literature. The test results indicate that the proposed GA based graph partitioning algorithm generates high quality partitions and are superior to spectral and multilevel graph partitioning algorithms.

AN EFFICIENT PRAM ALGORITHM FOR MAXIMUM-WEIGHT INDEPENDENT SET ON PERMUTATION GRAPHS

  • SAHA ANITA;PAL MADHUMANGAL;PAL TAPAN K.
    • Journal of applied mathematics & informatics
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    • v.19 no.1_2
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    • pp.77-92
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    • 2005
  • An efficient parallel algorithm is presented to find a maximum weight independent set of a permutation graph which takes O(log n) time using O($n^2$/ log n) processors on an EREW PRAM, provided the graph has at most O(n) maximal independent sets. The best known parallel algorithm takes O($log^2n$) time and O($n^3/log\;n$) processors on a CREW PRAM.

AN OPTIMAL PARALLEL ALGORITHM FOR SOLVING ALL-PAIRS SHORTEST PATHS PROBLEM ON CIRCULAR-ARC GRAPHS

  • SAHA ANITA;PAL MADHUMANGAL;PAL TAPAN K.
    • Journal of applied mathematics & informatics
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    • v.17 no.1_2_3
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    • pp.1-23
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    • 2005
  • The shortest-paths problem is a fundamental problem in graph theory and finds diverse applications in various fields. This is why shortest path algorithms have been designed more thoroughly than any other algorithm in graph theory. A large number of optimization problems are mathematically equivalent to the problem of finding shortest paths in a graph. The shortest-path between a pair of vertices is defined as the path with shortest length between the pair of vertices. The shortest path from one vertex to another often gives the best way to route a message between the vertices. This paper presents an $O(n^2)$ time sequential algorithm and an $O(n^2/p+logn)$ time parallel algorithm on EREW PRAM model for solving all pairs shortest paths problem on circular-arc graphs, where p and n represent respectively the number of processors and the number of vertices of the circular-arc graph.

Parallel Algorithm for Determining Connectedness of Context Free Graph Languages (CFGL 연결성 결정에 대한 병렬 알고리듬)

  • 방혜자;이철희
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.30B no.1
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    • pp.10-17
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    • 1993
  • This paper analyzes succinct graph descriptions and its complexity of connectivity problems on context free graph languages under various restrictions. It defines SNLC(Simple Context Free Node Label Controlled) grammar and presents reduction method that solves graph problems without expanding the hierarchical description. It exemplifies the method by giving efficient solutions to connectivity problems on graphs and presents parallel algorithm for reduction and analyzes the complexity. Its results will help application of desing for NETWORK. CAD. VLSI and other engineering problems.

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EFFICIENT ALGORITHMS TO COMPUTE ALL ARTICULATION POINTS OF A PERMUTATION GRAPH

  • Pal, Madhumangal
    • Journal of applied mathematics & informatics
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    • v.5 no.1
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    • pp.141-152
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    • 1998
  • Based on the geometric representation an efficient al-gorithm is designed to find all articulation points of a permutation graph. The proposed algorithm takes only O(n log n) time and O(n) space where n represents the number of vertices. The proposed se-quential algorithm can easily be implemented in parallel which takes O(log n) time and O(n) processors on an EREW PRAM. These are the first known algorithms for the problem on this class of graph.

A Parallel Algorithm for Measuring Graph Similarity Using CUDA on GPU (GPU에서 CUDA를 이용한 그래프 유사도 측정을 위한 병렬 알고리즘)

  • Son, Min-Young;Kim, Young-Hak;Choi, Sung-Ja
    • KIISE Transactions on Computing Practices
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    • v.23 no.3
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    • pp.156-164
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    • 2017
  • Measuring the similarity of two graphs is a basic tool to solve graph problems in various applications. Most graph algorithms have a high time complexity according to the number of vertices and edges. Because Graphics Processing Units (GPUs) have a high computational power and can be obtained at a low cost, these have been widely used in graph applications to improve execution time. This paper proposes an efficient parallel algorithm to measure graph similarity using the CUDA on a GPU environment. The experimental results show that the proposed approach brings a considerable improvement in performance and efficiency when compared to CPU-based results. Our results also show that the performance is improved significantly as the size of the graph increases.

(An O(log n) Parallel-Time Depth-First Search Algorithm for Solid Grid Graphs (O(log n)의 병렬 시간이 소요되는 Solid Grid 그래프를 위한 Depth-First Search 알고리즘)

  • Her Jun-Ho;Ramakrishna R.S.
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.7
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    • pp.448-453
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    • 2006
  • We extend a parallel depth-first search (DFS) algorithm for planar graphs to deal with (non-planar) solid grid graphs, a subclass of non-planar grid graphs. The proposed algorithm takes time O(log n) with $O(n/sqrt{log\;n})$ processors in Priority PRAM model. In our knowledge, this is the first deterministic NC algorithm for a non-planar graph class.

Performance Analysis of a Parallel Mesh Smoothing Algorithm using Graph Coloring and OpenMP (그래프 컬러링과 OpenMP를 이용한 병렬 메쉬 스무딩 알고리즘의 성능 분석)

  • Shin, Myeonggyu;Kim, Jibum
    • Journal of the Institute of Electronics and Information Engineers
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    • v.53 no.6
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    • pp.80-87
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    • 2016
  • We propose a parallel mesh smoothing algorithm using graph coloring and OpenMP library for shared memory many core computer architectures. The proposed algorithm partitions a mesh into independent sets and performs a parallel mesh smoothing using OpenMP library. We study the effect of using various graph coloring and color reordering algorithms on the efficiency of performing the proposed parallel mesh smoothing algorithm. We also investigate the influence of using various OpenMP loop scheduling methods on the parallel mesh smoothing efficiency.

THE OPTIMAL SEQUENTIAL AND PARALLEL ALGORITHMS TO COMPUTE ALL HINGE VERTICES ON INTERVAL GRAPHS

  • Bera, Debashis;Pal, Madhumangal;Pal, Tapan K.
    • Journal of applied mathematics & informatics
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    • v.8 no.2
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    • pp.387-401
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    • 2001
  • If the distance between two vertices becomes longer after the removal of a vertex u, then u is called a hinge vertex. In this paper, a linear time sequential algorithm is presented to find all hinge vertices of an interval graph. Also, a parallel algorithm is presented which takes O(n/P + log n) time using P processors on an EREW PRAM.