• Title/Summary/Keyword: Loop Splitting

Search Result 18, Processing Time 0.029 seconds

A Loop Transformation for Parallelism from Single Loops

  • Jeong, Sam-Jin
    • International Journal of Contents
    • /
    • v.2 no.4
    • /
    • pp.8-11
    • /
    • 2006
  • This paper describes several loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops into parallel loops.

  • PDF

Parallelism for Single Loops with Multiple Dependences

  • Jeong, Sam-Jin
    • International Journal of Contents
    • /
    • v.3 no.3
    • /
    • pp.15-19
    • /
    • 2007
  • We review some loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the iteration and distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops with one dependence as well as with multiple dependences into parallel loops.

An Efficient Loop Splitting Method on Single Loop with Non-uniform Dependences (비균일 단일루프에서의 효율적인 루프 분할 방법)

  • Jeong Sam-Jin
    • The Journal of the Korea Contents Association
    • /
    • v.5 no.4
    • /
    • pp.204-211
    • /
    • 2005
  • This paper introduces three loop splitting methods such as minimum dependence distance method, Polychronopoulous' method, and first dependence method for exploiting parallelism from single loop which already developed. And it also Indicates their several problems. We extend the first dependence method which is the most effective one among three loop splitting methods, and propose more powerful loop splitting method to enhance parallelism on single loop. The proposed algorithm solves several problems, such as anti-flow dependence and g=gcd(a,c) > 1, that the first dependence method has.

  • PDF

Loop Splitting for On-the-fly Race Detection of Sharded-memory Parallel Programs (공유 메모리 병렬 프로그램의 수행중 오류 탐지를 위한 루프 분리)

  • Song, Tae-Seob
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.16 no.3
    • /
    • pp.391-398
    • /
    • 2012
  • Detecting races is important for debugging shared-memory parallel programs, because the races result in unintended non-deterministic executions of the programs. Previous on-the-fly techniques to detect races in parallel programs with general inter-thread coordination show serious space overhead which depends on the maximum parallelism of the program. Therefore, this paper presents a loop splitting technique for on-the-fly race detection of parallel programs which is more efficient in space complexity than previous techniques. This loop splitting technique is the debugged program which preserves semantics of the original program. Monitering loop splitting program in on-the-fly can detect first races.

Parallelism for Single Loops with Non-uniform Dependences (비균일 단일루프에서의 병렬화)

  • Jeong, Sam-Jin
    • Proceedings of the Korea Contents Association Conference
    • /
    • 2006.11a
    • /
    • pp.565-569
    • /
    • 2006
  • This paper reviews some loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops into parallel loops.

  • PDF

Parallelism for Nested Loops with Simple Subscripts

  • Jeong, Sam-Jin
    • International Journal of Contents
    • /
    • v.4 no.4
    • /
    • pp.1-6
    • /
    • 2008
  • In this paper, we propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the iteration and distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences (MPSL). By the extension of the MPSL method, we also apply to exploit parallelism from nested loops with simple subscripts, based on cycle shrinking and loop interchanging method. The algorithms generalize how to transform general single loops with non-uniform dependences as well as nested loops with simple subscripts into parallel loops.

Automatic Mesh Generation with Quadrilateral Finite Elements (사각형 유한요소망의 자동생성)

  • 채수원;신보성;민중기
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.17 no.12
    • /
    • pp.2995-3006
    • /
    • 1993
  • An automatic mesh generation scheme has been developed for finite element analysis with two-dimensional, quadrilateral elements. The basic strategies of the method are to transform the analysis domain into loops with key nodes and the loops are recursively subdivided into subloops with the use of best split lines. Finally by using the basic loop operators, the meshes are completed. In this algorithm an eight-node loop operator is proposed, which is useful in the area where the change of element size is large and the splitting criteria for subdividing the loops have also been modified to the existing algorithms. Lines, arcs, and cubic spline curves are used to define the boundaries of analysis domain. Sample meshes for several geometries are presented to demonstrate the robustness of the algorithm.

An Algorithm for Splitting a Box by a Loop and Its Applications in Manufacturing

  • Kheerwal, Anoop;Shanmuganathan, Vivekananda;Shringi, Rohitashwa;Karunakaran, Karuna P.
    • International Journal of CAD/CAM
    • /
    • v.3 no.1_2
    • /
    • pp.85-95
    • /
    • 2003
  • During the design of dies and molds, the cavity of the object is obtained by subtracting it from a surrounding rectangular block. This box is subsequently split into two halves by the parting surface. Similar problems also occur in some RP processes such as LOM, SGC, SLS and 3DP where the machine produces a block inside which the prototype is buried. Determining the orientation of the object inside the box and the corresponding parting surface taking appropriate constraints into account have been addressed by several researchers. However, given the parting surface, the problem of splitting the box development of a software package called OptiLOM (now a module of an RP software Magics 8.0), the authors realized non-triviality of this problem since the loop can spread over as many as 5 faces of the box. In this paper, the authors have tried to bring out the importance of this problem and have presented their algorithm to solve it.

Flow Control on Wind Turbine Airfoil with a Vortex Cell (와류 셀을 이용한 풍력블레이드 에어포일 주위 유동 제어)

  • Kang, Seung-Hee;Kim, Hye-Ung;Ryu, Ki-Wahn;Lee, Jun-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.40 no.5
    • /
    • pp.405-412
    • /
    • 2012
  • A flow control on airfoil installed a vortex cell for high efficiency wind turbine blade in stationary and dynamic stall conditions have been numerically investigated by solving the compressible Navier-Stokes equations. The numerical scheme is based on a node-based finite-volume method with Roe's flux-difference splitting and an implicit time-integration method coupled with dual time step sub-iteration. The computed result for the airfoil in the stationary showed that lift-drag ratio increases due to low pressure by the vortex cell. The oscillating airfoil with the vortex cell showed that the magnitude of hysteresis loop is reduced due to the enhanced vortex in the cell.

Feasibility Study of Superconducting Fault Current Limiter Application to Korean Power System

  • Kim, Hak-Man;Kim, Jong-Yul
    • Progress in Superconductivity and Cryogenics
    • /
    • v.5 no.1
    • /
    • pp.103-106
    • /
    • 2003
  • The short circuit current problem is one of the operational problems that need to be solved by power system engineers in Korea. It is an important issue in the Seoul metropolitan area especially because of highly meshed configuration. Currently, it is regulated by changing 154 kV system configuration from loop connection to radial system, by splitting of the bus where load balance can be achieved, and by upgrading circuit breaker rating. A development project for 154 kV/2 KA SFCL application to 154 kV transmission system after 2010 is proceeding. In this paper, a feasibility study of superconducting fault current limiter (SFCL) is carried out in Seoul metropolitan area to find out the effects of its application and feasibility. This study shows that it can reduce fault current considerably, and as it can minimize the upgrading of circuit breaker rating, the economic potential of SFCL is evaluated positively.