• Title/Summary/Keyword: 내부적 비결정성

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Potential Races Detection in Shared-Memory Programs with Internal Nondeterminism (내부적 비결정성을 가진 공유 메모리 프로그램의 잠재적 경합 탐지)

  • Jung, Min-Sub;Kim, Young-Joo;Ha, Ok-Kyoon;Jun, Yong-Kee
    • Proceedings of the Korea Information Processing Society Conference
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    • 2008.05a
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    • pp.553-556
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    • 2008
  • 임계구역을 가진 공유 메모리 기반의 병렬 프로그램에서 발생하는 경합은 프로그래머가 의도하지 않은 비결정적인 수행 결과를 초래하므로 반드시 디버깅해야 한다. 이러한 경합을 수행 중에 탐지하는 기존의 기법들은 임계구역의 실행순서에 의해서 발생하는 내부적 비결정성이 존재하지 않는 프로그램에 대해서만 경합의 존재를 검증할 수 있다. 본 논문에서는 내부적 비결정성을 가진 프로그램에 존재하는 비결정적 접근사건을 정적으로 분석하고, 이 정보를 이용하여 수행 중에 경합을 탐지함으로써 잠재되어 있는 경합까지 탐지할 수 있는 도구를 제안한다. 제안한 도구는 비결정성이 포함된 합성프로그램과 공인된 OpenMP 벤치마크 프로그램인 Microbenchmark를 이용하여 경합 검증이 가능함을 보인다.

A Preprocessor for Detecting Potential Races in Shared Memory Parallel Programs with Internal Nondeterminism (내부적 비결정성을 가진 공유 메모리 병렬 프로그램에서 잠재적 경합탐지를 위한 전처리기)

  • Kim, Young-Joo;Jung, Min-Sub;Jun, Yong-Kee
    • The KIPS Transactions:PartA
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    • v.17A no.1
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    • pp.9-18
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    • 2010
  • Races that occur in shared-memory parallel programs such as OpenMP programs must be detected for debugging because of causing unintended non-deterministic results. Previous works which verify the existence of these races on-the-fly are limited to the programs without internal non-determinism. But in the programs with internal non-determinism, such works need at least N! execution instances for each critical section to verify the existence of races, where N is the degree of maximum parallelism. This paper presents a preprocessor that statically analyzes the locations of non-deterministic accesses using program slicing and can detect apparent races as well as potential races through single execution using the analyzed information. The suggested tool can deterministically monitor non-deterministic accesses to occur in OpenMP programs so that this tool can verify the existence of races even if it is used any race detection protocol which can apply to programs with critical section. To prove empirically this tool, we have experimented using a set of benchmark programs such as synthetic programs that involve non-deterministic accesses, OpenMP Microbenchmark, NAS Parallel Benchmark, and OpenMP application programs.

A Study on the Warpage of Injection Molded Parts for the rapid Cooling and Heating Device (급속냉각·가열장치에 따른 사출성형품의 휨에 관한 연구)

  • Lee, Min;Kim, Tae-Wan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.8
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    • pp.5074-5081
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    • 2015
  • A method for improving the warpage of the plastic part is a method of removing residual stress of the plastic product. that a non-uniform cooling are appeared in the injection molding process make uniform cooling. this study was developed the Rapid heating and cooling device used peltier module for uniform cooling. Make the Rapid heating and cooling device(RCHD), for Traditional water cooling device(TWCD) method and the Rapid heating and cooling method warpage were compared and were analyzed and the materials used amorphous ABS polymer. various warpage were compared for the process parameters such as packing pressure, packing time, resin temperature, mold temperature, In the amorphous ABS polymer, TWCD method has higher warpage than RCHD method and show the result to be a bit more uniform cooling. The distribution state of the ABS polymer was confirmed Through the Scanning electron microscope. In the TWCD method the distribution state of the polymer be densely distributed, and RCHS method be distributed wider than TWCD method. this is that injection molded parts be seen that cooling was made uniformly, As the temperature of the mold is gradually progress, Particles of the polymer is increased this is that internal stress was reduced.