• Journal of KIISE:Computer Systems and Theory
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• v.26 no.8
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• pp.884-894
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• 1999

순서적 동기화 및 내포 병렬성을 포함하는 공유메모리 병렬 프로그램에서의 경합(race)은 프로그램 수행에서 원하지 않은 비결정성(nondeterminism)을 야기할 수 있기 때문에 반드시 탐지되어져야 한다. 특히 프로그램 수행에서 최초경합(first race)을 탐지하는 것은 중요한데, 그 이유는 이 경합을 제거하면 다른 경합이 나타나지 않을 수도 있기 때문이다. 본 논문에서는 결정적 공유메모리 병렬프로그램을 위한 2단계 수행중 (two-pass on-the-fly) 최초경합 탐지 기법을 제시하며, 이것은 공유메모리 병렬 프로그램의 특정 수행에서 "최초로 발생되는" 경합들을 탐지하는 기법이다. 그리고 HPF 컴파일러를 이용하여 본 탐지 프로토콜을 공인된 벤치마크 프로그램에 적용하여, 병렬 프로그램 디버깅 시 고려하여야 할 파라미터들에 대한 실험으로부터 본 기법의 효율성을 보였다.Abstract Detecting races is important in debugging shared-memory parallel programs which have ordered synchronization and nested parallelism, because the races result in unintended non- deterministic executions of the programs. The first races are important in debugging, because the removal of such races may make other races disappear. It is even possible that all races reported would disappear once the first races are removed. This paper presents a new two-pass on-the-fly algorithm to detect the first races in such parallel programs. The algorithm reported in this paper is an on-the-fly algorithm that detects the races that "occur first" in a particular execution of shared-memory parallel programs. The experiment has accomplished, where two certified benchmark programs which can be executed under High Performance Fortran environments to get some parameters which improve debugging performance with our algorithm. with our algorithm.

• IE interfaces
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• v.12 no.2
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• pp.305-311
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• 1999

Robot task program is needed to control and manage a Robot without explicitly describing the robot program by user which includes commands, procedures, geometric and signal data in the detail level. To use the Robot task program, a computer system is required to convert the Robot task into the Robot program, which can be understood by the Robot. In this paper, the systemic method for automatic generation of explicit Robot programs (ERP) from task-level commands is described. Specifically, a 3-step procedure including Robot task decomposition, task synchronization and ERP generation is presented.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.8
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• pp.723-728
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• 2015

In the conventional hot rolling process, the defects of products such as scratches occur due to impact and friction. Impact occurs as a result of the contact of between rollers and the slab. Also, friction occurs in the rolling process. To improve these defects, a variety of processes were developed. The flying touch method is also one of the processes to reduce defects and uses a movable upper roller. To use this unfixed roller, the impact and frictions between rollers and the slab should be minimized. This paper proposes a hot rolling process simulator to verify and test the efficiency of the flying touch method. The simulator was designed to verify the method. This paper also proposes a new impact reducing method and velocity synchronization method which are simulated to realize the method.

• The KIPS Transactions:PartA
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• v.13A no.3 s.100
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• pp.205-210
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• 2006

To assist developing robust multithreaded software, we develop a thread monitoring system for multithreaded Java programs, which can trace or monitor running threads and synchronization. We design a monitoring system which has options to select interesting threads and synchronizations. Using this tool, programmers can monitor only interesting threads and synchronization in more details by selecting options. It also provides profile information after execution, which summarizes behavior of running threads and synchronizations during execution. We implement the system based on code inlining, and presents some experimental results.

• Journal of Embryo Transfer
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• v.32 no.3
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• pp.159-163
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• 2017

The artificial insemination (AI) is one of the best assisted reproductive technologies for increasing reproductive capacity and facilitating the genetic improvement in farm animals. AI has been used in Uganda for over 60 years, but a small population of the total herd has been used. This study was conducted to investigate the efficacy of AI with estrus synchronization technique and to propose ways of improving the productivity of dairy farms through AI services in Uganda. In total, 78 cows from 11 dairy farms were selected for timed-AI. Synchronization was performed according to the ovsynch programs followed by AI using frozen semen from Korean Holstein (0.5 ml straws). Pregnancy rate was varying among farms (0-50%) and the overall pregnancy rate was 28.2%. Cows in luteal phase at the time of treatment was 40.0% whereas that in follicular phase was 20.8%. After treatment, cows that showed normal estrus signal were 45.5% (25/55). Abnormal estrus was categorized into pre-estrus (9.1%), cystic ovaries (21.8%), anestrus (18.2%) and delayed ovulation (5.5%), respectively. These results imply that an assured protocol for timed-AI should be developed to improve the productivity of dairy farms through AI services in Uganda.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10a
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• pp.263-264
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• 2007

• Proceedings of the Korean Information Science Society Conference
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• 1999.10c
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• pp.774-776
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• 1999

공유메모리 병렬프로그램에서의 경합은 프로그램 수행에서 원하지 않는 비결정성을 야기할 수 있기 때문에 반드시 탐지되어져야 한다. 기존의 탐지 기법들은 경합을 탐지하기 위해서 공유 자료구조를 사용하므로 심각한 병목현상을 일으킨다. 본 논문에서는 동기화가 있는 프로그램에서 병목현상을 줄임으로써 탐지의 효율성을 높임과 동시에, 최초로 발생한 경합을 탐지하기 위해서 감시대상이 되는 접근사건들의 수를 감소시키는 기법을 제시한다. 이러한 목적을 위해서 사건선택 알고리즘과 실제적인 실험결과를 통해 본 기법의 효율성을 보인다.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.962-970
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• 2000

Multithreading is attractive in that it can tolerate memory latency and synchronization by effectively overlapping communication with computation. While several compiler techniques have been developed to produce multithreaded codes from functional languages programs, there still remains a lot of works to implement loops effectively. Executing lops in a style of multithreading usually causes some overheads, which can reduce severely the effect of multirheading. This paper suggests several methods in terms of architectures or compilers which can optimize loop execution by multithreading. We then simulate and analyze them for the matrix multiplication program.

• The Transactions of the Korea Information Processing Society
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• v.6 no.2
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• pp.485-496
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• 1999

Comparing with sequential programming, parallel programming has additional complexity due to the consideration of parallelism, communication and synchronization of processes. A synergism between users and compliers should be established, each assisting the other to produce high quality parallel programs. On the above underlying philosophy, we developed a parallel Object-Oriented specification language, POOSL, as preliminary works. However, it is still likely to hard for users to write parallel program because users have to consider grammar of POOSL and to write text-based parallel program. It would be more desirable to provide users wit visual environment for effective parallel programming. Therefore, we propose a visual programming environment. VEPO(Visual environment for Parallel Object-Oriented Programming), based on POOSL in order that users can develop parallel programs more easily and conveniently. It aims at supporting a programming environment in which users can represent their programs more naturally and visually I parallel manner with object-oriented concept and essential steps during parallel program development such as program specification, compilation, execution and animation of execution are integrated. VEPO has useful features for parallel processing. Especially, complicated parallel codes for synchronization and communication of processes are automatically generated in the translation phase, so users can be relieved of writing error-prone parallel codes. The system is targeted to the transputer-based parallel system, MC-3. The graphic user interface of VEPO was implemented using Visual C++. Visual programs descirbed on VEPO are translated into Inmos C and executed on MC-3.

• The Transactions of the Korea Information Processing Society
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• v.2 no.1
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• pp.119-129
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• 1995

In this paper, we propose a schedulatility analysis method for real-time programs. Several approaches to anlayzing schedulability have been developed, but since these approaches use a fixed priority scheduling method and/or traverse all possible state spaces, there take place exponential time and space complexity of these methods, Therefore it is necessary to reduce the state space and detect schedulability at earlier time. Our schedulability analysis method uses a minimum unit time taken to terminate synchronization action, a minimum unit time taken to terminate actions after synchronization, and a deadline of processes to detect unschedulability at earlier time and dynamic scheduling scheme to reduce state space. We conclude that our method can detected unschedulability earlier 50 percent unit time than Fredette's method.