• Title/Summary/Keyword: 정기시(定期市)

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Optimazation of Power System Stabilizer Based on Hybrid System Modeling (하이브리드시스템 모델링 기반 전력시스템안정기 최적화)

  • Baek, Seung-Mook;Park, Jung-Wook
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.46-47
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    • 2007
  • 전력시스템안정기는 전력시스템의 저주파 댐핑을 효율적으로 향상시키기 위해 사용되는 제어기이다. 전력시스템안정기의 동적 특성은 위상 보상기의 이득과 시정수와 같은 선형 파라미터와 출력 리미터와 같이 비평활, 비선형 특성을 나타내는 비선형 파라미터에 영향을 받는다. 기존의 선형 제어 방법인 고유치 분석을 통한 선형 파라미터의 최적화 방법은 소신호 동작 범위에 대한 최적화 기법이기 때문에 큰 상정사고 시 효과적인 댐핑 향상을 보장할 수 없게 된다. 이를 극복하기 위하여 하이브리드 시스템에 신경회로망을 임베디드화하여 체계적인 방법으로 비선형 파라미터를 최적화한 후, 고유치 분석을 통해 선형 파라미터를 최적화함으로 전력시스템안정기의 성능 향상을 도모할 수 있다.

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Storage Reliability Prediction Model for Missile subjected to Non-periodic Test and Periodic Inspection excluding Overlapped Failures (수시점검 및 정기검사 시 고장의 중복을 배제한 유도탄 저장신뢰도 예측 모델)

  • Jo, Boram;Ahn, Jangkeun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.599-604
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    • 2018
  • For missile systems, sustaining high reliability and ensuring economical maintenance are very important. In the Republic of Korea, for most missiles, periodic inspection is mandatory for missiles in the field. Every fixed number of years, they are returned to the ordnance depot to be tested and repaired if faults are found. Almost all missiles have a built-in test (BIT) capability. With the BIT, faulty missiles can be isolated anytime during operations or storage in the launchers. So the reliability and the maintenance costs of the missiles greatly depend on the length of the inspection cycle and the BIT/inspection quality. In this paper, we suggest a model for predicting the storage reliability of missiles subjected to non-periodic tests and periodic inspections, excluding overlapping failures. Some numerical examples are given. This model will be useful for determining the length of the periodic inspection cycle.

Study on the Poets Inserted in (취유부벽정기) (<취유부벽정기>의 삽입 시와 서사 구조)

  • Park, Il-yong
    • Journal of Korean Classical Literature and Education
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    • no.15
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    • pp.421-461
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    • 2008
  • Miss Ki, the heroine of (취유부벽정기) is the image on which Hong-saeng's mind is projected. And the mind of Hong-saeng(홍생) is the allegory of Kim, si-seop's(김시습) mind to king Dan-jong. So I think the mind of Ki who thinks patriotism is more important than her life is the allegory of Kim si-seop's patriotic sentiment to king Dan-jong. And I think the sorrow of Hong-saeng for the ruins of Ko-choseon(고조선) means sorrow of Kim, si-seop's(김시습) for the death of Dan-jong's. They felt sorrowful because values that they considered as absolute ones were damaged. However, everything in the world are fatally changed. Although people think the most important thing they think now is never changed, after long time they cannot but see all is changed. At last people realize the thing seemed most important will disappear in vain. So the writer of (취유부벽정기) made a image of Miss Ki who is a nymph of moon and was the princess of Ko-choseon to awaken Hong-saeng. He intended to change hong-saeng's mind to king Dan-jong with the change of Miss Ki's mind to her father. But the writer knew the fact that though Hong-saeng changed his mind, he could not become happy. So he wanted to transcend the real world, but he can't. After all he expressed his wants in fantastic lunar world.

An Empirical Study on the Economic Benefit of Space Chartering (정기선 선복 확보를 위한 Space Chartering의 경제성에 관한 연구)

  • Park, Doo-Jin;Kim, Hyun;Nam, Ki-Chan
    • Journal of Navigation and Port Research
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    • v.30 no.8 s.114
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    • pp.663-668
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    • 2006
  • This thesis tries to evaluate the economic benefit of space chartering in comparison with time chartering with respect to mega container ships. For this it reviews the method of obtaining ship's carrying capacity such as time chartering and space chartering. Based on this, it tries to make comparison between the time chartering and space chartering on economic base. Finally, it suggest the economic benefit of space chartering with direction for further study.