• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.3
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• pp.64-69
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• 2011

The spherical flange was designed to apply to a cryogenic high pressure pipe of a liquid rocket engine. It is designed that the spherical flange is able to be assembled and kept airtight up to $2.5^{\circ}$ of the axial misalignment between the combined components. It increases the degree of freedom of the engine assembly. The spherical flange is composed of a ball and socket joint, a metal seal, spherical type bolts and washers. The prototype was verified by leak test at the room temperature and the cryogenic temperature. Additionally the strength test and the destructive test were performed at the room temperature.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.921-926
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• 1998

CANFLEX 연료봉 다발의 3000 시간 내구성 시험 기간 동안 속도센서를 사용하여 압력관 내부에 장전된 연료봉 다발의 진동을 측정하였다. 압력관 내부에 장전된 연료봉의 진동측정은 고온, 고압, 그리고 공간적 제약 때문에 가속도계나 스트레인 게이지 같은 접촉센서로는 측정할 수 없다. 비접촉 센서를 사용하면 이러한 난점을 해결하고 압력관 내부에 장전된 연료봉 다발의 진동을 측정할 수 있다. 속도센서는 비접촉 센서로서 가우스(gauss)의 크기를 감지하여 전압을 출력하는 센서이지만, 측정거리, 주파수, 그리고 속도와 가우스가 비선형이기 때문에 교정을 한 후에 사용하여야 한다. 본 본문에는 속도센서의 교정방법과 압력관 내부에 고온, 고압의 유체가 흐를 때 발생하는 연료봉 다발의 진동특성을 구하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.604-607
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• 2000

All of rubber tubes for force pump are imported from aboard there for locallization of these tubes is make a great contribution of Korean industry In this study compare with existing product of japan and designed the new one that is for our actual circumstances. Experimental work was performed to two kinds of specimen and compression test is performed for them. As a result specimen type A has a better restoration than other and minimum thickness is must over 12mm.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.350-351
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• 2019

High Voltage Direct Current (HVDC) 시스템은 고압 직류 송전을 위한 시스템이다. 고압 직류 송전을 위해서는 전력변환기가 교류전력을 직류전력으로 변환해주어야 하는데, 최근에는 모듈형 멀티레벨 컨버터(Modular Multilevel Converter, MMC)가 많이 적용되고 있다. 모듈형 멀티레벨 컨버터는 단위 서브모듈이 직렬로 구성되어야 하는데 기구적으로 하나의 밸브 구조물에 6개의 서브모듈이 일정한 간격을 두고 위치하게 된다. 모듈형 멀티레벨 컨버터의 특징 중에 하나는 예비모듈이 구성되어 가용율을 높일 수 있다는 것이다. 본 논문에서는 서브모듈의 IGBT 폭파에 의해 발생되는 플라즈마가 주변 서브모듈에 도달해 절연파괴를 발생시키는지 확인하였다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.4
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• pp.287-292
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• 2011

To evaluate the pressure-resistant performance of underwater equipment, hyperbaric chamber test facility which can make the hydrostatic pressure is used. In this test, strain gage is generally applied to measure the strain of object under test is suitable for measuring a tiny deformation, but it can not measure a large deformation. Thus this paper suggests a method to estimate the over -order deformation of object under test by the image processing with the image acquired from underwater camera in the hydrostatic test. The main procedure of suggested method comprises the first step to find significant points by processing the image two dimensionally and the second step to estimate a deformation of object under test by tracking the motion of these points. If completing the remained research which is estimating the deformation and comparing it with a real one, it can be a method to measure the over -order deformation of object under test.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.8
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• pp.886-892
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• 2013

Hydraulic hose assemblies are used as piping components for construction machinery, automobile, aircraft, industrial machinery, machine tools, and machinery for ships. Then the reliability of hose assemblies is important because total hydraulic system, which used to deliver the fluid power ($P^*Q$) needed to flexibility in the piping system, is not operated if the hose assembly failed in the system. The data of the accelerated life test estimated through the shape parameter(${\beta}$) resulting of the Weibull distribution analysis. This study has tried to reduce the test time resulting from varying impulse pressure range and the flexing diameter. Accelerated life test model for the test results was adopted the GLL(generalized log linear) and the accelerated indexes are identified as 6.64 for the pressure and 4.46 for flexing radius. Also, it found that shape parameter is 6.19, scale parameter(${\eta}$) is $1.035{\times}108$, which were adopted the pressure 35 MPa and the flexing diameter R100 mm in the used condition.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.37-40
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• 2008

We have concentrated on the performance improvement of each part for durability, safety and cost of high pressure storage system for fuel cell vehicle so far. But for the mass production of fuel cell vehicle, it is necessary to evaluate durability and safety in system module. We built the standard to evaluate and collision safety of high pressure storage system for fuel cell vehicle, and could verify reliability of high pressure storage system.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.175-178
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• 2011

본 연구에서는 기존의 고압으로 작동되는 고압 미분무 건과는 달리 Twin-Fluid의 Turbulence 및 Break-up 현상 등을 이용하여 저압상태에서 작동하며 경량화 및 소형화에 성공하여 기존 소방관의 진입이 어려운 장소 또는 수원으로부터 멀리 떨어진 곳에서 원활한 소화활동을 위해 개발한 저압용 미분무 건의 성능을 화재소화능력 시험을 통해 입증하였다. 화재 소화능력 시험을 수행한 결과 물과 질소가 Mixing Chmaber 내부에서 혼합되면서 두 유체간의 상호작용 및 운동 에너지으로 인해 물의 액적이 미세하게 Atomizing되어 목재화재는 물론 유류화재의 진압에 있어서도 우수한 성능을 확인할 수 있었다.

• Proceedings of the Korean Nuclear Society Conference
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• 2004.05a
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• pp.265.2-265.2
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• 2004

• Tunnel and Underground Space
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• v.26 no.5
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• pp.409-417
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• 2016

The shale gas is emerging as one of the oil and gas resources which can replace the traditional oil and gas resources. As the shale layer where the shale gas is deposited has low permeability, the hydrofracturing method is required to improve the productivity. This study is designed to conduct the laboratory hydrofracturing test on the samples which are modeled after the drilling hole having the general drilling hole and spiral groove. And compare the initial fracturing pressure and fluid contact between them in order to the result of the hydrofracturing depending on the shape of the drilling hole. In addition, the results were compared with the numerical modeling values from 3DEC and they were also compared with the data from the advance researches. It was found from the study that rather than the contact area of the high pressures water, the force concentration depending on the form of guide hole was more effective in the hydrofracturing.