• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.130-130
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• 2017

비닐하우스의 골조를 구성하는 파이프는 부식을 방지할 목적으로 아연도강관을 사용한다. 그러나 시간이 지남에 따라 아연도금량 감소와 여러 외부 환경인자 등에 의하여 부식이나 침식이 진행되어, 외관상 녹이 생기고 강도와 연신율 등이 감소하게 된다. 이는 비닐하우스 전체의 내구성을 저하시키는 요인으로 작용하게 되는데, 이를 평가하기 위한 방법이나 기준은 미비한 실정이다. 이에 본 연구에서는 농업시설의 내구성을 평가하기 위한 방법의 하나로 각기 다른 경과년수를 갖는 비닐하우스로부터 채취한 서까래 파이프의 인장 시험을 실시하였다. 인장 시험에 사용된 서까래 파이프는 (구)시설원예시험장에 설치되어 있는 비닐하우스에서 경과년별로 채취하였으며, 지중매설부와 지상노출부로 구분하여 시편을 제작하였다. 인장 실험 결과 서까래 파이프의 경과년이 오래될수록 시편의 인장 강도는 작아지는 경향을 보이고 있으나, 파단연신율은 경과년과 연관성을 찾아보기 어려운 것으로 나타났다. 그리고 동일한 경과년을 갖는 서까래 파이프 시편에서 지중매설부의 인장 강도와 파단연신율이 지상노출부에 비해 대체로 작게 측정되었으며, 경과년이 증가할수록 인장 강도의 감소폭이 커지는 경향을 보이는 것으로 나타났다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.1493-1494
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• 2013

파이프 로봇은 검사원이 접근하기 어려운 높은 지역에 설치되어 있는 파이프 및 기기의 건전성을 검사하기 위해 사용된다. 높은 지역의 파이프를 이동할 경우 지상에서 파이프 로봇을 조종하는 방법으로는 파이프를 잡기 힘들다. 그러므로 파이프 로봇의 카메라 영상을 이용하여 파이프 로봇의 파이프 잡기가 필요하다. 본 논문에서는 카메라 영상을 이용하여 파이프 로봇이 파이프를 잡기 위한 영상처리 알고리즘을 제시한다.

• Journal of Power System Engineering
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• v.15 no.3
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• pp.18-24
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• 2011

In this study, the reflection of the L(0,2), axially symmetric guided elastic wave from defects in pipes above ground is examined using finite element method. Phase and group velocity dispersion curves for the pipe were presented for the selection of the excitation mode. Some simple signal processing was applied to determine the amplitude of each of the reflected waves and to calculate the reflection coefficient. The results show the reflection coefficient of this mode is very close to a linear function of the circumferential extent of the defect. The motivation for the work was the development of a technique for inspecting chemical plant pipelines, but the study addresses the nature of the reflection function and its general applicability.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.87-92
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• 2019

The purpose of this study is to investigate the preparation time of fire-fighting water for public fire hydrants and ground, underground fire hydrants. The equipment preparation time for stage 1 was 20.50 seconds for ground type and 24.67 seconds for underground type. The reason for this difference in preparation time is that an underground fire hydrant requires additional standpipes to connect to the main conduit of Paru and the underground hydrant, which open the manhole cover. Water tank Maintenance joint with water hose male coupling of the second stage was similar to that of the ground type of 48.50 seconds and underground water tipe of 49.00 seconds. This is because the operation of connecting the fire hose to the maintenance tank of the water tank car is the same. In the third stage, the water pipe connection was 43 seconds for ground type and 174.33 seconds for underground type. The reason why the time for connecting the water pipe to the fire hydrant is large difference is that the underground fire hydrant is opened by opening the manhole cover, After connecting the stand pipe to the fire hydrant, the additional process of connecting the water pipe to the stand pipe is required, which is considered to have greatly increased the time required. The opening of Water Control Valve and spindle Valve in the fourth stage was 66.50 seconds for the ground type and 78.83 seconds for the underground type. This difference is due to the fact that the spindle of the ground fire hydrant is located on the main body and can be easily opened, but the underground type is located next to the main body under the manhole and requires additional time to connect the opening equipment.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.196-201
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• 2020

In order to increase the durability of the pipe framed greenhouse, galvanized steel pipes with four corrosion protection treatments were installed in the greenhouse. After 20 years, experiments on surface corrosion and strength change were conducted. Control (untreated) pipes exposed in the atmosphere showed a 1.3% reduction in strength, but little difference from other treatments. The strength of heavy protective coating pipes buried in the ground decreased by 0.6%, showing little change, but untreated pipes decreased by 15.7%. And antirust paint and asphalt coating pipes decreased by 4.2~4.4%. Pipes exposed in the atmosphere did not show severe corrosion in all samples. There was no change in heavy protective coating pipes, and no rust was found in antirust painting pipes either and there was only slight discoloration. Asphalt coating pipes discolored black and some rust was found, and untreated pipes were rusted by 20~30% of the surface. However, untreated pipes buried in the ground were completely rusted, and asphalt coating pipes were rusted by 80~90% of the surface. Antirust painting pipes were rusted by 20~30%, and heavy protective coating pipes did not change almost. The heavy protective coating treatment showed a clear corrosion protection effect even in the parts buried in the ground, and the antirust painting treatment also showed some corrosion protection effect. Therefore, it is judged to be applicable to the field of pipe framed greenhouses.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.674-677
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• 2010

본 논문에서는 지반에 매립된 파이프에서 전파되는 유도초음파의 종파 모드 특성을 분석하였다. 지상 배관과는 달리 매립 배관에서는 주변 매질로 유도초음파의 누설이 발생할 수 있으며, 이로 인하여 유도초음파의 감쇠가 상대적으로 커질 수 있다. 따라서 본 연구에서는 유도초음파의 여러 특성들 중 종파 모드의 감쇠 특성을 중점적으로 분석하였다. 감쇠에 영향을 미치는 지반의 파동 특성(밀도, 체적종파속도, 체적횡파속도)을 결정하기 위하여 포화도와 다짐을 고려하였다. 포화도가 증가할수록 지반의 체적종파속도와 체적횡파속도는 감소하며, 다짐된 지반은 밀도와 체적종파속도, 체적횡파속도를 증가시킨다. 이와 같은 조건으로 결정된 지반의 파동 특성치와 배관의 물성치를 바탕으로 유도초음파 종파 모드의 감쇠 곡선을 계산하고, 특성을 분석하였다. 결과적으로 포화도가 증가할수록 종파 모드의 감쇠는 감소하는 경향을 나타내었고, 다짐이 증가할 경우 감쇠는 전반적으로 증가하는 경향을 나타냄을 알 수 있었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.49-50
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• 2021

광산 분야 등의 채굴을 위한 천공 과정에서 현재 진행 중인 천공 위치의 실시간 측정이 요구되는데 이를 위해 드릴 후면에 부착된 센서 정보를 로드 파이프를 통해 지상으로 전송할 수 있는 통신방식을 제안하였다. 드릴 후면에 장착된 센서에서 검출된 신호는 송신부에서 변조를 통해 로드 파이프로 전송하고, 수신부에서는 이에 대응되는 복조 과정을 통해 센서 데이터를 추출하였다. 제안된 방법의 검증을 위해 설계된 장치를 사용하여 실험을 수행하였으며, 실험 결과 제안된 방법에 의한 데이터 송수신이 정상적으로 동작함을 확인하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.730-736
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• 2019

The demand for natural gas, which is considered an environmentally friendly energy source, is increasing, and at the same time, the market share of large pipelines for natural gas supply is increasing continuously. On the other hand, the corrosion of such large pipelines reduces the efficiency of natural gas transportation. Therefore, this study aims to establish a strategy for securing the patent rights of related technologies through quantitative analysis of patents on energy-independent high-efficiency corrosion prevention technology for large-scale pipelines for natural gas supply. In this patent technology trend study, Korean, US, Japanese, and European patents filed, published, and registered by June 2018 were analyzed, and a technical classification system and classification criteria were prepared through expert discussion. To use fuel cells as an external power source to prevent the corrosion of natural gas large-scale pipelines, it is believed that rights can be claimed using an energy control system and methods having 1) branch structures of pipeline and facility designs (decompressor/compressor/heat exchanger) and 2) decompression/preheating and pressurization/cooling technology of high pressure natural gas.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.1052-1057
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• 2004

A small-scale loop heat pipe with polypropylene wick was fabricated and tested for its thermal performance. The container and tubing of the system was made of stainless steel and several working fluids were used to see the difference in performance including methanol, ethanol, acetone, R134a, and water. The heating area was 35 mm ${\times}$ 35 mm and there were nine axial grooves in the evaporator to provide a vapor passage. The pore size of the polypropylene wick inside the evaporator was varied from 0.5 m to 25 m. The size of condenser was 40 mm (W) ${\times}$ 50 mm (L) in which ten coolant paths were provided. The inner diameter of liquid and vapor transport lines were 2.0 mm and 4.0 mm, respectively and the length of which were 0.5 m. The PP wick LHP was operated with methanol, acetone, and ethanol normally. R134a was not compatible with PP wick and water was unsuitable within operating limit of $100^{\circ}C$. The minimum thermal load of 10 W (0.8 W/cm2) and maximum thermal load of 80 W (6.5 W/cm2) were achieved using methanol as working fluid with the condenser temperature of $20^{\circ}C$ with horizontal position.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.2
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• pp.96-102
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• 2003

The thermal design of MGSE(Mechanical Ground Support Equipment) panel is performed for thermal vacum thest of Ka-band EQM(Engineering Qualification Model) payload of communications and broadcasting satellite. The thermal environments are predicted to evaluate the performance of transponder equipments in the thermal vacum chamber. SINDA is used to verify the thermal design of the heat pipe layout. Embedded 16 heat pipes in the EQM payload developed for Ka-band trasponder equipments are designded properly. The heat fluz loaded on the external facesheet is 265W/㎡ for the hot platear function test of the traspinder equipments, and the zero heat flux for the cold plateau case. The maxium predicted heat transport capability is 2723 W-cm.