• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.743-749
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• 2009

In this study, the field test for suction drain method which does not require a surcharge load and a sealing sheet was performed at west seashore's site constructed by the dredged and reclaimed clay. The improvements of soft ground by suction drain method was analyzed by the results of real-time field measurement, SPT(Standard Penetration Test) and laboratory tests. The results indicated that the soft ground improvement is effective the vertical drain method used with vacuum pressure rather than surcharge load with considering settlements, dissipation of pore water pressure and shear strength.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.51-56
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• 2004

The sand compaction pile (SCP) method, which forms a composite ground by driving sand piles into clay deposit, is the most commonly used soil improvement techniques in many countries for more than 30 years. Installation of sand compaction piles reduces the amount of consolidation settlement and increases the bearing capacity of soft clay deposit. In this paper, field survey conducted to investigated the consolidation behavior of the composite ground improved by SCPs. It is suggested that the measured consolidation velocity is later than design theory, however measured consolidation settlement is higher than design theory.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.672-679
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• 2008

During recent years, the large soft ground improvements very rapidly increase with industrial development and it is the types and scales of structure that is enlarged by degree. Then, we must enter construct equipment to improve soft ground and we fulfilled works by carrying out soft clay soil to gain trafficability for them. For improving the soft ground, we lay geotextile on soft clay ground and fill the filter sand that can drain the pore water. Then, we landfill cover soil for come by trafficability of construction tools. Ater that we penetrate vertical drain for dehydration through soft ground. there are very complicated works. For these reason we suggest the methods of soft ground improvement constructions.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1132-1135
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• 2008

In this study, a circular and indoor soil tank foundation was manufactured to study the improvement according to the degree of turbulence arising from PBD penetration, using the existing plate-type shoe and improved V-type shoe to change the degree of turbulence. Furthermore, to study the foundation improvement effect, the strength, settlement speed in the turbulence area were compared according to the shoe penetration. The results of the study showed that the V-type shoe reduced the strength coefficient decrease effect, and the foundation improvement effect according to the degree of turbulence was identified.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1365-1371
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• 2009

A new s-wave probe, called "MudFork", has been recently developed and is used in accurate measurements of shear wave velocities of soft soils. In previous researches, some instrumental defects of the probe have been reported. Bending deformation of probe is caused by small section modulus of blades, and open-ended bender elements are vulnerable to damage during penetration. Herein, we improved the MudFork to solve these problems. Field tests at Sinan, Jeollanamdo using the improved MudFork were conducted. Results from MPT are compared with the results from CPT.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1998.04a
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• pp.3-3
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• 1998

KF-16 항공기용 F100-229 엔진 부품 중 국내에서 생산되는 부품에 대한 초도품 품질보증방법의 일환으로 내구성시험을 국내에서 수행하였다. 그동안 국내에서의 항공기 엔진산업은 사용중인 엔진의 정비 혹은 민항기 엔진 일부 부품을 기계 가공하여 납품하는 수준이었으므로 특별한 품질보증 시험이 요구되지 않았으나, KFP 사업을 시작하면서 일부 주요부품은 국내에서 직접 생산하여 KF-16 항공기용 엔진에 장착하게 되므로 완제 엔진을 조립 생산할 수 있는 능력의 확보뿐만 아니라 적절한 품질보증 대책이 요구되었다. 이에 따라 국내 생산된 완제 엔진의 조립성과 일부 단품에 대한 품질보증 확보방안으로 엔진의 개발 및 부품개량시 설계수명 및 설계규격의 만족여부를 검증하는 시험인 엔진 내구성시험(Engine Accelerated Mission Test)기법을 적용하여 1차와 2차에 걸쳐 품질보증시험을 수행하였다. 시험결과 완제 엔진의 조립성, 추진성능, 부품의 내구도 확인에 의한 품질보증 적합성 여부를 확인할 수 있었으며, 본 시험평가 기법을 통하여 시험 후 부품의 검사 및 평가방법과 기준을 제시하였고, 군용 엔진 내구성시험의 요구조건, 시험절차, 시험항목 등을 확립하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.03a
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• pp.347-354
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• 2002

In this paper, when structures are constructed in the soft ground with poor bearing capacity at Incheon International Airport(railroad area), as for the grouting columns built In soft ground by high pressure jet grouting with Triple tube rod(super injection grouting), the effects on reinforcement and bearing capacity of ground are investigated. A unconfined compressive strength tests has been performed on the specimens sampled from the grouting columns and a mass plate bearing test has been performed on a grouting column. The test results show that super injection grouting has a sufficient effect on composite ground improved of foundation ground and reatraint of settlement of structure.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.114-115
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• 2015

개량한 플라즈마 소스를 이용하여 Al doped ZnO (AZO) 박막을 증착하였다. 이 실험에서 박막의 증착두께를 200nm로 고정하였고 공정압력과 기판사이 거리는 4 mTorr과 4 cm로 정하였다. 인가전력 그리고 윗 타겟 인가전압을 변수로 하였을 경우 AZO 박막의 방향성과 결정성을 XRD로 측정하고 분석하였고 박막의 전기적 특성을 Hall measurment로 측정하였다. 그 결과 인가파워가 2W/cm2, 윗 타겟 인가전압이 0 W 일 때 박막의 전기적 특성이 가장 좋게 나타났다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.189-192
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• 2004

Test Facility for hot firing test of small size liquid rocket engine has been developed to research the cooing characteristics of kerosene for cylinder part especially. Propellants for the tests are kerosene and liquid oxygen as fuel and oxidizer respectively and they are fed by gaseous nitrogen. The engine components used hot firing test except for cylinder are cooled by tap-water. Valves for supply of propellants and coolants are controlled by pneumatically. System control and data recording are conducted automatically.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.04a
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• pp.19-19
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• 1999

155mm 탄에 항력감소장치(Base Bleed Unit)를 부착하여 탄의 비행중에 형성되는 탄저부의 항력(Base Drag)을 감소시켜 사거리를 연장하는 무기체계가 미국을 비롯한 많은 국가에서 실용화되고 있다. 국내에서는 국과연 주관사업으로 이미 신형자주포에 적용되는 155mm 탄의 항력감소장치를 개발, 사거리 약 35%를 증가하여 실용화 단계에 있다. 또한 최근에는 미제 M864급인 155mm 성능개량 DPICM(Dual purpose Improved Conventional Munition)탄과 동등 성능을 갖는 탄의 개발이 요구되어, 이의 항력감소제인 저연소속도 추진제를 개발하여 155mm DPICM탄에 적용한 결과 약 20%의 사거리가 증가된 미제와 동등한 성능의 항력감소제를 개발하여, 이를 보고한바 있다.