• Proceedings of the KIEE Conference
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• 2008.04b
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• pp.28-30
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• 2008

본 논문은 국내 실정에 적합한 초고압 가공 직류 송전(HVDC)선로 설계를 위해서 세계적으로 처음 시도되는 가변 기능을 지닌 Proto Type HVDC 실규모 시험선로의 설계와 구축에 대해 소개한다. 시험선로는 초고압 직류송전시 발생하는 이온의 흐름에 의한 이온전류 밀도, 대전 전압, 지표면 전계강도 등 이온류(Ion류(流))에 의한 전기환경장애 및 코로나 영향을 검토하여 환경 친화적 HVDC 송전선로 설계기준을 도출하는데 있다. 이에 따라 HVDC 실규모 시험선로는 요크, 특수 애자련, 특수 arm을 사용하여 철탑의 극간 배치, 도체 배치 변경 및 지상고 변경이 가능하도록 winch를 채용하여 절연설계 조건의 유동성, 환경, 지지물, 송전기자재, 경제성 및 운용의 효율성을 종합적으로 고려할 수 있도록 특수한 형태로 설계되었으며, 본 논문은 상용 가공 HVDC 송전방식의 적용에 앞서 현재의 상황을 고려한 가공 HVDC 실증시험을 수행하기 위한 시험선로의 설계 및 구축에 대하여 기술하였다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.5
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• pp.355-374
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• 2022

Soil conditioning improves the performance of EPB (earth pressure balance) shield TBMs (tunnel boring machines) by reducing shear strength, enhancing workability of the excavated soil, and supporting the tunnel face during EPB tunnelling. The mechanical and rheological behavior of the excavated muck mixed with additives should be properly evaluated to determine the optimal additive injection condition corresponding to each ground type. In this study, the laboratory pressurized vane test apparatus equipped with a vane-shaped rheometer was developed to reproduce the pressurized condition in the TBM chamber and quantitively evaluate rheological properties of the soil specimens. A series of the pressurized vane tests were performed for an artificial sand soil by changing foam injection ratio (FIR) and polymer injection ratio (PIR), which are the injection parameters of the foam and the polymer, respectively. In addition, the workability of the conditioned soil was evaluated through the slump test. The peak and yield stresses of the conditioned soil with respect to the injection parameters were evaluated through the rheogram, which was derived from the measured torque data in the pressurized vane test. As FIR increased or PIR decreased, the workability of the conditioned soil increased, and the maximum torque, peak stress, and yield stress decreased. The peak stress and yield stress of the specimen from the laboratory pressurized vane test correspond to the workability evaluated by the slump tests, which implies the applicability of the proposed test for evaluating the rheological properties of excavated soil.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.267-269
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• 2007

콘크리트 중의 철근이 염분에 의해 부식되는 것을 억제 또는 예방하고, 각종 부식 환경으로부터 구조물의 수명을 연장할 목적으로 사용되는 방청혼화제의 최적 formulation과 그에 대한 물성 및 성능 시험을 실시하였다. 철근 부식에 대한 방청 메카니즘의 이해와 방청 혼화제의 formulation에 따른 물성시험과 성능평가를 실시하여 최적 조건을 확립하였다. 성능평가는 콘크리트 공시체의 Slump, 공기량, 압축강도(3일, 7일, 28일) 측정과 함께 염수침지시험 동의 방청성능 평가를 실시하였다.

• Journal of the KSME
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• v.33 no.5
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• pp.449-455
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• 1993

지금까지의 CANDU 사고이력과 관련된 문제점을 살펴보면 핵연료 채널의 부적절한 설계 및 설치 그리고 부적절한 압력관 가동조건 등에 많은 문제점이 있었다. 이러한 의미에서 CANDU의 안전성은 압력관의 건전성으로부터 확보된다 하여도 과언이 아니다. 그러나 CANDU에서 차지 하는 중요성에 비추어 압력관의 사용환경은 매우 열약하다. 따라서 가동중 압력관 건전성 위협 요인에 대한 정기적인 검사, 시험 및 평가는 CANDU 안전성확보의 첫걸음이 된다. 특히 건전 성평가에 필요한 주요자료가 압력관 인출시험결과로부터 확보됨을 고려할 때 압력관 인출시험을 국내에서 수행할 수 있는 능력을 확보하는 것 또한 우리에게 부과된 과제라 할 것이다.

• Analytical Science and Technology
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• v.21 no.3
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• pp.174-182
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• 2008

The study on the development of rapid analytical method of PCBs containing waste was performed by considering the extraction, column cleanup process, analytical condition and so on. In the established method, new sample clean-up procedure, new quantification peaks and temperature program were introduced. Method detection limit of the method was 0.5 mg/L, and the method could save the total run time to 2/3, therefore save the analysis cost, The new rapid analytical method of transformer oil was suggested to the waste official test method.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.632-636
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• 2017

In this study, we design an altitude test facility for hypersonic propulsion engine by constructing a test facility and cold flow test. Cold flow test is performed both with and without test models. The results show that the facility can simulate almost similar altitude condition without any significant change in pressure regardless of test models. We also constructed a database that might be useful for a variable test in the future.

• The Journal of the Acoustical Society of Korea
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• v.42 no.2
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• pp.161-167
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• 2023

Recently, floor impact sound has become a serious social problem in Korea. There is an increasing need to improve floor impact sound performance using floor covering installed on the floor of apartment houses. KS F ISO 717-2 and KS F 2863 require measurement under conditions in which the resilient material is not installed. But most apartment houses in Korea install resilient materials to reduce floor imapct sound. The performance evaluation method of floor covering should provide reduced performance for use by residents of apartment houses with resilient materials. Therefore, this paper proposes a reduction performance evaluation under the conditions in which a resilient material is installed to verify the performance of floor covering.

• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.153-163
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• 2003

Electronic equipments and make other electronic systems to operate abnormally by means of electromagnetic interference, or can operate abnormally themselves by electromagnetic interference of other electronic systems. Therefore, electronic equipments are required to reduce their electromagnetic interference as small as for other systems to operate properly and operate properly within electromagnetic interference from other electronic systems. In order to prove that electronic equipments meet such requirements, they should undergo electromagnetic environmental test. In this study, we introduce electromagnetic environmental requirements, test procedures and test results of gimbal engine actuation system of KSR-III.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.361-364
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• 2010

본 연구에서는 최근 건설산업의 대형화, 복잡화 등으로 인해 설계와 시공의 불확실성 증가로 대두되고 있는 개방형 BIM 환경에서의 품질검토를 관점으로 표준적인 검증 프로세스에 활용되고 있는 표준 포맷인 IFC를 기반으로 호환성을 시험하였다. 개방형 BIM기반의 품질 검토는 물리정보 품질, 논리정보 품질, 데이터 품질로 구분할 수 있으며, 본 연구에서는 각 품질 검토의 구분에 따라 다양한 측면으로의 호환성 시험을 수행하였다. 그에 따라 호환성 시험 결과를 도출하고, 현 상황의 문제점 및 해결방안을 제시하여 향후 효율적인 개방형 BIM 환경에서의 품질 검토를 위해 필요한 요구 조건 및 적용 방향을 제시하였다.

• Journal of the Korean Data and Information Science Society
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• v.27 no.6
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• pp.1593-1600
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• 2016

This paper suggests a temperature guidance for requirements which must be addressed in the preparation of specifications for military equipment used in land applications in the Korean peninsula. In general, the equipment should be designed to operate during all but a certain small percentage of the time. Daegu and Yangpyeong are the hottest and coldest regions by month, respectively, based on surface weather observations over 132 regions from 1904 to 2014. The 1-percent high and low temperatures for land environment in the South Korea are $38.7^{\circ}C$, and -$29.0^{\circ}C$, respectively. This paper also presents the temperature values occurring for specified frequencies of occurrence during the most severe month. Diurnal cycles associated with the hottest and coldest top one-percent temperatures, including associated solar radiation, relative humidity, and wind-speed are provided.