• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2821-2829
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• 2011

Since the KTX was in operation in 2004, a number of researches on increasing the train speed have been conducted. Currently, the Honam High-speed train system is designed for the operation velocity of 350km/h. The societal demand expects higher operation speed, whereas the existing construction method and design specification are questioned in the KTX operation in the velocity over 350 km/h. In this study, a full-scale model test was conducted to obtain the preliminary data that is necessary to understand deformation characteristics of the reinforced road bed and the subgrade layers. In the full-scale model test, direct arrival seismic tests, crosshole seimic test, in-situ bender element test and sensing bar test were employed to measure the stiffness and deformation of the trackbed. The systematic analysis on the different set of measurements enhances the understanding of the behavior of the trackbed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.653-657
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• 2005

The commercial contract was made firstly in the world for one set of high temperature superconducting(HTS) cable system between buyer, Korea Electric Power Research Institute and seller, Sumitomo Electric Industries, Ltd. in August 2004. After fabrication, test and examination, the HTS cable system will be installed at the KEPRI's test field in Gochang, Jeonbuk province from the time of July 2005. KEPRI is preparing measurement and test facilities for field test of the HTS cable system and carrying out researches into the design and construction of superconducting cable test building, evaluation of cooling performance, measurement of AC loss, analysis of the quench phenomena due to excess current and means of linking the HTS cable system to the existing electric power supplying system. The constitution of, the method to install and the plan of test operation of the HTS cable system will be presented in this paper.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.293-301
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• 2005

The CSG(Cemented Sand and Gravel) method is construction technique using as raw materials earth and gravel generated from a local construction site, mixing them with cement and rolling with vibration rollers. Recently, The use of this method for cofferdam and large dam is gradually increasing in Japan. The purpose of an CSG mix design is to develop project specific properties to meet the structure design requirements. But uniform mix design of CSG method has not yet been established. The experience of practitioners from the geotechnical and concrete disciplines has given rise to two genernal approaches to mix design for CSG. This paper reports the concept of how to set the mix design according to modified Proctor compaction test process and the test results on properties such as compaction, compressive strength and modulus of elasticity that obtained by unconfined compression test.

• 콘크리트학회논문집
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• 제16권1호
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• pp.70-78
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• 2004

NATM 시공에서 급결제의 사용은 일반화되어 있으나 품질 및 시험기준의 제정은 미흡한 실정이다. 본 연구는 숏크리트용 급결제에 대한 국내외 품질기준 비교 및 시험을 수행하여 규격의 적정성을 평가하였다. 실리케이트계, 알루미네이트계 및 시멘트광물계 급결제의 알칼리함유량이 매우 높게 나타나 사용골재의 반응성 평가에 대한 관리 및 시험빈도를 높여야 할 것으로 생각된다. 또한 응결시험결과 BS 시험방법이 정량적인 것으로 판단되었으나, 실리케이트계 및 알칼리프리계 급결제는 첨가방법에 따라 응결시간이 큰 차이를 나타내었다. 압축강도는 실리케이트계, 알루미네이트계 및 급결성 시멘트 광물계의 재령 1일 강도는 $90kgf/cm^2$ 이상으로 한국콘크리트학회 규준을 만족하나 플래인 모르타르 강도대비 재령 28일 압축강도비는 알칼리프리계를 제외하고 $50{\~}65\%$ 정도를 나타내었다. 따라서 재료특성 및 국내터널 시공방법 반영과 품질향상을 도모할 수 있는 규격제정이 시급히 요망되었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2008년도 추계 학술논문 발표대회
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• pp.235-239
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• 2008

Cable systems are a construction of elements carrying only tension and no compression or bending in membrane structure. Tensile membrane structures are most often used as roofs as they can economically and attractively span large distances. But cable systems have weaknesses to vibration by earthquake, wind and vehicle loads. Damage detection of cable systems by using existing safety diagnosis is difficult to detect the characteristic change of overall structural action. If cable snaps are occurred to cable release and tear in tension structures, these are set up a vibration. So, we used piezo-electric materials, and The principle of operation of a piezoelectric sensor is that a physical dimension, transformed into a force, acts on two opposing faces of the sensing element. In this study, the development on test method of cable system is proposed and tested by tensile strength using piezo-electric materials.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 춘계 학술논문 발표대회 2부
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• pp.35-37
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• 2011

This study was a comparison result between the laboratory and mock up test to apply the ultra high strength concrete to CFT(Concrete Filled Tube) structure. The investigated result of tendency and quality similarity of each specimen, was set up a management range according to checking the validity and suitability analysis. Also, It wil be utilized to data as construction guidelines of CFT.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.93-94
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• 2019

When the fire door is recently installed in the field, there are frequent cases where the fire door is manufactured with fire door having low quality or different structure compared to the performance that the fire door producer has confirmed in the performance test or the construction specification. In order to improve the on-site quality management of the fire door, we comprehensively classify the quality management items of the fire door according to the management subject and the step by stage and set the field quality management procedure, the field quality management inspection item, regulations and standardized checklists were presented.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.140-141
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• 2020

Concrete has a lower thermal conductivity or thermal diffusion coefficient compared to other building materials, so it is widely used as fireproof compartment material or refractory material for structures. However, in the event of thermal damage such as fire, cement curing agents and aggregates act differently, resulting in heat generation or deterioration of tissue due to dehydration, resulting in deterioration of physical properties and fire resistance. Therefore, in this study, the processing structure of cement paste is measured through nitrogen absorption method. The test specimen is a cement paste of 40% W/C and is set at 1000 ℃ under heating temperature conditions. As the temperature rose, the micro-pore mass below was reduced based on about 0.01 감소m, but the air gap above that was increased.Thus, in the range of pores measured in nitrogen adsorption, the air mass tended to decrease under high temperature conditions.

• 한국환경복원기술학회지
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• 제8권4호
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• pp.81-90
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• 2005

This study aimed to address problems and suggest solutions in applying seed mixture design criterior of the slope revegetation works according to "The guidelines of Slope revegetation design and construction" proposed by the Ministry of Construction and Transportation. To do this, the planting thickness was set to be the same 2cm while the composition of seeds was made different, which was planted in artificial slopes and fields. The main results were summarized as follows. In the test, when applying the provisional standards of the plant mixtures proposed by the Ministry of Construction and Transportation, tree seeds and native plants were found poor coverage effect in the early stage in all test plots due to introduced grasses. This was because introduced winter grasses which grew well in the early stage, could grow densely, so it might hamper the growth of other plants. Therefore, it was found desirable that standards for seed mixing should be adjusted down by 10% and the ratio of introduced grasses in the mixture should be lowered to 25% while native plants should increase to 20-25%.

• 한국수자원학회논문집
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• 제42권10호
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• pp.795-807
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• 2009

본 연구에서는 부트스트랩(Bootstrap) 기법을 이용하여 측우기 강우량 관측계열(CWK)과 근대우량계 강우량 관측 계열(MRG)에 대해 동질성 분석을 실시하였다. 서로 다른 두 자료계열에 대한 전통적인 통계적 동질성 검정 방법은 모집단의 분포형을 알고 있어야 검정결과가 유효하였기 때문에 모집단의 분포가 복잡한 기상자료들은 이러한 전통적 방법을 사용하여 동질성을 파악하는 것이 매우 어려웠고 결과로 제시된 통계적 유의성에 대해서도 의심의 여지가 있었다. 이러한 이유로 본 논문에서는 모집단을 가정하지 않아도 되는 비모수적 모의 방법인 부트스트랩 기법을 이용하여 모집단을 직접 추정한 후 경험누가확률분포를 산정하여 두 자료계열간 통계적 동질성 검정을 실시하였다. 분석 결과 CWK와 MRG는 미소한 기후의 경년변화(trend)의 영향을 제외하면 동질성을 가진 자료로 볼 수 있었다.