• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.289-289
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• 2022

Waterlogging tolerance of corn is one of the important factor for cultivate in paddy soil condition to increase cultivation area and self-sufficiency of corn in Korea. In order to develop elite waterlogging tolerance corn, the new corn lines bred by crossing wild corn, Teosinte, and cultivated corn inbred lines. Five accessions among the 2 species, Zea mays sub spp. mexicana and Zea mays spp. parviglumis, of 81 Teosinte were selected through the waterlogging treatment. The waterlogging treatments were implemented for 7 days at the seedling(V3) stage. The inbred lines were developed by crossing 5 teosinte accessions and cultivated corn lines and they were estimated waterlogging tolerance. It was screened and analyzed the metabolites extracted from roots of 19KT-32(KS141 × teosinte) that was treated waterlogging. We selected 8 of 180 metabolites like as γ-aminobutyric acid(GABA), putrescine, citrulline, Gly, and Ala that expression was remarkably changed over 2.5-times, 7 metabolites increased and 1 metabolite decreased in waterlogging, respectively. Glutamate decarboxylase(GAD) catalyzing GABA accumulation gene have 10 haplotypes, and exon1 was highly conserved, but identified to 135 SNPs after the first intron. Among the 135 SNPs, the number of transversion mutations (52) surpassed the number of transition mutations (38). Most of metabolites were related to abiotic stress in plant that it regulated to pH, osmotic pressure K⁺/Ca⁺⁺ and ATPase activity. We are analyzing the association using these results for increase breeding efficiency.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2439-2449
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• 2011

Existing grade crossings between railway and roadway area gradually changed to grade separation systems by the law. In the case of new roadway construction which crosses railways, it shall be grade separation system in principle. With the railway underground crossing method, many practices have been developed which can minimize rail displacements and avoid rail release. With these methods, the effects to the train can be reduced. The underground crossing methods can be identified as open-cut methods and non open-cut methods. The open-cut methods include temporary support methods and special rail construction methods. Also the non open-cut methods includes pipe roof methods, front jacking methods, messer shield methods, NTR methods and JES methods. Among these, the most suitable method is applied considering safety, economy, class of each rail system (train passing frequency and velocity), etc. In the non open-cut methods, the cost and duration shall be increased to keep existing rail system during construction. In the open-cut methods which use plate girders, the rail speed shall be restricted due to the displacement and vibration of the girder. In this study new grade separation methods were developed. With this method, the safety during construction can be increased. This method refines temporary support methods, but pc slab girder with huge stiffness is applied instead of plate girders. With this method, the rail displacement can be reduced and higher safety can be obtained during construction. Also construction cost and duration can be minimized because the temporary work and the overburden soil depth can be reduced.

• 한국측량학회지
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• 제13권1호
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• pp.77-83
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• 1995

수치지도 제작의 일반화 기법은 대축척 실측 지도를 이용한 소축척 편집 지도의 자동 제작과 수치 지도 데이터 베이스 구축 등의 활용 분야에 필수적 요소이다. 본 연구는 수작업으로 처리되고 있는 편집도의 제작을 자동화하기 위한 방안으로 디지탈 환경하에서의 일반화 기법에 대한 연구로서 Zero-Crossing알고리즘을 국립지리원 발행 l/5,000지도 6도엽에 포함되어 있는 전남 여수 일대의 해안선에 적용, 다양한 단순화 허용 범위에 의해 수치 지도를 제작하여 편집도와 도해적인 표현 방법에 대한 문제점을 비교 분석하였다. 또한, Zero-Crossing알고리즘에 의한 단순화의 효용성을 입증하기 위해 Douglas-Peucker알고리즘을 이용한 단순화 결과와 비교 분석을 하였으며, 단순화의 허용 범위별로 일반화가 이루어진 수치 지도와 수작업으로 제작된 편집도와의 비교를 통해 일반화된 Line에 대한 평가를 도출하고, 단순화 허용 범위의 선택에 따른 효율성을 판단하기 위해 일반화 처리 결과의 데이타 용량을 분석하였다.

• Geomechanics and Engineering
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• 제32권1호
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• pp.111-123
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• 2023

The slope of an open cut tunnel is located above the exit of the Leijia tunnel on the Changgan high-speed railway. During the excavation of the open cut tunnel foundation pit, the slope slipped twice, a large landslide of 92500 m³ formed. The landslide body and unstable slope body not only caused the foundation pit of the open cut tunnel to be buried and the anchor piles to be damaged but also directly threatened the operational safety of the later high-speed railway. Therefore, to study the stability change in the slope of the open cut tunnel under heavy rain and excavation conditions, a 3D numerical calculation model of the slope is carried out by Midas GTS software, the deformation mechanism is analyzed, anti-sliding measures are proposed, and the effectiveness of the anti-sliding measures is analyzed according to the field monitoring results. The results show that when rainfall occurs, rainwater collects in the open cut tunnel area, resulting in a transient saturation zone on the slope on the right side of the open cut tunnel, which reduces the shear strength of the slope soil; the excavation at the slope toe reduces the anti-sliding capacity of the slope toe. Under the combined action of excavation and rainfall, when the soil above the top of the anchor pile is excavated, two potential sliding surfaces are bounded by the top of the excavation area, and the shear outlet is located at the top of the anchor pile. After the excavation of the open cut tunnel, the potential sliding surface is mainly concentrated at the lower part of the downhill area, and the shear outlet moves down to the bottom of the open cut tunnel. Based on the deformation characteristics and the failure mechanism of the landslides, comprehensive control measures, including interim emergency mitigation measures and long-term mitigation measures, are proposed. The field monitoring results further verify the accuracy of the anti-sliding mechanism analysis and the effectiveness of anti-sliding measures.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.466-471
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• 2017

Pantograph must be correctly attached to catenary to continuously supply stable power to railway vehicle, and the device used here is Auxiliary Air Compressor (ACM). The existing ACM used the DC motor that included commutator and brush. Since maintenance and repair by mechanical friction are essential for the DC motor, BLDC motor studies have been conducted to improve this. A three-phase BLDC motor does $120^{\circ}$ two-phase commutation through hall sensors in general. However, since hall sensor is vulnerable to heat and can run only when all three sensors work normally, sensorless control method has been studied to solve this. Using back EMF Zero Crossing Point (ZCP) detection method, this paper will introduce a stable switching sensing method that has a non-commutation area in a low speed zone.

• 응용통계연구
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• 제33권5호
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• pp.541-553
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• 2020

Receiver operating characteristic (ROC) 곡선은 민감도와 특이도로 표현되며, ROC 곡선을 이용하는 최적분류점도 민감도와 특이도만을 반영하지만, 본 연구에서는 질병률과 효용을 추가하여 고려하는 기대효용함수를 연구한다. 특히 교차하는 ROC 곡선들의 area under the ROC curve (AUC) 값들이 유사한 경우에 특정한 부분의 부분 AUC를 비교해야 한다. 본 연구에서는 정의된 민감도 직선과 특이도 직선을 바탕으로 각각 높은 민감도와 특이도를 나타내는 부분 AUC를 제안한다. ROC 곡선들이 교차하고 동일한 AUC 값을 갖는 다양한 분포함수를 설정하여, 민감도 직선과 특이도 직선을 이용하여 구한 부분 AUC를 비교하면서 모형의 판별력을 향상시키는 방법을 제안한다.

• 시스템엔지니어링학술지
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• 제19권1호
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• pp.39-43
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• 2023

In ground weapon systems, the design and analysis technology for water operation stability is a relatively unknown area compared to maritime weapon systems. Through this study, it was confirmed that our weapon system satisfies the criteria for stability on the water when considering the operational concept and operational performance. However, there is a limitation of the study that it did not perform verification tests on the actual system. Therefore, in the future research and weapon system acquisition process, a procedure to prove the stability through freeboard analysis using the actual system is required.

• 대한교통학회지
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• 제33권2호
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• pp.136-144
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• 2015

중앙버스전용차로도 도입으로 인해 무단횡단이 증가하였고 보행 교통 사망자 수 증가의 문제가 지속적으로 제기되고 있다. 이러한 중앙버스전용차로 횡단보도부 교통안전 수준 증진을 위해서는 공학적이고 분석적인 노력이 필요하다. 본 연구에서는 향후 보행안전시설 연구의 기반자료를 마련하기 위해 중앙버스전용차로 정류소 횡단보도부 보행자의 보행행태 자료를 분석한다. 중앙버스전용차로 형태 중 무단횡단이 가장 많이 관측되는 '분리형 횡단보도' 형태인 서울시 '고속버스터미널역'을 조사지점으로 선정하여 영상자료를 수집하였다. 수집된 보행자 자료를 공간적 측면과 시간적 측면에서 위반행태를 분석하였다. 분석 결과 공간적 위반 보행자는 37.8%로 시간적 위반 보행자 3.4%에 비해 11.1배 높게 분석되었다. 본 연구를 통해 시간적 위반 보행자에 편중된 안전시설이 아닌 무단횡단 보행자의 절대 다수에 해당하는 공간적 위반 보행자에 안전대책도 필요하며 향후 시 공간적 위반 보행자의 무단횡단을 함께 억제하는 안전시설이 필요함을 제언한다.

• 대기
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• 제17권4호
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• pp.381-391
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• 2007

The characteristics of flow around a single obstacle with fixed height and varied length and width are numerically investigated using a computational fluid dynamics (CFD) model. As the obstacle length increases, flow distortion near the upwind side of the obstacle increases and the size of the recirculation zone behind the obstacle also increases. As the obstacle width increases, the size of the recirculation zone decreases, despite almost invariable flow distortion near the upwind side of the obstacle. Flow passing through an obstacle is separated, one part going around the obstacle and the other crossing over the obstacle. The size of the recirculation zone is determined by the distance between the obstacle and the point (reattachment point) at which both the flows converge. When the obstacle width is relatively large, flows are reattached at the obstacle surface and their recoveries occur. Resultant shortening of the paths of flows crossing over and going around decreases the size of the recirculation zone. To support this, the extent of flow distortion defined based on the change in wind direction is analyzed. The result shows that flow distortion is largest near the ground surface and decreases with height. An increase in obstacle length increases the frontal area fraction of flow distortion around the obstacle. In the cases of increasing the width, the frontal area fraction near the upwind side of the obstacle does not change much, but near the downwind side, it becomes larger as the width increases. The frontal area fraction is in a better correlation with the size of the recirculation zone than the building aspect ratios, suggesting that the frontal area fraction is a good indicator for explaining the variation in the size of the recirculation zone with the building aspect ratios.

• 한국철도학회논문집
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• 제12권5호
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• pp.788-792
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• 2009

철도는 그동안 친환경 교통수단으로 알려져 왔다. 그러나 토양환경보전법 제정 이전 수십 년간 인지하지 못하는 토양오염들이 철도 시설 부지에서 유발되어 왔다. 철도차량기지 등에서는 철도차량 유지관리 및 수선을 위해 사용되어진 많은 폐기물과 유기용제들이 부지 내에 투기되어온 것들이 사실이다. 이들 부지의 개발과 활용을 위해서는 과거의 오염지역에 대한 정차가 선결되어야 하는데, 본 연구는 차량기지의 토양 오염현황과 복원 대책을 제안하기 위해 수행되어 졌다. 차량기지 내 폐기물 투기 지역에서는 유류오염물질인 TPH 성분과 몇몇 중금속 성분이 토양오염 기준치를 초과하는 것으로 나타났으며, 기지 내 선로와 분기기에 대한 조사에서는 분기기 하부에서 유류오염물질이 관측되었다. 원위치, 또는 굴착 후 정차 등의 방법이 오염정화를 위해 적용되어질 수 있으며, 현장의 특성을 고려하고, 모의시험을 통해 적절한 정화 방법을 채택할 경우 현장의 오염정화를 완성할 수 있을 것이다.