• Journal of Korean Society of Transportation
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• v.26 no.3
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• pp.187-197
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• 2008

While driving a highway, A driver gets lots of information through geometrical structure, traffic situation, signs on the road. He gets most of the information by visual sense. Acceleration or deceleration and driving direction depend on sight distance. Therefore, it's essential to secure a driver's sight distance for a safe drive. However, design guides of geometrical structure and sight distance suggest respective standards of horizontal and vertical alignment. They do not indicate quantitative standard of combined alignment. Currently, element separated on a two-dimensional projected plane are available, but they do not guarantee safe and pleasant design. I will use the existent model analysing three-dimensional sight distance through mathematical calculation and sort a variety of geometrical structure element and type. In these researches, we will look at how much three-dimensional sight distance is overestimated or underestimated compared to two-dimensional. I will develop a program which predicts traffic velocity on the curvature of two-lane provincial road. stopped sight distance and three-dimensional sight distance will be compared at a predicted drive velocity. I will suggest the way to evaluate road consistency.

• Journal of Korea Fair Competition Federation
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• no.110
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• pp.2-9
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• 2004

필자는 국가 간 국민소득의 차이는 국민 개개인의 자질보다도 그 국가가 보유하고 있는 제도의 품질 차에서 비롯된다고 믿고 있다. 그러므로 이러한 제도들은 정부가 생산하여 국민에게 공급하여야 하는 공공재이고 눈에 보이는 도로, 항만보다도 훨씬 더 중요한 사회간접자본이다. 그래서 지금쯤이면 25년 이전의 공정거래법의 골격을 지금의 발전된 우리 국가와 경제의 수준에 맞추어서 전반적으로 한 단계 업그레이드 할 것을 진지하게 검토할 때가 되었다고 생각하는 것이다.

• Proceedings of the Korean Nuclear Society Conference
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• 1998.05b
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• pp.814-819
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• 1998

원자력 발전소의 운영개선에 2차 방사성폐기물을 줄여야 하는 것은 중요한 과제이다. 기존 세탁 법은 2차 방사성폐기물을 상당히 많이 배출는데, 개선방안으로 초임계 유체($CO_2$)를 이용한 제염가능성을 알아보았다. 본 연구에서 순광유, 그리고 산업용으로 쓰이는 기어유와 그리스의 초임계 $CO_2$ 내에서의 용해도와, 제거율을 구하였다. 용해도 측정 실험에서는 초임계 상태에서 압력에 따라 용해도가 급격히 증가하였으며 반응시간 또한 매우 빨라 확산성이 매우 우수하였다. 실제 적용을 위해 소량의 첨가용매를 사용한다면 더욱 큰 성과가 기대된다.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.2
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• pp.136-141
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• 2000

This study was conducted to analyze the properties of the roasted dandelion tea prepared after various pre-treatments such as pre-drying, steaming and air blast drying. The dandelion tea was prepared by roasting the pre-treated dandelion leaves and its total yield, pH, soluble solid content, turbidity, browning and sensory value were evaluated. Total yield and soluble solid content were the highest in case of air blast drying. Turbidity and browning degree were similar in all the teas regardless of their pre-treatment including pre-drying, steaming or air blast drying. The best palatability in the sensory evaluation was obtained at the steaming condition for 60 sec without pre-drying. Longer air blast drying time resulted in the increase in the a and b values. turbidity, browning degree, total yield and soluble solid content in the air blast dried tea.

• Proceedings of the KOR-KST Conference
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• 1999.10a
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• pp.297-302
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• 1999

• Magazine of korean Tunnelling and Underground Space Association
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• v.7 no.2
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• pp.61-69
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• 2005

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.85-94
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• 2016

Lane Designation is defined as reasonable road management to ensure the road safety and enhance road efficiency. While the lane designation system was abolished in 1999, it was redefined because of the increasing number of large vehicles in the passing lane, violent on driving and traffic accidents in 2000. The needs of improvement on operating the lane designation has been increasing more in recent due to the low ratio of compliance with the system and difficulties to keep the right lane due to need of turning and demand of widening of designates lane for two-wheeled vehicles and truck. In this study, we presented the improvement plan through the question survey, simulation analysis, safety evaluation. It found a problem that the low-speed vehicle is to use the upper level roadway, difficulties of supervision, the imbalance in the lane use, imbalance traffic and does not match the international standards. This study suggested five different alternatives through the survey. micro simulation has used in order to examine each alternative by management effectiveness and feasibility. It analyzed the traffic speed, efficiency, traffic balance of alternatives. Also, safety evaluation conducted in terms of the range of field-of-view to ensure the easiness of field of view by various configurational difference between the vehicles. By the analysis results of such indicators, This study presents proposals for improvement in operating designated lane that low-speed-big-sized vehicles keep to the right lane, and high-speed-small sized vehicles keep to the left lane.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.81-85
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• 2022

Mist-CVD is known to have advantages of low cost and high productivity method since the precursor solution is misting with an ultrasonic generator and reacted on the substrate under vacuum-free conditions of atmospheric pressure. However, since the deposition distribution is not uniform, various efforts have been made to derive optimal conditions by changing the angle of the substrate and the position of the outlet to improve the result of the preceding study. Therefore, in this study, a deposition distribution uniformity model was derived through the shape and position of the substrate support and the conditions of inlet flow rate using the particle tracking method of computational fluid dynamics (CFD). The results of analysis were compared with the previous studies through experiment. It was confirmed that the rate of deposition area was improved from 38.7% to 100%, and the rate of deposition uniformity was 79.07% which was higher than the predicted result of simulation. Particle tracking method can reduce trial and error in experiments and can be considered as a reliable prediction method.

• Journal of the Semiconductor & Display Technology
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• v.21 no.3
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• pp.101-104
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• 2022

Mist-CVD is known to have advantages of low cost and high productivity compared to ALD and PECVD methods. It is capable of reacting to the substrate by misting an aqueous solution using ultrasonic waves under vacuum-free conditions of atmospheric pressure. In particular, Ga₂O₃ is regarded as advanced power semiconductor material because of its high quality of transmittance, and excellent electrical conductivity through N-type doping. In this study, Computational Fluid Dynamics were used to predict the uniformity of the thin film on a large-area substrate. And also the deposition pattern and uniformity were analyzed using the flow velocity and particle tracking method. The uniformity was confirmed by quantifying the deposition cross section with an FIB-SEM, and the consistency of the uniformity prediction was secured through the analysis of the CFD distribution. With the analysis and experimental results, the match rate of deposition area was 80.14% and the match rate of deposition thickness was 55.32%. As the experimental and analysis results were consistent, it was confirmed that it is possible to predict the deposition thickness uniformity of Mist-CVD.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.10a
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• pp.121-124
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• 1996

본 연구에서는 개선된 계층적 분석과정(AHP)을 사용하여 국산 신형 중형차의 우선 순위를 평가한다. AHP 모형은 외관, 성능, 안전성, 경제성, 영업사원, 사후정비의 주 기준과 39개 세부기준으로 구성된다. 구현의 특징을 (1) 샘플 크기가 작은 그룹의사결정 문제로 한정할 때, 한 의사결정자의 전체 쌍비교 행렬보다는 일관성비율이 한계치 이하의 행렬 만을 고려하였고, (2) 중요도 도출 과정에서 평가기준은 쌍비교 방식을, 대안은 레이팅 기법을 결합하였으며, (3) 그룹 중요도는 일관성 비율의 역수를 사용하였다. 사례 연구로 국내 자동차 판매 영업대표와 운전자를 대상으로 각각 평가기준에 대한 중요도와 레이팅 값을 도출, 3대 경쟁 차조의 우선순위를 비교 분석한다.