• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.501-506
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• 2006

With the development of Geospatial Technology (GT), many countries and industries have been expanding their investment in constructing a cyber territory. As the critical components of this cyber territory, three-dimensional models and virtual reality contents based on these models of urban areas in particular have been considered. These models and contents can be intensively used for a city to decide the policies efficiently and to attract the interests of peoples while planning and performing large projects. In this study, we have thus constructed the 3D models and virtual reality contents of the large areas along the CheongGye stream to visualize the environment of these areas before and after the CheongGyeCheon restoration project being completed. Furthermore, we propose efficient methods to construct and visualize these large models, such as tile mapping and multiple LOD application.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2006.04a
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• pp.457-462
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• 2006

Coastline has been considered as fundamental geographic information of a nation. Recently, the coastlines of higher resolution and accuracy with less update period ever than before are increasingly required. This requirement cannot be easily satisfied with the most traditional methods based on field survey such as leveling or GPS measurements. The newly developed airborne LIDAR system can be used as a promising alternative since it rapidly acquire numerous three-dimensional points densely sampled from the terrain around the coastline. Hence, in this study we developed a nearly automatic method to extract the coastline from LIDAR data and applied it to real data to verify its performance. From the comparison of the extracted coastlines with those from a digital map, we conclude that the proposed method can provide more accurate and precise lines.

• Journal of the Korean Society of Visualization
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• v.8 no.2
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• pp.40-44
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• 2010

Thermal comfort inside a passenger car has been receiving large attention in automobile industries. Especially, the performance of windshield defroster is important in the design of a car to ensure passenger comport and safety. Thereby, better understanding on the ventilation flow along the vehicle windshield is essential to evaluate the performance of windshield defroster. However, most previous studies dealt with the defrost flow using CFD (computational fluid dynamics) calculations or scale-down model experiments. In this study, a real commercial automobile was used to investigate the flow discharged from the vehicle defroster and the ventilation flow along the windshield using a PIV velocity field measurement technique. The experimental data would be useful to understand the flow characteristics in detail and also can be used to validate numerical predictions.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.5
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• pp.773-776
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• 2011

This study was focused on a certain clinical symptom, which could applicated by Pyeongwi-san, and the radical treatment. Pyeongwi-san is applicable to dampness retention in the spleen and stomach, accompanied by abdominal fullness, anorexia, nausea and regurgitation. Main action of Pyeongwi-san is to dry dampness, invigorate the spleen, promote the flow of gi, and regulate the stomach. The herbal remedy drying dampness like Pyeongwi-san however, is just indicatio symptomatica therefore radical treatment must be used together. Jeunginmaegchi, a medical book written by Gyeong-Myeong Jin, who was lived in Myeong dynasty. This book contains many clinical applicable symptoms and constituents derived from Pyeongwi-san. The herbal prescriptions composing Pyeongwi-san is composed of Changchul, Hubak, Jinpi, Gamcho. The major action of these herbs is drying dampness. Therefore, it shoud be seriously consider that curative therapy must eliminate the cause of endogenous dampness.

• 대한예방의학회:학술대회논문집
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• 2005.10a
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• pp.343-343
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• 2005

• Tribology and Lubricants
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• v.10 no.2
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• pp.5-19
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• 1994

일반적으로 상대운동을 하는 모든 물체에는 마찰이 존재하며 각 경우에 상응하는 적절한 윤활을 하고 있지만 마모(Wear)는 필연적으로 발생된다. 마찰 부위에 형성되는 마모정도에 따라 경 마모(Mild Wear), 평 마모(Normal Wear), 중 마모(Severe Wear) 등이 발생되며 이로인해 윤활유 속에는 다량의 마모 입자들이 존재하게 됨으로써 마모를 가속시키는 요인으로 작용하여 손상(Failure)의 원인이 되기도 한다. 마찰부위의 마모 및 손상은 엔진에서도 마찬가지로 그 수명 및 성능과 관계가 있고 경제적인 문제와 직결되므로 상세한 분석 및 평가가 요망된다. 또한 엔진 설계 및 원활한 작동유지를 위해서 정확한 마모 예측과 그 평가방법이 요구된다. 이를 토대로 엔진 손상을 미연에 방지할 수 있으며, 실제 설계과정에 마모정도를 고려한 가장 최적의 설계인자를 제공할 수 있다고 본다. 본 논문에서는 손상부위에서 발생가능한 여러가지 마모형태를 분류하여 그 특징을 정리하였고, 이를 바탕으로 실제 엔진의 마모 및 손상 등의 평가에 적용할 수 있는 엔진의 부품별 평가자료를 만드는데 주안점을 두었다.

• Transactions of Materials Processing
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• v.7 no.1
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• pp.72-80
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• 1998

This study is concerned with the thermo-biscoplastic finite element analysis of hot tube extrusion through square dies with a mandrel. The problem is treated as a non-steady state and the ALE description is used due to abruptly turning flow at the die aperture. Since the contact heat transfer coefficient and the friction factor are required in the analysis experiments are also carried out to determine the values, In order to apply ceramics to an extrusion die the study is focussed on under-standing the characteristics of the process. The simulated results provide the useful informations such as metal flow temperature distribution stress state etc. The elastic analysis of the dies is carried out to obtain the stress state of the ceramic dies.

• Journal of Welding and Joining
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• v.21 no.4
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• pp.75-79
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• 2003

The welding distortion of a hull structure in the shipbuilding industry is inevitable at each assembly stage. This geometric inaccuracy caused by the welding distortion tends to preclude the introduction of automation and mechanization and needs the additional man-hours for the adjusting work at the following assembly stage. To overcome this problem, a distortion control method should be applied. For this purpose, it is necessary to develop an accurate prediction method which can explicitly account for the influence of various factors on the welding distortion. The validity of the prediction method must be also clarified through experiments. For the purpose of reducing the weld-induced bending deflection, this paper proposes the plastic counter-deforming method (PCDM) using the line heating as the optimum distortion control method. The validity of this method has been substantiated by a number of numerical simulations and actual measurements.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.1159-1163
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• 2005

자연하천에서의 유량측정은 직$\cdot$간접유속측정을 통하여 이루어진다. 홍수기는 주로 봉부자에 의한 방법을 이용하고 평$\cdot$갈수기에는 파샬플룸이나 유속계에 의한 방법을 이용한다. 이 방법은 측정지점의 상태 또는 기술자의 숙련도에 따라 많은 오차를 발생시키고 연속적인 관측의 어려움을 가진다. 본 연구는 자연하천의 기본적인 수리학적 정보와 하천의 수리특성을 나타내는 조도계수를 유량규모별로 추정하여 유량을 산정하는 기법을 활용하여 자연하천 유량자료의 연속적인 획득이 가능한 프로그램을 개발하였다. 대상지점으로 금강 대청댐 하류 공주지점을 선정하여 2003년$\~$2004년의 유량실측 자료를 바탕으로 유량 측정하고, 단면의 적절한 조도계수를 추정하여 유량을 산정하였다. 이를 통하여 기존 수위-유량관계곡선식의 신뢰성을 평가하고, 실측값에 근사한 유량을 연속적으로 산정할 수 있도록 하였으며, 이를 적용하여 향후 수문해석, 유출분석등에 활용하고자 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.612-615
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• 2006

In this study, we compared and analyzed the floor impact noise insulation performance produced by the rating methods. The rating methods are using reversed A-weighting curve, A-weighted sound pressure levels(dB(A)). The results of this study are(1)dB(A) by the specified frequency is 0.5dB(A) at light weight and 2.5dB(A) at heavy weight upper than all pass dB(A)(2)the rating using reversed A-weighting curve is 5dB lower than dB(A)(3)the number of rating using reversed A-weighting curve mainly depends on impact noise pressure level of 63Hz in heavy weight but dB(A) does not.