• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1939-1944
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• 2004

Recently, several kinds of experimental and computational studies are being carried out to investigate the WIG aerodynamic characteristics which are of practical importance to develop the new ground transportation vehicle system. These works are mainly based upon conventional wind tunnel tests, but many problems associated with the WIG aerodynamic characteristics cannot be satisfactorily resolved due to the wind tunnel blockage effects or string problems to support the test object. To do this, it is necessary to develop a novel simulator appropriate to the WIG aerodynamics. The objective of the present study is to clarify the aerodynamic characteristics of a new developed WIG simulator, which is able to imitate real WIG flow circumstances such as gradually decelerating and accelerating flows.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.302-304
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• 2019

탄소 순환과 수문 순환의 관계를 이해하기 위해서는 효율적인 물 사용과 실제 물 사용 간의 비율로 정의되는 용수효율(Water Use Efficiency; WUE)을 정량화 하는 것이 필요하다. 특히 용수효율을 평가하기 위해서는 탄소 순환의 주요 인자인 총 1차 생산량(Gross Primary Productivity; GPP)과 순 1차 생산량(Net Primary Productivity; NPP)을 산정하는 것이 중요하다. 본 연구에서는 전 세계적으로 가장 많이 활용되고 있는 지면 모형 중 하나인 Community Land Model(CLM)을 활용하여 동아시아 지역에서의 GPP와 NPP를 산정하였다. 모형을 통해서 산정된 광역의 GPP와 NPP는 Flux tower에서 관측된 지점 자료를 활용하여 검증할 예정이다. 또한 지면 모형에서 획득한 동아시아 지역의 GPP와 NPP에 대한 공간 분포를 분석하여 탄소 순환 인자들에 대한 시공간적인 변화에 대하여 확인하고자 한다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.7 no.3
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• pp.160-166
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• 1978

Heat loss to the ground in ondol heating system is analyzed mathematically using conformal mapping and variable transformations, Both two-and three-dimensional systems are analyzed. Heated house is assumed to be rectangular shape. Mean value of heat loss to the ground can be obtained using Figure 2. Effects of thermal parameters to heat loss are discussed. Numerical examples are also given.

• Journal of Korean Orthopaedic Sports Medicine
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• v.7 no.1
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• pp.33-36
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• 2008

Purpose: The purpose of this study was to evaluate the mechanism of injury in the anterior cruciate ligament tears sustained in participation in soccer. Materials and methods: 50 patients whose knees were injured during playing soccer were enrolled in this study. The mean age was 27 years old, 47 were male and 3 female. 15 of them were either professional or amateur soccer players, the rest were non-professional. The injury mechanism was investigated by evaluation of the medical records or by telephone interview. Results: The injury mechanism involved contact injuries in 17 patients and non-contact in 33. 41 patients were bearing weight on the involved side at the time of injury, and 9 patients were not. In cases of contact injury, 9 of the 17 patients had sustained a valgus force to the knee, and 5 patients had varus force, 11 patients had their foot planted, and 6 did not. Among those patients with a planted foot, 3 patients were injured by the rotation of the thigh, 1 patient was injured by hyperextension, and there were no deceleration mechanism injuries. In non-contact injuries, 30 out of 33 patients had their foot planted at time of injury and only 3 patients did not. Of these 30 patients, 16 were injured by the rotation of thigh, 6 sustained a varus force on the knee joint and 5 had a valgus force, 5 were injured by hyperextension, and 2 by deceleration. 3 patients, who did not have their foot planted, were injured while kicking with the involved leg. Conclusions: For soccer players in this series, the most common mechanisms resulting in anterior cruciate ligament tears were non-contact, most often by rotation of the torso over a planted foot. In contact injuries, the most common mechanism was the application of valgus force by tackle.

• Journal of Digital Convergence
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• v.16 no.9
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• pp.365-374
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• 2018

This study aims at understanding the components of on-line newspaper and how each newspaper's layout configuration is differentiated through the analysis on the websites of 10 general daily newspapers in the news stand of NAVER. The collection of data was implemented twice, and One-Way ANOVA was used as an analyzing way. The content of the analysis was carried out based on the types of visual images, the number of photo-based articles and title-based articles, the size of image for the main story, etc. As a result of analysis, the rate of news articles with the audios, videos, cards and slides differentiated from paper-based newspaper was low, and also the news articles using the informative graphics and the graphic sources were very small in number. As a whole, the newspapers in the news stand of NAVER showed that they attempt to make a distinction of their newspaper layout by using a variety of editorial techniques. The significance of this paper is to offer a basic clue to the editing formation to promote the news consumption of newspapers. Under the circumstance that the ecology of media is rapidly being reformed by new media technology, the continuous study of how the newspaper layout should be changed will be needed.

• Korean Journal of Applied Biomechanics
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• v.18 no.1
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• pp.107-115
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• 2008

The purpose of this study was to investigate muscle activity and vertical ground reaction force(F) in children with Down syndrome(DS) during vertical jump. Six DS and one healthy child performed vertical jump. Four muscles(Biceps femoris, Rectus femoris, Tibialis anterior & Gastrocnemius) and F were analyzed. Gastrocnemius in DS showed lower muscle activity in a propulsive phase. Impulse during 0.3sec before toe-off in DS displayed lower value than that in the healthy child. The second peak of F in DS occurred later than that in the healthy child, so DS performed landing with their knee more flexed. The first and second peak of F and loading rate to the second peak of F in DS showed lower value than those in the healthy child. Therefore, DS might have lower ability to absorb the force while landing from a vertical jump.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.1
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• pp.39-48
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• 2012

Filtering process that separates ground and non-ground points from LIDAR data is important in order to create the digital elevation model (DEM) or extract objects on the ground. The purpose of this research is to select the most effective filtering algorithm through qualitative and quantitative analysis for the existing filtering method used to extract ground points from LIDAR data. For this, four filtering methods including Adaptive TIN(ATIN), Perspective Center-based filtering method(PC), Elevation Threshold with Expand Window(ETEW) and Progressive Morphology(PM) were applied to mountain area, urban area and the area where building and mountains exist together. Then the characteristics for each method were analyzed. For the qualitative comparison of four filtering methods used for the research, visual method was applied after creating shaded relief image. For the quantitative comparison, an absolute comparison was conducted by using control points observed by GPS and a relative comparison was conducted by the digital elevation model of the National Geographic Information Institute. Through the filtering experiment of the LIDAR data, the Adaptive TIN algorithm extracted the ground points in mountain area and urban area most effectively. In the area where buildings and mountains coexist, progressive morphology algorithm generated the best result. In addition, as a result of qualitative and quantitative comparisons, the applicable filtering algorithm regardless of topographic characteristics appeared to be ATIN algorithm.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.2
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• pp.140-148
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• 2007

The remote sensing observations of land surface properties are inevitably influenced by the landscape heterogeneity. In this paper, we introduce a geostatistical technique to provide a quantitative interpretation of landscape heterogeneity in terms of key land surface parameters. The study areas consist of the two KoFlux sites: (1) the Gwangneung site, covered with temperate mixed forests on a complex terrain, and (2) the Haenam site with mixed croplands on a relatively flat terrain. The semivariogram and fractal analyses were performed for both sites to characterize the spatial heterogeneity of two radiation parameters, i.e., land surface temperature (LST) and albedo. These parameters are the main factors affecting the reflected longwave and shortwave radiation components from the two study sites. We derived them from the high-resolution Landsat ETM+ satellite images collected on 23 Sep. 2001 and 14 Feb. 2002. The results of our analysis show that the characteristic scales of albedo was >1 km at the Gwangneung site and approximately 0.3 km at the Haenam site. For LST, the scale of heterogeneity was also >1 km at the Gwangneung site and >0.6 to 1.0 km at the Haenam site. At both sites, there was little change in the characteristic scales of the two parameters between the two different seasons.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.5
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• pp.451-457
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• 2015

This paper presents the analytical closed form solution for the impact load of a collision between rigid bodies and its application to a spent nuclear fuel disposal canister accidentally dropped and impacted on the ground. This paper performed a study on the numerical rigid body dynamic analysis to compute the impact load between two rigid bodies, especially, the impulsive force which is applied to the spent nuclear fuel disposal canister in the accidental drop and impact event on the ground. Through this study the impulsive force which is occurring in the spent nuclear fuel disposal canister under accidental drop and impact event on the ground and required in the process of structural safety design of the canister is computed numerically. The main content of this numerical study is about the technical method how to compute the impulsive force applied to the canister under the accidental drop and impact event on the ground by using the commercial computer code for the rigid body dynamic analysis. On the basis of this study a problem to compute the impulsive force which is occurring in the canister in the case of collision with the ground is numerically treated. This numerically computed impulsive force is compared with the theoretical value, which shows a good agreement.

• KLA journal
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• v.46 no.1 s.356
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• pp.46-51
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• 2005

작년 한해 '해외도서관 사정'지면은 세계 각지에서 활동하고 있는 많은 도서관인들의 도움으로 꾸며졌다. 올해는 전 세계 도서관인들의 모임인 국제도서관협회연맹(IFLA, International Federation of Library Associations and Institutions) 산하조직인 47개 분과(Section)와 4개의 토론그룹(Discussion Groups)의 역할과 활동을 간략히 살펴보는 지면을 마련하여, 범지구적인 도서관계의 고민과 과제가 무엇인지 알아보는 한편 1년6개월 앞으로 다가온 '2006 서울 세계도서관정보대회(WLIC)'에 대한 도서관계의 관심을 모으는 시간을 갖고자 한다.