• Journal of the Society of Disaster Information
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• v.8 no.1
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• pp.71-80
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• 2012

It is necessary to establish guidelines when we selecting the civil defense evacuation facilities through quantitative analysis by civil defense evacuation facilities volume. The purpose of this study is to evaluate according to population density and distribution of the capacity of evacuation facilities. The results of this study are as follows. First, it is necessary to consider the capacity of evacuation facilities in order to set up the exact districts of civil defense evacuation facilities. Second, basic data based on to compare the condition of civil defense evacuation facilities is produced by an analysis on evacuation status of the target region. Third, it is proved to consider topographical conditions which do not move the shortest distance. Fourth, in order to create a realistic model, it is necessary to consider the model set various parameters.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.662-665
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• 2008

This research attempts to develop 4D CAD function to support optimal road design by expanding the existing 4D CAD utilization system, which focused on construction phase, to the design phase. The functions such as earthwork simulation for selecting of road alignment, alternative route simulation and structure type simulation were suggested as functions to support road design. Through those virtual reality (VR) functions, visual confirmation of the condition of route and earthwork Is possible by the developed system, and an optimal alternative route can be selected by carrying out layout simulation of the alternative route. The functions presented in this research provide the decision making tools based virtual model for efficient support to road design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.3
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• pp.275-282
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• 2015

Recently, Vecna BEAR type robot to save injured individuals from inaccessible areas has been developed to minimize the loss of life. Because this robot is driven on rough terrain, there is a risk of rollover and vibration, which could impact the injured. In order to guarantee its stability, an algorithm is required that can estimate the speed limits for various environments in real time. Therefore, a dynamic model for real-time analysis is needed for this algorithm. Because the tracks used as the driving component of Vecna BEAR type robot consist of many parts, it is impossible to analyze the multibody tracks in real time. Thus, a lumped track model that satisfies the requirements of a short computation time and adequate accuracy is required. This study performed lumped track modeling, and the traction force was verified using RecurDyn, which is a dynamic commercial program.

• Journal of the Korean association of regional geographers
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• v.12 no.6
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• pp.631-644
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• 2006

The study area is a pocket beach which consisted of sandy beach, dune, agricultural land and residential area etc. The coastal dune area is classified to foredune, dune plain, secondary (or back) dune. The foredune area is covered by herbaceous dune plants(ex. Carex kobomugi, Wedelia prostrata, etc.), whereas the dune plain area is covered by herbs and shrubs(Vitex rotundifolia). The most inner area, secondary dune, is planted by pine forest(Pinus thunbergii). The mean size of the beach and dune sediments ranges from 1.1 to $1.8{\Phi}$, which mean these values are higher than normal sediments. Sorting and Skewness is $0.6{\sim}-1.2{\Phi}$ and $-2.7{\sim}1.6{\Phi}$ respectively. We found that the soil formation process in the secondary dune area has been progressed rapidly from the analysis of fine grain content, organic matter content, and CEC.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.59-59
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• 2011

파랑의 전파와 변형에 대한 연구에는 수심방향으로 적분한 2차원방정식인 완경사방정식과 Boussinesq 방정식을 기반으로 한 수치모형을 이용한 연구가 최근까지 가장 활발하게 진행되어 오고 있다. 그러나 실제 구조물의 설계에는 2차원 수치모형에서 고려할 수 없는 수심방향 유속에 기인한 정확도의 문제로 인해 구조물의 형상과 재원을 설계하기 위한 정교한 수치모형실험이 어려워 주로 수리모형실험에 의존해 왔다. 수리모형실험은 실제 현상을 가장 잘 재현해낼 수 있어 신뢰성이 매우 높지만 다양한 실험을 수행하기가 어렵고 많은 시간과 비용이 소요되는 단점이 있다. 이에 따라 최근 수심방향으로 완전한 운동방정식인 Navier-Stokes 방정식을 푸는 3차원 수치모형에 대한 연구가 활발히 진행되고 있다. 이론적으로 매우 우수한 모형이긴 하나 정확도 높은 결과를 얻기 위해서는 매우 조밀한 격자를 필요로 하기 때문에 아직까지 막대한 계산시간이 필요하다는 단점이 있으나 컴퓨터 기술이 급격한 속도로 발전하고 있어 Navier-Stokes 방정식 모형의 적용 가능성은 계속 높아지고 있다. 파랑변형을 다루는 수치모형실험을 수행할 때 외부조파를 사용할 경우 구조물이나 지형에 의해 반사되어 나온 파랑이 조파지점에 도달할 때 실험영역으로 재 반사되는 문제가 발생한다. 이를 해결하기 위해 내부조파기법의 개발에 대한 연구가 필수적이었으며, 자유수면변위를 변수로 사용하는 모형의 경우 그 연구가 매우 활발하게 진행되어 왔다. 한편, Navier-Stokes 방정식 모형의 경우 자유수면변위를 변수로 사용하는 2차원 모형에 비해 상대적으로 연구가 미흡하였다. 본 연구에서는 기존의 연직 2차원 Navier-Stokes 방정식 모형에 사용된 연속방정식에 질량 원천항을 추가하는 내부조파기법을 도입하여 3차원 수치모형에서 고립파를 내부조파하고, 급경사에서의 고립파의 처오름 및 처내림 현상을 수리모형 실험결과와 비교 및 분석하였다. 수치모형은 Navier-Stokes 방정식을 엇갈림 격자체계에서 계산하는 동수압 모형으로서, Two-step projection 기법을 사용하는 유한차분모형을 사용하였다. 본 수치모형은 난류의 해석을 위해서 상대적으로 큰 에디(eddy)만을 고려하는 SANS(spatially averaged Navier-Stokes) 방정식을 계산하는 LES(large-eddy-simulation) 기반의 수치모형으로, 난류 모델링을 위해 Smagorinsky LES 모형을 사용한다. 또한, 압력장의 계산을 위해 Bi-CGSTAB 기법을 이용하여 Poisson 방정식의 해를 구하였으며, 자유수면 추적을 위하여 2차 정확도의 VOF(volume-of-fluid) 기법을 사용하였다. 수치모형실험이 전체적으로 수리모형실험에서 관측한 파랑의 처오름 및 처내림 현상을 잘 재현하고 있는 것으로 나타났으며, 정량적인 비교를 통해 수치모형의 성능을 검증하였다.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.11-16
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• 2011

This study was conducted to identify the morphological characteristics and variations level by site environment of native bermudagrass (Cynodon spp.) from costal and island region in South Korea. Soil chemical properties and morphological characteristics were investigated. There were significant differences in plant height, leaf width, leaf length, cotton on leaf blade, stolon, and number of seed per spike depending on where they were collected from natural habitat. We have discovered a variety of variation among the investigated traits in Korean native bermudagrass ecotypes. There were broad leaf and fine leaf types of native bermudgarass in S. Korea. Adaptability was in very high on inadequate environment in bermudagrass with broad leaf types, it has also been suggested that management worth in terms of use. These results may provide basic information for bermudagrass breeding development and the collected types during this investigation would be worth being preserved as genetic resources for further breeding purposes.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.255-259
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• 2003

The technique of birdeye image generation of terrain through the use of satellite digital images and digital maps are very important elements and have applications in planning establishment as well as the actual design of several construction work in complex fields. This paper studies stereo perspective image generation as a possibility through 3-dimensional analysis combined with digital elevation data and remotely sensed images. For this, first of all, ortho-images generated by very accurate GCP and DEM from contour file makes 3-dimensional terrain analysis possible and allows stereo-viewing at the highway construction planning sites. So, we developed the technical methods for the 3-dimensional approach on the planning sites of highways by use of perspective orthoimages. From this research diverse terrain analysis is possible through stereo perspective image generation, and can leads to various application in road construction through gain study results from access to realtime virtual spatial on the objects area in korea.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.159-166
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• 2014

Beatrix Farrand was America's first female landscape architect and Dumbarton Oaks in Washington, D.C., USA site of her best known garden design. The purpose of this study is to identify characteristics of the American Neoclassical tendencies in the early 1900s and Farrand's style through an analysis of Dumbarton Oaks. The results of analysis indicated that although Dumbarton Oaks was influenced by many European classic gardens, the garden has the unique style which reflects regional contexts and culture based on the philosophy of arts and crafts movement, The major characteristics of the late Neoclassical style in America can be summarized as follows. First, A series of terraced gardens were connected by paths and stairways and natural terrain was preserved as much as possible. Second, the formal and informal style coexist and the symmetric and asymmetric forms are well-balanced throughout the garden. Third, selection of plant materials and planting methods, influenced by both classical gardens and the Arts and Crafts style in UK, are in harmony with the space configuration and shape.

• Journal of Korean Society for Geospatial Information Science
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• v.7 no.1 s.13
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• pp.21-28
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• 1999

NGIS and other related public projects have contributed to the generalized use of the digital maps. The accuracy and cost-effectiveness of such digital maps can be enhanced from the integrated use with airphotos and satellite imagery. This study mainly focuses on the investigation of a efficient way of integrating the digital map and image data along with searching for a proper standard format for the easier distribution of image data. This includes a thorough investigation of the available oversea image data-DoQ, DEM, DRG-and exisiting data transfer format such as widely used Geo TIFF and BIIF, supported by ISO. Also, major advantages and problems from integrating both data have been discussed to seek alternatives. The major conclusion from the study includes the need for more supports to activate the use of image data by policy-makers and the establishment of standards towards BIIF considering the accuracy, exchangeability, and trends.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.2
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• pp.85-91
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• 2006

This study deals with the flow over a flat plate with repeated roughness elements of 2-dimensional rectangular shape, which can be applied into the study on the natural geographical roughness and the turbulent flow on roughened solid surface. Part 1 of the study showed that the ratio between the spacing and the height of roughness elements plays a crucial role in developing the flow pattern near wall surface. The present study complements the turbulence characteristics, the utilization of friction velocity as well as integral parameters. Results confirmed that k-type roughness(s/H=7 or 14) is certainly a more effective means than d-type roughness (s/H=3.5) in thickening the viscous region.