• 대기
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• 제26권1호
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• pp.111-126
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• 2016

In the numerical weather model, surface properties can be defined by various parameters such as terrain height, landuse, surface albedo, soil moisture, surface emissivity, roughness length and so on. And these parameters need to be improved in the Seoul metropolitan area that established high-rise and complex buildings by urbanization at a recent time. The surface roughness length map is developed from digital elevation model (DEM) and it is implemented to the high-resolution numerical weather (WISE-WRF) model. Simulated results from WISE-WRF model are analyzed the relationship between meteorological variables to changes in the surface roughness length. Friction speed and wind speed are improved with various surface roughness in urban, these variables affected to temperature and relative humidity and hence the surface roughness length will affect to the precipitation and Planetary Boundary Layer (PBL) height. When surface variables by the WISE-WRF model are validated with Automatic Weather System (AWS) observations, NEW experiment is able to simulate more accurate than ORG experiment in temperature and wind speed. Especially, wind speed is overestimated over $2.5m\;s^{-1}$ on some AWS stations in Seoul and surrounding area but it improved with positive correlation and Root Mean Square Error (RMSE) below $2.5m\;s^{-1}$ in whole area. There are close relationship between surface roughness length and wind speed, and the change of surface variables lead to the change of location and duration of precipitation. As a result, the accuracy of WISE-WRF model is improved with the new surface roughness length retrieved from DEM, and its surface roughness length is important role in the high-resolution WISE-WRF model. By the way, the result in this study need various validation from retrieved the surface roughness length to numerical weather model simulations with observation data.

• 한국지구과학회지
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• 제39권1호
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• pp.46-52
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• 2018

이 논문은 자체 개발된 드론을 이용하여 사진측량기술을 적용하여 3차원 수치지표면모델(DSM)개발 연구를 수행하였다. 이 DSM을 개발하기 위하여 제주도 지역을 선정하여 24장의 사진을 개발된 드론으로 직접 촬영을 수행하였다. 촬영된 사진의 정확한 3차원 좌표를 부여하기 위하여, 10개의 지표기준점(GCP)점을 선정하여 상대측위 지구위치시스템(DGPS)측량을 실시하였다. 사진의 정확도를 평가하기 위하여 3개의 GCP점을 선정하여 사진상의 좌표와 지상점의 좌표의 정확도를 비교하였다. 사진좌표계과 지상좌표계의 정확도를 평가한 결과 수평오차는 8.8-14.7 cm로 나타났으며, 연직오차는 12.4 cm로 나타났다. 이 정확도는 국토지리정보원(NGII)이 인정하는 1/1,000 수치지도의 정확도를 가지는 측량결과이다. 이 연구를 통하여 본 연구에서 개발된 드론과 사진측량기법이 제주지역에서 우리가 원하는 DSM자료를 얻는데 유용한 기술임을 알 수 있었다.

• 한국환경과학회지
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• 제28권2호
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• pp.259-266
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• 2019

Two main sources of data, meteorological data and land surface characteristics, are essential to effectively run a distributed rainfall-runoff model. The specification and averaging of the land surface characteristics in a suitable way is crucial to obtaining accurate runoff output. Recent advances in remote sensing techniques are often being used to derive better representations of these land surface characteristics. Due to the mismatch in scale between digital land cover maps and numerical grid sizes, issues related to upscaling or downscaling occur regularly. A specific method is typically selected to average and represent the land surface characteristics. This paper examines the amount of flooding by applying the FLO-2D routing model, where vegetation heterogeneity is manipulated using the Manning's roughness coefficient. Three different upscaling methods, arithmetic, dominant, and aggregation, were tested. To investigate further, the rainfall-runoff model with FLO-2D was facilitated in Yongdam catchment and heavy rainfall events during wet season were selected. The results show aggregation method provides better results, in terms of the amount of peak flow and the relative time taken to achieve it. These rwsults suggest that the aggregation method, which is a reasonably realistic description of area-averaged vegetation nature and characteristics, is more likely to occur in reality.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권4호
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• pp.1738-1756
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• 2020

To improve the accuracy and realism of the virtual surgical simulation system, this paper proposes an optimized mass-spring model with shape restoration ability based on volume conservation to simulate soft tissue deformation. The proposed method constructs a soft tissue surface model that adopts a new flexion spring for resisting bending and incorporates it into the mass-spring model (MSM) to restore the original shape. Then, we employ the particle swarm optimization algorithm to achieve the optimal solution of the model parameters. Besides, the volume conservation constraint is applied to the position-based dynamics (PBD) approach to maintain the volume of the deformable object for constructing the soft tissue volumetric model base on tetrahedrons. Finally, we built a simulation system on the PHANTOM OMNI force tactile interaction device to realize the deformation simulation of the virtual liver. Experimental results show that the proposed model has a good shape restoration ability and incompressibility, which can enhance the deformation accuracy and interactive realism.

• 한국지리정보학회지
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• 제12권1호
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• pp.54-63
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• 2009

해안 침식에 따른 해안선 변화를 모니터링하기 위해 해빈의 표면 자료를 획득하기 위한 다양한 방법들이 적용되어 오고 있다. 본 연구는 지상용 레이저 스캐너와 RTK-GPS를 활용하여 해빈 지형을 구현하여 구축할 수 있는 가능성을 제시하고자 한다. 지상 레이저 스캐닝을 실시하여 20cm 측점 간격으로 취득된 3차원 자료와 수치 사진으로부터 화상이 피복된 수치표면모형을 생성하였다. 또한 7개월 후에 동일 지역을 1초 수신 간격의 RTK-GPS를 이용하여 직접 측정하여 1.9cm의 측량 정확도로 해빈 모형을 구현하였다. 계절적으로 많은 변화가 예상되는 해빈 지역에 즉각 대응적이면서 양호한 결과를 요하는 측정일 경우는 지상용 레이저 스캐너의 활용이 가능하며, RTK-GPS는 해빈 모형의 측점수와 관계가 있어 측점을 직접 관측해야 하는 애로사항이 있지만 지상용 레이저 스캐너에서 발생하는 사각지대를 보정하면서 3차원 모형을 구현할 수 있다. 따라서 동해안 해빈의 지역적 특성을 고려할 때 RTK-GPS와 지상용 레이저스캐너의 조합 활용하여 해빈 모형 자료를 구축하는 것이 보다 정밀한 방법일 것이다.

• 한국측량학회지
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• 제39권1호
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• pp.47-54
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• 2021

건설현장에서 토공물량 산정은 설계에서 시공에 이르기까지 공사비에 큰 영향을 주는 요소로 정확한 값을 산출하는 것이 중요하다. 본 연구에서는 토공물량 산정을 위해 드론 사진측량과 드론 LiDAR를 이용한 방법으로 지형모델을 생성하였다. 드론 사진측량 방법으로 연구대상지의 DSM (Digital Surface Model) 및 정사영상을 구축하였으며, 드론 LiDAR를 이용해 연구대상지의 DEM (Digital Elevation Model)을 구축하였다. 각각의 방법으로 생성된 지형모델에 대한 정확도 평가를 수행하여 각각의 방법이 수평방향 0.034m, 0.035m, 수직방향 0.054m, 0.025m의 차이를 나타내어 지형모델 구축을 위한 드론 사진측량과 드론 LiDAR의 활용성을 제시하였다. 연구대상지의 토공물량 산정 결과, 드론 사진측량은 GNSS 측량 성과와 1528.1㎥의 차이를 나타내었으며, 드론 LiDAR는 160.28㎥의 차이를 나타내었다. 토공물량의 차이는 식생 및 가건물로 인한 지형모델의 차이로 판단되며, 연구를 통해 드론 LiDAR에 의한 물량산정의 효율성을 제시할 수 있었다. 향후 추가적인 연구를 통해 GNSS (Global Navigation Satellite System) 측량과 드론 LiDAR를 활용한 방법으로 산림지역에서의 지형모델 구축 및 활용성에 대한 평가가 이루어진다면 드론 LiDAR를 이용한 지형모델 구축의 활용성을 제시할 수 있을 것이다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 가을 학술발표회 논문집
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• pp.371-378
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• 1999

A prototype computer program was developed which visualizes various kinds of geotechnical information using 3D object graphics techniques. The program integrates various kinds of geotechnical data such as surface geology map, boreholes data, geophysical data as well as man made subsurface structures. It also reads NGIS DXF map and generates digital elevation model from iso-elevation line layer of the DXF map. All the data are put into a 3D model as 3D objects. The created 3D model can be viewed and analysed in a interactive 3D way.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.22-27
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• 1998

A grid-based soil moisture routing model(GRISMORM) was developed to assess the information of groundwater recharge using spatial data such as Landsat TM and digital elevation model etc.. The model predicts the hydrologic components, that is, surface runoff, subsurface runoff, baseflow and evapotranspiration at each grid elements by grid-based water balance computation.

• Asia pacific journal of information systems
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• 제26권1호
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• pp.80-108
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• 2016

Contemporary organizations strive for customer agility through the deployment of digital technologies on customer-focused operations to build enduring customer relationships, with mobile apps being one of its prominent examples. Drawing on prior agility and ECT literature, this study proposes a model to examine customers' view of a firm's customer agility. Our empirical test of conceptual model from data collected in a field study from 128 customers demonstrated that the conceptual model offers good explanation for customers' view of a firm's customer agility through relationships among customer expectations-customer perceived firm's responsiveness-satisfaction. Data were analyzed using PLS, polynomial modeling, and response surface methodology to examine the relationships between customers' digital interactions with the firm, influence of digitized interactions on customer expectations, customers' evaluation of firm's responsiveness, and subsequent customer satisfaction.

• 한국환경과학회지
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• 제33권6호
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• pp.435-442
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• 2024

We investigated the accuracy of surface air temperature prediction according to the selection of land-use data and initial meteorological data using the Weather Research and Forecasting model-v4.2.1. A numerical experiment was conducted at the Daegu Dyeing Industrial Complex. We initially used meteorological input data from GFS (Global forecast system)and GDAPS (Global data assimilation and prediction system). High-resolution input data were generated and used as input data for the weather model using the land cover data of the Ministry of Environment and the digital elevation model of the Ministry of Land, Infrastructure, and Transport. The experiment was conducted by classifying the terrestrial and topographic data (land cover data) and meteorological data applied to the model. For simulations using high-resolution terrestrial data(10 m), global data assimilation, and prediction system data(CASE 3), the calculated surface temperature was much closer to the automatic weather station observations than for simulations using low-resolution terrestrial data(900 m) and GFS(CASE 1).