• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.1
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• pp.94-104
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• 2004

The purpose of this study is to analyze various hydraulic characteristics using SMS (Surface Water Modeling System) RMA2 model. It is based on 2-D finite element method. River reaches (13.8km) from Gyeongan gauge station to the inlet of Paldang lake was selected. Finite element was made by RIMGIS Data, and the analysis of river-changes was operated by unsteady flow. The sediment concentration and bed change was simulated using SED2D model. This River's velocity was distributed that 0.05~3.85m/s and bed change was changed about 0.0003~0.0135m.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.68-68
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• 2016

하천의 사행 및 합류 형상은 복잡한 나선 흐름을 발생시킨다. 그 중 이차류는 사행에 의한 편수위 형성과 횡단 압력의 불균형, 그리고 수심에 따라서 변화하는 원심력에 의하여 형성된다. 이러한 흐름은 주로 3차원 모형으로 재현할 수 있으며 이에 관련된 연구는 계속 이루어졌으나 3차원 모형의 구성과 사용에는 상당한 시간 및 노력이 요구된다. 본 연구에서는 이러한 이차류의 영향을 수심적분된 2차원 모형으로 구현하고자 하였으며 이를 위해 이차류 연직 분포에 대한 기존 연구를 확인하고, 이러한 연직 분포를 표현할 수 있는 경험식을 3차원 모형인 FLOW3D를 통해 모의하고 개발하였다. 3차원 모형을 다양한 사행반경을 갖는 실험 사행수로에 적용하여 사행도에 따른 민감도를 분석하고 경험식을 개발하였다. 개발된 식은 2차원 수리해석 모형인 RAMS(River Analysis and Modeling System)에 적용되었다. RAMS는 수심 적분된 2차원 천수 방정식을 지배방정식으로 사용하는 수리해석모형인 HDM-2D를 해석엔진으로 사용하며, 이차류의 영향을 반영하기 위하여 개발한 수직분포 경험식을 분산 응력항 형태로 적용하였다. 모형의 적용성 확인을 위하여 사행 실험수로 및 합류수로에 모의를 수행하였다. 사행수로 및 합류수로는 실험 경계조건과 동일한 상류 입력 유량과 하류 경계조건을 사용하여 결과를 비교하였다. 사행수로 모의 결과 유속분포의 거동이 실험수로의 사행으로 인하여 2차류 효과로 주 흐름이 바깥쪽으로 기울어짐을 일부 재현하였다. 합류수로의 경우 기존 모형에 비하여 분산 응력항이 포함된 본 모형이 실측값에 근접하였는데 이는 이차류가 발생하는 영향으로 하류에 유속편차가 줄어드는 영향을 더 정확히 묘사한 것으로 판단된다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.557-562
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• 2006

In order to predict the dispersion of suspended sediment arising from dredging operation in port and navigation channel, a hybrid model for dispersive transport of turbidity plume was developed using Lee's(1998) hybrid method. Using hybrid modeling scheme advection-diffusion equation was solved by the forward particle-tracking method for advection process and by the fixed Eulerian grid method for diffusion process. To examine numerical model simulation in accuracy, the simulated results for 1-D, 2-D, and 3-D cases were compared with the analytical solutions including Kuo, et al's (1985) 3-D mathematical model. The model results were in a good agreement with the analytical solutions and mathematical model for the dispersion of turbidity plume.

• Journal of Korean Society of Transportation
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• v.30 no.5
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• pp.43-59
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• 2012

It is generally assumed about trip distribution estimation model that growth factor model's estimation accuracy is higher than that of other models in short-term and that gravity model's estimation accuracy is higher than that of other models in long-term. For validation of such assumptions, this study compares estimation accuracies of each estimation model using 3year(1988, 1992, 2004) O-D tables from Daegu city. Each estimation model's accuracy were compared by mid-size and large-size zone as well as short-term and long-term target years. The results show that the trip distribution estimation model selection by usual assumption is not always right.

• Journal of the Korean Data and Information Science Society
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• v.28 no.3
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• pp.547-557
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• 2017

The health-related quality of life data are commonly skewed and bounded with spike at the perfect health status, and the variance tended to be heteroscedastic. In this study, we have developed a prediction model for EQ-5D using linear regression model, beta regression model, and extended beta regression model with mean and precision submodel, and also compared the predictive accuracy. The extended beta regression model allows to model skewness and differences in dispersion related to covariates. Although the extended beta regression model has higher prediction accuracy than the linear regression model, the overlapped confidence intervals suggested that the extended beta regression model was superior to the linear regression model. However, the expended beta regression model could explain the heteroscedasticity and predict within the bounded range. Therefore, the expended beta regression model are appropriate for fitting the health-related quality of life data such as EQ-5D.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.143-148
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• 2008

This Study is about driving simulation after road design by 3D-GIS in digital elevation model from digital aerial photogrammetry. For designing roads efficiently it's very important to consider geographical features before design when analyze the view. Nevertheless, existing studies is mainly restricted in the mountainous, despite of using digital map or aerial photogrammetry and the study which used aerial photo in the area where the road designing is made really is not get executed. Therefore, this study will do 3D-road design and driving simulation by appling really road design data to topography, on the basis of digital elevation generated from aerial photogrammetry.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.3
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• pp.191-200
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• 2011

Levee failure cause the huge amount of damage to human and property. Overflow and erosion of levee are primary cause of a break in a levee but the analysis of breach pattern and impact is partially inadequate. The flow characteristics of meandering rivers are very important in field of river hydraulics that should be studied in practical viewpoints relating to river levee. In meandering the secondary flow that rotary direction is changed reciprocally occurs in three dimension is known. In this study flow characteristics of local river are considered and of meandering channels are analyzed using CCHE2D and FLOW3D. The stability and accuracy of models are examined comparing the measuring and analyzed data for the experimental channel and natural river(Namgang). Consequently, the flow characteristics in a meandering river are suggested precisely and it is essential that river levees having meandering river should be analyzed.

• The Journal of the Korea Contents Association
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• v.12 no.9
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• pp.136-145
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• 2012

This research proposes a pattern making method for women's bodice by the characters of body types and develops bodice dress forms on their body shapes applying 3D body scan data. 515 women's body scan data was collected and analyzed factor and cluster analysis. Three body types were characterized in normal, obese, and slim group. In each group, 10 subjects were selected. 20 parts in 3D anthropometric data were measured using Autocad program. The amount of waist dart was calculated and three types of basic bodice pattern were developed using the calculated darts data. The amount and the position of front dart and side dart were different at obese group in comparison of normal and thin group. The three types of basic bodice model were made by the basic bodice pattern, and each model was scanned by 3D scanner to make 3D bodice dress forms. Three types of bodice dress forms were rendered using 3D max program. Bodice dress forms had the dart lines and were useful to draft patterns to fit their body shape.

• Proceedings of the ESK Conference
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• 2004.10a
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• pp.44-44
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• 2004

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.3
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• pp.23-27
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• 2008

The new conjunctive surface-subsurface flow model at a large scale was developed by using a 1-D Diffusion Wave (DW) model for surface flow interacting with the 3-D Volume Averaged Soil-moisture Transport (VAST) model for subsurface flow for the comprehensive terrestrial water and energy predictions in Land Surface Models (LSMs). A selection of numerical implementation schemes is employed for each flow component. The 3-D VAST model is implemented using a time splitting scheme applying an explicit method for lateral flow after a fully implicit method for vertical flow. The 1-D DW model is then solved by MacCormack finite difference scheme. This new conjunctive flow model is substituted for the existing 1-D hydrologic scheme in Common Land Model (CLM), one of the state-of-the-art LSMs. The new conjunctive flow model coupled to CLM is tested for a study domain around the Ohio Valley. The simulation results show that the interaction between surface flow and subsurface flow associated with the flow routing scheme matches the runoff prediction with the observations more closely in the new coupled CLM simulations. This improved terrestrial hydrologic module will be coupled to the Climate extension of the next-generation Weather Research and Forecasting (CWRF) model for advanced regional, continental, and global hydroclimatological studies and the prevention of disasters caused by climate changes.