• Journal of Korean Society for Geospatial Information Science
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• v.15 no.3
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• pp.27-32
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• 2007

3D based information is demanded increasingly as cities grow three dimensionally and buildings become large and complex. The use of 3D GIS is also getting attention as fundamental data for ubiquitous computing applications such as location-based guidance, path finding and emergency escaping. However, most 3D modeling techniques are focused on the visualization of buildings or terrains and do not have topological structures required in spatial analyses. In this paper, we introduce a method to incorporate topological relationship into 3D models by combining 2D GIS layers and 3D model. We divide indoor spaces of a 3D model into discrete objects and then define the relationship with corresponding features in 2D GIS layers through database records. We also show how to construct hallways network in the 2D-3D integrated building model. Finally, we test different cases of route finding situations inside a building such as normal origin-destination path finding and emergency evacuation.

• Journal of Game and Entertainment
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• v.2 no.1
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• pp.64-70
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• 2006

CAD system is a very important technology in designing many products which we are using today. This CAD technology have enlarging its area into 3D CAD systems with the development of computer graphics technologies. In particular, such advances have also been realized in special area such as the CAD system for designing shoes. 3D CAD systems for shoes design must provide compatibility between 3D and 2D data because shoes are made using 2D parts of pieces of leather or cloth. Many designers get high performances using 2D shoe CAD systems because they have had long practices with the 2D systems. Therefore, to get the mapping between 2D modeling and 3D modeling is one of very important components in 3D CAD system. In this paper, we proposed a flattening method that convert 3D shoes data to 2D data.

• Journal of the HCI Society of Korea
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• v.2 no.2
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• pp.1-9
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• 2007

In this paper, we propose a reconstruction technique of the lost hair region for 3D human actor modeling. An active depth sensor system can simultaneously capture both color and geometry information of any objects in real-time. However, it cannot acquire some regions whose surfaces are shiny and dark. Therefore, to get a natural 3D human model, the lost region in depth image should be recovered, especially human hair region. The recovery is performed using both color and depth images. We find out the hair region using color image first. After the boundary of hair region is estimated, the inside of hair region is estimated using an interpolation technique and closing operation. A 3D mesh model is generated after performing a series of operations including adaptive sampling, triangulation, mesh smoothing, and texture mapping. The proposed method can generate recovered 3D mesh stream automatically. The final 3D human model allows the user view interaction or haptic interaction in realistic broadcasting system.

• Journal of Digital Convergence
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• v.10 no.10
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• pp.447-456
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• 2012

In space design or form design step, recognized necessity of digital design practical use. Also, deduced systematized analysis method that can use various function of CAD system actively. These method can promote the practical use because third dimensional digital design escapes plan and design process in concept that get presentation result after is completed, establishes role of effective and systematic digital design at planning and design of space or form. This uses by a design tool that ease designer's judgment and space and form analysis in architectural planning and design process that third dimension digital design is not part by a simplicity design tool. Share and takes advantage of digital design process method that is deduced in this study, need continuance of connection study for more effective and systematic digital design methodology deduction. Need public ownership of teaching material development and teaching method that can deliver extended third dimension digital design process.

• Journal of the Korean Society for Railway
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• v.14 no.1
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• pp.11-18
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• 2011

This paper proposed a new 2-D multi-body dynamic modeling technique to analyze overriding behaviors taking place during train collision. This dynamic model is composed of nonlinear springs, dampers and masses by considering the deformable characteristics of carbodies as well as energy absorbing structures and components. By solving this dynamic model for rollingstock, energy absorbing capacities of collision elements, accelerations of passenger sections, impact forces applied to interconnecting devices, and overriding displacements can be well estimated. For a case study, we chose KHST (Korean High Speed Train), obtained crush characteristic data of each carbody section from 3-D finite element analysis, and established a 2-D multi-body dynamic model. This 2-D dynamic model was simulated under the train-to-train collision scenarios, and evaluated with 3-D virtual testing model. It was founded from the simulation results that this 2-D dynamic model could well predict overriding behaviors, and the modeling technique of carbody deformation was very important in overriding estimation.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.414-414
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• 2020

고전 천수방정식을 적용한 2차원 도시홍수 모델링에서는 지형의 정확한 반영을 위해 고해상도 격자가 요구되며 이는 많은 계산시간과 노력을 필요로 한다. 최근에는 다공성 천수방정식을 적용한 도시홍수해석으로 많은 계산 노력이 요구되는 도시홍수모델링의 한계를 극복한 연구가 많이 이루어지지고 있다. 이러한 연구는 도시 홍수에서 흐름이 공간적으로 변화할 때 불균일 공극이 존재하므로 격자의 크기를 다르게 하여 이러한 불균일성을 해결하고자 하는 등방성 천수모형의 적용에서 시작되었다. 하지만, 등방성 공극을 고려한 도시홍수 해석모형은 대표요소체적(REV)보다 더 큰 격자의 적용을 해야 하는 제한성을 가진다. 반면, 비등방성 공극은 대표요소체적의 적용이 필요하지 않아 불균일 공극의 크기에 관계없이 이론상으로는 동일한 해상도의 격자가 사용가능하긴 하지만, 실제 도시홍수 해석에서 중요하면서도 도전적인 연구이다. 본 연구에서는 도시홍수의 효율적 계산을 위해 비등방성 공극을 고려한 적분형 다공성 천수방정식을 기반으로 하는 2차원 도시홍수 해석모형을 개발하였다. 모형의 개발을 위해, 적용 격자내에서 도시지역의 건물이 차지하는 길이 및 면적을 산정하고 그 값을 2차원 천수방정식에 적용 가능하도록 체적공극(𝜙_j)와 면적공극(𝜓_k)을 2차원 고전 천수방정식에 추가하였다. 개발모형은 고전 천수방정식, 등방성 공극 고려(미분형 다공성) 천수방정식 및 비등방성 공극 고려(적분형 다공성) 천수방정식의 적용이 가능하여, 각 모형에 적합한 2차원 격자 생성, 각 모형의 매개변수를 보정 그리고 정확성, 효율성, 적용성이 비교 가능하다. 각 모형의 정확성과 효율성 비교를 위해 3가지의 오차 비교 (구조적 오차, 격자크기 오차, 공극 모형 오차), 계산시간 비교, 공간 변동성 검증을 위한 수심 종단형상 비교하였다.

• Geophysics and Geophysical Exploration
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• v.15 no.1
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• pp.33-38
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• 2012

A resistivity method has been applied to wide range of engineering and environmental problems with the help of automatic and precise data acquisition. Thus, more accurate modeling and inversion of time-lapse monitoring data are required since resistivity monitoring has been introduced to quantitatively find out subsurface changes With respect to time. Here, we used the finite element method (FEM) for 3D resistivity modeling since the method is easy to realize complex topography and arbitrary shaped anomalous bodies. In the FEM, the linear elements, also referred to as first order elements, have certain advantages of simple formulation and narrow bandwidth of system equation. However, the linear elements show the poor accuracy and slow convergence of the solution with respect to the number of elements or nodes. To achieve the higher accuracy of finite element solution, high order elements are generally used. In this study, we developed a 3D resistivity modeling program using high order Serendipity elements. Comparing the Serendipity element solutions for a cube model with the linear element solutions, we assured that the Serendipity element solutions are more accurate than the linear element solutions in the 3D resistivity modeling.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1087-1092
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• 2006

몰입도가 높은 가시화 기법 중 하나인 입체 영상은 차세대 미디어의 표준으로 최근 크게 주목 받고 있다. 그러나 일반 2차원 영상과는 달리 입체 영상은 3차원의 기하정보가 존재해야만 영상을 생성하는 것이 가능하다. 따라서 3차원의 기하정보가 존재하지 않는 2차원 영상을 이용한 입체 영상의 저작은 매우 어려운 문제이다. 본 논문은 영상 기반 모델링 기법을 활용하여 단안 영상으로부터 입체 영상을 생성하기 위한 입체 영상 저작 도구를 제안한다. 이를 위해 입력된 영상에서 사영 기하 정보를 사용하여 깊이 정보를 추론함으로써 3차원 환경을 구성하는 전역 깊이 정보 추출 방법과 영상 내에 존재하는 사물의 정확한 깊이 정보로 수정하기 위한 부분 깊이 정보 수정 방법을 제안한다. 또한, 추출한 깊이 정보로부터 몰입감이 높은 입체 영상의 시점을 결정하기 위한 대화식 입체 영상 미리 보기 기능을 제안한다. 본 논문에서 제안한 기법은 2차원 영상 저작 도구인 포토샵의 플러그인으로 구현함으로써 범용성을 높였다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.1
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• pp.33-42
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• 2002

A method of automatic 3D tunnel modeling is proposed. The proposed method used the parametric representation of geometry and a hierarchical and relational data structure. These two bases provide the generalization and extension for 3D tunnel modeling. Especially, these two fundamentals ion the basis iota representing the characteristics of the tunnel structure for analysis. The constant-curvature characteristic is exploited to generate 3D mesh on the tunnel surface. This is attributed to the advantage that any 2D automatic mesh generation algorithm can be applied to 3D mesh modeling.

• TTA Journal
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• s.35
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• pp.66-79
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• 1994

PCS OAM & P에서 데이터를 정의하는 2가지 표준방법에는 Structure of Management Information(SMI)와 Management Information Base(MIB)가 있는데 MIB란 망설비를 망관리 차원에서 모델링 및 정보화하는 것으로 효율적이고 체계적인 망설비의 정의를 위해 객체지향적 모델링 기법을 이용하여야 한다. MIB를 정의하기 위해서는 정보모델링(Information Modelling)과정이 우선되어야 하는데 이는 관리하고자 하는 시스템의 범위를 규정하는 작업이다. 특히 정보모델링과정은 객체 지향적 설계기법에 의한 inheritance 기법을 사용하는데 여기서는 이에 대한 개요 및 PCS에서의 관리서비스 및 기능을 기술하였으며 이는 아직 표준화단계를 위해 검토중이다.