• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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• pp.382-387
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• 2004

As the increasing needs in the industrial filed, many studies for the 3D CAD system are carried out. There are two types of 3D CAD system. One is manifold modeler, the other is non-manifold modeler. In the manifold modeler only 3D objects can be modeled. In the non-manifold modeler 3D, 2D, 1D, and 0D objects can be modeled in a unified data structure. Recently there are many studies on the non-manifold modeler. Most of them are focused on finding unknown topological entities and representing all kinds of topological entities found. In this paper, efficient data structure is selected. The boundary information on a face and an edge is included in this data structure. The boundary information on a vertex is excluded considering the frequency of usage. Because the disk cycle information is not required in most case of modeling. It is compact. It stores essential non-manifold information such as loop cycle and radial cycle. A suitable Euler-Poincare equation is studied and selected. Using the efficient data structure and the selected Euler-Poincare equation, 18 basic Euler operators are implemented. Several 3D models are created using the implemented modeler. A non-manifold modeling can be carried out using the implemented 3D CAD system. The results of this paper could be used in the further studies such as an implementation of Boolean operators, and a translation of 2D CAD drawings to 3D models.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2007년도 하계종합학술대회 논문집
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• pp.211-212
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• 2007

Pose-variation factors present a significant problem in 2D face recognition. To solve this problem, there are various approaches for a 3D face acquisition system which was able to generate multi-view images. However, this created another pose estimation problem in terms of normalizing the 3D face data. This paper presents a 3D head pose-normalization method using 2D and 3D interaction. The proposed method uses 2D information with the AAM(Active Appearance Model) and 3D information with a 3D normal vector. In order to verify the performance of the proposed method, we designed an experiment using 2.5D face recognition. Experimental results showed that the proposed method is robust against pose variation.

• 한국측량학회지
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• 제19권3호
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• pp.291-300
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• 2001

본 연구에서는 위성영상헤더정보를 이용한 3차원 위치정보 취득을 위한 위성영상처리 시스템을 개발하였으며, 본 시스템은 5개의 모듈로 구성되어 있다. 자료처리모듈은 영상헤더정보를 읽은 후 자료처리에 필요한 데이터 파일을 생성하고, 궤도 모델링과 센서 모델링을 수행하는 처리과정이다. 3D 모듈은 자료처리모듈에서 얻은 결과를 이용하여 3차원 위치를 결정하는 과정이며, 대화창처리모듈은 3D 모듈 처리과정을 수행하는데 있어서 단영상 및 입체 영상이용과 영상중심시간 보정 등을 처리하는 과정이다. 본 시스템은 헤더정보와 최소 기준점(1∼2점)을 이용하여 기존 소프트웨어보다 경제적이고 효과적으로 3차원 위치정보를 취득 할 것으로 기대된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.952-956
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• 1995

It is known that the 3D Solid CAD system can provide various information which is useful for implementing CAPP and CAE. However the commercial 3D CAD systems available today do not support the handling of non-geometric information such as geometry tolerance and surface finish. It is impossible to input the non-geometric information during designof parts while CAPP needs the information for selecting machine tools. fiztures, inspection method, etc. In this paper the need of research on handling tolerance information In 3D CAD systems is considered. The development of inspection planning support system is also explained with an example. The development of inspection planning support systm receives the design geometry information from the 3D CAD system in the form of 2D draft and generates the inspection data base and the inspection sheet through the user interaction.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 춘계학술발표회논문집
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• pp.203-208
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• 2004

Recently, digital image is increasing greatly practical use degree in several industry fields including construction. And interest about 3D digital image that can express practical object realistically is augmented greatly. In this study, developed 3D digital image generation system based on digital photogrammetry and created 3D digital image for object. And, wished to verify of 3D digital image through comparative analysis with processing result by digital photogrammetry system been using much the latest for acquisition of 3D information. Also, wished to apply to surface information acquisition about rock slope and execute investigation about discontinuity of joint etc. As the result, could created 3D digital image for object using the 3D digital image generation system developing in this study, and acquire surface information about rock slope efficiently.

• 산업경영시스템학회지
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• 제44권4호
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• pp.186-192
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• 2021

Recently, the demand for more precise and demand-oriented customized spatial information is increasing due to the 4th industrial revolution. In particular, the use of 3D spatial information and digital twins which based on spatial information, and research for solving social problems in cities by using such information are continuously conducted. Globally, non-face-to-face services are increasing due to COVID-19, and the national policy direction is also rapidly progressing digital transformation, digitization and virtualization of the Korean version of the New Deal, which means that 3D spatial information has become an important factor to support it. In this study, physical objects for cities defined by world organizations such as ISO, OGC, and ITU were selected and the target of the 3D object model was limited to buildings. Based on CityGML2.0, the data collected using a drone suitable for building a 3D model of a small area is selected to be updated through road name address and building ledger, which are administrative information related to this, and LoD2.5 data is constructed and urban space. It was intended to suggest an object update method for a 3D building among data.

• 한국건설관리학회논문집
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• 제5권4호
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• pp.107-114
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• 2004

4D 모델은 프로젝트 수행 이전에 다양한 공정대안을 비교 검토해볼 수 있는 기능을 제공하나 아직 그 활용이 미비한 실정이다. 이는 4D 모델의 구현에 수반되는 기술적, 경제적 문제에 기인하는 바 크다. 본 논문에서는 3D모델 정보의 활용을 통해 이러한 문제의 해결방안을 제시하였다. 즉, 기 생성된 3D 모델 정보를 가공하여 동일한 3D 모델에 대해 여러 가지 공정대안을 신속하게 생성해내는 공정 자동생성 기능을 이용함으로써 기존 4D시스템 연구에서 문제점으로 지적되었던 정보 변경에 따른 4D 모델 재구현 문제를 상당부분 개선하였다. 또한, 특정 작업기간에 따른 소요물량을 간편하게 산출해내는 물량정보 검색 기능을 통해 4D 모델의 대안검토 기능을 보완하였다. 특히 공정 자동생성 기능에서는 수평 및 수직적 우선순위의 조정을 통해 부재간, 층간 우선순위를 결정할 수 있도록 함으로써 공정순서를 신속하게 생성해낼 수 있는 환경을 제공하였다. 이것은 3D 모델이 변경되지 않은 상태에서 다양한 공정대안의 신속한 생성을 통한 비교 검토에 효과적으로 활용할 수 있으며, 3D 모델이 변경된 경우에도 4D 모델 생성을 위한 이후의 작업과정을 손쉽게 진행시켜 나갈 수 있는 장점이 있다. 아울러 3D 모델로부터 생성되는 물량정보와 공정계획 결과로부터 생성되는 일정정보를 연계시킴으로써 간편하게 일정별 소요물량 정보를 검색할 수 있게 하였다.

• 한국CDE학회논문집
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• 제8권2호
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• pp.122-132
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• 2003

STEP AP218 has a standard schema to represent the structural model of a midship section. While it helps to exchange ship structural models among heterogeneous automation systems, most shipyards and classification societies still exchange information using 2D paper drawings. We propose a feature parameter input method to generate a 3D STEP model of a ship structure from 2D drawings. We have analyzed the ship structure information contained in 2D drawings and have defined a data model to express the contents of the drawing. We also developed a QUI for the feature parameter input. To translate 2D information extracted from the drawing into a STEP AP2l8 model, we have developed a shape generation library, and generated the 3D ship model through this library. The generated 3D STEP model of a ship structure can be used to exchange information between design departments in a shipyard as well as between classification societies and shipyards.

• 한국산업정보학회논문지
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• 제20권3호
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• pp.81-86
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• 2015

본 논문에서는 인체의 CT/MRI에서 단층 촬영된 무릎관절을 영상처리 과정을 거쳐 3차원 관절 모델을 제작하였다. 실제 무릎관절의 형상을 추출할 때 설정 조건에 따라 3차원 형상정보가 달라질 수 있다. 이러한 미세한 3차원 형상정보의 차이에 따른 무릎관절의 구동특성을 분석하기 위해 2가지의 관절 모델을 3차원 프린터를 이용하여 제작하였다. 제작된 관절모델을 이용하여 관절구동 시 압축력 실험을 수행하였고 형상의 차이에 따라 결과값의 차이가 발생하였다. 따라서 생체모방형 바이오리액터를 개발할 경우에는 형상정보의 차이에 대한 연구가 선행되어야 할 것으로 사료된다.

• 대한원격탐사학회지
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• 제22권3호
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• pp.221-228
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• 2006

In this study, an integrated 3D modeling and rendering system dealing with 3D urban landscape features such as terrain, building, road and user-defined geometric ones was designed and implemented using $OPENGL\;{|}\;ES$ (Embedded System) API for mobile devices of PDA. In this system, the authoring functions are composed of several parts handling urban landscape features: vertex-based geometry modeling, editing and manipulating 3D landscape objects, generating geometrically complex type features with attributes for 3D objects, and texture mapping of complex types using image library. It is a kind of feature-based system, linked with 3D geo-based spatial feature attributes. As for the rendering process, some functions are provided: optimizing of integrated multiple 3D landscape objects, and rendering of texture-mapped 3D landscape objects. By the active-synchronized process among desktop system, OPENGL-based 3D visualization system, and mobile system, it is possible to transfer and disseminate 3D feature models through both systems. In this mobile 3D urban processing system, the main graphical user interface and core components is implemented under EVC 4.0 MFC and tested at PDA running on windows mobile and Pocket Pc. It is expected that the mobile 3D geo-spatial information systems supporting registration, modeling, and rendering functions can be effectively utilized for real time 3D urban planning and 3D mobile mapping on the site.