• 대한공간정보학회지
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• 제12권2호
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• pp.37-42
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• 2004

반만년 숭고한 문화유산을 지니고 있는 민족으로서 우수한 문화유산을 영구 보존하고 후손에 잘 전승하여야 하며, 세계에 널리 알려야 할 필요가 있다. 이러한 필요성을 인식하고 컴퓨터 기술의 발단에 따라 최근 국내외에서 문화재 및 역사적 가치를 지닌 구조물에 대한 3차원 데이터베이스 구축, 문화재 복원 및 사이버 공간에서 전시 기술 등에 관한 연구가 활발히 이루어지고 있다. 따라서, 본 연구에서는 문화재의 3차원 도형자료를 3차원 좌표취득이 용이한 사진측량기법으로 취득하고, VRML을 이용하여 문화재의 다양한 색상이나 질감 등 정성적 특성을 표현할 수 있는 3차원 모델링 기법을 제시하고자 한다.

• 대한기계학회논문집A
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• 제38권8호
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• pp.869-874
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• 2014

임의형상 제작기술을 이용하면 원하는 형상을 빠르게 제작할 수 있다. 하지만 임의형상 제작기술을 직접 제품을 생산하기 위한 제조기술에 적용하기 위해서는 문제점들이 있다. 이에, 하나의 대안으로써 다중재료 임의형상 제작기술이 주목 받고 있다. 특히 다중재료 임의형상 제작기술을 이용하면 기존의 2 차원 PCB 와는 다른, 회로 소자의 배열 및 외부 형상의 제약이 적은 3 차원 회로 장치를 제작 할 수 있다. 본 연구에서는 3 차원 회로 장치 제작을 위하여 FDM 방식과 직접주사 방식을 통합한 장치를 설계하고, 이 장치를 이용하여 3 차원 회로장치를 제작하였다. 즉, LED와 조도센서를 이용한 3 차원 회로 장치를 제작하여 작동을 확인하였으며, 자동화된 3 차원 회로 장치의 제작을 위한 임의형상 제작 기술과 직접주사 기술이 통합된 시스템 개발에 대한 기초연구를 수행하였다.

• Geomechanics and Engineering
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• 제17권3호
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• pp.287-294
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• 2019

The finite element method (FEM) is widely used to evaluate the seismic performance of pile-supported buildings. However, there are problems associated with modeling the pile end resistance using the FEM, such as the dependence on the mesh size. This paper proposes a new method of modeling around the pile tip to avoid the mesh size effect in two-dimensional (2D) analyses. Specifically, we consider the area of influence around the pile tip as an artificial constraint on the behavior of the soil. We explain the problems with existing methods of modeling the pile tip. We then conduct a three-dimensional (3D) analysis of a pile in various soil conditions to evaluate the area of influence of the soil around the pile tip. The analysis results show that the normalized area of influence extends approximately 2.5 times the diameter of the pile below the pile tip. Finally, we propose a new method for modeling pile foundations with artificial constraints on the nodal points within the area of influence. The proposed model is expected to be useful in the practical seismic design of pile-supported buildings via a 2D analysis.

• 대한의용생체공학회:의공학회지
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• 제15권2호
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• pp.201-208
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• 1994

Many three-dimensional object modeling and display methods for computer graphics and computer vision have been developed. Recently, with the help of medical imaging devices such as computerized tomography, magnetic resonance image, etc., some of those object modeling and display methods have been widely used for capturing the shape, structure and other properties of real objects in many medical applications. In this paper, we propose the reconstruction and display method of the three-dimensional object from a series of the cross sectonal image. It is implemented by using the automatic threshold selection method and the contour following algorithm. The combination of curvature and distance, we select feature points. Those feature points are the candidates for the tiling method. As a results, it is proven that this proposed method is very effective and useful in the comprehension of the object's structure. Without the technician's responce, it can be automated.

• 한국생활과학회지
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• 제24권4호
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• pp.555-569
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• 2015

During a design process of a protective equipment for sports activities, minimizing movement restrictions is important for enhancing its functions particularly for protection. This study presents a three-dimensional(3D) modeling methodology for designing baseball catcher's leg guards that will allow maximum possible performance, while providing necessary protection. 3D scanning is performed on three positions frequently used by a catcher during the course of a game by putting markings on the subject's legs at 3cm intervals : a standing, a half squat with knees bent to 90 degrees and 120 degrees of knee flexion. Using data obtained from the 3D scan, we analyzed the changes in skin length, radii of curvatures, and cross-sectional shapes, depending on the degree of knee flexion. The results of the analysis were used to decide an on the ideal segmentation of the leg guards by modeling posture. Knee flexions to 90 degrees and to $120^{\circ}$ induced lengthwise extensions than a standing. In particular, the vertical length from the center of the leg increases to a substantially higher degree when compared to those increased from the inner and the outer side of the leg. The degree of extension is varied by positions. Therefore, the leg guards are segmented at points where the rate of increase changed. It resulted in a three-part segmentation of the leg guards at the thigh, the knee, and the shin. Since the 120 degree knee-flexion posture can accommodate other positions as well, the related 3D data are used for modeling Leg Guard (A) with the loft method. At the same time, Leg Guard (B) was modeled with two-part segmentation without separating the knee and the shin as in existing products. A biomechanical analysis of the new design is performed by simulating a 3D dynamic analysis. The analysis revealed that the three-part type (A) leg guards required less energy from the human body than the two-part type (B).

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2003년도 추계학술발표대회 논문집
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• pp.71-74
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• 2003

The cell modeling homogenization method to derive the constitutive equation considering the microstructures of the fiber reinforced composites has been previously developed for composites with simple microstructures such as 2D plane composites and 3D rectangular shaped composites. Here, the method has been further extended for 3D circular braided composites, utilizing B-spline curves to properly describe the more complex geometry of 3D braided composites. For verification purposes, the method has been applied for orthotropic elastic properties of the 3D circular braided glass fiber reinforced composite, in particular for the tensile property. Prepregs of the specimen have been fabricated using the 3D braiding machine through RTM (resin transfer molding) with epoxy as a matrix. Experimentally measured uniaxial tensile properties agreed well with predicted values obtained fer two volume fractions.

• 한국멀티미디어학회논문지
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• 제23권5호
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• pp.673-682
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• 2020

Buildings are becoming more and more high-rise and large-scale in recent years, so in the event of a disaster such as a fire, enormous human and economic damage is expected. Therefore, management, security, and fire control are essential for large buildings in the city. Because these large buildings are very complex outside and inside, they need a three-dimensional control based on 3D modeling rather than a simple flat-oriented control. To do this, this paper designed and implemented a building control system based on 3D modeling. Specifically, we designed a 3D building / facility editing module for 3D modeling of buildings, a 3D based control module for building control, and a linkage module that connects information such as firefighting equipment, electrical equipment and IoT equipment. Based on this design, a building control system based on 3D modeling was implemented.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2002년도 학술대회지
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• pp.531-534
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• 2002

건설 프로젝트는 갈수록 대형화${\cdot}$복잡화되고 있으며, 이에 따라 대형 건설업체들은 시간적${\cdot}$지리적으로 상이한 환경의 많은 프로젝트를 수행하는 것이 오늘날의 현실이다. 이러한 흐름에 따라 Collaboration System을 포함한 여러 종류의 웹 기반 정보시스템들을 구축${\cdot}$활용하고 있는 실정이다. 그러나, 시스템들의 내용을 살펴보면, 2차원 평면 위주의 도면 및 Picture들을 활용하여 공사 진행 정도 및 현황을 체크하고 확인하는데 국한되어 있다. 따라서, 해외-본사 간 지리적${\cdot}$문화적 차이가 존재하는 상이한 환경에서 설계 변경 등과 같은 문제 발생 시 원활한 문제 해결 저해 및 시간적 지연을 야기시키고 있다. 이에 본 연구에서는 세부적으로 Web 3D 및 3D 라이브러리들을 소개하고, 결과적으로 Web 3D을 이용한 3차원 공사 구조물 모델링 활용 방안을 제시해 보고자 한다.

• 국제초고층학회논문집
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• 제3권4호
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• pp.311-323
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• 2014

This paper introduces recent applications of three-dimensional building/construction data modeling (3D) and building information modeling (BIM) to large-scale complex building construction projects in Japan. Recently, BIM has been utilized as a tool in construction process innovation through planning, design, engineering, procurement and construction to establish a front-loading-type design building system. Firstly, the background and introduction processes of 3D and BIM are described to clarify their purposes and scopes of applications. Secondly, 3D and BIM applications for typical large-scale complex building construction projects to improve planning and management efficiency in building construction are presented. Finally, future directions and further research issues with 3D and BIM applications are proposed.

• 한국산업융합학회 논문집
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• 제3권2호
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• pp.107-114
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• 2000

Recently the studies on the vibration and the noise of a helical gear transmission have been focused on the many researchers. The manufacturing error and the deformation of the tooth profile, which generates the vibration and the noise of the gear transmission, are main factors. The major purpose of this study is to develop an optimal design program for reducing the vibration and the noise of the helical gear. To obtain the these results, we restrain the helical gear from the deformation of the tooth profile and increase the contact ratio within the optimal design program. Furthermore we made the three-dimensional solid modeling of the helical gear from the AutoCAD and the Pro/Engineer. This model will be available to generate the finite element model and the NC code.