• Journal of Electrical Engineering and Technology
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• 제10권5호
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• pp.2046-2051
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• 2015

Currently, most high-voltage gas circuit breakers (CBs) include asymmetrical geometries in the shield, the tank, the hot-gas exhaust, and the connection parts for bushings. For this reason, a 3-dimensional (3-D) analysis of the insulation capability is necessary, rather than a 2-D analysis. However, a 3-D analysis has difficulties due to the computational time and complex modeling. This paper presents a 3-D analysis considering the asymmetry in high-voltage gas CBs and a technique to reduce the calculation time. In the proposed technique, the arc plasma requiring the most computational time is first calculated by a 2-D analysis. Then, the results such as pressure, temperature, and velocity are input as a source for the 3-D analysis. This technique is applied to a 145kV self-blast-type CB and the analysis result exhibits good agreement with the experimental result.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2000년도 사면안정 학술발표회
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• pp.213-220
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• 2000

Numerical modeling of cut slope has some limits in simulating the real slopes. In the case of 2D analysis of slope stability, it is assumed that slope is simply straight even when it is concave or convex in plan view. In this study, 3D analysis in curved shape slopes has been conducted for the comparison with 2D analysis in terms of failure mode and factor of safety. For this, 3D analysis by FLAC3D was compared with 2D analysis in plane strain condition and axi-symmetric model condition by FLAC. It was also observed how safety factors of slopes were affected by the variation of the tensile strength and cohesion, which are important variables to decide whether the slope fails or not. 2D analysis of concave slopes under plane strain condition showed much smaller safety factors by 16-40 % errors depending on the radius of curvature of slopes, compared to the more realistic values from 3D analysis. In case of convex slopes, the lower values by 7-10 % has been reported. 2D analysis of axi-symmetric model showed also smaller safety factors by 6-10 % and by 2-4 %, in case of concave and convex slopes, respectively. Such results are expected to contribute to the better understanding of failure process and could be applied for improved design of slopes.

• 한국구조물진단유지관리공학회 논문집
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• 제4권2호
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• pp.113-129
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• 2000

This study evaluates the behavior and strength of an anchorage zone of the prestressed concrete box girder bridge on the Kyungboo highway railroad using the 2D SUB-3D STM approach and a linear elastic finite element analysis. The 2D SUB-3D STM approach utilizes several two-dimensional sub strut-tie models that represent the compressive and tensile stress flows of each projected plane of the three-dimensional structural concrete in the selection of a three dimensional strut-tie model, evaluation of the effective strengths of the concrete struts, and verification of the geometric compatibility condition and bearing capacity of the critical nodal zones in the selected three-dimensional strut-tie model. The finite element analysis uses an 8-node brick element and the longitudinal prestressing force is considered as the equivalent nodal force. Analysis results show that the 2D SUB-3D STM approach and linear elastic finite element method can be effectively applied to the analysis and design of three-dimensional structural concrete including a prestressed concrete box girder anchorage zone.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.339-349
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• 2017

Purpose: This review focuses on the major 3-D image reconstruction techniques and their applications in plant and animal morphological analysis. Methods & Results: This paper begins with an overview of major 3-D image reconstruction techniques and their basic principles. Subsequently, their applications in plant and animal morphological analysis are reviewed. A discussion on the limitations and future research direction of 3-D imaging techniques for accurate, fast measurements and modeling of plant and animal morphological analysis follows. Conclusions: Owing to the increasing demand for plant and animal morphological analysis, the application of 3-D imaging techniques will increase in popularity among researchers and the agricultural industry.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.32-35
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• 1996

This paper analyzes characteristics of PMLSM using 3 dimensional equivalent magnetic circuit network method (3-D EMC). PMLSM of which the effective electric-airgap is not only very large, but also the width is finite width lateral edges has much leakage flux. Therefore, 2-D analysis method cannot consider it so carefully that 3-D analysis method must required. 3-D EMC which will be used for analysis of PMLSM performs modeling of it including solt and teeth structure, uses the magnetic motive force of stator winding and permanent magnet as source. and calculates magnetic flux density and force considering nonlinear characteristics of materials. we verified analysis validity by comparing simulation results with expermental results.

• 한국위성정보통신학회논문지
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• 제8권2호
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• pp.68-73
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• 2013

최근의 3D 입체 영상 관련 기술의 발달은 스마트폰을 포함한 모바일 단말에서도 3D 입체 영상 서비스의 상용화를 가능하게 하고 있다. 스마트폰에서의 3D 입체 영상 서비스는 무안경 3D 디스플레이와 스테레오스코픽 3D 기술을 이용하고 있으며, 스테레오스코픽 이미지 관련 기술들은 지속적으로 활발히 연구가 진행되고 있다. 3D 입체 영상 서비스를 위하여 각각 다른 표준 H.264/AVC, H.264/AVC SEI, H.264/MVC가 MPEG에서 제정되었다. 본 논문에서는 최근 새롭게 대두되고 있는 모바일 단말에서의 스테레오스코픽 3D 기술의 발전과 특히 안드로이드 폰에서의 3D 서비스를 위한 비데오 포맷과 기능들에 초점에 맞추어 기술적 특성에 관한 분석을 행함으로서 그 활용성을 확인하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권4호
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• pp.262-269
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• 2010

Introduction: Accurate diagnosis and treatment planning are very important for orthognathic surgery. A small error in diagnosis can cause postoperative functional and esthetic problems. Pre-existing 2-dimensional (D) chephalogram analysis has a high likelihood of error due to its intrinsic and extrinsic problems. A cephalogram can also be inaccurate due to the limited anatomic points, superimposition of the image, and the considerable time and effort required. Recently, an improvement in technology and popularization of computed tomography (CT) provides patients with 3-D computer based cephalometric analysis, which complements traditional analysis in many ways. However, the results are affected by the experience and the subject of the investigator. Materials and Methods: The effects of the sources human error in 2-D cephalogram analysis and 3-D computerized tomography cephalometric analysis were compared using Simplant CMF program. From 2008 Jan to 2009 June, patients who had undergone CT, cephalo AP, lat were investigated. Results: 1. In the 3 D and 2 D images, 10 out of 93 variables (10.4%) and 11 out 44 variables (25%), respectively, showed a significant difference. 2. Landmarks that showed a significant difference in the 2 D image were the points frequently superimposed anatomically. 3. Go Po Orb landmarks, which showed a significant difference in the 3 D images, were found to be the artificial points for analysis in the 2 D image, and in the current definition, these points cannot be used for reproducibility in the 3 D image. Conclusion: Generally, 3-D CT images provide more precise identification of the traditional cephalometric landmark. Greater variability of certain landmarks in the mediolateral direction is probably related to the inadequate definition of the landmarks in the third dimension.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
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• pp.880-884
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• 2002

According to the development of computer technology, especially in 3D graphics and visualization, the interest for 3D GIS has been increasing. Several commercial GIS softwares are ready to provide 3D function in their traditional 2D GIS. However, most of these systems are focused on visualization of 3D objects and supports few analysis functions. Therefore in this paper, we design not only a spatial operation processor which can support spatial analysis functions as well as 3D visualization, but also implement a prototype to operate them. In order to support interoperability between the existing models, the proposed spatial operation processor supports the 3D spatial operations based on 3D geometry object model which is designed to extend 2D geometry model of OGIS consortium, and supports index based on R$^*$-Tree. The proposed spatial operation processor can be applied in 3D GIS to support 3D analysis functions.

• 대한기계학회논문집A
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• 제26권12호
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• pp.2605-2614
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• 2002

This paper describes an analysis method based on the experimental parameter for the 0.9kW starter motor of vehicle with permanent magnet and pole core, and analyzed the influence by the effect of pole core of starting motor by using the 2D-FEM analysis technique to reflect the structural characteristic of 3D. A starter motor consists mainly of armature, yoke and permanent magnet with the pole core. Additionally, there is different the axial length of each part. Therefore, the effective of analysis method is needed to improve the characteristic of it. This paper approached the 2D-FEM analysis estimated by the 3D-EMCN(Three Dimensional Equivalent Magnetic Circuit Network) instead of the 3D-FEM analysis to minimize parameters. As a result, this paper is proposed the validity of 2D-FEM analysis and obtained reasonable results for improving a performance.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제30권6호
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• pp.546-553
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• 2008

Purpose: The purpose of this study was to estimate validity of posterior anterior cephalometric and 3D-CT for orbital canting analysis. Materials and methods: Three trained observers classified two patients group using standardized frontal photographs of facial asymmetry patients. Group A consisted of patients with facial asymmetry and orbital canting(n=19), and group B consisted of patients with only facial asymmetry(n=43). Orbital canting was measured with line of bilateral inferior orbitale. Orbital canting measurement was done with posterior anterior cephalometric and 3D-CT. Each horizontal reference line was established by bilateral GWSO(cephalometric), FZS(3D-CT). Maxillary canting and mandibular deviation angle were also measured and analyzed with orbital canting. Results: The mean orbital canting was $3.03{\pm}1.00^{\circ}$ in Group A and $1.11{\pm}0.76^{\circ}$ in Group B in frontal photograph. The mean orbital canting was $1.20{\pm}0.74^{\circ}$ in group A and $1.22{\pm}0.65^{\circ}$ in group B by cephalometric analysis(p>0.05). In 3D-CT, orbital canting was almost paralleled with horizontal reference line. The orbital canting, maxillay canting and mandibular deviation between two groups showed no significant differences except madibular deviation in 3D-CT. Conclusion: Common analysis of posterior anterior cephalometric and 3D-CT is not valide method to evaluate orbital canting for facial asymmetry patients with orbital canting.