• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 추계학술발표회 논문집
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• pp.157-162
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• 2003

The 3D Image which embodies real object to 3D space of computer enables various geometrical analysis as well as visualization of complex 3D shape by giving sense for the real and cubic effect that can not be offered in 2D image. Human gives real object to same physical properties in 3D space imagination world of computer, and it is expected that this enables offering of various information by user strengthening interface between human-computer to observe object in real condition. In this study, formal style routine of 3D image creation applying digital photogrammetry was designed for more practical, highly trusty 3D image creation, and the system was emboded using object-oriented technique which strengthen user interface. Also, the discontinuity information about rock slope using 3D image is acquired that is orientation, persistence, spacing and aperture etc.

• 정보처리학회논문지B
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• 제10B권2호
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• pp.135-142
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• 2003

본 논문은 영상내 객체정보의 정확한 복원을 위하여, 연속된 2차원 영상으로부터 특정 객체의 특징점을 추출하고, 특징점의 위치 데이터들로부터 원형의 3차원 모양 및 모션 정보를 복원하는 알고리즘과 결과를 제시하였다. 2차원 영상의 특징점 검출을 위해서는 물체와 배경이 명확히 구별되는 실험영상 환경에서 색상변환을 통한 자동 추출 방법을 사용하였다. 추출된 2차원 객체의 특징점들로부터 3차원 모앙, 움직임 정보를 복원하기 위하여 스테레오 카메라와 준원근 카메라 모델을 적용하고 SVD(SinEuiar Value Decomposition)에 의한 인수분해연산을 수행하였다. 준원근 카메라 모델의 근본적인 문제인 깊이정보의 복원 에러가, 스테리오 영상 분석에 의해 최소화 되었다. 본 논문에서 제시된 방법들의 성능을 객관적으로 평가하기 위하여 크기와 위치가 알려진 3차원 물체에 대해 실험을 행하였으며, 영상의 21개 특징점 위치와 공간상에서의 3개 방향으로의 움직임 각도를 연산에 의해 복원한 후 원형의 데이터와 비교하여 본 알고리즘의 정확성을 증명하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.557-561
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• 2008

Shape memory alloys (SMA) have interesting features which are the superelastic effect (SE), shape memory effect (SME), two-way SME (TWSME), and so on. These are utilized in actuation factor. The thermo-mechanical constitutive equations of SMA proposed by Lagoudas et al. were employed in the present study for simulating SMA truss structures. The constitutive equation includes the necessary internal variables to account for the material transformations and is utilized in the non-linear finite element procedure of three dimensional truss structures that composed SMA bar (wholly or partially). In this study, we observed which element should be actuated to get a desired shape (actuation shape) from computational analysis. To reach this goal, we apply SMA constitutive equation to non-linear finite element formulation. And then, we simulate two-way shape memory effect as well as superelastic effect of various three dimensional truss using SMA.

• 한국의류산업학회지
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• 제19권6호
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• pp.804-812
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• 2017

This study builds a database that can be reflected in the production of dress form for fitting by typifying the upper body shape of a senior male. This study analyzed the 3D shape data of 405 persons of the 5th Size Korea. The age range is from 50s 210 persons and 60s 205 persons. Analysis items to identify upper body shape of senior males consisted of 51 items. 3D shape data were also measured using a Geomagic Design ${\times}$ program for the analysis of the upper body of the senior male required for the dress form of this study. The reference point was based on the Size Korea 2010 3D measurement standard and created points (Back-protrusion) on shape data. As a result of the senior men type, the senior men's body type was classified into four types:1. Overall, the upper body is a large body type and the most undistorted overall body type 2. Width / Thickness Flatness is the largest and vertical length factor is the smallest abdominal obesity type 3. Severe flexion of the back part type 4. The upper body is small and the scapular bending is severe. The elderly body type showed a high distribution ratio in the type with severe flexion. The development of a dress form that reflects the cause of the finery issue can improve the fit of ready-to-wear.

• 복식문화연구
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• 제26권1호
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• pp.95-108
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• 2018

This study analyzed the body shape of the body of 17~19 years old female students using the SPSS 20.0 statistical program according to the 7th Korea Human Body Survey. Factor analysis was based on six factors including body size, body height, shoulder length, and width, upper body length, hip length, and shoulder inclination related factors. Through this cluster analysis, the body shape of late adolescent female student was classified into four types. Body type 1 was the highest body height factor, and the upper body length and the hip length factor were lower. It was analyzed as 'Long leg in the body'. Body type 2 is the 'narrow shoulder skinny type' with high hip and shoulder slope factors and low body size, body height, shoulder length, and width factor. Body type 3 showed body size, shoulder length, height and hip length factor, and body height factor was rather low 'low hip obese body shape'. Body type 4 was analyzed as 'lower shoulder long upper body type' with higher upper body length factor and lower body size and shoulder slope factor. It is thought that when the pattern is made, it is possible to produce excellent patterns by fitting the dimensions of the body, as well as the dimensions of the shoulder width, the slope, and the hip length.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.764-771
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• 2006

The use of 3-D finite elements for the eigen analysis of beam-like structures with arbitrary section shape may not be practical in certain cases, from the aspect of CPU time. In this connection, this paper presents a systematic algorithm for decomposing an arbitrary section into finite number of basic ones and computing essential sectional quantities required for the eigen analysis using the beam theory. The numerical accuracy of the proposed method is assesed from the comparison with the 3-D finite . element method.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2001년도 봄 학술발표회 논문집
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• pp.347-354
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• 2001

In this study, 3-D FEM analysis are carried out to investigate the effect of the corners and re-entrant corners which can't be analysed by 2-D analysis. The excavation shape is re-entrant type conditions. The wall displacement, earth pressure and effectiveness of the corner struts are investigated in the re-entrant case, The 3D analysis are peformed to evaluate the effect of various factors, such as re-entrant corner size, excavation depth, and presence of struts. The wall displacement and earth pressures are influenced the size of re-entrant corner. Therefore, the effect of re-entrant corner should be considered in the evaluation of the earth pressure and displacement of the corners. Finally, strut-support systems are not effective at the re-entrant corner.

• 대한조선학회논문집
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• 제42권6호
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• pp.631-636
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• 2005

One and three dimensional whipping response analyses of a naval surface combatant subjected to an underwater explosion bubble pulse were carried out to compare the efficiency and accuracy according to the modeling methods. In 1-D analysis, program UNDEXWHIP developed by KIMM was used, which is based on the thin-walled Timoshenko's beam theory and on the modal analysis method using wetted vibratory modes of the hull girder. In 3-D analysis, three finite element models were suggested using LS-DYNA/USA code, such as 3-D beam model considering geometric shape of wetted side shell, coarse and fine 3-D F.E. models. Through the comparison of results from the 1-D and 3-D analyses, it could be confirmed that 1-D analysis result is in good agreement with 3-D analysis ones, and that fine 3-D F.E. model, shock analysis one, is also used both in the shock response and whipping response analyses for the analyst effort and time savings.

• 에너지공학
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• 제27권4호
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• pp.13-19
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• 2018

본 연구에서는 위상최적화에 기초한 발전설비용 버터플라이 밸브 디스크 부품의 경량설계가 수행되었다. 이때 상용 유한요소해석 소프트웨어가 사용되었으며 기존 상용 밸브 디스크의 외형을 유지시키면서 내부의 불필요 공간을 제거하여 경량구조를 갖도록 하였다. 먼저 밸브 디스크의 원판과 브라켓을 분리하여 각각 최적설계 하였다. 최적의 형상이 선정되면 이들을 조립하여 3차원 경량 밸브 디스크 모델을 완성하였다. 이후 이 모델에 설계 압력을 적용하여 유한요소해석 후 구조적 안전성을 확인하였다.

• 한국콘텐츠학회논문지
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• 제11권6호
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• pp.106-115
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• 2011

본 논문에서는 기존에 제시된 쉐이딩 알고리즘들이 음영 표현을 통해 3차원 물체의 형태를 효과적으로 전달하는지 평가하고 검증한다. 8가지 스타일로 쉐이딩된 10개의 3차원 물체 중의 한 개의 이미지를 사람들에게 보여주고 물체 표면의 여러 곳의 위치에서 곡면의 법선 벡터와 일치하도록 측정기(gauge)의 방향을 조정하도록 요청하는 스터디를 수행한다. 이 실험에서 수집한 법선 벡터 추정치가 사람들 간에 서로 일치하는지 비교하고 또한 실제 3차원 곡면 모델의 법선 벡터와 일치하는지도 비교한다. 본 논문의 실험을 통하여 물체의 음영을 표현하는 방법에 따라서 사람들이 물체의 형태를 다르게 해석한다는 사실을 보인다. 또한, 기존의 쉐이딩 알고리즘들 중에서 음영 톤의 단계수가 많고 톤 단계가 전반적으로 균일하게 분포되어 있는 특성을 가지는 알고리즘이 물체의 형태를 보다 효과적으로 표현하는 것으로 나타났다. 본 논문에서 수집한 실험 데이터 및 분석 결과는 물체의 형태를 효과적으로 전달하는 것을 목적으로 하는 새로운 CG 쉐이딩 알고리즘을 설계하는데 활용 가능할 것으로 기대된다.