• 제목/요약/키워드: 3-D Structure

검색결과 6,771건 처리시간 0.036초

Deformable Surface 3D Reconstruction from a Single Image by Linear Programming

  • Ma, Wenjuan;Sun, Shusen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권6호
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    • pp.3121-3142
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    • 2017
  • We present a method for 3D shape reconstruction of inextensible deformable surfaces from a single image. The key of our approach is to represent the surface as a 3D triangulated mesh and formulate the reconstruction problem as a sequence of Linear Programming (LP) problems. The LP problem consists of data constraints which are 3D-to-2D keypoint correspondences and shape constraints which are designed to retain original lengths of mesh edges. We use a closed-form method to generate an initial structure, then refine this structure by solving the LP problem iteratively. Compared with previous methods, ours neither involves smoothness constraints nor temporal consistency, which enables us to recover shapes of surfaces with various deformations from a single image. The robustness and accuracy of our approach are evaluated quantitatively on synthetic data and qualitatively on real data.

Fe-Al 전이금속 화합물의 자성과 결정구조의 상관관계에 대한 밀도범함수연구 (Density Functional Study on Correlation between Magnetism and Crystal Structure of Fe-Al Transition Metal Compounds)

  • 윤원석;김인기
    • 한국자기학회지
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    • 제21권2호
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    • pp.43-47
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    • 2011
  • Fe-Al 계의 전이금속 화합물은 구조적 안정성과 자성에 대한 이견이 많은 것으로 알려져 있다. 본 연구에서는 B2, $L1_2$, 및 $D0_3$ 구조를 갖는 Fe-Al 계 화합물의 자성과 원자구조의 상관관계를 논의하기 위해 전전자 총퍼텐셜선형보강평면파(all-electron fullpotential linearized augmented plane wave; FLAPW) 방법을 이용하여 일반기울기 근사(generalized gradient approximation; GGA) 하에서 계산하였다. 고려한 모든 구조에서 강자성이 비자성에 비해 안정한 것으로 계산되었다. Fe 원자의 계산된 스핀 자기모멘트는 B2, $L1_2$ 구조에서 각각 0.771 ${\mu}_B$, 2.373 ${\mu}_B$의 값을 얻었고, $D0_3$ 구조의 Fe(I) 및 Fe(II) 원자들은 각각 2.409 ${\mu}_B$, 1.911 ${\mu}_B$로 계산 되었다. $Fe_3Al$의 같은 조성을 갖는 $L1_2$$D0_3$ 구조간의 안정성을 조사하기 위하여 형성 엔탈피 계산을 통해 강자성 상태에서 16 meV/atom의 에너지 차이로 $D0_3$ 구조가 $L1_2$ 구조보다 더 안정함을 확인하였다. 이 결과는 실험연구와 잘 일치하며, 원자구조와 전자구조의 분석을 통해 구조적 안정성과 자성에 대해 이해하였다.

근사 모델링을 이용한 웹 기반 3D 패션쇼 애니메이션 구현 (Implementation of 3D Fashion Show Animation Based on Web using Similar Modeling)

  • 조진애;양옥렬;남명우;이용주;정성태;정석태;이강일
    • 한국산학기술학회논문지
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    • 제7권1호
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    • pp.33-38
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    • 2006
  • 본 논문은 웹 기반 3D 패션몰 구축 시 필요한 3D 모델의 패션쇼 애니메이션 설계 기법 및 구현방법에 대해 제안한다. 3D MAX를 이용하여 제작된 3D 모델을 XML(Extensible Markup Language) 형식으로 출력시킨 후, D3D(Direct 3D)를 사용하여 제작된 ActiveX 컨트롤을 이용하여 웹상에 구현하였다. 소비자가 웹기반 패션몰에서 선택한 다양한 의상을 입은 3D 모델의 패션쇼 애니메이션을 구현하기 위해, 기본형태의 3D 모델에 계층적 구조를 가진 근사 의상을 이용하여 표현하였다. 근사의상은 표준 의상 조각들을 설계하고 제작한 후, 이를 조합하는 방식으로 구현하였으며, 여기에 텍스처를 맵핑하여 소비자가 선택한 의상의 근사 모델이 표현 될 수 있도록 구현 하였다.

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3DP 폴리머-패브릭(3D Print Polymer-Fabric Structure)을 적용한 패션디자인 연구 (A Study of Fashion Design Applying a 3D Print Polymer-Fabric Structure)

  • 임소영;전재훈
    • 한국의류산업학회지
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    • 제25권2호
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    • pp.139-152
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    • 2023
  • Despite efforts to apply 3D print (3DP) technology in the field of fashion and endless discussions about the possibility of future development, in reality, it is difficult to utilize 3DP technology in fashion for reasons related to material, technology, and cost constraints. The purpose of this study was to supplement the limitations of 3DP technology in order to promote its utilization in fashion and simultaneously find a solution to achieve aesthetic satisfaction in the design method. Specifically, through the development of fashion products with a 3DP polymer-fabric structure to which the parametric design methodology has been applied, this study explored the possibility of practical application and proposes a new 3DP fashion design method. The 3DP polymer-fabric developed as a result of the research was stably adhered to the fabric. Additionally, the study confirmed the possibility of making 3DP clothes that are amenable to the wearer's activities, as it was verified that cutting and sewing tailored to the human body's curvature and structure can be performed. The design process using the 3DP polymer-fabric presented in this study is meaningful in that it suggests a solution to complement the limitations of modern technology in connection with designers' creativity. Moreover, the design process presented in this study is expected to contribute to the commercialization and generalization of 3DP by providing practical help to allow fashion experts to utilize 3DP technology.

혈관표면의 3차원 재구성을 위한 Deformable model의 정확성 검증에 관한 연구 (A Verification of the Accuracy of the Deformable Model in 3 Dimensional Vessel Surface Reconstruction)

  • 김호철;오장석;김형률;조성범;선경;김민기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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    • pp.3-5
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    • 2005
  • Vessel boundary detection and modeling is a difficult but a necessary task in analyzing the mechanics of inflammation and the structure of the microvasculature. In this paper we present a method of analyzing the structure by means of an active contour model(using GVF Snake) for vessel boundary detection and 3D reconstruction. For this purpose we used a virtual vessel model and produced a phantom model. From these phantom images we obtained the contours of the vessel by GVF Snake and then reconstructed a 3D structure by using the coordinates of snakes.

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PBG 구조를 이용한 전력 증폭기의 효율 및 선형성 개선에 관한 연구 (A Study on the Improvement of Efficiency and Linearity of Power Amplifier using PBG Structure)

  • 김병희;박천석
    • 한국전자파학회논문지
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    • 제12권7호
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    • pp.1182-1190
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    • 2001
  • 본 논문에서는 마이크로스트립 선로상의 금속부분을 일부 제거한 형태의 Photonic bandgap (PBG) 구조의 특성을 분석하고 형태를 최적화 한 후 전력 증폭기에 적용하여 고조파 동조를 수행하였다. 이 구조는 제작 및 접지에서 타 구조에 비해 유리하다. PCB 제작 과정의 오차를 줄이기 위해 단위 격자의 크기를 수직방향으로 증가시키고, 테이퍼 선로를 이용하여 입출력을 50 $\Omega$으로 유지시켰다. EM 시뮬레이션으로 PBG 구조의 특성을 분석하고 설계하였으며, 최종적으로 통과대역 손실 0.3~0.4dB, 저지대역폭 6~7GHz의 특성을 얻었다. 전력 증폭기에 PBG구조를 적용한 후 출력 전력은 0.72~0.99dB, PAE는 1.14~7.8 %, 3차 IMD는 1 dBc 증가하는 결과를 얻을 수 있었다.

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Rend 3D R-tree : 3D R-tree 기반의 이동 객체 데이터베이스 색인구조 연구 (Rend 3D R-tree: An Improved Index Structure in Moving Object Database Based on 3D R-tree )

  • 임향초;임기욱;남지은;이경오
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2008년도 추계학술발표대회
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    • pp.878-881
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    • 2008
  • To index the object's trajectory is an important aspect in moving object database management. This paper implements an optimizing index structure named Rend 3D R-tree based on 3D R-Tree. This paper demonstrates the time period update method to reconstruct the MBR for the moving objects in order to decrease the dead space that is produced in the closed time dimension of the 3D R-tree, then a rend method is introduced for indexing both current data and history data. The result of experiments illustrates that given methods outperforms 3D R-Tree and LUR tree in query processes.

Simplified robustness assessment of steel framed structures under fire-induced column failure

  • Jiang, Binhui;Li, Guo-Qiang;Yam, Michael C.H.
    • Steel and Composite Structures
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    • 제35권2호
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    • pp.199-213
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    • 2020
  • This paper proposes a Global-Local Analysis Method (GLAM) to assess the progressive collapse of steel framed structures under fire-induced column failure. GLAM obtains the overall structural response by combining dynamic analysis of the heated column (local) with static analysis of the overall structure (global). Test results of two steel frames which explicitly consider the dynamic effect during fire-induced column failure were employed to validate the proposed GLAM. Results show that GLAM gives reasonable predictions to the test frames in terms of both whether to collapse and the displacement verse temperature curves. Besides, several case studies of a two-dimensional (2D) steel frame and a three-dimensional (3D) steel frame with concrete slabs were conducted by using GLAM. Results show that GLAM gives the same collapse predictions to the studied cases with nonlinear dynamic analysis of the whole structure model. Compared with nonlinear dynamic analysis of the whole structure model, GLAM saves approximately 70% and 99% CPU time for the cases of 2D and 3D steel frame, respectively. Results also show that the load level of a structure has notable effects on the restraint condition of a heated column in the structure.