• Title/Summary/Keyword: 3 차원 재구축

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Occluded Object Motion Tracking Method based on Combination of 3D Reconstruction and Optical Flow Estimation (3차원 재구성과 추정된 옵티컬 플로우 기반 가려진 객체 움직임 추적방법)

  • Park, Jun-Heong;Park, Seung-Min;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.21 no.5
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    • pp.537-542
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    • 2011
  • A mirror neuron is a neuron fires both when an animal acts and when the animal observes the same action performed by another. We propose a method of 3D reconstruction for occluded object motion tracking like Mirror Neuron System to fire in hidden condition. For modeling system that intention recognition through fire effect like Mirror Neuron System, we calculate depth information using stereo image from a stereo camera and reconstruct three dimension data. Movement direction of object is estimated by optical flow with three-dimensional image data created by three dimension reconstruction. For three dimension reconstruction that enables tracing occluded part, first, picture data was get by stereo camera. Result of optical flow is made be robust to noise by the kalman filter estimation algorithm. Image data is saved as history from reconstructed three dimension image through motion tracking of object. When whole or some part of object is disappeared form stereo camera by other objects, it is restored to bring image date form history of saved past image and track motion of object.

A 3D Terrain Reconstruction System using Navigation Information and Realtime-Updated Terrain Data (항법정보와 실시간 업데이트 지형 데이터를 사용한 3D 지형 재구축 시스템)

  • Baek, In-Sun;Um, Ky-Hyun;Cho, Kyung-Eun
    • Journal of Korea Game Society
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    • v.10 no.6
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    • pp.157-168
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    • 2010
  • A terrain is an essential element for constructing a virtual world in which game characters and objects make various interactions with one another. Creating a terrain requires a great deal of time and repetitive editing processes. This paper presents a 3D terrain reconstruction system to create 3D terrain in virtual space based on real terrain data. In this system, it converts the coordinate system of the height maps which are generated from a stereo camera and a laser scanner from global GPS into 3D world using the x and z axis vectors of the global GPS coordinate system. It calculates the movement vectors and the rotation matrices frame by frame. Terrain meshes are dynamically generated and rendered in the virtual areas which are represented in an undirected graph. The rendering meshes are exactly created and updated by correcting terrain data errors. In our experiments, the FPS of the system was regularly checked until the terrain was reconstructed by our system, and the visualization quality of the terrain was reviewed. As a result, our system shows that it has 3 times higher FPS than other terrain management systems with Quadtree for small area, improves 40% than others for large area. The visualization of terrain data maintains the same shape as the contour of real terrain. This system could be used for the terrain system of realtime 3D games to generate terrain on real time, and for the terrain design work of CG Movies.

Failure Study for Knee Joint Through 3D FE Modeling Based on MR Images (자기공명영상 기반 3차원 유한요소모델링을 통한 무릎관절의 파손평가)

  • Bae, Ji-Yong;Park, Jin-Hong;Song, Seong-Geun;Park, Sang-Jin;Jeon, In-Su;Song, Eun-Kyoo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.6
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    • pp.533-539
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    • 2009
  • In this study, the femur, the tibia, the articular cartilage and the menisci are three dimensionally reconstructed using MR images of healthy knee joint in full extension of 26-year-old male. Three dimensional finite element model of the knee joint is fabricated on the reconstructed model. Also, the FE models of ligaments and tendons are attached on the biologically suitable position of the FE model. Bones, articular cartilages and menisci are considered as homogeneous, isotropic and linear elastic materials, and ligaments and tendons are modeled as truss element and nonlinear elastic springs. The numerical results show the contact pressure and the von Mises stress distribution in the soft tissues such as articular cartilages and menisci which can be regarded as important parameters to estimate the failure of the tissues and the pain of the patients.

국가인적자원 개발 방향과 전문대학의 과제

  • Gang, Mu-Seop
    • Proceedings of the KIEE Conference
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    • 2001.07e
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    • pp.151-156
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    • 2001
  • (1) 21세기 우리나라가 선진국에 진입하여 초일류 국가로 발돋움하기 위해서 반드시 해결해야 할 과제는 지식기반사회로의 성공적인 이행과 디지털 경제 시대에의 능동적인 대응임. (2) 지식기반사회 그리고 디지털 경제시대는 정보와 지식이 가치 창출과 경쟁력의 핵심 원천인 동시에 경제활동의 중심이 되며, 이러한 지식과 정보를 창출 획득, 활용 할 수 있도록 하기 위한 인적자원개발 관리가 국가 발전의 핵심 전략임. (3) 대다수 OECD 회원국에서는 이미 지난 세기말부터 지식기반사회로 이행하기 위한 국가 발전의 핵심 전략으로 인적자원개발 관리에 관심과 정책을 총집결하여 왔으며, 국가 차원의 교육개혁추진과 관련부처의 통폐합 등 인적자원개발 관리체제를 재구축 하였음. (4) 부존자원이 전무하여 사람에 의존할 수밖에 없는 우리나라도 다각적으로 인적자원개발 관리에 관심을 보이고, 정책을 펼쳐왔지만 아직 국가 차원의 인적자원개발 관리체제가 미흡하여 정책의 일관성이 결여되어 있을 뿐만 아니라 곳곳에 인적자원개발 관리의 비효율 비능률이 초래되고 있음.

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3D Analysis of Crack Growth in Metal Using Tension Tests and XFEM (인장 실험과 XFEM을 이용한 금속 균열 성장의 3 차원적 분석)

  • Lee, Sunghyun;Jeon, Insu
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.38 no.4
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    • pp.409-417
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    • 2014
  • To prevent the occurrence of fractures in metal structures, it is very important to evaluate the 3D crack growth process in those structures and any related parts. In this study, tension tests and two simulations, namely, Simulation-I and Simulation-II, were performed using XFEM to evaluate crack growth in three dimensions. In the tension test, Mode I crack growth was observed for a notched metal specimen. In Simulation-I, a 3D reconstructed model of the specimen was created using CT images of the specimen. Using this model, an FE model was constructed, and crack growth was simulated using XFEM. In Simulation-II, an ideal notch FE model of the same geometric size as the actual specimen was created and then used for simulation. Obtained crack growth simulation results were then compared. Crack growth in the metal specimen was evaluated in three dimensions. It was shown that modeling the real shape of a structure with a crack may be essential for accurately evaluating 3D crack growth.

Production of 3D Mongyudowondo with Reinterpretation of Traditional Paintings (전통회화의 재해석을 통한 3차원 몽유도원도 제작)

  • Kim, Jong-il;Kim, Jong-chan;Cho, Seung-il;Kim, Eung-Kon;Joo, Hae-jeong;Kim, Cheeyong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.116-119
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    • 2009
  • Culture is an element of showing the quality of life as the factor that a human can become a human being. Furthermore, culture plays a role to make something new and a source for a higher value-added business. In 21C, the term of cultural contents to combine art with digital technology was derived. In this paper, we reconstruct a 3D Mongudowondo which is improved a plain appreciation into a 3D experience of traditional picture to make better user's convenience and approach. It is a device of restoration for cultural contents and a graft on virtual reality after reinterpreting 15C pictures and analyzing text and image.

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Numerical analysis of fracture mechanisms for porous calcium phosphate (다공성 칼슘포스파이트에 대한 파괴분석)

  • Park, Jin-Hong;Bae, Ji-Yong;Shin, Jae-Bum;Jeon, In-Su
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1301-1302
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    • 2008
  • In this study, the fracture strength for fracture mechanism porous calcium phosphate made from sintered with ${\beta}$-tricalcium phosphate obtained by wet precipitation procedure is analyzed using finite element method and experiment measurement. First, three $3{\times}3{\times}3mm^3$ and $5{\times}5{\times}5mm^3$ specimens are prepared and tomographic images of one $5{\times}5{\times}5mm^3$ specimen are obtained by micro focus X-ray CT. The compression tests using the specimens are carried out to measure the elastic modulus and fracture strength to analyze the fracture mechanism of porous calcium phosphate specimen. The tomographic images are reconstructed by 3D reconstruction program. The finite elements are directly built up in the reconstructed specimen. The numerical simulation for the compression tests is performed using the element. The mechanism of calcium phosphate of simulation are obtained by the compression tests using there cylindric specimen of height 19.5 mm and diameter 10 mm. From the results, the applicability of porous calcium phosphate is evaluated to care fracture and vacant bone of a patient as the reinforcement material.

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Subjectivity Study on the Employment Supporting for Students with Disabilities in College (대학의 장애학생 취업지원에 관한 주관성 연구)

  • Lee, Jae-Hwan;Sung, Hyeok-Je
    • The Journal of the Korea Contents Association
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    • v.15 no.1
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    • pp.197-210
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    • 2015
  • The purpose of this study is to find out subjective perception types and needs of interested group on the employment supporting for students with disabilities in college by Q methodology, then to search for political measures to support employment for students with disabilities in the implication of the sorted subjective perception types. The result of the study showed that there are four major sorts of subjectivities on the employment supporting for students with disabilities in college : external dependence(Type1), disability-friendly (Type2), demand tailored(Type3), internal role emphasis(Type4). The result of the study could check that there was necessary reconstruction to disability-friendly infrastructure based on interset and willness on the employment supporting for students with disabilities in college. In addition to that there was necessary to job creation of government, to build network of industry to successful labor market entry of students with disabilities.

Development of Hip Joint Mechanical Stem for Minimally Invasive Surgery (최소침습술을 위한 고관절 메커니컬 스템의 개발)

  • Lee, Sunghyun;Bae, Ji-Yong;Jeon, Insu
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.37 no.7
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    • pp.703-708
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    • 2013
  • Conventional total hip joint replacement(THR) surgery requires a long incision and long rehabilitation time. The stem used in THR is inserted into the cancellous bone of the femur where it plays the role of the artificial joint. Minimally invasive surgery(MIS) has been devised to reduce muscle damage to patients. In this study, a mechanical stem was developed on the basis of MISto reduce the incision length through the principle of the gear. The mechanical stem consists of six components. A prototypical model for a mechanical stem was fabricated using an acryl-based polymer, and its workability was confirmed. To actualize the mechanical stem, a three-dimensional Bio-CAD modeling technique was applied. The hip joint area based on computed tomography(CT) was reconstructed. The safety of the mechanical stem by applying more load than the weight of a man under virtual surgery environment conditions was confirmed by finite element analysis.

Development of Rotordynamics Program Based on the 2D Finite Element Method for Flywheel Energy Storage System (2차원 유한요소법을 적용한 플라이휠 에너지 저장 장치 동특성 해석 프로그램 개발)

  • Gu, Dong-Sik;Bae, Yong-Cae;Lee, Wook-Ryun;Kim, Jae-Gu;Kim, Hyo-Jung;Choi, Byeong-Keun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.11
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    • pp.1757-1763
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    • 2010
  • Flywheel energy storage system (FESS) is defined as a high speed rotating flywheel system that can save surplus electric power. The FESS is proposed as an efficient energy storage system because it can accumulate a large amount of energy when it is operated at a high rotating speed and no mechanical problems are encountered. The FESS consists of a shaft, flywheel, motor/generator, bearings, and case. It is difficult to simulate rotor dynamics using common structure simulation programs because these programs are based on the 3D model and complex input rotating conditions. Therefore, in this paper, a program for the FESS based on the 2D FEM was developed. The 2D FEM can model easier than 3D, and it can present the multi-layer rotor with different material each other. Stiffness changing of the shaft caused by shrink fitting of the hub can be inputted to get clear solving results. The results obtained using the program were compared with those obtained using the common programs to determine any errors.