• Title/Summary/Keyword: Three-dimensional Model

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Development of three-dimensional image modelling of meridian and acupoint (경락경혈의 3차원 영상모델 구현을 위한 시제품 개발연구)

  • Yin, Chang-Shik;Park, Hi-Joon;Lee, Hye-Jung
    • Korean Journal of Acupuncture
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    • v.25 no.4
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    • pp.167-174
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    • 2008
  • Objectives : Acupuncture points and meridians have been usually depicted as a two dimensional drawing and verbal description. Recently, imaging and three-dimensional image processing technologies have been introduced into medical fields such as anatomy and virtual operation, for the purpose of enhanced efficiency in research and education. This study attempted an image modelling of the meridian and acupoint in the upper limb region. Methods : A vector image model of an arm was produced and medical information on the meridian and acupoint of the arm region was incorporated. Results : A 3D modelling of the acupuncture meridian and acupoint in the upper limb region was produced along with a user console to control the presentation of related information and to facilitate visualization of the 3D model images. Conclusions : A 3D modelling of the acupuncture meridian and acupoint will be an efficient platform for an education and research.

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An improved 1D-model for computing the thermal behaviour of concrete dams during operation. Comparison with other approaches

  • Santillan, D.;Saleteb, E.;Toledob, M.A.;Granados, A.
    • Computers and Concrete
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    • v.15 no.1
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    • pp.103-126
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    • 2015
  • Thermal effects are significant loads for assessing concrete dam behaviour during operation. A new methodology to estimate thermal loads on concrete dams taking into account processes which were previously unconsidered, such as: the evaporative cooling, the night radiating cooling or the shades, has been recently reported. The application of this novel approach in combination with a three-dimensional finite element method to solve the heat diffusion equation led to a precise characterization of the thermal field inside the dam. However, that approach may be computationally expensive. This paper proposes the use of a new one-dimensional model based on an explicit finite difference scheme which is improved by means of the reported methodology for computing the heat fluxes through the dam faces. The improved model has been applied to a case study where observations from 21 concrete thermometers and data of climatic variables were available. The results are compared with those from: (a) the original one-dimensional finite difference model, (b) the Stucky-Derron classical one-dimensional analytical solution, and (c) a three-dimensional finite element method. The results of the improved model match well with the observed temperatures, in addition they are similar to those obtained with (c) except in the vicinity of the abutments, although this later is a considerably more complex methodology. The improved model have a better performance than the models (a) and (b), whose results present larger error and bias when compared with the recorded data.

Numerical modeling of Atmosphere - Surface interaction considering Vegetation Canopy (식물계를 고려한 지표-대기 상호작용의 수치모의)

  • 이화운;이순환
    • Journal of Environmental Science International
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    • v.3 no.1
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    • pp.17-29
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    • 1994
  • An one dimensional atmosphere-vegetation interaction model is developed to discuss of the effect of vegetation on heat flux in mesoscale planetary boundary layer. The canopy model was a coupled system of three balance equations of energy, moisture at ground surface and energy state of canopy with three independent variables of $T_f$(foliage temperature), $T_g$(ground temperature) and $q_g$(ground specific humidity). The model was verified by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HYPEX-MOBHLY experiment. As the result, both vegetation and soil characteristics can be emphasized as an important factor iii the analysis of heat flux in the boundary layer. From the numerical experiments, following heat flux characteristics are clearly founded simulation. The larger shielding factor(vegetation) increase of $T_f$ while decrease $T_g$. because vegetation cut solar radiation to ground. Vegetation, the increase of roughness and resistance, increase of sensible heat flux in foliage while decrease the latent heat flux in the foliage.

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A study on the rigid bOdy placement task of robot system based on the computer vision system (컴퓨터 비젼시스템을 이용한 로봇시스템의 강체 배치 실험에 대한 연구)

  • 장완식;유창규;신광수;김호윤
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.1114-1119
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    • 1995
  • This paper presents the development of estimation model and control method based on the new computer vision. This proposed control method is accomplished using a sequential estimation scheme that permits placement of the rigid body in each of the two-dimensional image planes of monitoring cameras. Estimation model with six parameters is developed based on a model that generalizes known 4-axis scara robot kinematics to accommodate unknown relative camera position and orientation, etc. Based on the estimated parameters,depending on each camers the joint angle of robot is estimated by the iteration method. The method is tested experimentally in two ways, the estimation model test and a three-dimensional rigid body placement task. Three results show that control scheme used is precise and robust. This feature can open the door to a range of application of multi-axis robot such as assembly and welding.

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A Study on the Temperature Distribution and Deformation of Case in Shrinkage Fit Process(II) - Deformation Measurement and Deformation Analysis Model - (열박음 공정이 케이스의 온도분포 및 변형에 미치는 영향(II) - 변형 계측 및 변형 해석 모델 정립 -)

  • 장경복;정진우;강성수;최규원;박찬우;조상명
    • Journal of Welding and Joining
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    • v.19 no.5
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    • pp.492-498
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    • 2001
  • In the previous study, temperature monitoring of case about shrinkage fit process was performed and heat transfer model was developed in detail by feedback and tuning among monitoring result, process investigation, and analysis result. The gap element in contact between case and core was effectively used in analysis model. In present study, following things are performed to solve deformation of case due to shrinkage fit process on the basis of previous result. Above all, mechanical material properties of case are measured by case specimen for deformation analysis considering weldment of case. Deformation of case before and after shrinkage fit process is measured, too. Three dimensional deformation model is developed by the comparison and inspection between these experimental data and analysis results. Deformation analysis is simulated with the result of heat transfer analysis, in other words, non-coupled analysis is used. Finally the countermeasure for deformation is brought up through those.

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Development of Three-Dimensional Contact Model of Human Knee Joint During Locomotion (보행 중 인체 슬관절의 3차원 접촉 모델 개발)

  • Kim, Hyo-Shin;Park, Seong-Jin;Mun, Joung-Hwan
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.11 s.176
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    • pp.182-189
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    • 2005
  • The human knee joint is the intermediate joint of the lower limb that is the largest and most complex joint in the body. Understanding of joint-articulating surface motion is essential for the joint wear, stability, mobility, degeneration, determination of proper diagnosis and so on. However, many studies analyzed the passive motion of the lower limb because of the skin marker artefact and some studies described medial and lateral condyle of a femur as a simple sphere due to the complexity of geometry. Thus, in this paper, we constructed a three-dimensional geometric model of the human knee from the geometry of its anatomical structures using non-uniform B-spline surface fitting as a study for the kinematic analysis of more realistic human knee model. In addition, we developed and verified 6-DOF contact model of the human knee joint using $C^2$ continuous surface of the inferior region of a femur, considering the relative motion of shank to thigh during locomotion.

A Study on the 3-D CNC Cutting Planning and Simulation by Z-Map Model (Z-Map 모델을 이용한 3차원 CNC 가공계획 및 절삭시뮬레이션에 관한 연구)

  • 송수용;김석일
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1994.10a
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    • pp.683-688
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    • 1994
  • Recently, the Z-Map model has been used widely to represent the three dimensional geometric shape and to achieve the cross-section and point evaluation of the shape. In this paper, the CNC cutting planning and simulation modules for product with three dimensional geometric shape are realized based on the Z-Map model. The realized system has the various capabilities related to the automatic generation of tool path for the rough and finish cutting processes, the automatic elimination of overcut, the automatic generation of CNC program for a machining center and the cutting simulation. Especially, the overcut-free tool path is obtained by using the CL Z-Map models which are composed of the offset surfaces of the geometric shape of product.

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Three-dimensional Active Shape Model for Object Segmentation (관심 객체 분할을 위한 삼차원 능동모양모델 기법)

  • Lim, Seong-Jae;Ho, Yo-Sung
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.335-336
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    • 2006
  • In this paper, we propose an active shape image segmentation method for three-dimensional(3-D) medical images using a generation method of the 3-D shape model. The proposed method generates the shape model using a distance transform and a tetrahedron method for landmarking. After generating the 3-D model, we extend the training and segmentation processes of 2-D active shape model(ASM) and improve the searching process. The proposed method provides comparative results to 2-D ASM, region-based or contour-based methods. Experimental results demonstrate that this algorithm is effective for a semi-automatic segmentation method of 3-D medical images.

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An Improved Finite Element Analysis Model of Offshore Cable-Supported Structures (해양 케이블 지지구조물의 구조해석을 위한 개선된 유한요소해석모델)

  • KIM SUN-HOON;SONG MYUNG-KWAN;NOH HYUK-CHUN
    • Journal of Ocean Engineering and Technology
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    • v.18 no.6 s.61
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    • pp.51-57
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    • 2004
  • In this study, the improved three-dimensional analysis model designed for a more accurate analysis of marine cable-supported structures, is presented. In this improved analysis model, the beam elements, of which the stability function is derived using Taylor's series expansions, are used to model space frame structures, and the truss elements. The equivalent elastic modulus of the truss elements is evaluated on the assumption that the deflection curve of a cable has a catenary function. By using the proposed three-dimensional analysis model, nonlinear static analysis is carried out for some cable-supported structures. The results are compared with previous studies and show good agreement with their findings.

A Study on Rigid body Placement Task of based on Robot Vision System (로봇 비젼시스템을 이용한 강체 배치 실험에 대한 연구)

  • 장완식;신광수;안철봉
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.11
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    • pp.100-107
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    • 1998
  • This paper presents the development of estimation model and control method based on the new robot vision. This proposed control method is accomplished using the sequential estimation scheme that permits placement of the rigid body in each of the two-dimensional image planes of monitoring cameras. Estimation model with six parameters is developed based on the model that generalizes known 4-axis scara robot kinematics to accommodate unknown relative camera position and orientation, etc. Based on the estimated parameters, depending on each camera the joint angle of robot is estimated by the iteration method. The method is experimentally tested in two ways, the estimation model test and a three-dimensional rigid body placement task. Three results show that control scheme used is precise and robust. This feature can open the door to a range of application of multi-axis robot such as assembly and welding.

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