• Title/Summary/Keyword: Three dimensional body

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Direct frequency domain analysis of concrete arch dams based on FE-(FE-HE)-BE technique

  • Lotfi, Vahid
    • Computers and Concrete
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    • v.1 no.3
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    • pp.285-302
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    • 2004
  • A FE-(FE-HE)-BE procedure is presented for dynamic analysis of concrete arch dams. In this technique, dam body is discretized by solid finite elements, while the reservoir domain is considered by a combination of fluid finite elements and a three-dimensional fluid hyper-element. Furthermore, foundation rock domain is handled by three-dimensional boundary element formulation. Based on this method, a previously developed program is modified, and the response of Morrow Point arch dam is studied for various conditions. Moreover, the effects of canyon shape on response of dam, is also discussed.

Three-dimensional Analysis for Three-phase Spacers in Gas Insulated System (3차원 전계해석 기법을 이용한 GIS 삼상 일괄형 스페이서 고찰)

  • Kang, J.S.;Lee, B.W.;Kang, S.M.;Oh, I.S.
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1620-1622
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    • 2003
  • Recently, as the technology for the development of high voltage power apparatus using SF6 gas has made remarkable progress, it became possible to develop more compact power apparatus adopting single body substation system. In these gas insulated power apparatus, it is impossible to achieve perfect and safe insulation using only SF6 gas, because some solid insulation parts should be installed to support current-carrying conductor parts for electrical and mechanical safety. When spacers were installed in SF6 gas insulation system, they were exposed to severe electrical intensification which could reduce system insulation performance and restrict the rated operating voltage So, it is necessary to clarify the dielectric characteristics of spacers by analytically and experimentally, in order to design and develop more compact and optimum gas insulated systems. In this paper, the field distribution of three-phase spacers were investigated using three dimensional electrostatic field analysis tool adopting BEM method. And the obtained results were compared to the conventional two dimensional computations. According to these three dimensional calculations, it was possible to find out weak points in the spacer more clearly and these results could be applied to design more compact and optimum three phase spacer developments.

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FLUID-BODY INTERACTION ANALYSIS OF FLOATING BODY IN THREE DIMENSIONS (3차원 부유체의 유체-물체 연성해석)

  • Go, G.S.;Ahn, H.T.
    • Journal of computational fluids engineering
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    • v.20 no.2
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    • pp.103-108
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    • 2015
  • Fluid-body interaction analysis of floating body with six degree-of-freedom motion is presented. In this study, three-dimensional incompressible Navier-Stokes equations are employed as a governing equation. The numerical method is based on a finite-volume approach on a cartesian grid together with a fractional-step method. To represent the body motion, the immersed boundary method for direct forcing is employed. In order to simulate the coupled six degree-of-freedom motion, Euler's equations based on rigid body dynamics are utilized. To represent the complex body shape, level-set based algorithm is utilized. In order to describe the free surface motion, the volume of fluid method utilizing the tangent of hyperbola for interface capturing scheme is employed. This study showed three different continuums(air, water and body) are simultaneously simulated by newly developed code. To demonstrate the applicability of the current approach, two different problems(dam-breaking with stationary obstacle and water entry) are simulated and all results are validated.

Simulation of Three-Dimensional Turbulent Flows around an Ahmed Body-Evaluation of Turbulence Models- (Ahmed Body 주위의 3차원 난류유동 해석 - 난류모델의 평가)

  • Myong, H.K.;Jin, E.;Park, H.K.
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.7
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    • pp.873-881
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    • 1997
  • A numerical simulation has been carried out for three-dimensional turbulent flows around an Ahmed body. The Reynolds-averaged Navier-Stokes equation is solved with the SIMPLE method in general curvilinear coordinates system. Several k-.epsilon. turbulence models with two convective difference schemes are evaluated for the performance such as drag coefficient, velocity and pressure fields. The drag coefficient, the velocity and pressure fields are found to be changed considerably with the adopted k-.epsilon. turbulence models as well as the finite difference schemes. The results of simulation prove that the RNG k-.epsilon. model with the QUICK scheme predicts fairly well the tendency of velocity and pressure fields and gives more reliable drag coefficient. It is also demonstrated that the large difference between simulations and experiment in the drag coefficient is due to relatively high predicted values of pressure drag from vertical rear end base.

Detection of Simulative Foreign Body Using three Dimensional Reconstruction Technique, Introduction and Application (삼차원 재건 기술을 이용한 모의 이물 탐색)

  • Yoo, Young Sam;Kim, Dong Won
    • Korean Journal of Bronchoesophagology
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    • v.17 no.1
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    • pp.40-45
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    • 2011
  • Background and Objectives Detailed information about the impacted esophageal foreign body is essential for safe extraction. Three dimensional reconstruction technique was applied to know shape, size and location of the simulative foreign bodies of stone, hyoid bone and endotracheal tube. Materials and Methods Submandibular gland stone, hyoid bone and endotracheal tube were used to simulate impacted foreign bodies. Axial CT, multi-planar reconstruction, volume of interest and virtual camera of Rapidia software were used to get information about the simulative foreign bodies from CT data. Shape and size were compared with the real materials. Exact locations were measured in appropriate modes of Rapidia. Results Shapes of the simulative foreign bodies matched well with the real materials. Size and location could be measured in various modes with some variable results. Conclusion 3D technique can be applied to get information about the simulative foreign bodies. This technique could be applied to the impacted esophageal foreign body.

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A Research of Madeleine Vionnet's Work II (Madeleine Vionnet의 작품에 관한 연구II -연구대상 작품의 제작되어진 패턴을 중심으로-)

  • 박선경
    • The Research Journal of the Costume Culture
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    • v.4 no.1
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    • pp.93-109
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    • 1996
  • Madeleine Vionnet, a representative designer of the 1920′s, who made prefectly organized clothes with unique formativeness was the first to express fabric in a modern method and was called "The architect of fashion". This is because she developed a three dimensional design by expressing cloth-she rejected corset, should pad, etc-into elegant curved lines that do not stick to the body. By granting meaning to the beauty of the body and its movement in her own unique ways, she emphasized the formativeness in her work and gave shape to creative artistry. Expecially with the "Bias-Cut" she could express the lines of the body more flexibly and could make geometrical styles like the diamond shape dress or the triangle dress more effectively. Using the "Tired Bias cut" and "Handkerchief point" she let the skirt hemline dangle irregularly in geometrical forms, thus showing modern formative sense which forms a three dimensional solidness along the movement of the human body. Thus far, analyzed how the contemporary trend of art was reflected in her designs by studying her work; also investigated through her artistic characteristics and pattern method. Also be tried to find out what can be learned through her artistic view and superb formativeness as a designer.

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A Study ef Biomechanical Response in Human Body during Whole-Body Vibration through Musculoskeletal Model Development (전신 진동운동기 사용시 인체에 대한 생체역학적 특성 분석을 위한 가상 골격계 모델의 개발 및 검증)

  • Choi, Hyun-Ho;Lim, Do-Hyung;Hwang, Seon-Hong;Kim, Young-Ho;Kim, Han-Sung
    • Journal of the Korean Society for Precision Engineering
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    • v.25 no.5
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    • pp.155-163
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    • 2008
  • This study investigated biomechanical response through the 3-dimensional virtual skeletal model developed and validated. Ten male subjects in standing posture were exposed to whole body vibrations and measured acceleration on anatomical of interest (head, $7^{th}$ cervical, $10^{th}$ thoracic, $4^{th}$ lumbar, knee joint and bottom of the vibrator). Three dimensional virtual skeletal model and vibration machine were created by using BRG LifeMOD and MSC.ADAMS. The results of forward dynamic analysis were compared with results of experiment. The results showed that the accuracy of developed model was $73.2{\pm}19.2%$ for all conditions.

Fashion Design of Disassembly and Assembly Based on Geometrical Analysis of the Body Figure (인체 형태의 기하학적 분석에 기반한 분해와 조합의 패션디자인 개발)

  • Kyung-Jin, Lee
    • Journal of the Korea Fashion and Costume Design Association
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    • v.26 no.1
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    • pp.61-76
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    • 2024
  • The purpose of this study is the development of an experimental design that aims to implement three-dimensional fashion design by observing the human body, extracting and combining geometric shapes and forms, and focusing on attempts to decompose the geometry of the human body in art history. Considering the characteristics of fashion design, which inevitably reflect human images visually, this study considered works by deriving geometric shapes and forms of the human body and focusing on decomposition and combination to apply them to fashion design. The results obtained through the development of fashion design through decomposition and combination based on geometric human body analysis are as follows. First, geometric analysis of the human body as an object of expression continues from the history of Cubism to modern fashion design. Second, the geometric shapes of the human body that appear in contemporary fashion design maximize visual effects through three-dimensional composition, emphasizing simplicity while showing originality through various expressions. Third, when exploring the geometric shapes of a moving human body, it was possible to extract a wide variety of shapes and forms through drawing and simplifying the human body's movements. Fourth, the formative method of fashion design was introduced and used for the aesthetic combination of objects for fashion design through decomposition and combination. This study was able to show unique and diverse combinations of visually concise and ordered geometric shapes in the expression of fashion design by decomposing and combining them. The significance of these geometric forms is that they can diversify formative informativeness in the expression of fashion design with modern compositional beauty.

Analysis of added resistance of a ship advancing in waves (파랑중에서 전진하는 선박의 부가저항 해석)

  • 이호영;곽영기
    • Journal of Ocean Engineering and Technology
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    • v.11 no.2
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    • pp.91-99
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    • 1997
  • This paper presents theoretical formulations and numerical computations for predicting first-and second-order hydrodynamic force on a ship advvancing in waves. The theoretical formulation leads to linearized radiation and diffration problems solving the three-dimensional Green function integral equations over the mean wetted body surface. Green function representing a translating and pulsating source potantial for infinite water depth is used. In order to solve integral equations for three dimentional flows using Green function efficiently, the Hoff's method is adopted for numerical calculation of the Green function. Based on the first-order solution, the mean seconder-order forces and moments are obtained by directly integrating second-order pressure over the mean wetted body surface. The calculated items are carried out for analyzing the seakeeping characteristics of Series 60. The calculated items are hydrodynamic coefficients, wave exciting forces, frequency response functions and addd resistance in waves.

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A Study on Turbulent Flow Fields around Ships (선체주위 난류유동장의 해석에 관한 연구)

  • Lee S. H.;Park J. J.
    • Journal of computational fluids engineering
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    • v.1 no.1
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    • pp.64-70
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    • 1996
  • Three dimensional turbulent flow fields around ships are simulated by a numerical method. Reynolds Averaged Navier-Stokes equations are used where Reynolds stresses are approximated by Baldwin-Lomax and Sub-Grid Scale(SGS) turbulence models. Body-fitted coordinate system is introduced to conform three dimensional ship geometries. The governing equations are discretized by a finite volume method. Temporal derivatives are approximated by the forward differencing and the convection terms are approximated by the QUICK or Kawamura scheme. The 2nd-order centered differencing is used for other spatial derivatives. Pressure and velocity fields are simultaneously iterated by the Highly Simplified Marker-And-Cell method. To verify the numerical method and turbulence models, flow fields around ships are simulated and compared to the experiments.

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