• Title/Summary/Keyword: Mesh deformation

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A Study on Realtime Mesh Deformation of 3D Avatar Body (3D 아바타의 실시간 체형 변형에 관한 연구 - 메쉬모핑 기법을 이용한 아바타 및 아이템의 체형변형)

  • Shin, In-Sup
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.688-692
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    • 2008
  • All items from the 3d avatar system should be made to fit the avatar's physical form. However this method is not only a disadvantage in an economical perspective, but also it is difficult to satisfy the client's needs of avatar's variety form. To provide various forms of the avatars, the work load naturally increases. This research is about changing the 3d avatar's body shape based on 3d mesh morphing which allows the 3d avatar with smallest data possible. The result mesh could be generated from source and target mesh with the deformation ratio and all 3d items like hair style, pants, shoes and etc, which was made to fit to basic mesh also could be deformed automatically, to fit them to the result mesh as is. Even if the different physical avatar mesh body such as children style is added to 3d avatar system, it is not necessary to make the 3d avatar items which is fit to the new physical body, New avatar mesh body will be adopted to the 3d avatar system in real time.

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AUTOMATIC MESH GENERATION AROUND SHIP HULL USING THE MACRO (매크로 기능을 이용한 선박 격자의 자동 생성 기법)

  • Lee, J.H.;Rhee, S.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.71-76
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    • 2009
  • The research to predict the resistance performance of the ship using the CFD analysis is increasing. For the CFD numerical analysis the computational mesh, which is proper to computational model, has to be made before the analysis is begun. In the parametric study, even though the deformation of each case is not very sharp, the whole computational mesh should be regenerated according to the conventional way. Hence, lots of effort is needed to repeated mesh generation work. To solve these problems, the automatic mesh generation method using the macro function of commercial CAD program and mesh generation program is introduced in this study. First, in the CAD program, by using the macro function and putting the deformation rate of bow and stern in lengthwise, the repeated modeling work is performed automatically. Next, the generated geometries are read by the mesh generation program and the proper mesh for the geometry is created automatically also using the macro function. The hybrid mesh which has unstructured grid near the bow and stern and structured grid in the remaining part of domain is used. The verification of the developed method is done by applying the method to predict the resistance performance of the podded propulsion cruise ship of the Daewoo Shipbuilding & Marine Engineering (DSME) in the cases of different length of bow and stern and pod set in different position. The author believes that the introduced method can help to make the database to optimize the resistance performance of the ship in various cases can be constructed without difficulty.

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3D Shape Optimization of Electromagnetic Device Using Design Sensitivity Analysis and Mesh Relocation Method (설계민감도해석과 요소망 변형법을 이용한 전자소자의 3차원 형상최적화)

  • ;Yao Yingying
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.7
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    • pp.307-314
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    • 2003
  • This paper presents a 3D shape optimization algorithm for electromagnetic devices using the design sensitivity analysis with finite element method. The structural deformation analysis based on the deformation theory of the elastic body under stress is used for mesh renewing. The design sensitivity and adjoint variable formulae are derived for the 3D finite element method with edge element. The results of sensitivity analysis are used as the input data of the structural analysis to calculate the relocation of the nodal points. This method makes it possible that the new mesh of analysis region can be obtained from the initial mesh without regeneration. The proposed algorithm is applied to the shape optimization of 3D electromagnet pole to net a uniform flux density at the target region.

Comparison of the fracture resistances of glass fiber mesh- and metal mesh-reinforced maxillary complete denture under dynamic fatigue loading

  • Im, So-Min;Huh, Yoon-Hyuk;Cho, Lee-Ra;Park, Chan-Jin
    • The Journal of Advanced Prosthodontics
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    • v.9 no.1
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    • pp.22-30
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    • 2017
  • PURPOSE. The aim of this study was to investigate the effect of reinforcing materials on the fracture resistances of glass fiber mesh- and Cr-Co metal mesh-reinforced maxillary complete dentures under fatigue loading. MATERIALS AND METHODS. Glass fiber mesh- and Cr-Co mesh-reinforced maxillary complete dentures were fabricated using silicone molds and acrylic resin. A control group was prepared with no reinforcement (n = 15 per group). After fatigue loading was applied using a chewing simulator, fracture resistance was measured by a universal testing machine. The fracture patterns were analyzed and the fractured surfaces were observed by scanning electron microscopy. RESULTS. After cyclic loading, none of the dentures showed cracks or fractures. During fracture resistance testing, all unreinforced dentures experienced complete fracture. The mesh-reinforced dentures primarily showed posterior framework fracture. Deformation of the all-metal framework caused the metal mesh-reinforced denture to exhibit the highest fracture resistance, followed by the glass fiber mesh-reinforced denture (P<.05) and the control group (P<.05). The glass fiber mesh-reinforced denture primarily maintained its original shape with unbroken fibers. River line pattern of the control group, dimples and interdendritic fractures of the metal mesh group, and radial fracture lines of the glass fiber group were observed on the fractured surfaces. CONCLUSION. The glass fiber mesh-reinforced denture exhibits a fracture resistance higher than that of the unreinforced denture, but lower than that of the metal mesh-reinforced denture because of the deformation of the metal mesh. The glass fiber mesh-reinforced denture maintains its shape even after fracture, indicating the possibility of easier repair.

A STUDY ON A GRID DEFORMATION USING RADIAL BASIS FUNCTION (Radial Basis Function을 사용한 격자 변형에 대한 연구)

  • Je, S.Y.;Jung, S.K.;Yang, Y.R.;Myong, R.S.;Cho, T.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.04a
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    • pp.121-124
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    • 2009
  • A moving mesh system is one of the critical parts in a computational fluid dynamics analysis. In this study, the RBF(Radial Basis Function) which shows better performance than hybrid meshes was developed to obtain the deformed grid. The RBF method can handle large mesh deformations caused by translations, rotations and deformations, both for 2D and 3D meshes. Another advantage of the method is that it can handle both structured and unstructured grids with ease. The method uses a volume spline technique to compute the deformation of block vertices and block edges, and deformed shape.

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Haptic Simulation with s-FEM (s-FEM 을 이용한 햅틱 시뮬레이션)

  • Jun, Seong-Ki;Cho, Maeng-Hyo
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.780-785
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    • 2007
  • Accurate and fast haptic simulations of deformable objects are desired in many applications such as medical virtual reality. In haptic interactions with a coarse model, the number of nodes near the haptic interaction region is too few to generate detailed deformation. Thus, local refinement techniques need to be developed. Many approaches have employed purely geometric subdivision schemes, but they are not proper in describing the deformation behavior of deformable objects. This paper presents a continuum mechanics-based finite element adaptive method to perform haptic interaction with a deformable object. This method superimposes a local fine mesh upon a global coarse model, which consists of the entire deformable object. The local mesh and the global mesh are coupled by the s-version finite element method (s-FEM), which is generally used to enhance accurate solutions near the target points even more. The s-FEM can demonstrate a reliable deformation to users in real-time.

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Improved Optimal Approximated Unfolding Algorithm of a Curved Shell Plate with Automatic Mesh Generation (자동 메쉬 생성을 적용한 향상된 자유 곡면의 최적 근사 전개 알고리즘)

  • Ryu C.H.;Shin J.G.
    • Korean Journal of Computational Design and Engineering
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    • v.11 no.3
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    • pp.157-163
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    • 2006
  • Surfaces of many engineering structures, especially, those of ships are commonly made out of either single- or double-curved surfaces to meet functional requirements. The first step in the fabrication process of a three-dimensional design surface is unfolding or flattening the surface, otherwise known as planar development, so that manufacturers can determine the initial flat plate which is required to form the design shape. In this paper, an algorithm for optimal approximated development of a general curved surface, including both single- and double-curved surfaces, is established by minimizing the strain energy of deformation from its planar development to the design surface. The unfolding process is formulated into a constrained nonlinear programming problem, based on the deformation theory and finite element. Constraints are subjected to the characteristics of the fabrication method. And the design surface, or the curved shell plate is subdivided by automatic mesh generation.

Haptic Simulation for Deformable Object with s-FEM (s-FEM을 이용한 변형체 햅틱 시뮬레이션)

  • Jun Seong-Ki;Choi Jin-Bok;Cho Maeng-Hyo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.373-380
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    • 2006
  • Accurate and fast haptic simulations of deformable objects are desired in many applications such as medical virtual reality. In haptic interactions with a coarse model, the number of nodes near the haptic interaction region is too few to generate detailed deformation. Thus, local refinement techniques need to be developed. Many approaches have employed purely geometric subdivision schemes, but they are not proper in describing the deformation behavior of deformable objects. This paper presents a continuum mechanics-based finite element adaptive method to perform haptic interaction 'with a deformable object. This method superimposes a local fine mesh upon a global coarse model, which consists of the entire deformable object. The local mesh and the global mesh are coupled by the s-version finite element method (s-FEM), which is generally used to enhance accurate solutions near the target points even more. The s-FEM can demonstrate a reliable deformation to users in real-time.

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The Study of Structural Stability by Stacking Method of the Axial Blade (축류 블레이드의 스태킹 방식에 의한 구조 안정성 연구)

  • Jeong, Cheol-Young;Ko, Hee-Hwan;Park, Jun-Young
    • The KSFM Journal of Fluid Machinery
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    • v.15 no.1
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    • pp.46-51
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    • 2012
  • This study is to confirm the deformation of blade when the location of stacking is moving. Also, it desire to determine the most stable location of stacking from the analysis. In the previous study, it is Known that moving the location of stacking is not influence to the aerodynamic performance. In this study SolidWorks premium 2010 SP4 is used for structure analysis. In reference blade and other 3 model analysis, the two mesh type is used, one is standard mesh type in SolidWorks, the other is curvature-based mesh type. The result of curvature-based mesh type is more stable than one of the standard mesh type regardless of mesh size, the number of mesh. The deformation of blade tip is the smallest, when the location of stacking is identical to the center of gravity of the blade section profile. So, if possible is design, this study recommends that the location of stacking is identical to the center of gravity the blade.

A new moving-mesh Finite Volume Method for the efficient solution of two-dimensional neutron diffusion equation using gradient variations of reactor power

  • Vagheian, Mehran;Ochbelagh, Dariush Rezaei;Gharib, Morteza
    • Nuclear Engineering and Technology
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    • v.51 no.5
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    • pp.1181-1194
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    • 2019
  • A new moving-mesh Finite Volume Method (FVM) for the efficient solution of the two-dimensional neutron diffusion equation is introduced. Many other moving-mesh methods developed to solve the neutron diffusion problems use a relatively large number of sophisticated mathematical equations, and so suffer from a significant complexity of mathematical calculations. In this study, the proposed method is formulated based on simple mathematical algebraic equations that enable an efficient mesh movement and CV deformation for using in practical nuclear reactor applications. Accordingly, a computational framework relying on a new moving-mesh FVM is introduced to efficiently distribute the meshes and deform the CVs in regions with high gradient variations of reactor power. These regions of interest are very important in the neutronic assessment of the nuclear reactors and accordingly, a higher accuracy of the power densities is required to be obtained. The accuracy, execution time and finally visual comparison of the proposed method comprehensively investigated and discussed for three different benchmark problems. The results all indicated a higher accuracy of the proposed method in comparison with the conventional fixed-mesh FVM.