• Title/Summary/Keyword: Point to Mesh

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The Effect of Glass Fiber Reinforcing Materials and Thermocycling on the Transverse Strength of Denture Base Resin (유리 섬유 의치상 레진 강화재와 열 순환이 의치상 굽힘 강도에 미치는 영향)

  • Jin, Sung-Eun;Cho, In-Ho
    • Journal of Dental Rehabilitation and Applied Science
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    • v.29 no.4
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    • pp.327-336
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    • 2013
  • This study aimed to investigate the reinforcing effect of two kinds of glass fiber, Quarts Splint$^{TM}$ Mesh and SES MESH$^{(R)}$ and to evaluate the effect of the thermocycling on the transverse strength of the denture base and on the reinforcing effect of the reinforcements. 20 specimens of the size of $2.5{\times}10.0{\times}65.0mm$ were fabricated for each group; control group, metal mesh reinforcement group, Quarts Splint$^{TM}$ Mesh reinforcement group and SES MESH$^{(R)}$ reinforcement group. To find the difference made by the thermocycling, 10 specimens of each reinforcement group were treated by thermocycling. 3-point bending test was performed to measure the transverse strength of the denture base resin. The specimens reinforced with SES MESH$^{(R)}$ and Quarts Splint$^{TM}$ Mesh showed significantly higher transverse strength than the control group (P<.05), and significantly lower transverse strength than the specimens reinforced with the metal mesh (P<.05). Thermocycled specimens were lower in transverse strength than non-thermocycled specimens in the control group, metal mesh group, Quarts Splint$^{TM}$ Mesh group and SES MESH$^{(R)}$ group, however significant difference (P<.05) was found only in the control group.

A Study on the Determination of Closing Level for Finite Element Analysis of Fatigue Crack Closure

  • Choi, Hyeon-Chang
    • Journal of Mechanical Science and Technology
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    • v.14 no.4
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    • pp.401-407
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    • 2000
  • An elastic-plastic finite element analysis is performed to investigate detailed closure behavior of fatigue cracks and the numerical results are compared with experimental results. The finite element analysis performed under plane stress using 4-node isoparametric elements can predict fatigue crack closure behavior. The mesh of constant element size along crack surface can not predict the opening level of fatigue crack. The crack opening level for the constant mesh size increases linearly from initial crack growth. The crack opening level for variable mesh size, is almost flat after crack tip has passed the monotonic plastic zone. The prediction of crack opening level using the variable mesh size proportioning the reversed plastic zone size with the opening stress intensity factors presents a good agreement with the experimental data regardless of stress ratios.

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Development of High-Performance FEM Modeling System Based on Fuzzy Knowledge Processing

  • Lee, Joon-Seong
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.4 no.2
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    • pp.193-198
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    • 2004
  • This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of tree-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, (b) generation of nodes, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Voronoi diagram method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional solid structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

Influence of Compression and Granule Size on Dissolution Rate of Acetaminophen, Fenbufen, and Mefenamic Acid Tablets (정제(錠劑)의 과립도(顆粒度) 및 임계타정압(臨界打錠壓)이 용출속도(溶出速度)에 미치는 영향(影響))

  • Ryu, Jang-Ha;Kim, Johng-Kap
    • Journal of Pharmaceutical Investigation
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    • v.13 no.4
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    • pp.191-195
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    • 1983
  • Acetaminophen, fenbufen, and mefenamic acid tablets were formulated with the same additives, granulated to different sizes, ranging $30{\sim}200mesh$, and compressed by pressure of $0.5{\sim}2.0\;ton{\cdot}cm^{-2}$. The hardness and disintegration time of the three tablets were determined. The dissolution rates of the three tablets at critical point of pressure were investigated. The results showed that fenbufen, and mefenamic acid tablet had critical compression pressure of $1.0\;ton{\cdot}cm^{-2}$, but acetaminophen tablet had that of $1.5\;ton{\cdot}cm^{-2}$. Neverthless, three tablets were disintegrated within 5 min. Among the three tablets, mefenamic acid tablet followed zero order of dissolution and the rate constants were as fellows; $1.68 \;mg{\cdot}min^{-1}\;(30{\sim}50mesh),\;1.76mg{\cdot} min^{-1}\;(50{\sim}80\;mesh)\;and\;4.85\;mg{\cdot}min^{-1}\;(80{\sim}200mesh)$.

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Pointwise Convergence for the FEM in Poisson Equations by a 1-Irregular Mesh (포아송 방정식에서 1-Irregular Mesh를 이용한 유한요소법의 수렴성에 관한 연구)

  • Lee, Hyoung;Ra, Sang-Dong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.11
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    • pp.1194-1200
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    • 1991
  • The FEM is a computer-aided mathematical technique for obtaining approximate solution to the differential equations. The pointwise convergence defines the relationship between the mesh size and the tolerance. This will play an important role in improving quality of finite element approximate solution. In the paper. We evaluate the convergence on a certain unknown point with a 1-irregular mesh refinement and spectral order enrichment. This means that the degree of freedom is minimized within a tolerance.

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Automatic Mesh Generation System for a Novel FEM Modeling Based on Fuzzy Theory (퍼지이론을 이용한 FEM 모델링을 위한 자동 요소분할 시스템)

  • Lee Yang-Chang;Lee Joon-Seong;Choi Yoon-Jong;Kim Nam-Yong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.3
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    • pp.343-348
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    • 2005
  • This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of free-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of nodes, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional solid structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

Automatic Mesh Generation System for a Novel FEM Modeling Based on Fuzzy Theory (퍼지이론을 이용한 FEM 모델링을 위한 자동 요소분할 시스템)

  • Lee Joon-Seong;Lee Yang-Chang;Choi Yoon-Jong
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.04a
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    • pp.139-142
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    • 2005
  • This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of free-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of nodes, and (c) generation of elements. One of commercial sol id modelers is employed for three-dimensional sol id structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well control led by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional sol id structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

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Acceleration of Mesh Denoising Using GPU Parallel Processing (GPU의 병렬 처리 기능을 이용한 메쉬 평탄화 가속 방법)

  • Lee, Sang-Gil;Shin, Byeong-Seok
    • Journal of Korea Game Society
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    • v.9 no.2
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    • pp.135-142
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    • 2009
  • Mesh denoising is a method to remove noise applying various filters. However, those methods usually spend much time since filtering is performed on CPU. Because GPU is specialized for floating point operations and faster than CPU, real-time processing for complex operations is possible. Especially mesh denoising is adequate for GPU parallel processing since it repeats the same operations for vertices or triangles. In this paper, we propose mesh denoising algorithm based on bilateral filtering using GPU parallel processing to reduce processing time. It finds neighbor triangles of each vertex for applying bilateral filter, and computes its normal vector. Then it performs bilateral filtering to estimate new vertex position and to update its normal vector.

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A Mesh Watermarking Using Patch CEGI (패치 CEGI를 이용한 메쉬 워터마킹)

  • Lee Suk-Hwan;Kwon Ki-Ryong
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.42 no.1
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    • pp.67-78
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    • 2005
  • We proposed a blind watermarking for 3D mesh model using the patch CEGIs. The CEGI is the 3D orientation histogram with complex weight whose magnitude is the mesh area and phase is the normal distance of the mesh from the designated origin. In the proposed algorithm we divide the 3D mesh model into the number of patch that determined adaptively to the shape of model and calculate the patch CEGIs. Some cells for embedding the watermark are selected according to the rank of their magnitudes in each of patches after calculating the respective magnitude distributions of CEGI for each patches of a mesh model. Each of the watermark bit is embedded into cells with the same rank in these patch CEGI. Based on the patch center point and the rank table as watermark key, watermark extraction and realignment process are performed without the original mesh. In the rotated model, we perform the realignment process using Euler angle before the watermark extracting. The results of experiment verify that the proposed algorithm is imperceptible and robust against geometrical attacks of cropping, affine transformation and vertex randomization as well as topological attacks of remeshing and mesh simplification.

A High Quality Mesh Generation for Surfaces in the Use of Interval Arithmetic

  • Kikuchi, Ryota;Makino, Mitsunori
    • Proceedings of the IEEK Conference
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    • 2002.07b
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    • pp.1153-1156
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    • 2002
  • In this parer, a high quality mesh generation method by using interval arithmetic is proposed. In the proposed method, the variance of a tangent vector at the point is considered by the automatic differentiation. From the variance, sampling points on the surface are judged whether it is adequate or not, which is calculated by the interval arithmetic. Then Delaunay triangulation is performed to the obtained sampling points, and a set of meshes is generated. The proposed method is hard to overlook the local variation of surfaces.

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