• Title/Summary/Keyword: Three-Dimensional Analysis

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Automated FEA Simulation of Micro Motor (마이크로 모터의 자동화된 FEA 시뮬레이션)

  • Lee Joon-Seong
    • Journal of the Korea Society for Simulation
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    • v.11 no.3
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    • pp.13-22
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    • 2002
  • This paper describes an automated evaluation of electrostatic field for micro motors whose sizes range 10 to 103um. Electric field modeling in micro motors has been generally restricted to in-plane two-dimensional finite element analysis (FEA). In this paper, the actual three-dimensional geometry of the micro motor is considered. An automatic FE mesh generation technique, which is based on the fuzzy knowledge processing and computational geometry techniques, is incorporated in the system, together with one of commercial FE analysis codes and one of commercial solid modelers. The system allows a geometry model of concern to be automatically converted to different FE models, depending on physical phenomena to be analyzed, electrostatic analysis and stress analysis and so on. The FE models are then exported to the FE analysis code, and then analyses are peformed. Then, analytical analysis and FE analysis about the torque generated by electrostatic micro motor are performed. The starting torque is proportional to $V^2$, the calculated starting torque from the two-dimensional analytical solutions are three times larger than those from the three-dimensional FE solutions.

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Motion Recognition using Principal Component Analysis

  • Kwon, Yong-Man;Kim, Jong-Min
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.4
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    • pp.817-823
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    • 2004
  • This paper describes a three dimensional motion recognition algorithm and a system which adopts the algorithm for non-contact human-computer interaction. From sequence of stereos images, five feature regions are extracted with simple color segmentation algorithm and then those are used for three dimensional locus calculation precess. However, the result is not so stable, noisy, that we introduce principal component analysis method to get more robust motion recognition results. This method can overcome the weakness of conventional algorithms since it directly uses three dimensional information motion recognition.

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Evaluation of the marginal and internal gaps of three different dental prostheses: comparison of the silicone replica technique and three-dimensional superimposition analysis

  • Park, Jin-Young;Bae, So-Yeon;Lee, Jae-Jun;Kim, Ji-Hwan;Kim, Hae-Young;Kim, Woong-Chul
    • The Journal of Advanced Prosthodontics
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    • v.9 no.3
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    • pp.159-169
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    • 2017
  • PURPOSE. The purposes of this study were to evaluate the marginal and internal gaps, and the potential clinical applications of three different methods of dental prostheses fabrication, and to compare the prostheses prepared using the silicone replica technique (SRT) and those prepared using the three-dimensional superimposition analysis (3DSA). MATERIALS AND METHODS. Five Pekkton, lithium disilicate, and zirconia crowns were each manufactured and tested using both the SRT and the two-dimensional section of the 3DSA. The data were analyzed with the nonparametric version of a two-way analysis of variance using rank-transformed values and the Tukey's post-hoc test (${\alpha}=.05$). RESULTS. Significant differences were observed between the fabrication methods in the marginal gap (P < .010), deep chamfer (P < .001), axial wall (P < .001), and occlusal area (P < .001). A significant difference in the occlusal area was found between the two measurement methods (P < .030), whereas no significant differences were found in the marginal gap (P > .350), deep chamfer (P > .719), and axial wall (P > .150). As the 3DSA method is three-dimensional, it allows for the measurement of arbitrary points. CONCLUSION. All of the three fabrication methods are valid for measuring clinical objectives because they produced prostheses within the clinically acceptable range. Furthermore, a three-dimensional superimposition analysis verification method such as the silicone replica technique is also applicable in clinical settings.

Quality Analysis of Three-Dimensional Geo-spatial Information Using Digital Photogrammetry (수치사진측량 기법을 이용한 3차원 공간정보의 품질 분석)

  • Lee, Hyun-Jik;Ru, Ji-Ho;Kim, Sang-Youn
    • Journal of Korean Society for Geospatial Information Science
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    • v.18 no.4
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    • pp.141-149
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    • 2010
  • Three-dimensional geo-spatial information is important for the efficient use and management of the country and the three-dimensional expression and analysis of urban projects, such as urban plans devised by local governments and urban management. Thanks to the revitalization of the geo-spatial information service industry, it is now being variously used not only in public but also private areas. For the creation of high-guiltily three-dimensional geo-spatial information, emphasis should be placed on not only the quality of the source image and three-dimensional geo-spatial model but also the level of visualization, such as level of detail and texturing. However, in the case of existing three-dimensional geo-spatial information, its establishment process is complicated and its data are not updated frequently enough, as it uses ready-created digital maps. In addition, as it uses Ortho Images, the images exist Relief displacement. As a result, the visibility is low and the three-dimensional models of artificial features are simplified to reach LoD between 2 and 3, making the images look less realistic. Therefore, this paper, analyzed the quality of three-dimensional geo-spatial information created using the three-dimensional modeling technique were applied using Digital photogrammetry technique, using digital aerial photo images by an existing large-format digital camera and multi-looking camera. The analysis of the accuracy of visualization information of three-dimensional models showed that the source image alone, without other visualization information, secured the accuracy of 84% or more and that the establishment of three-dimensional spatial information carried out simultaneously with filming made it easier to gain the latest data. The analysis of the location accuracy of true Ortho images used in the work process showed that the location accuracy was better than the allowable horizontal position accuracy of 1:1,000 digital maps.

A Study on Three-Dimensional Slope Stability Analysis (3-차원(次元) 사면안정(斜面安定) 해석(解析)에 관한 연구(硏究))

  • Kim, Yeong-Su
    • Journal of Industrial Technology
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    • v.1
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    • pp.17-25
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    • 1981
  • Past research has concentrated on refining two-dimensional analysis techniques. Rather extensive comparisons of various two-dimensional methods have been made. This paper described a general three-dimensional method of analysis by which any geometrical condition and any c, phi soil can be analyzed. The results are as follows; 1. Factors of safety computed for 3-dimensional geometry differ considerably from ordinary 2-dimensional factors of safety. 2. 3-dimensional factors of safety are generally much higher than 2-dimensional factors of safety. However, situations appear to exist where the 3-dimensional factor of safety can be lower than the 2-dimensional factor of safety. 3. The F3/F2 ration appears to be quite sensitive to c, phi and to the slope.

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Optimal Design of Piezoelectric Cantilever Fan by Three-Dimensional Finite Element Analysis

  • Kim Byoung-Jai;Rho Jong-Seok;Jung Hyung-Kyo
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.5B no.1
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    • pp.90-94
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    • 2005
  • As the structure of the piezoelectric bimorph cantilever becomes increasingly more complicated, a more accurate and efficient analysis of piezoelectric media is needed. In this paper, the piezoelectric transducer is analyzed by using the three-dimensional finite element method. The validity of the three-dimensional finite element routine is confirmed by comparing the experimental result. The resonance characteristics, such as resonance frequency and anti-resonance frequency, of the piezoelectric cantilever are calculated by the experimentally verified three dimensional finite element method. Subsequently, the characteristics, such as mechanical displacement and impedance, are calculated at the resonance frequency. Besides, to design the piezoelectric bimorph cantilever shape that maximizes displacement at the tip, the ES (Evolution Strategy) algorithm is applied. Finally, optimal design for the fan of the piezoelectric cantilever is fulfilled to obtain maximum displacement at the tip. From these results, the application potentiality of the piezoelectric bimorph cantilever fan is identified.

Three-Dimensional Finite Element Analysis for Extrusion of the Underframe of a Railroad Vehicle (철도차량 마루부재 압출공정의 3 차원 유한요소해석)

  • Park K.;Lee Y. K.;Yang D. Y.;Lee D. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1999.05a
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    • pp.5-8
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    • 1999
  • The present work is concerned with three-dimensional finite element analysis of the hollow section extrusion process using a porthole die. For economic computation, mismatching refinement, an efficient domain decomposition method with different mesh density for each subdomain, is implemented. The proposed method improves the computational efficiency significantly, especially fur the three-dimensional analysis of extrusion problems. As a numerical example, extrusion of the underframe part of a railroad vehicle are analyzed. For three-dimensional mesh generation of a complicated shape with hexahedral elements, a modified grid-based approach with the surface element layer is utilized. The analysis results are then successfully reflected on the industrial porthole die design.

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Three-dimensional contact analysis of a composite joint with unsymmetric boundary condition (비대칭 경계조건을 가지는 체결부의 3차원 접촉응력해석)

  • 장기정;박노회;안현수;권진회;최진호
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.10a
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    • pp.110-113
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    • 2002
  • As a preliminary study for the three dimensional failure analysis of composite joints, the three dimensional stress analysis on a pin-loaded unidirectional-fabric hybrid composite joints are performed. The contact and frictions between composite plate and metal bush are considered in the finite element method by NASTRAN. Experiments are conducted to validate the accuracy and feasibility of the finite element technique for 25 specimens with 5 different geometries. The finite element and experimental results show the bush cap induces the unsymmetric deformation, stress distribution, and failure behavior through the thickness. The experiment also shows the failure loads are higher in the joint with bush cap than without it.

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Performance Prediction of Centrifugal Compressor Impellers using Quasi-Three-Dimensional Analysis (준삼차원 방법에 의한 원심 압축기의 성능예측)

  • Ahn, S.J.;Oh, H.W.;Kim, K.Y.
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.628-633
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    • 2001
  • This paper presents analysis of the flows through three different types of radial compressor by using quasi-three-dimensional analysis method. The method obtains two-dimensional solution for velocity distribution on meridional plane, and then calculates approximately the static pressure distributions on blade surfaces. Finite difference method is used for the solutions of governing equations. The compressors have low level compression-ratio and 12 straight radial blades with no sweepback. The results are compared with experimental data and the results of inviscid analysis with finite element method. It can be concluded that the agreement is good for the cases where viscous effects are not dominant.

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A Study on the Development of a High Speed Feeding Type Three-Dimensional Bending Machine (초고속 이송 방식 3차원 Bending Machine 개발에 관한 연구)

  • Lim, Sang-Heon;Lee, Choon-Man
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.11 s.176
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    • pp.91-98
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    • 2005
  • This study has been focused on the development of a high speed feeding type three-dimensional bending machine. It is designed for manufacture of copper pipe for heat exchangers. For the purpose of design of the machine, analysis of bending process, structural analysis and reliability evaluation of the machine by a laser interferometer are carried out. The analysis is carried out by FEM simulation using commercial softwares, DEFORM, MARC and CATIA V5. In addition, the machine has attained high accuracy and repeatability. In order to improve the accuracy of this machine, the maximum speed, positioning accuracy and repeatability of feed are measured by the laser interferometer. The final results of analysis are applied to the design of a high speed feeding type three-dimensional bending machine and the machine is successfully developed.