• Title/Summary/Keyword: sFEM

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Incremental Sheet Forming of Complex Geometry Shape and Its Optimization Using FEM Analysis (복잡한 형상제품의 인크리멘탈 성형과 FEM을 이용한 공정 최적화)

  • Nguyen, D.T.;Park, J.G.;Lee, H.J.;Kim, Y.S.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.207-212
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    • 2009
  • In order to optimize the press formability of incremental sheet forming for complex shape (e.g human face), a combination of both CAM and FEM simulation, is implemented and evaluated from the histories of stress and strain value by means of finite element analysis. Here, the results, using ABAQUS/Explicit finite element code, are compared with fracture limit curve (FLC) in order to predict and optimize the press formability by changing parameters of tool radius and tool down-step according to the orthogonal array of Taguchi's method. Firstly, The CAM simulation is used to create cutter location data (CL data). This data are then calculated, modified and exported to the input file format required by ABAQUS through using MATLAB programming. The FEM results are implemented for negative incremental sheet forming and then investigate by experiment.

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A FEM Analysis for Acetabular Component with Negative Poisson's Ratio in Total Hip Arthroplasty

  • 최재봉
    • Computational Structural Engineering
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    • v.8 no.4
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    • pp.17-23
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    • 1995
  • Based on the present FEM study for negative Poisson's-ratio UHMWPE, the following conclusions seem expected. 1) Negative Poisson's-ratio UHMWPE transfers less stresses to the subchondral or peripheral iliac bone, compared to the conventional UHMWPE with Poission's-ratio. 2) Negative Poisson's-ratio cup reduces stresses in UHMWPE cup itself as well as metal backing, and subchondral bone. 3) The reduction in periacetabular mechanical stresses would significantly reduce the rate of fatigue failure and consequently reduce the incidence of aseptic loosening of the cup due to wear or bone resorption.

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Application of Loop-Mediated Isothermal Amplification (LAMP) Assay to Rapid Detection of Methicillin-Resistant Staphylococcus aureus from Blood Cultures

  • Baek, Yun-Hee;Jo, Mi-Young;Song, Min-Suk;Hong, Seung-Bok;Shin, Kyeong-Seob
    • Biomedical Science Letters
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    • v.25 no.1
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    • pp.75-82
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    • 2019
  • We developed the multiplex LAMP assay using 16S rRNA, femA and mecA genes for direct detection of the methicillin resistance in Staphylococci from positive blood culture. To simultaneously recognize Staphylococci genus, S. aureus and methicillin resistance, three sets of six primers for 16S rRNA, femA and mecA were designed, respectively. The performance of LAMP assay was affirmed using VITEK system for the phenotypic methods of identification and for oxacillin and cefoxitin antimicrobial susceptibility. The optimal condition for LAMP assay was obtained under $64^{\circ}C$ for 50 min. The detection limit was determined to be of 20 copies and CFU/reaction ($10^4CFU/mL$). For clinical application of comparison with phenotypic methods, the sensitivity and specificity of the LAMP with femA gene for detecting S. aureus was 95.31% and 100%, respectively. The sensitivity and specificity of the LAMP with mecA gene for detecting methicillin resistance was 98.46% and 100%, respectively. The multiplex LAMP assay with femA and mecA gene successfully detected all of MRSA (38 isolates) isolates from 103 Staphylococci in blood cultures. The LAMP assay developed in this study is sensitive, specific, and of excellent agreement with the phenotypic methods.

On prediction temperature and microstructure change in large cast-forged product (대형 주.단조품의 온도 및 조직변화 예측에 관한 연구)

  • Lee, M.W.;Lee, Y.S.;Lee, S.W.;Kim, S.S.;Moon, Y.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.10a
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    • pp.414-419
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    • 2009
  • Good control of thermal energy helps to increase characteristics and eliminate defects of large cast-forged part, such as large sized forged shell. Thermal energy control is a important factor. We have studied about forging process and after heat treatment process by FEM simulation. There are three ways of process. Changes of temperature and microstructure for forged shell were predicted according to temperature declination in large cast-forged product. So we will be able to choose the proper time from heat treatment conditions by FEM simulation.

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The Determination of Initial Blank Shape by Using the One-Step FEM (One-Step FEM을 이용한 초기 블랭크 형상 결정에 관한 연구)

  • Jung, Dong-Won;Lee, Sang-Je
    • Journal of Ocean Engineering and Technology
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    • v.13 no.3 s.33
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    • pp.21-28
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    • 1999
  • In this paper, a finite element method for the determination of initial blank shape in sheet metal forming process will be introduced. The initial blank shape is determined by the only one step from the final to the initial blank. The used finite element inverse method adopted Henky's deformation theory, Hill's anisotropic yield criterion and simplified boundary conditions. Based on this theory. a three-dimensional membrane finite element code was developed. The developed code will be applied to several sheet metal forming examples for the demonstration of its validity.

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Design of the voice coil type LOA using FEM analysis (전자장이론을 적용한 FEM해석에 의한 보이스코일 평판형 LOA설계)

  • Jang, S.M.;Seo, J.H.;Jeong, S.S.;Park, H.C.;M, S.J.;Park, C.I.;Jeong, T.Y.
    • Proceedings of the KIEE Conference
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    • 1996.07a
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    • pp.216-218
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    • 1996
  • In this paper, it is treated the design and characteristics analysis of the voice coil type LOA which is composed of a voice coil type mover and permanent magnets. The design is acomplished using FEM analysis to make up the magnetic circuit. And the characteristics of LOA are analyzed to be used on the control system for the earthquake-proof experiments.

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A Study on the Vibration Characteristics Analysis of Composite Materials by Using Electronic Speckle PatternInterferometry Method (전자처리 스페클 패턴 간섭법을 이용한 복합재료의 진동 특성 해석에 관한 연구)

  • 김형택;정현철;양승필
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.388-392
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    • 1995
  • The Electronic Speckle Pattern Interferometry(ESPI) has been applied to many technical problems such as deformation and displacement measurement, strain visualization and surface roughness monitoring. Composite materials have various complicated characteristics depending on the ply materials,ply orientations,ply stacking sequences and boundary conditions. Therefore, it is difficult to analyze composite material. For efficient use of composit materials in engineering applications, the dynamic behavior such as, natural frequencies and modal patterns should be identified. This studying presents FEM results for the free vibration of symmetrically laminated composite as [30/-30/90] $_{s}$. The natural frequencies of laminated composite rectangular plates having the boundary condition(:2-edge clamped) are experimentally obtained. In order to demonstrate the validity of the experiment,FEM analysis using ANSYS was performed and natural frequencies experimentally obtained is compared with calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.t.

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휴대폰 FEM(Front End Module) 기술동향 연구

  • Lee, Jae-Yeong;Choe, Se-Hwan
    • Information and Communications Magazine
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    • v.28 no.11
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    • pp.16-23
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    • 2011
  • 휴대폰은 스마트화되면서 퍼스널 컴퓨터에 버금가는 성능으로 발전하고 있다. 또한 모바일 환경에서 높은 데이터 전송 속도 및 많은 사용자가 동시에 사용할 수 있는 시스템을 적용하고 있다. 차세대 이동통신서비스나 B4G(Beyond 4 Generation)에서는 다중밴드/다중 모드/다중경로 처리구조의 융합 단말기가 시장을 형성하게 되며, 갈수록 휴대폰의 RF Front-End는 복잡하게 된다. 또한 FEM(Front End Module)의 성능은 단말기 시스템의 품질(QoS, Quality of Services)을 좌우하는 핵심부품으로 High Data Rate를 위하여 고성능화가 요구되고 있다. 본고에서는 FEM의 발전 트랜드와 구성하는 블록도 및 주요 핵심부품의 특성과 모듈의 소형화 패키징 기술에 관하여 제시하였다. 또한 4G LTE와 Wimax듀얼밴드 Tx/Rx통합 FEM을 소개하였고, 향후에 구성되게 되는 Future FEM의 블록도를 제시하였다.