• Title/Summary/Keyword: ale

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Finite Element Analysis of Axisymmetric Hot Extrusion Through Continuous Dies Using the Arbitrary Lagrangian-Eulerian Description (곡면금형을 통한 축대창 열간 압출의 ALE 유한요소 해석)

  • 강연식;양동열
    • Transactions of Materials Processing
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    • v.4 no.1
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    • pp.69-78
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    • 1995
  • The arbitrary Lagrangian-Eulerian(ALE) finite element analysis is applied to the axisymmetric hot extrusion through continuous dies. In order to simulate hot forming problems, an ALE scheme for temperature analysis is proposed. The computed results are compared with experimental results as with those by pure Lagrangian method. In the present study mesh control is accomplished by the use of isoparametric mapping of quadrilaterals.

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A Design for Korean Phrase Structure Grammar(KPSG) in ALE (ALE를 이용한 한국어 문법의 설계)

  • Choi, Woon-Ho;Chang, Suk-Jin
    • Annual Conference on Human and Language Technology
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    • 1998.10c
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    • pp.217-221
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    • 1998
  • 본 논문에서는 한국어의 전산처리를 위한 문법 모형 개발의 일부분으로 HPSG에 기반한 문법 모형의 개발을 시도한다. 문법 모형의 개발에는 ALE(Attribute Logic Engine)를 이용하며, 보문 구조와 보조 용언 구문을 분석하기 위한 사전구조 및 문법 규칙을 제시한다. 그리고 문의 종류 (Sentence Type:ST)와 문계(Sentence Level: SL), 시제, 존대 등을 분석해서 표상하기 위한 유형 계층 및 어휘부, 문법 규칙, 문법 원리 등을 제시한다.

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An ALE Finite Element Formulation for Rigid-Viscoplatic Materials and Its Application to Axisymmetric Extrusion through Square Dies (ALE 묘사에 근거한 강-점소성 유한요소 수식화와 축대칭 평금형 압출에의 적용)

  • 강연식;양동열
    • Transactions of Materials Processing
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    • v.3 no.2
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    • pp.156-166
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    • 1994
  • An arbitrary Lagrangian-Eulerian (ALE) finite element method has been developed. The finite element formation is derived and implemented for rigid-viscoplastic materials. The developed computer program is applied to the analysis of axisymmetric square die extrusion, which has many difficulties with updated Lagrangian approach. The results are compared with those from updated Largrangian approach. The results are compared with those from updated Lagrangian finite element program. Updating scheme of time dependent variables and mesh control are also examined.

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FE Analysis of Three Dimensional Backward Extrusion Using the ALE description (ALE 묘사에 왜한 3차원 후방압출 해석)

  • 정상원;정용호;김규하;조규종
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.628-631
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    • 2002
  • This paper has executed FE-analysis to review the feasibility for developing the process, which produces the narrow-cubic type cans, using the Backward Impact Extrusion process instead of using current process, multi-stage deep drawing. Proposes an analysis method by applying ALE(Arbitrary Lagrangian-Eulerian) description to non-axisymmetric extrusion. which is appreciated as one of good solution to mesh distortion in case of the large deformation plasticity process that has mass flux, and considers the factors which affects forming-loads related to punch velocity and fulid status of material.

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Photoluminescence studies of ZnO thin films grown by atomic layer epitaxy (ALE법으로 증착된 ZnO 박막의 PL특성)

  • 임종민;홍현석;신경철;이종무
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.119-119
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    • 2003
  • ZnO는 최근에 발광소자로서의 가능성 때문에 주목받고 있다. ZnO 박막의 성장에는 주로 CVD법과 스퍼터법이 사용되는데, CVD법 중 하나로서 cyclic CVD라고도 불리는 ALE법은 기존 CVD법에 비하여 증착속도는 떨어지나 박막의 표면거칠기가 매우 작고 대면적의 증착에서도 두께균일도가 상당히 우수하며 증착온도가 낮은 장점이 있다. 본 연구에서는 발광소자로서 응용이 가능한 ZnO박막을 사파이어(0001) 기판위에 ALE법으로 증착하고 후열처리가 photoluminescencey(PL) 특성에 끼치는 효과를 조사하였다. DEZn(diethylzinc)와 $H_2O$를 소스로 사용하여 사파이어 기판위에 ZnO 박막을 성장시키었고 기판온도로서 ALE window 범위인 17$0^{\circ}C$와 CVD증착 온도범위인 40$0^{\circ}C$를 설정하여 증착 시키었다. 그 후 후열처리로서 산소분위기에서 800, 900, 100$0^{\circ}C$에서 1시간 열처리를 하였다.

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The characteristic of photoluminescence ZnO thin film deposited by ALE (ALE법으로 증착된 ZnO 박막의 photoluminescence 특성)

  • 신경철;임종민;김현우;이종무
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.11a
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    • pp.164-164
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    • 2003
  • UV 발광소자 재료로서 유망한 ZnO film을 ALE법으로 증착하고 photoluminescence특성을 조사하였다. Zn소스로서 DEZn(Diethylzinc)를, 산소 소스로서 DI water를 사용하였고 $N_2$ gas로서 챔버내에 주입된 소스물질을 purge하였다. ALE 공정온도 범위인 17$0^{\circ}C$와 CVD 반응온도 범위인 40$0^{\circ}C$로 ZnO 박막을 증착하고 이 시편을 산소 분위기에서 600-100$0^{\circ}C$의 온도로 1시간 동안 열처리하였다. 그리고 He-Cd laser를 사용하여 photoluminescence를 측정하였다. 17$0^{\circ}C$와 40$0^{\circ}C$ 에서 증착된 시편 모두 as-grown 상태에서는 거의 발광특성을 나타내지 못하였으나 후열처리를 거치면서 발광특성을 나타내었고 열처리 온도가 높을수록 발광강도가 증가하였다. 40$0^{\circ}C$에서의 증착된 시편의 경우는CVD반응이 발생하여 Zn-Zn결합이 많이 생성되어 열처리 온도가 증가하여도 발광강도가 약하였고 가시광 영역의 발광 또한 크게 증가하였으며 17$0^{\circ}C$에서 증착된 시편의 경우는 열처리 온도가 증가할수록 UV영역의 발광강도만이 크게 증가하였으며 가시광 영역의 발광은 거의 증가하지 않았다.

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An ALE Finite Element Method for Baffled Fuel Container in Yawing Motion

  • Cho, Jin-Rae;Lee, Hong-Woo;Yoo, Wan-Suk;Kim, Min-Jeong
    • Journal of Mechanical Science and Technology
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    • v.18 no.3
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    • pp.460-470
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    • 2004
  • A computational analysis of engineering problems with moving domain or/and boundary according to either Lagrangian or Eulerian approach may encounter inherent numerical difficulties, the extreme mesh distortion in the former and the material boundary indistinctness in the latter. In order to overcome such defects in classical numerical approaches, the ALE(arbitrary Lagrangian Eulerian) method is widely being adopted in which the finite element mesh moves with arbitrary velocity. This paper is concerned with the ALE finite element formulation, aiming at the dynamic response analysis of baffled fuel-storage container in yawing motion, for which the coupled time integration scheme, the remeshing and smoothing algorithm and the mesh velocity determination are addressed. Numerical simulation illustrating theoretical works is also presented.

A Study on the Slipping Problem for Cable-Membrane Structures (케이블-막구조물의 요소이동(slip)에 관한 연구)

  • Kim, Jae-Yeol;Kang, Joo-Won;Park, Sang-Min
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.5
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    • pp.95-105
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    • 2008
  • The objective of this study is find out the stressed condition, slipped direction and slipped dimension when some elements of cable-membrane structures are slipped from it's initially designed coordinates by external loads as wind or non uniform load and so on. In order to search the slipped behaviors of cable-membrane structures, a ALE finite element formulation is introduced. In these procedures, a stiffness matrix related with ALE concept is formulated and a FE analysis program for cable-membrane structures with slipped elements is developed.

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ECR Plasma Pretreatment on Sapphire and Silicon Substrates for ZnO ALE (ZnO ALE를 위한 Si, sapphire기판의 ECR 플라즈마 전처리)

  • Lim Jongmin;Shin Kyoungchul;Lee Chongmu
    • Korean Journal of Materials Research
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    • v.14 no.5
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    • pp.363-367
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    • 2004
  • Recently ZnO epitaxial layers have been widely studied as a semiconductor material for optoelectronic devices. Sapphire and silicon are commonly selected as substrate materials for ZnO epitaxial growth. In this communication, we report the effect of the ECR plasma pretreatment of sapphire and silicon substrates on the nucleation in the ZnO ALE (atomic layer epitaxy). It was found that ECR plasma pretreatment reduces the incubation period of the ZnO nucleation. Oxygen ECR plasma enhances ZnO nucleation most effectively since it increases the hydroxyl group density at the substrate surface. The nucleation enhancing effect of the oxygen ECR plasma treatment is stronger on the sapphire substrate than on the silicon substrate since the saturation density of the hydroxyl group is lower at the sapphire surface than that at the silicon surface.

Processing of Various RFID Reader Devices for ALE Middleware (ALE 미들웨어를 위한 다양한 RFID 리더 처리 방법)

  • Noh, Young-Sik;Byun, Yung-Cheol;Lee, Dong-Cheol
    • The Journal of the Korea Contents Association
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    • v.9 no.4
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    • pp.55-64
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    • 2009
  • For realizing ubiquitous computing, many research activities are geared towards various areas including embedded computing, RFID, USN, home networking, context-awareness, and etc. By using the ability of RFID technology to recognize a number of objects simultaneously, more convenient ubiquitous application services are effectively provided. In this case, RFID middleware playing a role as a bridge between RFID reader devices and application services is required as well. In this paper, we propose a method of handling a number of types of RFID reader devices in ALE middleware of EPCglobal. For this, the information of connection and data protocol for a reader device is stored in a database as ontology meta-data, and used to interpret the data read by a reader device. By adding ontology data into a database, even though an RFID device newly emerges, ALE middleware can not only handle the device, but also be effectively extended through reusing ontology data, without any changes in the middleware.