• Title/Summary/Keyword: physics simulation

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Optimization of Groove Sizing in CMP using CFD (CFD를 이용한 CMP의 Groove Sizing 최적화)

  • Jang, Ji-Hwan;Lee, Do-Hyung
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1522-1527
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    • 2004
  • In this paper, slurry fluid motion, abrasive particle motion, and effects of groove sizing on the pads are numerically investigated in the 2D geometry. Groove depth is optimized in order to maximized the abrasive effect. The simulation results are analyzed in terms of shear stress on pad, groove and wafer, streamline and velocity vector. The change of groove depth entails vortex pattern change, and consequently affects material removal rate. Numerical analysis is very helpful for disclosing polishing mechanism and local physics.

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Micromagnetic Simulations for Spin Transfer Torque in Magnetic Multilayers

  • You, Chun-Yeol
    • Journal of Magnetics
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    • v.17 no.2
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    • pp.73-77
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    • 2012
  • We investigate spin transfer torque (STT) in magnetic multilayer structures using micromagnetic simulations. We implement the STT contribution for magnetic multilayer structures in addition to the Landau-Lifshitz-Gilbert (LLG) micromagnetic simulators. In addition to the Sloncewski STT term, the zero, first, and second order field-like terms are also considered as well as the effects of the Oersted field due to the running current are addressed. We determine the switching current densities of the free layer with the exchange biased synthetic ferrimagnetic reference layers for various cases.

On Micro-Channel Flow and Mixing: A Review (마이크로-채널 유동과 혼합 : 재검토)

  • Jayaraj, Simon;Suh, Yong-Kweon
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.301-304
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    • 2006
  • This paper presents a review of the important recent literature available in the area of micro-channel flow analysis and mixing. The topics covered include the physics of flows in micro-channels and integrated simulation of micro-channel flows. Also the flow control models and electro-kinetically driven micro-channel flows are explained. A comparison of various mixing principles in micro-channels are provided in sufficient detail.

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A STUDY ON CANCER CELL INVASION WITH A THREE-DIMENSIONAL DYNAMIC MULTI-PHYSICS MODEL (3차원 동적 다중물리 모델 기반 암세포 증식과정 예측기술 개발)

  • Song, J.;Zhang, L.;Kim, D.
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.556-561
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    • 2010
  • This paper proposes a three-dimensional haptotaxis model to simulate the migration of the population of cancer cells. The invasion of the cancer cells relates with the hapto- and the effect of the energy between cells and (ECM). The diffuse interface model is employed, which incorporates haptotaxis mechanism and interface energies. The semi-implicit Fourier spectral scheme is adopted for efficient complications. The simulation results reveal rich dynamics of cancer cells migration.

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Optimization of Cutoff Shields in Projection Headlight Systems to Achieve High Intensity Gradient and Low Color Separation at the Cutoff Line

  • Joo, Byung-Yun;Ko, Jae-Hyeon
    • Journal of the Optical Society of Korea
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    • v.20 no.1
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    • pp.118-124
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    • 2016
  • The shape and location of the cutoff shield in a projection-type headlight system were optimized by a ray-tracing technique. A shield based on a Petsval surface showed better cutoff characteristics than a flat or cylindrical shield, such as a sharp intensity gradient and less color separation at the cutoff line. Adjustment of the shield’s location between the reflector and the aspheric lens further improved its cutoff characteristics.

Toughness of soft-hard composites and Wetting on Textured Substrates

  • Okumura, Ko
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2010.05a
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    • pp.4.1-4.1
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    • 2010
  • In the first part, after discussing works on nacre, a soft-hard composite found in nature, including a simulation on network mimicking nacre [1-4], we talk on a simple model of spider webs, another example of natural soft-hard structure [5]. We demonstrate that the web network is free of stress concentrations because the radial threads are stronger than the spiral threads. In the second part, after reviewing our works on wetting on textured surfaces [6-8], we discuss penetration into textured surface and instability of a liquid film on textured substrates during spin coating [9,10].

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Metastable Vortex State of Perpendicular Magnetic Anisotropy Free Layer in Spin Transfer Torque Magnetic Tunneling Junctions

  • You, Chun-Yeol;Kim, Hyungsuk
    • Journal of Magnetics
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    • v.18 no.4
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    • pp.380-385
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    • 2013
  • We find a metastable vortex state of the perpendicular magnetic anisotropy free layer in spin transfer torque magnetic tunneling junctions by using micromagnetic simulations. The metastable vortex state does not exist in a single layer, and it is only found in the trilayer structure with the perpendicular magnetic anisotropy polarizer layer. It is revealed that the physical origin is the non-uniform stray field from the polarizer layer.

Simulation of Pattern Formation and Solitions in Three-Wave Interactions (세 파동의 상호작용에 의한 패턴 형성 및 솔리톤의 전산모사)

  • Lee Hae Jun;Kim Jin Cheol;Kim Gwang Hun;Kim Jong Uk;Kim Chang Beom;Seok Hui Yong
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.02a
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    • pp.42-43
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    • 2003
  • The nonlinear three-wave interaction is an interesting topic having various applications in nonlinear optics, hydrodynamics, acoustic waves, and plasma physics. The resonant interaction between two laser pulses and a plasma wave plays important roles in plasma heating, laser reflection in the inertial confinement fusion (ICF), plasma wakefield generation, and ultra-intense laser pulse amplification and pulse compression using stimulated Raman backscattering (RBS). (omitted)

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MONTE CARLO DEPLETION UNDER LEAKAGE-CORRECTED CRITICAL SPECTRUM VIA ALBEDO SEARCH

  • Yun, Sung-Hwan;Cho, Nam-Zin
    • Nuclear Engineering and Technology
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    • v.42 no.3
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    • pp.271-278
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    • 2010
  • While the deterministic lattice physics/depletion codes use leakage-corrected critical spectrum (although approximate due to the B1 buckling search employed), Monte Carlo depletion codes currently in use do not have such a feature in spite of their heterogeneity and continuous-energy modeling capability. This paper describes an approach to Monte Carlo depletion with leakage-corrected critical spectrum derived from first principles. This is based on the concept of albedo eigenvalue treated as weight of the reflected neutron in Monte Carlo simulation.

Scientific and Technical Visualization for Ocean Process Simulations (해양과정시뮬레이션의 과학기술적가시화)

  • Choi Byung Ho
    • 한국전산유체공학회:학술대회논문집
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    • 1999.05a
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    • pp.1-10
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    • 1999
  • This paper briefly introduces the work done up to 1998 during the past twenty years for numerical modeling of ocean process focussing on the neighbouring seas of Korean Peninsula. Modeling of global ocean dynamics has also been performed as a pathway to understand the regional ocean dynamics. The ocean simulation produces a vast amount of multidimensional multivariate dataset therefore adoption of scientific and technical visualization techniques were essential to properly understand the physics involved.

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