• 제목/요약/키워드: Profile model

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유한 요소법을 이용한 다단패스 형상압연 공정 해석 (Analysis of Multi-Pass Shape Rolling Processes using Finite Element Method)

  • 김홍준;김태효;황상무
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 제3회 압연심포지엄 논문집 압연기술의 미래개척 (Exploitation of Future Rolling Technologies)
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    • pp.69-77
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    • 1999
  • Roll profile design in spape rolling with a complex-shaped part depends on the designer's experience, which is general, is acquired through costly trial-and-error process. As a prerequisite for developing a scientific approach to roll profile design, we present a finite element model to simulate 3-D deformation of complex-shaped parts occuring in multi-pass sequence. Demonstrated is the process model's capability to deal with rolling of a complex-shaped part.

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이온 주입된 Mosfet의 문턱 전압의 해석적 모델 (Analytical Threshold Voltage Model of Ion-Implanted MOSFET)

  • 이효식;진주현;경종민
    • 대한전자공학회논문지
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    • 제22권6호
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    • pp.58-62
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    • 1985
  • 이온 주입된 소형 MOSFET소자에 대한 해석적 문턱 전압 모델이 유도되었다. 일정한 도우핑 농도를 갖는 MOSFET에 적용되는 Yau 모델을 implanted channel구조와 bird's beat구조의 MOSFET에 대하여 적합한 형태로 수정하여 short channel 현상과 narrow width 현상을 정량적으로 설명하였다. Channel영역의 불순물 분포를 SUPREM 결과에서 2-step profile로 근사시켜 문턱 전압의 short channel model을 제안하였다. Weighting factor를 사용하여 bird's beat 영역의 불순물 분포를 고려함으로써 narrow width 현상을 성공적으로 설명하였다.

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Lyα Radiative Transfer: Modeling Spectrum and Surface Brightness Profile of Lyα Emitting Galaxies at z=3-6

  • 송현미;선광일;황호성
    • 천문학회보
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    • 제44권2호
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    • pp.37.1-37.1
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    • 2019
  • We perform Lyα radiative transfer calculations for reproducing Lyα properties of star-forming galaxies at high redshifts. We model a galaxy as a halo in which the density distributions of Lyα sources and HI plus dust medium are described with exponential functions. We also consider an outflow of the medium that represents a momentum-driven wind in a gravitational potential well. We demonstrate that this outflowing halo model with Lyα scattering can successfully reproduce both the spectrum and the surface brightness profile of eight star-forming galaxies at z=3-6 observed with MUSE. The best-fit model parameters (i.e., the outflowing velocity and optical depth) for these galaxies are in good agreement with other studies. We also demonstrate benefits of using spectrum and surface brightness profile simultaneously to the constraints on model parameters and thus spatial/kinematic distributions of medium. We examine the impacts of individual model parameters and intrinsic spectrum on emerging spectrum and surface brightness profile. Further investigations on the escape fraction, spatially resolved spectra, and the spatial extent of Lyα halos are presented as well.

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관개용수로에서의 수면곡선 계산 (Water Surface Profile Computations at Irrigation Channel Networks)

  • 김현준;박승우
    • 한국농공학회지
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    • 제30권3호
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    • pp.114-120
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    • 1988
  • A water surface profile computation model using a standard step procedure was developed for gradually varied flow at an irrigation channel network. Flow characteristics ab Banweol district near Suweon were field monitored during irrigation periol of 1987. The model was applied to the main system at the district and the simulation results were compared to the field data. The results are sumrnarized as follows ; 1. The simulated water surface profiles from the model were in good agreement with the measured water surface profiles at different flow rates. 2. The model applicability for defining a stage-discharge relationship at a channel reach was demonstrated with reasonable accuracy when water stage and friction factor were given. 3. The roughness coefficient was found to be a major factor sigrificantly affecting computed water surface profile among a few physical input parameters for the model.

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열간 압연 시 워크 롤의 열 변형 정밀 예측을 위한 유한요소법 기반의 온라인 모델 개발 (The development of FE-based on-line model for the precise prediction of work roll thermal profile in hot strip rolling)

  • 최지원;황한동;이중형;황상무
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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    • pp.329-335
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    • 2004
  • An, FE-based, on-line model is presented for the rapid and precise prediction of roll thermal profile in hot strip rolling. The validity of the model is demonstrated through comparison with FE-based off-line model which was verified by measurements. Also demonstrated is its capability of reflecting the effect of diverse process variables.

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차륜답면형상 마모에 따른 차량 주행안정성 영향 분석 (Analysis on the Running Stability of Rolling-stock according to Wheel Profile Wear)

  • 허현무;유원희
    • 한국정밀공학회지
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    • 제28권5호
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    • pp.551-558
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    • 2011
  • To analyze the effect of wear of wheel profile on the running stability of rolling-stock, theoretical and experimental studies were conducted on the profiles used in conventional lines. In experiment using 1/5 scale model to verify the results of the theoretical analysis, the test results of the critical speed for worn wheel profile samples show similar trend. In case of the conical type wheel profile(Profile 40), the equivalent conicity is increased with flange wear. But in case of the arc type wheel profile(Profile 20h), the equivalent conicity is decreased with flange wear. And the critical speed of the bogie was inverse proportion to the equivalent conicity. It is shown that the variation of the critical speed with the wheel wear could be changed according to the design concept and wear pattern of wheel profile. Results of the theoretical and experimental studies are discussed here.

산업공학 교과과정 이수체계에 관한 연구 (A Model of the Curriculum Flowchart for Industrial Engineering)

  • 홍성조
    • 공학교육연구
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    • 제16권6호
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    • pp.78-86
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    • 2013
  • This paper presents an undergraduate curriculum flowchart model for industrial engineering. Because Industrial Engineering deals with wider categories today than before, the coherent curriculum flowchart design is very difficult. We propose an effective approach using knowledge profile analysis for each course.

광안리 해수욕장의 최소 해빈폭 관리를 위한 양빈 설계 (Beach Nourishment Design for Minimum Beach Width Management at Gwangalli Beach)

  • 배선한;이정렬
    • 한국재난정보학회:학술대회논문집
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    • 한국재난정보학회 2015년 정기학술대회
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    • pp.141-143
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    • 2015
  • 본 연구는 해변의 양측에서 퇴적되고 해변 중앙에서 침식이 일어나고 있는 광안리 해수욕장에 최소 해빈폭을 최대로 하는 최적의 양빈 설계를 하고자 실시하였다. 광안리 해수욕장에 3가지 case의 양빈안을 수치 모의 시나리오로 구성하여 OneLine Shoreline Model을 적용하여 해빈폭의 시간적 변화를 모의하였으며, Cross-shore Profile Model을 적용하여 연평균 파고에 따른 전진폭과 최고 파고에 따른 침식폭을 추정하였다.

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불규칙한 수심단면에서 쇄파대 부근의 파고변형 (Wave Transformation near the Surfzone on the Arbitrary Beach Profile)

  • 최한규;강장수;이철응
    • 산업기술연구
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    • 제17권
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    • pp.261-275
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    • 1997
  • The objective of this paper is to develop two numerical model for predicting the wave height with set-up/down near the surfzone on a arbitrary beach profile. Two wave models, regular wave model and random wave model, are based on the energy flux equation with the energy dissipation effects. The developed numerical models are verified by comparison of numerical results with analytical solutions that are derived under the simple conditions. The characteristics of parameters included in each model are then investigated and decided to the range of behaviour by the sensitivity analysis. For sensitivity analysis, we carried out total 46 laboratory tests. Finally, the developed numerical models are applied to the field where the wave height near the surfzone has been measured. From the applications of numerical models, it is concluded that the developed numerical models may accurately predict the wave height with the set-up/down near the surfzone on a arbitrary beach profile.

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열연 공정 정상상태 판 프로파일 예측 - PartⅡ: 수식 모델 개발 (Prediction of Steady-state Strip Profile during Hot Rolling - PartⅡ: Development of a Mathematical Model)

  • 이재상;황상무
    • 소성∙가공
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    • 제25권1호
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    • pp.61-66
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    • 2016
  • In the current study, we present a new model for the prediction of the strip profile and the residual stresses. This new approach is an analytical model that predicts the residual stresses from the effect of post-deformation. Since the residual stress cannot exceed the yield strength of the material, post-yielding may possibly occur in the post-deformation zone prior to the strip reaching the steady-state zone. The prediction accuracy of the proposed model is examined through comparison with the predictions from 3-D finite element (FE) simulations.