• 제목/요약/키워드: Phenomenological

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무정형 고분자의 비선형 유전 특성(III) (Non-linear Dielectric properties of amorphous polymers(III))

  • 강대하;박상호;여희창;이영식
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1366-1368
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    • 2001
  • In this study it can be confirmed that the formula by the free-rotational dipole theory is similiar with that by the phenomenological theory and the non-linear permittivity is determined only with the third harmonic conponent of polarization. Various parameters of VDCN copolymers were obtained from fitting results with the related formula.

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THEORETICAL LINE PROFILES OF THE MAGNETIC COMPACT STARS

  • KIM YONGGI
    • 천문학회지
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    • 제29권spc1호
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    • pp.235-236
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    • 1996
  • Using a phenomenological model for the accretion onto the magnetic white dwarf, we calclliated some optical line profiles from the magnetosphere of such systems. Line profiles of these systems seem to be produced in the magnetosphere of the compact star due to the reemission of X-ray produced near the stellar surface. Some results of our new calculation and the analysis of these results will be presented. Our results show that the model used here can reproduce the observed optical line profiles and open the possiblity to determine the parameters of individual systems.

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원심압축기의 설계 개발을 위한 CFD의 응용과 전망 (CFD Application for Design and Development of Centrifugal Compressors)

  • 강신형
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 1995년도 추계 학술대회논문집
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    • pp.12-28
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    • 1995
  • CFD techniques are widely used for the design and development of turbomachinery. The design and performance prediction, evaluation of performace and analysis are all important for the successful development of the machinery. The characteristics of the sturcture and performace of the centrifugal compressor are reviewed for the effective application of CFD techniques. The examples of flow calculations through an impeller and a channel diffuser are presented and phenomenological aspects are discussed. The future research topics of CFD area are also suggested.

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Influence of geometry and loading conditions on the dynamics of martensitic fronts

  • Berezovski, Arkadi
    • Smart Structures and Systems
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    • 제4권2호
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    • pp.123-135
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    • 2008
  • Damping capacity of SMA damping devices is simulated numerically under distinct geometry and loading conditions. Two-dimensional numerical simulations are performed on the basis of a phenomenological model of dynamics of martensite-austenite phase boundaries. Results of the simulations predict the time delay and the value of the stress transferred to other parts of a construction by a damper device.

압연강판의 이방성에 관한 연구 (Study of anisoptopy of sheet metals)

  • 인정제
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 춘계학술대회논문집
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    • pp.153.1-156
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    • 1999
  • Based upon the experimental data from multi-stage tensile loading at angles to the rolling direction of steel sheets, anisotropic hardening rules are proposed. Experiments show that orthotropic anisotropy is maintained and the orientations of orthotropy axes are changed during tensile loading. A phenomenological model is proposed which includes the rotations of orthotropy axes, work hardening and kinematic hardening. Using the model, uniaxial tensile stress, R-value and tensile necking strain are predicted and compared with the experimental data.

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PHOTOABSORPTION OF X-RAYS IN THE MAGNETIC COMPACT STAR

  • Kim, Yong-Gi
    • Journal of Astronomy and Space Sciences
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    • 제9권2호
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    • pp.171-182
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    • 1992
  • Radiation due to accretion from an accretion disc around the intermediate polars and photoabsorption of this radiation in the accretion funnel have been taken into account as a phenomenological model to study the physics of the magnetic funnel in the magnetic compact star. The first results show that such a model scenario can be used to estimate some parameters in these systems. Some constraints of this model regarding to the observational data of one intermediate polar, EX Hya, are also discussed.

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Waspaloy의 열간 단조 공정중 재결정 거동과 결정립 성장에 대한 유한요소해석 (Computer Simulation of Recrystallization and Grain Growth during Hot Forging Process of Waspaloy)

  • 강경필;이경훈;이승욱
    • 소성∙가공
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    • 제17권2호
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    • pp.113-116
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    • 2008
  • Computer simulation of microstructure evolution during hot forging process is of great interest in recent years. Recrystallization model and grain growth model which use a phenomenological approach were summarized. The upsetting and cogging processes of waspaloy were simulated using $DEFORM^{TM}$ and the change in grain size were investigated in each deformation procedure.

현상적 모델에 기초한 플랜트시스템 고장감지기법 (Phenomenological Model Based Fault Diagnosis of Dynamic Plants)

  • 김재화;장태규
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1997년도 하계학술대회 논문집 B
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    • pp.456-458
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    • 1997
  • 본 논문에서는 플랜트의 계측신호들에 나타나는 현상적인 특징파형들을 감지하여 플랜트의 고장을 진단하는 기법을 제시하고, 플랜트의 고장시 나타나는 여러 특징 파형들의 전형인 oscillatory 파형을 감지하는 알고리즘을 prediction filtering 기법을 적용하여 얻는 과정을 기술하였다. 또한 이의 구체적 적용 예로 500MW급 화력발전소의 보일러 제어 시스템을 대상으로 여러 고장상황에 대한 고장감지 알고리즘을 설계하였고 제시한 기법의 유용성을 보이기 위한 시뮬레이션 적용 결과를 보였다.

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미세조직 변화를 고려한 열간 단조 공정에서의 유한요소해석 (Computer Simulation of Microstructure Evolution during Hot Forging of Waspaloy)

  • 강경필;이경훈;이승욱
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2007년도 추계학술대회 논문집
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    • pp.53-56
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    • 2007
  • Computer simulation of microstructure evolution during hot forging process is of great interest in recent years. Recrystallization model and grain growth model which use a phenomenological approach were summarized. For the waspaloy, upsetting process and cogging process were simulated using $DEFORM^{TM}$ and the change in grain size were investigated in each deformation procedure.

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위상 공액 거울에 흡착된 분자의 광학적 성질 (Optical Properties of Admolecules near a Phase -Conjugate Mirror)

  • 김영식
    • 한국진공학회지
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    • 제5권1호
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    • pp.33-38
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    • 1996
  • The induced linewidth, frequency shift and absorption spectrum for a molecular dipole in the vicinity of a phase -conjugate mirror have been investgated within a classical phenomenological model, with particularreference to the technique of optical phase conjugation by a surface. While the shifts and the widths show similar characteristics as those obtained recently by Bochove who considered the problem within the context of four-wave mixing, the results obtained in the present model can be defined uniquely with the possibility of an infinite lifetime for the excited admolecule . Furthermore, the absorption lineshape obtained here some interesting features which depend on both the magnitude and the phase of the complex reflectivity of the mirror.

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