• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2007.10a
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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.

• Journal of the Korean Vacuum Society
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• v.5 no.1
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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.

• Journal of Adhesion and Interface
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• v.13 no.1
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• pp.9-16
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• 2012

In order to describe external effects on the behavior of the adhesive tape, the semi-rigid body cylinder chain model for adhesive tape has been proposed as follows. Firstly the behavior of the tape is in detail investigated while it's being pulled off from the plate, and subsequently a relevant phenomenological model is designed. Then all the contributors affecting the force to peel out the tape from plate (hereafter, the pull out force) are clearly defined and their sensitivity analyses are made to set up the experimental reference condition, under which the angular dependence of the pull out force is measured in every $10^{\circ}$. The experimental data turn out to be in good agreement with the theoretical ones by our model within the measurement error, and the effects due to other factors are proved to be well explained from the phenomenological viewpoint. From these results, the concept of this study might be expected to be very useful for the test and evaluation of PSA types of adhesive tape.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.94-103
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• 1999

A model for the prediction of combustion and exhaust emissions of DI diesel engine has been formulated and developed . This model is a quasi-dimensional phenomenological one and is based on multi-zone combustion modelling concept. It takes into consideration, on a zonal basis ,detailed of fuel spray formation, droplet evaporation, air-fuel mixing, spray wall interaction, swirl , heat transfer, self ignition and burning rate . The emission model is considered with chemical equipment , as well as the kinetics of fuel. NO and soot reactions in order to calculate the pollutant concentrations within each zone and the whole of cylinder . The accuracy of prediction versus experimental data and the capability of the model in predicting engine heat release, cylinder pressure and all the major exhaust emissions on zonal and cumulative basis., is demonstrated. Detailed prediction results showing the sensitivity of the model bv various injection rates are presented and discussed.

• Bulletin of the Korean Chemical Society
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• v.14 no.4
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• pp.485-487
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• 1993

The critical behavior of the classical D-dimensional spin model (D${\ge}$2), which is intermediate model that link up the Ising (D = 1) and the spherical model (D = ${\infty}$), is studied for the case of constant coupling interaction independent of the spin-spin distance (Curie-Weiss model). Analytical results show that the critical behavior of the present model is in quantitative agreement with the prediction of the phenomenological mean-field theory independent of D. Critical temperature is calculated to be T$_c$=k/JD. This gives a quantitative explanation of the relationship between the spin degree of freedom and the critical temperature.

• Journal of the Korean earth science society
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• v.29 no.4
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• pp.352-362
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• 2008

This study explored pre-service teachers' mental models about eclipse phenomena to investigate their understandings on the earth science concept needed f3r an integrated approach. We conducted in-depth interviews with two different contexts on 30 secondary and 36 primary pre-service teachers participants, and analyzed phenomenological primitives (p-prims) and facets of causal explanations about eclipses. Based on this study, we identified four different levels of mental models about eclipses. Four mental models were categorized as (1) Screening model, (2) Orbital plane model, (3) Hybrid model, and (4) Shadow cast model. Screening model is a flawed mental model, orbital plane model is an incomplete correct mental model, and shadow cast model is a scientifically correct mental model. Hybrid model, composite of two or more mental models, use multiple mental models simultaneously. Orbital plane model was the most widespread mental model in secondary pre-service teachers group, whereas screening model was used frequently in primary group. It was found that the level of mental model could be determined by the level of facet and p-prims. We confirmed context sensitivity of the mental models and perceived the necessity of integrated approaches to promote progression of mental models. Implications of our findings for enhancing pre-service science teachers' topic-specific pedagogical content knowledge (PCK) associated with eclipse phenomena are also discussed here.

• Journal of Educational Research in Mathematics
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• v.15 no.4
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• pp.375-399
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• 2005

In this article, I identified many points of commonness and differences at)feared in the fraction units of three conspicuous textbooks -McLellan, MiC and Korea. After that, 1 evaluated these results with reference to more general didactics on which each text-book is based. A background theory of Mc-Lellan's textbook was Dewey's experientialism, and that of MiC was Freudenthal's realistic mathematics education. Through this study, I have reached the fact that these three textbooks could not exhibit the phenomenological wholeness of fraction. Driven by measuring number model which is very abstractive, McLellan's text-book is disregarding the lower level context. MiC textbook, driven by real context, is ignoring higher level model which is close to rational number concept. From an excess of formulation and practice of algorithm, Korea's textbook is overlooking the real context. It is necessary that a textbook which would display the phenomenological wholeness of fraction is developed.

• Journal of Korean Vacuum Science & Technology
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• v.3 no.1
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• pp.1-9
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• 1999

This paper presents a newly enhanced damage model in Monte Carlo (MC) simulation for the accurate prediction of 3-Dimensional (3D) as-implanted impurity and point defect profiles induced by ion implantation in (100) crystal silicon. An empirical electronic energy loss model for B, BF2, As, P and Si self implant over the wide energy range has been proposed for the ULSI device technology and development. Our model shows very good agreement with the SIMS data over the wide energy range. In the damage accumulation, we considered the self-annealing effects by introducing our proposed non-linear recomvination probability function of each point defect for the computational efficiency. For the damage profiles, we compared the published RBS/channeling data with our results of phosphorus implants. Our damage model shows very reasonable agreement with the experiments for phosphorus implants.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.1
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• pp.40-47
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• 2000

A model for the prediction of combustion and exhaust emissions of DI diesel engine has been formulated and developed. This model is a quasi-dimensional phenomenological one and is based on multi-zone combustion modelling concept. This model is developed based on the concept of Hiroyasu's multizone combustion models. It takes nozzle injection (spray) parameters, induction swirl into consideration and the models of zone velocity, air entrainment, fuel droplet evaporation and mixture combustion are upgraded. Various parameters, such as cylinder pressure, heat release rate, Nox and soot emission, and these parameters in the zone are simulated. The results are compared with the experimental ones, too.

• Journal of Korea Foundry Society
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• v.22 no.1
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• pp.11-16
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• 2002

Hot deformation behavior of GCD-50 cast iron has been investigated by employing the compressive test. Phenomenological deformation behaviors, which were modeled based on the dynamic materials model and the kinetic model, have been correlated with the microstructural change taken place during compression. Microstructural investigation revealed that the adiabatic shear band caused by the locallized deformation was taken place in low temperature and high strain rate. On the other hand, the wavy and curved grain boundaries, which repersent the occurrence of dynamic microstructure change such as dynamic recovery and dynamic recrystallization, were observed in high temperature and low strain rate. Deformation model based on hyperbolic sine law has also been suggested.