• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.159-159
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• 2000

Initial growth mode of Nb on Cu(100) is studied by scanning tunneling microscopy (STM) and density functional theory. Nb/Cu is immiscible at room temperature, but isolated Nb atoms are expected to be incorporated up to the second layer by DFT. STM shows that Nb atoms mix with Cu atoms in the first layer at room temperature and diffuse into the second layer upon annealing. In the second layer, Nb/induced features are preferentially found at step edges and appear as bright dots surrounded by dark rings. Details of comparison between experiment and theory will be discussed.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.788-791
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• 2006

The ion adsorption on an aligning layer deposited onto a conductive electrode in a liquid crystal (LC) cell has been shown to depend strongly on the dielectric constants of the layer and its thickness d. Calculations made in the framework of the three-layer electrostatic theory showed that, depending on those and other intrinsic parameter of the problems, it is possible to observe either ion attraction or repulsion at the aligning surface. Tentative measurements of the ion adsorption dynamics on the aligning layers with various d qualitatively agree with the theory. The results obtained allow the memory effect in LCs and the sticking effect in LC displays (LCDs) to be controlled effectively.

• 한국초전도학회:학술대회논문집
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• v.14
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• pp.36-36
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• 2004

• 한국초전도학회:학술대회논문집
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• 2007.07a
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• pp.29-29
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• 2007

• Korean Journal of Logic
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• v.12 no.2
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• pp.171-199
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• 2009

This essay will consider evolutionary views that attempt to capture the continuity of theory-change from Newtonian to Einsteinian physics via the formal aspects of these theories. Although it cannot be denied that the formal aspects such as 'correspondence principles' and 'covariance principles' provide important information concerning this theory-change, these formal properties are not sufficient to capture the essential elements of any evolutionary account of the development of Einstein's special and general theories of relativity from Newtonian mechanics.

• Nuclear Engineering and Technology
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• v.48 no.2
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• pp.482-494
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• 2016

The Feshbache-Kermane-Koonin (FKK) multi-step direct (MSD) theory of pre-equilibrium reactions has been used to compute the single-step cross-sections for some (p,${\alpha}$) reactions using the knock-on and pick-up reaction mechanisms at two incident proton energies. For the knock-on mechanism, the reaction was assumed to have taken place by the direct ejection of a preformed alpha cluster in a shell-model state of the target. But the reaction was assumed to have taken place by the pick-up of a preformed triton cluster (also bound in a shell-model state of the target core) by the incident proton for the pick-up mechanism. The Yukawa forms of potential were used for the proton-alpha (for the knock-on process) and proton-triton (for the pick-up process) interaction and several parameter sets for the proton and alpha-particle optical potentials. The calculated cross-sections for both mechanisms gave satisfactory fits to the experimental data. Furthermore, it has been shown that some combinations of the calculated distorted wave Born approximation cross-sections for the two reaction mechanisms in the FKK MSD theory are able to give better fits to the experimental data, especially in terms of range of agreement. In addition, the theory has been observed to be valid over a wider range of energy.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.196-199
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• 1999

The coexistence of the superconductivity and magnetism in the Ho1-xDyxNi2B2C is studied by using Ginzburg-Landau theory. This material violates the standard do Gennes scaling showing the coexistence and complex interplay of superconducting and magnetic order yielding an anomalous phase diagram. We propose a phenomenological model which includes two magnetic and two superconducting order parameters accounting for the multi-band structure of this material. We describe the magnetic fluctuations and order and demonstrate that they lead to anomalous behavior of the upper critical field. The doping dependence of Tc in Ho1-xDyxNi2B2C showing a reentrance behavior are analyzed yielding a very good agreement with experimental data.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.181-186
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• 2005

We demonstrate that the finite rate of dielectric relaxation in liquid crystals which has been ignored previously causes profound effects in the fast dielectric reorientation of the director. The phenomenon is relevant for submillisecond switching of the director when the switching rate approaches the rate of dielectric relaxation through the reorientation of the molecular dipoles. A submillisecond switching ($15-400\;{\mu}s$ for an optical retardation shift $0.3-2.2\;{\mu}m$ in $10-15\;{\mu}m$ thick cells) is demonstrated for dual frequency nematic cells with high pretilt that maximizes the dielectric torque acting on the director. We propose the theory of dielectric response in which the electric displacement depends not only on the present (as in the standard theory) but also on the past values of electric field and director. We design an experiment in which the standard "instantaneous" model and our model predict effects of opposite signs; the experimental data support the latter model.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.23.1-23.1
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• 2009

Space physics is more than fifty years old and is going through middle age. Looking back and thinking about what has been learned during the past fifty years, one finds that progress was made at the expense of exactness. Past observations have been interpreted using theory with unreal assumptions. Theory and models must be testable, verifiable and consistent with observations. Current theory cannot explain many important observational results that are relevant for understanding how space plasmas work. This talk will examine the current model of space plasma and assess its capabilities. We will then discuss the required level of theory and models that should be developed to advance space physics to the next tier.

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1315-1323
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• 2018

The classical-fluids density functional theory has been developed for studying the structural and the electrical properties of electrolyte solutions containing uniformly charged hard-spherical ions. The modified fundamental-measure theory has been used to evaluate the hard-sphere contribution. The mean-field approximation has been employed to calculate the cross correlation between the hard sphere contribution and the Coulomb interaction. The Poisson equation for ions carrying charges that are spatially separated has been solved. The present theory shows reasonably good agreement with the corresponding Monte Carlo simulation results. The calculated results show that the attraction between like-charged planar surfaces is the result of the intra-ionic correlation and depends strongly on the ion size, valence, mole fraction, and charge distribution of electrolytes.