• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.3
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• pp.95-100
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• 2004

This paper reports a potential problem in the electrical performance of the silicide film to silicon contacts with respect to the scaling trend in integrated circuit (IC) devices. The effects of elastic strain on the agglomeration of the coherent silicide film embedded in an infinite matrix are studied employing continuum linear elasticity and finite-difference numerical method. The interface atomic diffusion is taken to be the dominant transport mechanism where both capillarity and elastic strain are considered for the driving forces. Under plane strain condition with elastically homogeneous and anisotropic system with cubic symmetry, the dilatational misfit and the tetragonal misfit in the direction parallel to the film thickness are considered. The numerical results on the shape evolution agree with the known trend that the equilibrium aspect ratio of the film increases with the elastic strain intensity. When the elastic strain intensity is taken to be only a function of the film size, the flat film morphology with a large aspect ratio becomes increasingly unstable since the equilibrium aspect ratio decreases, as the film scales. The shape evolution results in a large decrease in contact to silicon area, and may deteriorate the electrical performances.

• Bulletin of the Korean Chemical Society
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• v.23 no.2
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• pp.253-261
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• 2002

Vibrational properties of ferrocyanide complex ion, $[Fe(CN)_6]^{4-}$ , have been studied based on the force constants obtained from the density functional calculations at B3LYP/$6-31G^{\ast\ast}$ level by means of the normal mode analysis using new bond angle and linear angle internal coordinates recently developed. Vibrations of ferrocyanide were manipulated by twenty-three symmetry force constants. The angled bending deformations of C-Fe-C, the linear bending deformations of Fe-C${\equiv}$N and the stretching vibrations of Fe-C have been quantitatively assigned to the calculated frequencies. The force constants in the internal coordinates employed in the modified Urey-Bradley type potential were evaluated on the density functional force field applied, and better interaction force constants in the internal coordinates have been proposed. The valence force constants in the general quadratic valence force field were also given. The stretch-stretch interaction and stretch-bending interaction constants are not sensitive to the geometrical displacement in the valence force field.

• Applied Chemistry for Engineering
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• v.26 no.5
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• pp.624-629
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• 2015

A biosensor including the homogenized tissue of mugwort embedded in carbon paste, which senses hydrogen peroxide, was constructed and its electrochemical properties were validated using voltammetry. The good linearity of Hanes-Woolf plot implied that the reduction reaction of substrate was catalyzed by mugwort peroxidase at the electrode surface. Also the small value of symmetry factor, 0.28, indicated that electrochemical kinetics of the sensor is very sensitive to the change of electrode potential. Many experimental results collected above proved that the dissociation of hydrogen peroxide is dependent on the catalytic power of mugwort peroxidase qualitatively and quantitatively at the surface of the mugwort electrode. It is our firm belief that the marketed HRP can be replaced with mugwort tissue.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.153-153
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• 2013

Turbomolecular pump (TMP) is widely used to obtain and maintain high vacuum by spinning turbine rotors to migrate gas molecules to the exhaust of the pump. However, performance of the TMP has not been well observed when it is influenced by strong magnetic field. Such study may give useful information about magnetic field tolerance of TMP, development of magnetic shielding technique for key components of TMP, etc. For this purpose, magnetic field induced by a circular current source was firstly designed and investigated. Using spherical coordinates and vector potential, magnetic field throughout the space including axis of rotation was calculated. Due to the rotational symmetry of the circular current source, induced magnetic field is azimuthally symmetric and, thus, is analyzed by radial and polar components of the magnetic fields. In order to enhance the numerical accuracy for the calculation, magnetic field was expressed by complete elliptic integrals of first and second kinds. According to the calculation, when 1 A of DC-current passes through a 1 turned circular wire with 50 cm of diameter, overall magnitude of the inducedmagnetic field was about 0.02 Gauss, which was used to the determination of the current and the number of turns of wires to fabricate the coil for the study on the magnetic field tolerance of TMP.

• Progress in Superconductivity
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• v.2 no.1
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• pp.43-46
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• 2000

We report on the tunneling spectroscopy of tunnel junctions using d-wave superconductor in relation to Andreev reflection. The zero bias conductance peak (ZBCP) which has maximum on [110] direction of ab-plane is observed on metal $Au/YBa_2Cu_3O_y$ tunnel junctions while it is suppressed on the ferromagnetic $Co/Au/YBa_2Cu_3O_y$ tunnel junctions. The effects of Andreev reflection on the differential conductance of each junction are dependent on the tunnel direction. For the $Co/Au/YBa_2Cu_3O_y$ junction, the suppression of Andreev reflection takes place by spin-polarized quasiparticles tunneling from a ferromagnetic material to a d-wave superconductor. By comparing these experimental results with recent theoretical works on Andreev reflection, the existence of Andreev bound state due to the d-wave symmetry of the pair potential is verified in high-$T_c$ superconductor.

• The Research Journal of the Costume Culture
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• v.23 no.1
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• pp.145-160
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• 2015

The purpose of this study is to review the concept and thinking structure of deconstruction theoretically and thereupon, analyze the visual beauty and wearable comfort of the clothing and further, discuss the aesthetic characteristics and values of the decentering phenomenon in the 21st century fashion. Deconstruction provides for an cognitive framework whereby we could comprehensively review the difficult-to-understand and imprudent creativity unravelling in the name of the post-modernism as well as the ambiguous visual beauty and wearable comfort of our contemporary fashion. In particular, deconstruction refuses such concepts involving the relationship between the conventional clothing and its components as order, symmetry, balance, harmony, perfection and simplicity and instead, attaches some sense of value to such relatively inferior concepts as disorder, asymmetry, unbalance, disharmony, imperfection and complexity, and thus, reflects them in the modes of aesthetic representations to create new aesthetics and expand the expressive potential.

• Journal of the Korean Ceramic Society
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• v.54 no.5
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• pp.422-428
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• 2017

Single-phase yellow phosphor, $CaGd_{2-x}ZrSc(AlO_4)_3:xCe^{3+}$ ($CGZSA:Ce^{3+}$), possessing cubic symmetry with varied $Ce^{3+}$ concentrations, was synthesized using the solid-state reaction method. The samples were characterized using X-ray diffraction (XRD), excitation spectra, emission spectra, thermal quenching, and decay curves. The cubic phase of $CGZSA:Ce^{3+}$ phosphor was confirmed via XRD analysis. The photoluminescence spectra of $CGZSA:Ce^{3+}$ phosphor demonstrated that the phosphor could be excited at the wavelength of 440 nm; a broad yellow emission band was centered at 541 nm. These results indicate that the phosphors are adequately excited by blue light and have the potential to function as yellow-emitting phosphors for applications in white light-emitting diodes.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.3
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• pp.43-50
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• 1984

A body form, which experiences minimum vertical wave-exciting forces in the vicinity of a prescribed wave frequency in water of finite depth, is obtained by an approximate method. Its configuration has the symmetry with respect to the vertical axis, expressed in terms of exponential functions. By distributing three-dimensional pulsating sources and dipoles on the immersed surface of the body, a velocity potential is determined and subsequently hydrodynamic forces including the 2nd-order time-mean drift forces are calculated. The dynamic behavior of the body moored in irregular waves is investigated numerically by using central difference method. Hereby irregular wave trains are simulated with examining its repeatability by comparing the resulting spectrum with original one. Numerical results indicated that the body form obtained from the present analysis possesses in general a favorable hydrodynamic characteristics in comparison with a spherical buoy and that the maximum excursion of the body can be significantly reduced by setting pre-tension of an appropriate amount in the mooring cable.

• Journal of the Korean Magnetics Society
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• v.17 no.4
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• pp.152-155
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• 2007

We have studied electronic structures and magnetic properties of $YMnO_3,\;ScManO_3$ with hexagonal structure using Full Potential Linearized Augmented Plane Wave (FLAPW) method based on LSDA method. LSDA calculation results show that multiferroic $YMnO_3$ shows energy gap due to hexagonal symmetry and magnetic interaction. Because of insulating gap and small Y ion, $YMnO_3$ shows magnetic and ferroelectric state. However, $ScMnO_3$ does not show the energy gap because of strong hybridization of Mn-O for LSDA calculation. We confirmed the stability of multiferroic state for $YMnO_3\;and\;ScManO_3$ using total energy calculations. The antiferromagnetic and ferroelectric states have the lowest energy about 100 meV.

• Journal of the Korean Electrochemical Society
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• v.7 no.1
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• pp.9-15
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• 2004

Cyclic voltammetry and chronocoulometry have been used for characterization of catechol violet (CV) at the hanging mercury drop electrode in acetic acid-sodium acetate buffer solution. At pH 2.94 a nearly symmetric cyclic voltammetric wave due to an irreversible weak adsorption of CV on mercury was obtained at concentration of $0.53{\mu}mol\;dm ^{-3}$. Under these conditions, CV adsorbes in a monolayer. Upon increasing the concentration, the symmetry of the wave decreases; it can be attributed to a mixed diffusion adsorption process. The amount of the adsorbed catechol violet on the HMDE expressed as surface concentration as well as the surface areaf occupied by one molecule$(\sigma)$ were calculated. It was found that the values obtained for f and o utilizing cyclic voltammetric and chrono-coulometry are almost identical. A 1:1 and 1:2 Th (IV)-CV complexes are formed on addition of thorium (IV) to catechol violet. These complexes are adsorbed and reduced on the HMDE at more negative potentials than the peak potential of free CV, Using the square-wave (SW) technique, the adsorptive cathodic stripping voltammetry, ACSV, of these complexes was studied. It was found that the SW-ACSV of Th(IV)-CV can be applied to the determination of thorium at the nanomole level. Optimum conditions and the analytical method of determination were presented and discussed.