• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.116-118
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• 2002

This paper presents leakage magnetic field and leakage inductance calculations in current transformer by means of 3-D Integral methods. From the distribution diagram of leakage magnetic flux to be analyzed using program called TRACAL 3, it confirms a parallel to the winding axis direction of the leakage flux lines in the air gap between the windings. The leakage inductances $L_{r1}\;and\;L_{r2}$ of the primary and secondary windings were calculated, their values are 4.23 mH and 0.49 mH, respectively. They are also similar to the measured values of the leakage inductances for the experimental verification, 4.06 mH and 0.47 mH.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.174-175
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• 2005

Initial growth stage was investigated for SiC homoepitaxial film growth using 'step controlled epitaxy' technique. When the off angel direction is located parallel along to the gas flow direction, the smoother surface can be obtained. On the on axis substrates, selective etching was detected both the etching and growth condition. It was deduced that the high ratio of C/Si in the source gas results in well developed steps and etched spiral around micropipes.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.404-407
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• 2008

In the present work, cross-roll rolling was carried out using a rolling mill in which the roll axis is tilted by $7.5^{\circ}$ towards the transverse direction of the rolled sample. The evolution of strain states during cross-roll rolling was investigated by three-dimensional finite element method (FEM) simulation. Parallel to cross-roll rolling, normal-rolling using a conventional rolling mill was also carried out in the same rolling condition for clarifying the effect of cross-roll rolling. It turned out that three shear rate components were all introduced to the rolled sample by the cross-roll rolling process, while only one shear rate component operated during normal-rolling.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.7
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• pp.52-60
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• 1998

In optical disc system, 4-wire actuator has undesired tilt which degenerates the performance of RF signal. This tilt occurs from moment around the axis parallel to the tangential direction of the disk. The main reason of the moment is the coupling effect between focus driving system and tracking driving system. This paper constructed tilt mechanism and analyzed tilt quantity due to the moment based on structural analysis and magnetic field analysis. And the experiment about tilt was executed. The results were compared and discussed about the difference. Then, the design method for reducing tilt angle was suggested.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.147-148
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• 2010

Recently, advancement in the visual technology has lead to the further development of the three dimensional (3D) imaging systems. The visual perception to view a pair of images simultaneously, is a crucial factor to build a stereoscopic 3D image. In this paper, we present the depth cues between the intensities of the two images when viewing with both eyes. Due to this stereoscopic effect, objects at different distances from the eyes differ in their horizontal positions, giving the depth cue of horizontal disparity. By simple image processing technique, we also present the binocular disparity map between the two images. A median filter has been used to filter out all the noises occurring in the disparity map image.

• Journal of the Korean Institute of Intelligent Systems
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• v.15 no.5
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• pp.621-625
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• 2005

In this paper we study the controllability for the nonlinear fuzzy integro-differential equations on $E_N^n$ by using the concept of fuzzy number of dimension n whose values are normal, convex, upper semicontinuous and compactly supported surface in $R^n$. $E_N^n$ the set of all fuzzy numbers in $R^n$ with edges having bases parallel to axis $X_1,\;X_2, ... , X_n$.

• Bulletin of the Korean Chemical Society
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• v.16 no.2
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• pp.120-125
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• 1995

Solid solutions of Pr2-xBaxNiO4±δ with K2NiF4-type structure were prepared in air and characterized by powder X-ray diffraction, Rietveld refinements, iodometry titrations, and conductivity measurements. The range of the solid solution was 0 ≤ x < 0.5. The crystal structure changes from orthorhombic (Fmmm) for x ≤ 0.1 to pseudo-tetragonal (I4/mmm) for x ≥ 0.2. The orthorhombic structure of x=0.1 transforms to tetragonal at low temperature. The bond distances obtained from the Rietvel analyses did not vary significantly with the Ba content except that of Ni-O (parallel to the c-axis) which showed an abrupt increase from x=0.1 to 0.2. The excess oxygen content (δ) decreases from 0.241 to 0.03 with increasing substituted Ba contents within the solution range. The samples are all semiconductors at the temperature range 4 < T < 300 K.

• Bulletin of the Korean Chemical Society
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• v.16 no.2
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• pp.143-148
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• 1995

Ketene (CH2CO) adsorption on Ag(111) has been studied in ultrahigh vacuum using electron energy loss spectroscopy and temperature programmed desorption. Ketene adsorbs molecularly on Ag(111) at temperatures below 126 K. The coverage increases linearly with exposure until saturation. No multilayer formation and no shift in desorption temperature with coverage were observed, indicating a lack of attractive interaction between adsorbate molecules. The desorption activation energy is estimated to be 7.8 kcal/mol by assuming first order kinetics and a pre-exponential factor of 1013 sec-1. The adsorption geometry of ketene on the surface is determined from the relative intensities of the vibrational energy loss peaks. The CCO axis of CH2CO is found to be almost parallel to (∼4°away from) the surface and the molecular plane is almost perpendicular to the surface (∼3°tilt).

• Structural Engineering and Mechanics
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• v.72 no.2
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• pp.155-168
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• 2019

This paper presents the results of an experimental investigation on the compressive strength of small scale concentrically axially loaded fiber-reinforced polymer (FRP) confined plain concrete columns, with cylinder concrete strength 19 MPa. For columns with circular (150-mm diameter) and square (150-mm side) cross sections wrapped with glass- and carbon-FRP sheets (GFRP and CFRP, respectively) applied with dry lay-up the effect of different jacket schemes and different overlap configurations on the confined characteristics is investigated. Test results indicate that the most cost effective jacket configuration among those tested is for one layer of CFRP, for both types of sections. In square sections the location of the lap length, either in the corner or along the side, does not seem to affect the confined performance. Furthermore, in circular sections, the presence of an extra wrap with FRP fibers parallel to the column's axis enhances the concrete strength proportionally to the axial rigidity of the FRP jacket. The recorded strains and the distributions of lateral confining pressures are discussed. Existing design equations are used to assess the lateral confining stresses and the confined concrete strength making use of the measured hoop strains.

• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.465-469
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• 1995

We have investigated the effects of deposition angle on structural and magnetic properties of e-beam evaporated ${(4-{\AA}\;Co/9.2-{\AA}\;Pt)}_{23}$ multilayer thin films prepared on tilted substrates. It was found that the [111] crystallographic orientations of the multilayer thin films were not aligned with colummar growth orientations and they were remained to be normal to the substrate planes even though the deposition angle was severely oblique up to $60^{\circ}$. The analysis of the torque curve reveal that the intrinsic anisotropy energy was monotonically decreased with the deposition angle but the easy axis orientation parallel to the substrate normal was not much influenced by deposition angle.