• Journal of the Korean Magnetics Society
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• v.5 no.5
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• pp.749-752
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• 1995

Electronic structures of the Heusler compounds, XMnSb (X=Ni, Pd, and Pt) are investigated systematically by using the linearized muffiu-tin orbital (LMTO) band method. LMTO band calculations yield that, by including the spinorbit interactions, the NiMnSb and PtMnSb are half-metallic, while PdMnSb is normal metallic at the experimental lattice constant. The effect of the spin-orbit interaction is substantial in PtMnSb, in contrast to NiMnSb and PdMnSb. The calculated X d and Mn 3d angular momentum projected local density of states's reveal that the hybridization between the Mn 3d X d states increases from X = Pt to Pd and Ni.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.1
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• pp.20-24
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• 2019

Ferroelectric material properties are strongly governed by domain structures and their evolution processes, but the evolution processes of complex domain patterns during a macroscopic electrical poling process are still elusive. In the present work, domain-evolution processes in a PZT ceramic near the morphotropic phase-boundary composition were studied during a step-wise electrical poling using piezoresponse force microscopy (PFM). Electron backscatter diffraction was used with the PFM data to identify the grain boundaries in the region of interest. In response to an externally the applied electric field, growth and retreat of non-$180^{\circ}$ domain boundaries wasere observed. The results indicate that ferroelectric polarization-switching nucleates and evolves in concordance with the pattern of the pre-existing domains.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.592-595
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• 2005

Concrete slab bridge is one of most common structures employed for local road constructions because of its simplicity in design and construction. Computer applications were developed to automate the repetitive computation for these simple structures. However, in most cases, managing the electronic documents produced by these applications has not been incorporated with design automation application yet. Resultant documents are often managed by individuals and disappear as time goes by due to lack of systemic management. This paper introduces a Web-based application developed to not only speed up the design process but also enhance the collection and manipulation of resultant electronic documents.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.810-812
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• 1998

We studied on the $\pi$-A isotherm of the L-$\alpha$-DLPC was measured at the air-water interface varying with the compressing speed and amounts of solutions for spreading. The molecular arrangement of deposited films were evaluated by measuring the absorption with the UVspectrometer. We made structures of metal(Au)/organic thin films (L-$\alpha$-DLPC)/Metal(Au), the number of accumulated layers are 3. And I-V characteristic of the device examined.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1465-1467
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• 1998

We studied on the made structures of metal(Au)/L-$\alpha$ -DLPC/metal(Au), and we examined electron through L-$\alpha$-DLPC LB films by means of current - voltage(I-V) measurement.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.1
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• pp.7-11
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• 2011

Sapphire substrate was patterned by a selective chemical wet etching technique, and GaN/InGaN structures were grown on this substrate by MOVPE (Metal Organic Vapor Phase Epitaxy). The surface of grown GaN on patterned sapphire substrate (PSS) has good morphology and uniformity. The patterned sapphire substrate LED showed better light output than conventional LED that improvement 50%. We think these results come from enhancement of internal quantum efficiency by decrease of threading dislocation and increase of light extraction efficiency. Also these LED showed more uniform emission distribution in angle than conventional LED.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.485-486
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• 2008

The network structure of $SnO_2$ nanowires was fabricated on the electrodes by a simple thermal evaporation process from Sn metal powders and oxygen gas. The diameter of the nanowires was $20\;{\sim}\;60\;nm$ depending on the processing conditions. The operating temperature of the sensor could be decreased down below $50^{\circ}C$ by controlling the properties of the nanowires and the structures of the electrodes. The sensitivities were $10\;{\sim}\;15$ when the $NO_2$ concentrations were $10\;{\sim}\;50\;ppm$ at the operating temperature of $50^{\circ}C$.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.435-438
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• 1988

The purpose of this study is to evaluate the discontinuity effects of two kinds of transmission lines. i.e. the strip line and the microstrip line which are popular transmission structures.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.297-298
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• 2006

In this paper, we propose a real-time surveillance system for security of important area such as military bases, prisons, and strategic infra structures. The proposed system recognizes the movement of objects in dark environments. First, the Multi-scale retinex (MSR) is processed to enhance the contrast of image captured in dark environments. Then, the enhanced input image is subtracted with the background image. Finally, each bounding box enclosing each objects are tracked. The center point of each bounding box obtained by the proposed algorithm provides more accurate tracking information. Experimental results show that the proposed system provides good performance even though an object moves very fast and the background is quite dark.

• Journal of Magnetics
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• v.16 no.3
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• pp.201-205
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• 2011

We performed total energy and electronic structure calculations for the basic ground state properties of Fe using the conventional generalized gradient approximation (GGA) and screened hybrid functionals as the form of the exchange-correlation functional. To that end, we calculated structural (equilibrium lattice constants, bulk moduli, and cohesive energies) and electronic (magnetic moments and densities of states) properties. Both functional calculations gave the correct ground state, the ferromagnetic bcc phase, in which the structural parameters agreed well with experimental results. However, the description of the cohesive energies and magnetic moments at the ground state exhibited different behavior from each other: the unusually small cohesive energy and large magnetic moment were observed in the screened hybrid functional calculations compared to the GGA calculations. The reason for the difference was examined by analyzing the calculated electronic structures.