• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2009.11a
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• pp.79-80
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• 2009

Aramid fabrics were photooxidized by UV/$O_3$ irradiation. The UV irradiation caused the oxygen content of the aramid fabric surface to increase and reduced the surface zeta potential, coupled with improved water wettability. The modified aramid fabrics showed higher affinity to cationic dyes which may be resultd from the newly introduced electrostatic interaction between cationic dyes and anionic dyeing sites on the photooxidized surface layers. Although color fastness to both staining and rubbing were good to excellent, color fastness to shade change was moderate.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.78-86
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• 1995

The structure of premixed turbulent flames in a constant-volume vessel was investigated using a microprobe method. The flame potential signal having one to eight peaks was detected in the case of turbulent flames, each of them being regarded as a flamelet existing in the flame zone. Based on this consideration, the flame propagation speed, the thickness of the flame zone, the number of flamelets and the separation distance between adjacent flamelets in the flame zone were measured. The experimental resuits of this work suggest the existence of "reactant islands" behind the flame front when the turbulence was intensified to some extent. The critical(lowest) ratio of turbulence intensity to the laminar burning velocity being found to be about 0.7 for the formation of reactant islands in this experiment.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.43.4-44
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• 2009

electron, ion, heavy ion으로 구성 된 plasma에서 hump type과 kink type(double layer)의 electrostatic solitary waves이 존재할 수 있다는 것을 pseudopotential method를 이용한 결과와 1d PIC(Particle-In-Cell) simulation method의 결과에서 각각 확인하였다. 1d PIC simulation에서 초기에 각각의 입자 종(species; electron, ion, heavy ion)의 밀도섭동(density perturbation)은 Gaussian 형태로 주었으며, 각각의 입자들의 drift velocity는 각각의 plasma 입자 종들의 thermal velocity로 나란한 방향으로 주었다.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.2
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• pp.80-87
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• 2011

Low temperature hole transport characteristics of gate-all-around p-channel metal oxide semiconductor (PMOS) type silicon nanowire field-effect-transistors with the radius of 5 nm and lengths of 44-46 nm are presented. They show coexisting two single hole states randomly switching between each other. Analysis of Coulomb diamonds of these two switching states reveals a variety of electrostatic effects which is originated by the potential of a single hole captured in the trap near the nanowire.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.63-66
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• 2000

In this paper, we present the simulation of the heterojunction bipolar transistor with different Emitter-Base junction structures. Our simulation results include effect of setback and graded layer. We prove the emitter efficiency's improvement through setback and graded layer. In 1995, the analytical equations of electric field, electrostatic potential, and junction capacitance for abrupt and linearly graded heterojunctions with or without a setback layer was derived. But setback layer and linearly graded layer's recombination current was considered numerically. Later, recombination current model included setback layer and graded layer will be proposed. New recombination current model also wile include abrupt heterojunction's recombination current model. In this paper, the material parameters of the heterojunction bipolar transistor with different Emitter-Base junction structures is introduced.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.67-70
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• 2000

In this paper, all SCR recombination currents including setback and graded layer's recombination currents are analytically introduced for the first time. Different emitter-base structures are tested to prove the validity of the model. In 1995, the analytical equations of electric field, electrostatic potential, and junction capacitance for abrupt and linearly graded heterojunctions with or without a setback layer was derived. But setback layer and linearly graded layer's recombination current was considered numerically. In this paper, recombination current model included setback layer and graded layer is proposed. New recombination current model also includes abrupt heterojunction's recombination current model. In this paper, new recombination current model analytically explains effects of setback layer and graded layer.

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.287-292
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• 2004

In order to understand the relationship between molecular structure of Metal-Organic Framework(MOF) and capacity of hydrogen absorption, quantum mechanical calculations and grand canonical Monte Carlo simulations have been carried out on a series of MOF-5 having various organic linkers. The calculation results about specific surface area and electron density for various frameworks indicated that the capacity of the hydrogen storage is largely dependent on effective surface area rather than the free volume. Based on the iso-electrostatic potential surface from density functional calculation and the amount of adsorbed hydrogens from grand canonical Monte Carlo calculation, it was also found that the electron localization ground organic linker plays an important role in hydrogen capacity of MOFs.

• Journal of Electrical Engineering and Technology
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• v.13 no.1
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• pp.393-399
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• 2018

An electrostatic boundary-value problem of a dielectric-wedge-backed, double-slotted conducting wedge is investigated to analyze an asymmetric coplanar waveguide with an infinite dielectric thickness using the Mellin transform and a mode-matching method. Our theoretical solution based on eigenfunction expansion and residue calculus is a rigorous and fast-convergent series form. Numerical computations are conducted to evaluate the potential field, capacitance, and characteristic impedance for various structures of the asymmetric coplanar waveguide. The computed results show good agreement with the simulated results.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1990-1991
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• 2007

Spacecrafts such as most of commercial satellites that are operating in the geostationary orbit can be subjected to intense irradiation by charged particles. The surface made of dielectric materials can therefore become probable sites for damaging electrostatic discharges. Thanks to a specially equipped chamber, the spatial environment can be reproduced experimentally in the laboratory. In this paper, the behavior of high energy electrons injected in polymers such as PolyMethylMetaAcrylate (PMMA) and Kapton is studied. Results obtained by surface potential technique, pulse-electro acoustic device and a cell based on the split Faraday cup system are analyzed and discussed.

• Proceedings of the KIEE Conference
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• 2002.11a
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• pp.236-238
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• 2002

A noble fiberoptic voltage sensor system utilizing an interferometric transducer has been introduced for high voltage measurement. The sensor system employs a fiberoptic Fabry-Perot interferometric strain sensor to convert voltage to displacement in an auxiliary movable electrode. The operating mechanism is based on the fact that the electrostatic force acting on the electrode system by the applied voltage results in strain variation on the Fabry-Perot interferometry. The experiment results show that the proposed voltage sensor has the potential to be extended to very high voltage system with appropriate auxiliary electrodes.