• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1993.05a
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• pp.113-116
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• 1993

A guided - wave electro - optical modulatored directional coupler $2{\times}2$ was fabricated on X-cut $LiNbO_3$ by proton exchange wi th self-aligned method. The Electode pattern was formed by the four extra gap electrode separtion within self-aligned electrode mask. Initial cross over state turned that by controlling the anneal ing process and self-aligned electrodes are used in fabricating the electro-optical modulatored directional coupler $2{\times}2$. The modulatored directional coupler $2{\times}2$ has very good figures of merits: the measured crosstalk was -28.2 dB and the modulating valtage of 3.2[V].

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.175-175
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• 2010

The etching characteristics with etch rate of ITO thin films in an $O_2/BCl_3$/Ar plasma were investigated. The etch rate of ITO thin films increased with increasing $O_2$ content from 0 to 10 % in $BCl_3$/Ar plasma, whereas that of ITO decreased with increasing $O_2$ content from 10 % to 30 % in $BCl_3$/Ar plasma. The maximum etch rate of 65.9 nm/min for the ITO thin films was obtained at 10 % $O_2$ addition. The etch conditions were the RF power of 500 W, bias power of 200 W, and process pressure of 2 Pa. The analysis of x-ray photoelectron spectroscopy (XPS) was carried out to investigate the chemical reactions between the surfaces of ITO thin films and etch species.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.475-475
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• 2014

Dye sensitized solar cells (DSSCs) are regarded as potential inexpensive alternatives to conventional solid-state devices. The flexible version, employing conductive-plastic-film substrates, is appealing for commercialization of DSSCs because it not only reduces the weight and cost of the device but also extends their applications. However, the need for high temperature does not permit the use of plastic-film substrate. So, development of low-temperature methods is therefore realization of flexible DSSCs. In this work, the electrophoretic deposition combined with hydrothermal treatment was employed to prepare nanocrystalline $TiO_2$ thin film at low temperature. We confirmed the prepared $TiO_2$ thin films with different voltages and deposition times in the electrophoretic deposition process. Properties of the $TiO_2$ films were investigated by various analysis method such as X-ray diffraction, field emission scanning electron microscopy (FESEM) and UV-visible spectrophotometer.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1851-1857
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• 2016

Existing devices are capable of communicating the OBD information only inside or close to the vehicle without supporting the data transmission to a external server. In this paper, we describe the implementation of IoT device, which can communicate the OBD information to the external server.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.443-443
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• 2012

We fabricated a-IGZO TFT with AZO/Ag/AZO transparent multilayer source/drain contacts by rf magnetron sputtering. Enhanced electrical device performance of a-IGZO TFT with AZO/Ag/AZO multilayer S/D electrodes (W/L = = 400/50 mm) was achieved with a subs-threshold swing of 3.78 V/dec, a minimum off-current of 10-12 A, a threshold voltage of 1.80 V, a field effect mobility of 10.86 cm2/Vs, and an on/off ration of 9x109. It demonstrated the potential application of the AZO/Ag/AZO film as a promising S/D contact material for the fabrication of the high performance TFTs.

• 연구논문집
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• s.33
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• pp.175-182
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• 2003

In this study, the wear resistance of the complex powder diffusion treated KS STD 61 has been investigatived. KS STD 61 tool steel was pretreated in quenching and tempering processes to obtain the tempered martensitic microstructure. The samples were packed with complex powder in steel pot($\Phi$90x60mm) and heated in a box furnace. the complex powder diffusion treatment are carried out at $540^{\circ}C$, $520^{\circ}C$, $500^{\circ}C$ for 40min, 1.5hr and 2.5hr. The microstructure, microhardness, wear resistance, and coating layer thickness of the complex powder diffusion treated samples were investigation. The weight loss of as heat treated sample was 0.4mg and that of the complex powder treated at $540^{\circ}C$ for 2.5hr was 0.17mg. These result means that the wear resistance of tool steels can be easily improved by the powder diffusion process at conventional tempering treatment temperature.

• Speech Sciences
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• v.7 no.4
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• pp.73-82
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• 2000

The perceptual judgement of nasality is still used in the assessment of velopharyngeal incompetence, but it should not be the sole criterion for speech nasality. Objective procedures may be used to assess velopharyngeal function, for example, nasometer, aerodynamics, x-ray, electromyography, nasoendoscopy, and videofluoroscopy can be utilized. The nasometer employs noninvasive measurement methods and measures with high levels of accuracy. The aim of this study was to obtain comprehensive nasalance data for Korean children, aged 7 years, and to investigate any gender differences within that age group. The results were as follow: 1. Statistically, gender has no significant effect on the nasalance of vowels /a/, /i/, /o/, /u/, /je/, /wi/) but the nasalance of the vowels /e/, /ja/) was higher in males (p<0.05). 2. There was no statistically significant effect of gender in plosives /p/, /ph/, /p'/, /t/, /th/, /t'/, /k/, /kh/, /k'/), affricatives /c/, /ch/, /c'/), and fricatives /s/, /s'/, /$\int$/). 3. The nasalance of the nasal consonants, /m/, /n/, /an/) is higher in males and only /n/, /an/ were statistically significant (p<0.05).

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.305-310
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• 1996

The objective of this paper is to develop computer assisted learning system for the education of cardiac disease using multimedia. Total 20 cases of disease was selected and their asculation, X-Ray, ECG, Sanography, Angiogram and RI-Study results can be shown on the computer screen. The references about cardiology, surgical process can be also shown on the screen and the computer can test and score their records for the evaluation. This system will be widely applied for the education of medicine combined wi th the communication network.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.622-627
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• 2014

A method to reduce the specific absorption rate(SAR) of the antenna for WiMAX mobile communication is proposed in this paper. The SAR reduction is achieved by miniaturizing the physical size of the antenna for the given resonance frequency by devising a metamaterial-composite right- and left-handed(CRLH) configuration-based radiator much smaller than the quarter-guided wavelength adopted a lot in the conventional planar inverted F antenna(PIFA) or modified monopole antenna. The proposed antenna is placed near the head-phantom and its SAR is evaluated by the full-wave simulations(SEMCAD X), where the metamaterial-inspired antenna is shown to have the lower value than a modified monopole as the reference in terms of the SAR.

• 보존과학연구
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• s.19
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• pp.61-74
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• 1998

Conservation Treatment Process 1. Inlaying is observed at the back and head of a sword to grasp the inner structure of relics by photographing X-ray. 2. After removing rust of surface, inlaying emerge. 3. After hardening, inlaying emerge to magnetite layer by standing Scapel and Vibrotool throught microscope. Charcterization 1. Most of domestic inlaying become designed to the head of a sword but this inlaying become designed to gold inlaying to the back of a sword. 2. Inlaying is the technique to groove V-shape on the surface of relice and to put gold thread in.