• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.11
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• pp.679-685
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• 2014

For the measurements of surface shape milled using FIB (focused ion beam), the silicon bulk, $Si_3N_4/Si$, and Al/Si samples are used and observed the shapes milled from different sputtering rates, incident angles of $Ga^+$ ions bombardment, beam current, and target material. These conditions also can be influenced the sputtering rate, raster image, and milled shape. The fundamental ion-solid interactions of FIB milling are discussed and explained using TRIM programs (SRIM, TC, and T-dyn). The damaged layers caused by bombarding of $Ga^+$ ions were observed on the surface of target materials. The simulated results were shown a little bit deviation with the experimental data due to relatively small sputtering rate on the sample surface. The simulation results showed about 10.6% tolerance from the measured data at 200 pA. On the other hand, the improved analytical model of damaged layer was matched well with experimental XTEM (cross-sectional transmission electron microscopy) data.

• Electrical & Electronic Materials
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• v.8 no.6
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• pp.699-707
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• 1995

The material that is both conductive in electricity and transparent to the visible ray is called transparent conducting thin film. It has many fields of application such as Solar Cell, Liquid Crystal display, Vidicon on T.V, transparent electrical heater, selective optical filter, and a optical electric device , etc. In the recent papers on several TCO( transparent conducting oxide ) material, the study is mainly focusing on ITO(indium tin oxide) because ITO shows good results on both optical and electrical properties. Nowaday, in the development of LCD(Liquid Crystal display), the low temperature process to reduce the production cost and to deposit ITO on polymer substrate (or low melting substrate) has been demanded. In this study, we prepared indium tin oxide(ITO) by a cylindrical DC magnetron sputtering with Indium-tin (9:1) alloy target instead of indium-tin oxide target. The resistivity of the film deposited in oxygen partial pressure of 5% and substrate temperature of 140.deg. C. is 1.6*10$\^$-4/.ohm..cm with 85% optical transmission in viaible ray.

• Design & Manufacturing
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• v.11 no.2
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• pp.15-19
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• 2017

Carbon fiber reinforced plastic (CFRP) is applied as structural material. CFRP is excellent in plane strength / stiffness and don't haves rust. Lightweight, rigid and robust at the same time as transportation material. Aluminum alloy and reinforcement material The application is increasing rapidly. In this study, the prototype of a semi - Monocoque structure frame, Longeron, Stringer, Skin of the aircraft, restraining the rigidity Clips of the aircraft was designated as the target product and the experiment was conducted. ln the experiment, (1) For CFRTP 3 points, data on heating, transfer, and cooling were measured using Thermo Couple, and optimum temperature required for flexible state was obtained. Heating was performed at a temperature 15% higher than the provided temperature. (2) By using a pneumatic press during molding, by dividing LH, center and RH according to the cooling time, thickness parameter of the target product due to the load is measured, and thickness control and time-deviations were analyzed and cross sections were observed with a low magnification microscope.

• Journal of the Korea Fashion and Costume Design Association
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• v.13 no.4
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• pp.29-39
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• 2011

The purpose of this study provides a high consumer-oriented wedding dress on the consumer and offering the consumer-oriented product and provide a basis data to develop a wedding shops so it can stable and manage of effective marketing. Wedding shop for a survey of consumer preference, and based on this wedding dress designed and made. The results are summarized as follows. First, when wearing wedding dresses and "graceful and feminine" image that seek to pursue an image that showed the highest response, "simple and stylish", "cute and vivid" image was in order. In the survey of wedding dress preference, lace is preferred, in tone of color white is preferred by and large. In silhouette, A-line is preferred most, in neckline, exposure of the shoulder, in sleeve length, sleeveless, in decoration, beads. Second, on the basis of these results, depending on the image to pursue the design, wedding was made of 3 creations. The work I is a target of the early 20s, the concept "simple and stylish", and A-line is adopted in silhouette focusing on modern simplicity, soft satin material used of high class. The work II is a target of the late 20s, the concept "cut and vivid", and fit-and-flare made of many folded tulle mesh material. The work ill is a target of the 30s overall, the concept "graceful and feminine", and high-waist- empire-line is adopted in silhouette, splendid lace material used, is of the gorgeous and mature beauty.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.2
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• pp.114-120
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• 2012

In this research, we prepared Ga doped zinc oxide(ZnO:Ga, GZO) targets each difference sintering temperature $700^{\circ}C$, $800^{\circ}C$, and doping rate 1 wt.%, 2 wt.%, 3 wt.%. The characteristics of thin film on glass substrates which deposited by facing target sputtering in pure Ar atmosphere are reported. Ga doped zinc oxide film is attracted material through low resistivity, high transmittance, etc. When prepared target powder's structure was investigated by scanning electron microscope, densification and coarsening by driving force was observed. For each ZnO:Ga films with a $Ga_2O_3$ content of 3 wt.% at input power of 45W, the lowest resistivity of $9.967{\times}10^{-4}{\Omega}{\cdot}cm$ ($700^{\circ}C$) and $9.846{\times}10^{-4}{\Omega}{\cdot}cm$ ($800^{\circ}C$) was obtained. the carrier concentration and mobility were $4.09{\times}10^{20}cm^{-3}$($700^{\circ}C$), $4.12{\times}10^{20}cm^{-3}$($800^{\circ}C$) and $15.31cm^2/V{\cdot}s(700^{\circ}C)$, $12.51cm^2/V{\cdot}s(800^{\circ}C)$, respectively. And except 1 wt.% Ga doped ZnO thin film, average transmittance of these samples in the range 350-800 nm was over 80%.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.869-873
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• 2002

$Cu_2ZnSnS_4$ (CZTS) thin film is one of the candidate materials for the solar cell. It has an excellent optical absorption coefficient as well as appropriate 1.4~1.5eV band gap. The purpose of this study is replacing a half of high-cost Indium(In) atoms with low-cost Zinc(Zn) atoms and the other half with low-cost Tin(Sn) atoms in the lattice of CIS. In annealing process of thin films deposited with mixture target, the thin films were appeared the peeling. The resistivity was decreased. Thin films were deposited on ITO glass substrates using a compound target which were made by $CU_2S$, ZnS, $SnS_2$ powder were sintered in the atmosphere of Al at room temperature by rf magnetron sputtering We investigated potentialities of a low-cost material for the solar cell by measuring of thin film composition, the structure and optical properties. We could get an appropriate $Cu_2ZnSnS_4$ composition A (112) preferred orientation was appeared without annealing temperature as shown in the diffraction peaks of the CIS cells and was available for photovoltaic thin film materials. The band gap increased from 1.4 to 1.7eV as the composition ratio of Zn/Sn.. The optical absorption coefficient of the thin film was above $10^4cm^{-1}$.

• Journal of Industrial Technology
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• v.25 no.B
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• pp.141-147
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• 2005

A target of this paper is to get some elementary experimental data on the energy harvesting using a piezoelectric material. A THUNDER series piezo material (TH7-R), which has been developed by NASA engineer is selected for this study. In order to provide a mechanical energy to the piezoelectric material, a mechanical motion vibrator and its driving electronics are designed. Using a simple PWM control, the excitation frequency of vibrating mechanical motion is varied. The generated electric power as a function of the excitation frequency is monitored and analyzed. This initial experiment shows a possible energy source using a piezoelectric material for the application to low-power consumed small electronic devices such as RFID, MEMS, and etc.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.3B no.2
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• pp.67-73
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• 2003

In this paper, the impedance of a piezoelectric transducer is calculated using the three-dimensional finite element method. The validity of numerical routine is confirmed experimentally. Using this numerical routine, the effects of material coefficients on piezoelectric actuators characteristics are analyzed. The material constants, which make significant effects, are selected and the relations between material constants are studied. Using these processes, three variables of material constants for a piezoelectric transducer are selected and the design sensitivity method is adopted as an inversion scheme. The validity of the inversion scheme for a piezoelectric transducer is confirmed by applying the proposed method to the sample piezoelectric transducer.

• English Language & Literature Teaching
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• v.11 no.1
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• pp.155-177
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• 2005

In the EFL context, Korean students don't have enough opportunities to directly experience the target culture, prompting the need to offer some well-organized culture education in class. The goals of this study are to analyze how many cultural contents are reflected in High School English textbooks and to suggest an implication for cultural learning. These textbooks were carefully examined, focusing on the cultural contents, by four categories: 'cultural skill section', 'cultural patterns', 'related language skills', and 'target countries'. The results of the analysis were like the following: First, although many of the textbooks are dealing with the culture skill sections, their contents were still wanting consistency and were small in quantity. Second, as for the cultural patterns, the pages dealing with behavioral culture were 43%, spiritual culture, 35.7%, material culture, 21.3%. Third, as for the related language skills, the cultural contents in the textbooks were organized in the order of listening, reading, speaking, writing, and cultural skill sections. Since it is impossible to separate language skills from culture, we suggest that the aspects of target culture should be incorporated in various forms into the learning situations. Fourth, as for the issue of target countries, the contents about the general or whole English culture were insufficient. So we suggest that English textbooks should play an essential role in providing students with various cultural information about various English speaking countries.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.39-42
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• 2002

The nuclear transmutation technology to Incinerate the long lived radioactive nuclides and produce energy during the incineration process is believed to be one or the best solutions. HYPER(${\underline{HY}}brid {\underline{P}}ower {\underline{E}}xtraction {\underline{R}}$eactor)is the accelerator driven transmutation system which is being developed by KAERI(Korea Atomic Energy Research Institute). Lead-bismuth(Pb-Bi) is adopted as a coolant and spallation target material. In this paper, we performed the thermal-hydraulic analysis of HYPER target using the commercial code FLUENT, and also calculated thermal and mechanical stress of the beam window using the commercial code ANSYS. It is found that there is an optimum value for the window diameter and the maximum allowable beam current can be increased to 17.3 mA for the inner diameter of windows, 40 cm. Finally, the other shapes such as uniform or scanned beam were considered. The results of FLUENT calculations show that the uniform type is preferable to the other shapes of the beam in terms of the window and target cooling and the maximum window temperature is lower than that of the parabolic beam by $58 ^{\circ}C$ for the beam current, 13 mA.