• Journal of the Society of Naval Architects of Korea
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• v.30 no.4
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• pp.112-126
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• 1993

In this paper, unified requirements of IACS on longitudinal strength of ships are investigated using nonlinear wave loads analyses under short term irregular waves. Also, analyses on IACS wave data were carried out for the purpose of presenting the guideline for future use. While keeping theoretical consistensy, the rule requirements for horizontal shear force, bending moment and torsional moment are newly proposed for the ships of large deck openings bases on the calculation results for 17 sample ships. The requirements for side shell hydrodynamic pressure are also presented. All the calculated results are compared with other Societies and present KR rules. These formula will be checked when corresponding requirements of structural scantling are determined.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1697-1702
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• 2010

It has been recognized for decades that the spherical bearing which is sliding on curved surface in the intrinsic behavior is optimized for the railway bridge requiring a large slope deflection. However, the spherical bearing is easily corrosived at the PSC girder bridge which is exposed to the outside so the normal function of bridge bearing is not fulfilled fully. It is common that the corrosion is happened at the operating plate of steel bridge bearing and generally it is necessary to replace the bridge bearing after 20~25 years. Accordingly, It costs multi billion dollars for maintenance each year and the necessity of improvement become a issue. Korea Rail Network Authority(KR) suggested to apply the Elastomeric bearing instead of Spherical bearing through the task of construction site of 2006. But the normal Elastomeric bearing is optimized for the Highway bridge so it needs the special consideration to satisfy each design condition required by railway bridge. As the result of examination of Elastomeric bearing at the railway bridge construction site, the stress is decreased by effective dispersion of earthquakes and the maintenance fee is also decreased.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.665-668
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• 1997

We fabricated a number of optical fiber Bragg gratings by varying the UV beam parameters such as the laser energy density, pulse repetition rate and exposing time. The reflectance and the Bragg wavelength shift of the fiber Bragg gratings formed with a KrF excimer laser in real time depend strongly on the UV beam parameters. The index changes in the gratings during the exposing time are well fitted to the well known equations.

• Child Health Nursing Research
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• v.12 no.2
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• pp.233-243
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• 2006

Purpose: This study was aimed to develop a WBI(Web Based Instruction) program on safety for 6th grades of elementary school students and to test the effects of it. Method: The web site is http://www.safeschool.co.kr. The effect of it was tested from Mar 24, to Apr 30, 2003. The subjects were 150 students. Data were analyzed with descriptive statistics, and $x^2$ test, t-test, and repeated measure ANOVA. Result: In the knowledge of the safety precaution, the preliminary test was mean 17.8, immediate post-test was mean 20.9 and 4 weeks post-test was mean 20.9, there were significant differences statistically among three points of time. In the attitude of the safety precaution, the preliminary test was mean 75.1, the immediate post-test was mean 80.8 and 4 weeks post-test was mean 80.4, which showed significant difference statistically among three points of time. For the motive of learning to the safety precaution, it was significantly higher statistically in the WBI. As a result, the WBI group had totally longer effects on knowledge, attitude and motivation of the safety accident prevention than the textbook-based instruction. Conclusion: WBI program be used in each class to provide more effective safety instruction.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.74-83
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• 2017

Coal-fired power plants supply roughly 50 percent of the nation's electricity but produce a disproportionate share of electric utility-related air pollution. Coal combustion technology can facilitate volume reduction of up to 90%, with the inorganic contaminants being captured in furnace bottom ash and fly ash residues. These disposal coal ash residues are however governed by the potential release of constituent contaminants into the environment. Accelerated carbonation process has been shown to have a potential for improving the chemical stability and leaching behavior of bottom ash residues. The aim of this work was to quantify the volume of $CO_2$ that could be sequestrated with a view to reducing greenhouse gas emissions and stabilize the contaminated heavy metals from bottom ash samples. In this study, we used PC boiler bottom ash, Kanvera reactor (KR) slag and calcined waste lime for measuring chemical analysis and heavy metals leaching tests were performed and also the formation of calcite resulting from accelerated carbonation process was investigated by thermo gravimetric and differential thermal analysis (TG/DTA).

• Human Ecology Research
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• v.53 no.3
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• pp.293-307
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• 2015

Social commerce has a large impact on the emergence of the concept of society and individual lives that is recognized as one of the most important business areas in the Internet environment. A marketing agency, Trend Monitor (http://www.trendmonitor.co.kr), conducted a survey on social commerce usage and satisfaction level; subsequently, we used survey result data from 221 adult males and females for our research sample. Data analyses were conducted by reliability test, confirmatory factor analysis, t -test or one-way analysis of variance, and structural equation model (SEM) with IMB SPSS ver. 21.0 and ver. AMOS ver. 21.0. This study focused on multi-dimensional consumer innovativeness and found three elements of acceptability, competence, and distribution. Empirical verification through SEM presented data that suggests the three consumer innovativeness factors have a direct positive effect on social commerce that causes factors to indirectly affect satisfaction levels. This study indicated that the main consumption patterns in modern society take advantage of social commerce and satisfaction by improving a market economy to promote restoration. First, this study considers consumer innovativeness to have three factors. Secondly, research results help to understand relations between consumer innovativeness, use and satisfaction with social commerce that can help the social commerce industry establish effective market strategies through consumer innovativeness. The conclusion discusses implications for academic research and marketing strategies.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.1884-1886
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• 2005

KrF 펄스 레이저 증착법(pulsed laser deposition: PLD)으로 ZnO 박막을 증착하여 평판 디스플레이 소자 구동용 박막 트랜지스터(thin film transistor) 소자를 제작하였다. 전도성이 높은 실리콘웨이퍼(c-Si, 하부전극) 기판 위에 LPCVD 법으로 silicon nitride 박막을 절연막으로 형성하고, 다양한 공정 조건에서 펄스 레이저 증착법으로 제작한 ZnO 박막을 증착하여 채널층으로 하였으며, Al 박막을 증착하고 패터닝하여 소스 및 드레인 전극으로 하였다. ZnO 박막의 증착 시에 기판 온도를 다양하게 조절하고 산소 분압을 변화시켜 ZnO 박막의 특성을 조절하였다. 제작된 박막의 표면특성은 AFM(atomic force microscopy)로 분석하고, 결정특성은 XRD(X-ray diffraction)로 조사하였다. ZnO 박막의 전기적 특성은 Hall-van der Pauw 법으로 측정하였고, 광학 투과도(optical transparency)를 UV-visible photometer로 조사하였다. ZnO-TFT 소자는 $10^6$ 수준의 on-off ratio와 $2.4{\sim}6.1cm^2/V{\cdot}s$의 전계효과이동도(field effect mobility)를 보였다.

• Journal of Korean Vacuum Science & Technology
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• v.2 no.2
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• pp.107-117
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• 1998

Epitaxial undoped and Sb-doped si films have been grown on Si(001) substrates at temperatures T between 80 and 750$^{\circ}C$ using energetic Si in ultra-high-vacuum Kr+-ion-beam sputter deposition(IBSD). Critical epitaxial thicknesses te, The average thickness of epitaxial layers, in undoped films were found to range from 8nm at Ts=80$^{\circ}C$ to > 1.2 ${\mu}$m at Ts=300$^{\circ}C$ while Sb incorporation probabilities $\sigma$sb varied from unity at Ts 550$^{\circ}C$ to 0.1 at 750$^{\circ}C$. These te and $\sigma$Sb values are approximately one and one-to-three orders of magnitude, respectively, higher than reported results achieved with molecular-beam epitaxy. Plan-view and cross-sectional transmission electron microscopy, high-resolution x-ray diffraction, channeling and axial angular-yield profiles by Rutherford back scattering spectroscopy for epitaxial Si1-x Gex(001) alloy films (0.15$\leq$x$\leq$0.30) demonstrated that the films are of extremely high crystalline quality. critical layer thicknesses hc the film thickness where strain relaxation starts, I these alloys wre found to increase rapidly with decreasing growth temperature. For Si0.70 Ge0.30, hc ranged from 35nm at Ts=550$^{\circ}C$ to 650nm at 350$^{\circ}C$ compared to an equilibrium value of 8nm.

• Laser Solutions
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• v.8 no.2
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• pp.21-32
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• 2005

The excimer laser ablation of a polymer occurs by the excitation of chemical bonds to energy levels that are above the dissociation energy. In this process, however, fragmented debris is finally ejected explosively by the scission of bonds and accumulates on the material surface. In the present work, a process for eliminating surface debris contamination generated by the laser ablation of a polymer is developed. The proposed approach for removing surface debris utilizes an erasable ink pasted on a polymide. The ink pasted polyimide is ablated by KrF excimer laser. The surface debris ejected from the polyimide is then combined with the ink layer on the polymer. Finally, both the surface debris and the ink layer are removed using adhesive tape or alcohol solvent. The results suggest that the erasable ink method is a simple, low cost, and extremely effective debris eliminating process.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.146.2-147
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• 2003

Two Korean isolates of Alfalfa mosaic virus (AHV-AZ, AMV-KR) were isolated from azuki bean and potato plants, respectively, and their pathologies were confirmed on some susceptible host plants including pepper, tobacco and red bean plants. Full length cDNAs to RNA1, RNA2 and RNA3 of the two Korean strains were amplified using the long-template reverse transcription (RT)-polymerase chain reaction (PCR) method. RT-PCR products covering entire regions for the three AMV genome RNAs were cloned. RNA transcripts were synthesized in vitro from each clones using T7 RNA polymerase and infectivity test was peformed in 9 reassortment sets of transcripts. All the combinations of reassorted transcripts were found to be infectious when inoculated onto Nicotiana benthamiana plants, and were not distinguishable to those of wild types. The full-length cDNA clones that were confirmed infectious were sequenced their nucleotide sequences. We will discuss sequence analysis of the two Korean isolates of AMV genomic RNA3 and compare reported foreign isolates of AMV.