• Journal of Advanced Marine Engineering and Technology
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• 제40권8호
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• pp.692-697
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• 2016

This study investigated the effect of surface roughness of zinc oxide (ZnO) layer on the growth of polycrystalline Si layer via an Al-induced layer exchange process. It was found that the growth rate, grain size, crystallization fraction, and preferential orientation of the polycrystalline Si layer were strongly influenced by the surface roughness of the underlying ZnO layer. As the roughness of the ZnO surface increased, a higher growth rate (~40 min) and preferential Si (100) orientation were obtained because of the spatial concentration fluctuations in the Al-Si alloy, induced by the surface roughness of the underlying ZnO layer.

• 한국표면공학회지
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• 제56권1호
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• pp.12-39
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• 2023

Diseases caused by air pollution and abnormal climate are occurring worldwide due to global warming. Accordingly, the international community has established a strategy to respond to climate change, and major countries have shifted their economic policies to eco-friendly industries. In this study, we investigate the current status of the renewable energy industry and that of responses to carbon neutrality and PM2.5 (air pollution) in the three major Northeast Asian countries of Japan, Korea, and China, covering changes in the corporate perceptions of Environment, Social, Governance and RE100. In more detail, the three major Northeast Asian countries, referred to as the climate villains in the international community, explain the importance of successful entry into the electric vehicles (EV) industry for a rapid transition to an eco-friendly industry. Moreover, we study the application of lightweight materials for vehicles to improve mileage in the EV industry and technical problems to be solved in the future.

• 한국환경과학회지
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• 제23권6호
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• pp.1067-1074
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• 2014

Life Cycle Assessment(LCA) has been carried out to evaluate the environmental impacts of glass bottle recycle. The LCA consists of four stages such as Goal and Scope Definition, Life Cycle Inventory(LCI) Analysis, Life Cycle Impact Assessment(LCIA), and Interpretation. The LCI analysis showed that the major input materials were water, materials, sand, and crude oil, whereas the major output ones were wastewater, $CO_2$, and non-hazardous wastes. The LCIA was conducted for the six impact categories including 'Abiotic Resource Depletion', 'Acidification', 'Eutrophication', 'Global Warming', 'Ozone Depletion', and 'Photochemical Oxidant Creation'. As for Abiotic Resource Depletion, Acidification, and Photochemical Oxidant Creation, Bunker fuel oil C and LNG were major effects. As for Eutrophication, electricity and Bunker fuel oil C were major effects. As for Global Warming, electricity and LNG were major effects. As for Ozone Depletion, plate glasses were major effects. Among the six categories, the biggest impact potential was found to be Global Warming as 97% of total, but the rest could be negligible.

• 복식문화학회:학술대회논문집
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• 복식문화학회 2000년도 International Costume Culture Conference
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• pp.91-92
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• 2000

• 한국고분자학회지:고분자과학과기술
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• 제21권1호
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• pp.33-40
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• 2010

• 한국의류학회지
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• 제39권5호
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• pp.778-788
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• 2015

This study evaluated the characteristics and sensibility of work clothes materials developed that took into account the work environment of major industrial settings, for which a selection was made according to spring/autumn use and winter use. The physical properties of the existing and test weaving of the work clothes materials were compared after the test weaving of work clothes materials through material design, which altered the yarn count, composition, weave and density of material. To evaluate sensibility of work clothes materials subjectively, seven ranks' semantic differential scale questions were developed with polar adjective pairs. The test weaving of work clothes materials showed improved performance (such as tensile strength, dimensional change, water vapor permeability, and color fastness) compared to the existing materials. The common factor analysis indicated that the explanatory power of the cumulative variance for the spring/autumn use and winter use was 71.19% and 69.53%, respectively.

• 한국비블리아학회지
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• 제32권4호
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• pp.5-24
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• 2021

본 연구의 목적은 대학생을 대상으로 비대면 온라인 수업에서의 강의 콘텐츠 운영 실태를 조사 분석하기 위해 수행되었다. 93명의 응답지를 분석한 결과, 첫째 응답자의 93.3%가 실시간 화상 강의(47.7%) 또는 녹화 강의(45.6%)의 형태의 온라인 강의를 수강한 것으로 나타났다. 둘째 교재로 사용한 콘텐츠를 분석한 결과, 교양(47.3%)과 전공(39.8%) 모두에서 전자책(자료)과 종이 책(자료)을 혼용하거나 전자 책 또는 자료(각각 36.6%, 37.6%)를 사용한 것으로 나타났다. 교재 이외에 외부자료는 전공과 교양 모두 웹자료(각각 47.6%, 40.5%)와 유튜브 자료(각각 33.3%, 48.0%) 활용이 높은 것으로 나타났다. 셋째 강의 내용 공유를 위한 콘텐츠는 교양 전공 모두에서 교수자가 정리, 저술한 PT 또는 텍스트 형태의 전자파일(각각 62.9%, 58.1%), 인터넷 자료(각각 16.7%, 19%), 종이 책 또는 자료(각각 10.4%, 12.3%) 순으로 나타났다. 전공과목에서는 93.5%가, 교양과목에서는 90.2%가 화면 현시 강의 콘텐츠에 만족하는 것으로 나타났다. 분석결과를 토대로, 첫째 멀티미디어 기반의 강의 콘텐츠를 개발할 것과 실시간 시험 감독 등이 가능한 평가 솔루션을 개발할 것을 제언하였다. 둘째 과제물에 대한 AI 기반의 표절검색, 과제지도, 과제평가 등이 가능한 과제물관리시스템을 개발할 것을 제언하였다. 셋째 유비쿼터스 개념에서 수업이 가능하도록 강의 교재 전자화를 위한 저작권문제 해결 방안을 제도화할 것을 제언하였다.

• 한국재료학회지
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• 제13권1호
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• pp.36-42
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• 2003

The oxidation behaviors of Y-Cr bilayer deposited on ferritic steel by magnetron-sputtering for application of the Fe-Cr alloys as interconnectors of planar-type solid oxide fuel cells (SOFCs) were studied. After oxidation at $800^{\circ}C$ for 40 hours, the major phase of $Y_2$$O_3$and the minor phase of $YCrO_3$, $Mn_{1.5}$ $Cr_{1.5}$ $O_4$and Cr$_2$SiO$_4$were formed in the Y/Cr bilayered samples, while the major phase of Cr$_2$O$_3$and the minor phase of $Y_2$$O_3$were formed as the major phase in the Cr/Y bilayered samples. The Log(ASR/T) that expresses electric resistance of the Y/Cr coated specimen with nonconducting $_Y2$$O_3$oxide showed high value of -2.80 Ω$\textrm{cm}^2$$K^{-1}$ / and that of the Cr/Y coated specimen with conducting $Cr_2$$O_3$oxide appeared to be -4.11 Ω$\textrm{cm}^2$$^{K}$ . The electric resistance of the Y/Cr coated specimen was largely increased due to the formation of high resistance oxide scales. However, the Cr/Y coated specimen did not show any increase in the electric resistance and had the long-term stability of oxidation because there was no formation of the secondary phases with low conductivity.

• 한국안전학회지
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• 제14권3호
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• pp.101-109
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• 1999

This study attempts to analyse the solid mixing in the feeder and the packing effect for pressure fluctuations in the fluidized bed. To study the mixing characteristics of solid in vibrating feeder for the stable operations of fluidized combustion, the system consisted of two groups of particles such that fine particles were located on the top of the coarse particles before vibratory mixing had started. The effects of packing materials on the pressure fluctuations in a fluidized bed were analysed by using a statistical method to interpret the behavior of fluidized bed. The experiments were carried out in a fluidized bed of 6.7cm-ID, and the experimental variables were particle sizes, of 115 to 1,015$\mu\textrm{m}$ in diameter and the multi-sized particles haying Rosin-Rammler and Gaussian distributions. The settled bed heights of particles to diameter ratios (L/D) were ranged from 0.5 to 2.0. And fluidizing of particles was carried out by air. The packing materials used were screen packing, and the properties of the pressure fluctuations in the fluidized bed were measured by a differential pressure transducer. The properties of the pressure fluctuations calculated were the mean, the standard deviation, and the major frequency of the power spectral density functions. From the characteristics of fluidizing, it was found that the standard deviation of pressure fluctuations could be effectively used to explain the fluidized phenomena, and the packing materials affected severely the properties of the pressure fluctuations. As a result, from the interpretation by spectral analysis, the effects of measuring radius of pressure fluctuations on standard deviation were constant in the case of the fluidized bed with and without packing materials. However, the effects of measuring the height of pressure fluctuations on standard deviations were linear increasing for the fluidized bed with packing materials, but were constant for the fluidized bed without packing materials at 4.5cm above the gas distributor. The major frequency of pressure fluctuations was found to be nearly independent of fluidized system. Also, the major frequency of pressure fluctuations decreased with increasing packing size, and it had maximum value at 10% of the packing amount.

• 대한심미치과학회지
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• 제7권1호
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• pp.32-40
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• 1998

Alveolar ridge augmentation and preservation techniques designed to reconstruct deformed alveolar ridge now occupy a major role in esthetic dentistry. Previously, deformed alveolar ridges were filled with plastic materials(porcelain or resin) of prosthesis to restore ridge contours, which resulted in larger teeth and food impaction under the pontic base. So, prostheses of this type were unacceptable and really detectable when patients smiled. But nowadays, alveolar ridge augmentation procedures enable the dentists to provide patients with fixed prostheses that are esthetic. The development of guided tissue regeneration technique and materials also have made a major impact on extending the scope of therapeutic horizons in dentistry.