• Journal of the Korean Vacuum Society
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• v.12 no.S1
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• pp.95-99
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• 2003

We successfully grew InN/GaN single quantum well structures by metal-organic chemical vapor deposition and confirmed their formation by optical and structural measurements. We speculate that relatively high growth temperature ($730^{\circ}C$) of InN layer enhanced the formation of 2-dimensional quantum well structures, presumably due to high adatom mobility. As the growth interruption time increased, the PL emission efficiency from InN layer improved with peak position blue-shifted and the dislocation density decreased by one order of magnitude. The high resolution cross-sectional TEM images clearly showed that the InN layer thickness reduced from 2.5 nm (without GI) to about I urn (with 10 sec GI) and the InN/GaN interface became very flat with 10 sec GI. We suggest that decomposition and mass transport processes on InN during GI is responsible for these phenomena.

• Hwankyungkyoyuk
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• v.23 no.4
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• pp.70-81
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• 2010

The present study aimed to understand high school students' environmental literacy for water and their attitudes toward environment. This study was conducted during the spring of the 2010 academic year with the participation of 123 students from a public international high school located in Seoul. The Environmental Science Literacy for Water test and the Revised New Ecological Paradigm scale were administered, and the data were analyzed by descriptive statistics and content analysis. The high school students in this study put strong emphasis on encouraging others to conserve water resources. This belief, however, was not aligned with self-recognition of their own roles in water supply shortages and other problematic water-use behavior. They also had difficulties in understanding the invisible part of matter transformations in water systems. Nevertheless, they showed favorable attitudes toward environmental conservation. In conclusion, the researchers suggest recognizing our own water problems and narrowing the gap between environmental and scientific knowledge of water and actual attitudes about the environment through curricular incorporation of interdisciplinary environmental science literacy into school science.

• Journal of the Korean Society of School Health
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• v.29 no.2
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• pp.71-80
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• 2016

Purpose: The purpose of this study is to examine the association between consuming high-caffeine energy drinks and suicidal ideation in Korean adolescents. Methods: This study used data drawn from the 2015 Korea Youth Risk Behavior Web_Based Survey. The data of 66,068 students in total (33,374 middle school students and 32,694 high school students) were included in the analysis. The $x^2$ test, univariate and multivariate logistic regressions were conducted with the use of SAS 9.3. Results: Adjusted for the variables associated with suicidal ideation, multivariate logistic regression revealed that consuming highly caffeinated energy drinks had a significant effect on suicidal ideation (middle school students, 1~2 times per week: OR=1.24, 3~4 times per week: OR=1.88, 5~6 times per week: OR=2.20, everyday: OR=2.66, high school students, 1~2 times per week: OR=1.26, 3~4 times per week: OR=1.84, 5~6 times per week: OR=2.42, everyday: OR=3.89). Conclusion: This study strongly suggests adolescents be provided with health education and information about consuming an adequate amount of high-caffeine energy drink and the drink's side effects. In addition, regulations and polices on high-caffeine drink intake should be implemented.

• Preventive Nutrition and Food Science
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• v.15 no.3
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• pp.184-188
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• 2010

The purpose of the present study was to evaluate the effects of red pepper seeds powder on lipid metabolism in rats fed high fat high cholesterol diet. Rats were divided into five experimental groups: normal diet group, high fat high cholesterol diet group, high fat high cholesterol diet with 5% red pepper seeds powder supplemented group (SA group), high fat high cholesterol diet with 10% red pepper seeds powder supplemented group (SB group) and high fat high cholesterol diet with 15% red peeper seeds powder supplemented group (SC group). The serum triglyceride (TG) and cholesterol contents, and LDL-cholesterol and atherogenic index (AI) of the red pepper seed powder supplemented groups were significantly decreased compared to the HF group. The serum HDL-cholesterol contents of the red pepper seed powder supplemented groups were increased compared to the HF group. However, there was no significant difference in the serum HDL-cholesterol among all experimental groups. The hepatic TG and cholesterol contents of the red pepper seed powder supplemented groups were significantly decreased compared to the HF group. The fecal total cholesterol and triglyceride contents of the red pepper seeds powder supplemented groups were significantly increased compared to the HF group. These results suggest that supplementation of red pepper seed powder may have a pronounced impact on markers of lipid metabolism in serum and liver of rats fed high fat high cholesterol diets.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.97-99
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• 2017

Our understanding of dust emission, interaction, and evolution, is evolving. In recent years, electric dipole emission by spinning dust has been suggested to explain the anomalous microwave excess (AME), appearing between 10 and 90 Ghz. The observed frequencies suggest that spinning grains should be on the order of 10nm in size, hinting at polycyclic aromatic hydrocarbon molecules (PAHs). We present data from the AKARI/Infrared Camera (IRC) due to its high sensitivity to the PAH bands. By inspecting the IRC data for a few AME regions, we find a preliminary indication that regions well-fitted by a spinning-dust model have a higher $9{\mu}m$ than $18{\mu}m$ intensity vs. non-spinning-dust regions. Ongoing efforts to improve the analysis by using DustEM and including data from the AKARI Far Infrared Surveyor (FIS), IRAS, and Planck High Frequency Instrument (HFI) are described.

• Journal of the Korean Ceramic Society
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• v.52 no.5
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• pp.320-324
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• 2015

Optimization of the fabrication process of NiO-yttrium doped barium zirconate (BZY) composite anode substrates using tape-casting for high performance thin-film protonic ceramic fuel cells (PCFCs) is investigated. The anode substrate is composed of a tens of microns-thick anode functional layer laminated over a porous anode substrate. The macro-pore structure of the anode support is induced by micron-scale polymethyl methacrylate (PMMA) pore formers. Thermal gravity analysis (TGA) and a dilatometer are used to determine the polymeric additive burn-out and sintering temperatures. Crystallinity and microstructure of the tape-cast NiO-BZY anode are analyzed after the sintering.

• Journal of the Korean institute of surface engineering
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• v.57 no.3
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• pp.165-178
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• 2024

In semiconductor memory device manufacturing, the capability for high aspect ratio contact (HARC) etching determines the density of memory device. Given that there is no standardized definition of "high" in high aspect ratio, it is crucial to continuously monitor recent technology trends to address technological gaps. Not only semiconductor memory manufacturing companies such as Samsung Electronics, SK Hynix, and Micron but also semiconductor manufacturing equipment companies such as Lam Research, Applied Materials, Tokyo Electron, and SEMES release annual reports on HARC etching technology. Although there is a gap in technological focus between semiconductor mass production environments and various research institutes, the results from these institutes significantly contribute by demonstrating fundamental mechanisms with empirical evidence, often in collaboration with industry researchers. This paper reviews recent studies on HARC etching and the study of dielectric etching in various technologies.

• Journal of the Korean Society of School Health
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• v.20 no.1
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• pp.53-61
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• 2007

Purpose: The purpose of this study on education and skill of Basic life Support Training in Middle and High School Students. Methods: The Basic life support training courses are taught mostly by Emergency Medical Technician and Paramedic. Sixty five middle school students, Seventy eight High school students and forty six adult received tuition in Basic life support training and subsequently completed questionnaires, test and interviews to assess their theoretical knowledge regarding their likelihood of performing Basic life support training. Under the supervisor, The subjects were evaluated by comparing basic life support education and skill data collected and the education sessions consisted of a 30min video tape. The Basic life support skill sessions used Laerdal manikin, and the data stored from the HeartSim were collected for further analysis. The students were asked to practice what they had been. A statistical analysis was done using the SPSS version 13. Results: Their average age of middle school students were 15.3±1.2 years, high school students (17.3±1.8), and adults(38.3±2.3). The total of 189 subjects were evaluated. The criteria used in the study had the following results First, We found that middle and high school students scored higher than adult. The scores were statistically significant to teach and evaluate the education evaluation showed that the adults scored lower than the middle and high school students. Second, We found that high school students and adult scored higher than middle school students. The scores were statistically significant to teach and evaluate the skills evaluation showed that the middle school students scored lower than the high school students and adult. Conclusion: We found that middle and high school students were superior to adult counterparts in understanding the basic life support education. We found that high school students and adult scored higher than middle school students in the BLS skill training. An expansion of basic life support training to middle and high school students is demanded. The Basic life support skills training seems to be retained between 6 and 12 months. The basic life support training should included in the school education curriculum in school.

• Human Ecology Research
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• v.53 no.1
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• pp.1-16
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• 2015

This study aims to examine the effects of high school students' time management behaviors on their satisfaction with educational consumption and school life. Three hundred seventy-six high school students in Seoul participated in this investigation. The SPSS ver. 19.0 program was adopted for the descriptive analysis, factor analysis, Cronbach's ${\alpha}$, and multiple regression analysis. The results of the present study can be summarized as follows: first, the levels of time management behavior, satisfaction with educational consumption at school, and satisfaction with school life were relatively high. Second, an analysis of the relative influence on satisfaction with educational consumption revealed that the students' time management behavior was the most influential factor, followed by academic achievement. As the levels of time management behavior and academic achievement were high, the level of satisfaction with educational consumption was high. Finally, an analysis of the relative influence of satisfaction with school life also revealed that the students' time management behavior was the most influential factor, followed by academic achievement. Based on the findings, that is, the effects of high school students' time management behavior and other involved variables on their satisfaction with educational consumption and school life, a future study can present specific ways to enhance the level of satisfaction with educational consumption and school life.

• Corrosion Science and Technology
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• v.17 no.2
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• pp.81-89
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• 2018

In this study, the effect of Nb alloying element on the corrosion fatigue properties of high strength steel is investigated by conducting fatigue experiments under corrosive condition and hydrogen induced condition, potentiodynamic polarization test, tensile test and surface analyses. Nb element is added to enhance the mechanical property of medium carbon steel. This element forms MX-type phases such as carbides and nitrides which are playing an important role in the grain refinement. The grain refinement is one of the effective way to improve mechanical property because both tensile strength and toughness can be improved at the same time. However, MX-type phase precipitates can be a susceptible site to localized corrosion in corrosive environment due to the potential difference between matrix and precipitate. The obtained results showed that Nb-added steel improved corrosion fatigue property by grain refinement. However, it is degraded for hydrogen-induced fatigue property due to Nb, Ti-inclusions acting as a stronger trap.