• Sleep Medicine and Psychophysiology
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• v.10 no.1
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• pp.32-38
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• 2003

Objectives: The purpose of this study is to investigate the effects of stress and personality on sleep patterns, and further, to identify potential correlations between stress and personality characteristics. Methods: A total of 174 healthy college students were subjects for this study. Participants filled out the Daily Stress Inventory before sleep and the Modified Pittsburgh Sleep Quality Index after sleep on three consecutive days. They also filled out the 16 Personality Factor Questionnaire (16-PF), BDI (Beck Depression Inventory) and STAI (State-Trait Anxiety Inventory). Results: Minor stresses highly correlated with subjective sleep quality and symptoms of non-restorative sleep. However, total sleep time, sleep latency, awakening frequency, and frequency of dreams were not explained by stress scores. The O (guilty feeling), C (low ego strength) and Q4 (high anxiety) factors of the 16-PF also highly correlated with symptoms of non-restorative sleep and significantly affected sleep patterns. BDI and STAI scores also correlated with the above personality factors and minor stresses. Conclusion: This study showed that minor stresses impaired the restorative effects of sleep. Personality characteristics such as low ego strength, high levels of anxiety, and feelings of guilt were vulnerable to minor stresses. Minor stress, various personality characteristics, different coping patterns, and emotional response are highly correlated with each other and affect sleep patterns.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.161-176
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• 2021

In this study, one of the distributed hydrologic models, VELAS, was used to analyze the variation of hydrologic elements based on water balance analysis to evaluate the groundwater recharge in more detail than the annual time scale for the past and future. The study area is located in Yanggok-ri, Seobu-myeon, Hongseong-gun, Chungnam-do, which is very vulnerable to drought. To implement the VELAS model, spatial characteristic data such as digital elevation model (DEM), vegetation, and slope were established, and GIS data were constructed through spatial interpolation on the daily air temperature, precipitation, average wind speed, and relative humidity of the Korea Meteorological Stations. The results of the analysis showed that annual precipitation was 799.1-1750.8 mm, average 1210.7 mm, groundwater recharge of 28.8-492.9 mm, and average 196.9 mm over the past 18 years from 2001 to 2018 in the study area. Annual groundwater recharge rate compared to annual precipitation was from 3.6 to 28.2% with a very large variation and average 14.9%. By the climate change RCP 8.5 scenario, the annual precipitation from 2019 to 2100 was 572.8-1996.5 mm (average 1078.4 mm) and groundwater recharge of 26.7-432.5 mm (average precipitation 16.2%). The annual groundwater recharge rates in the future were projected from 2.8% to 45.1%, 18.2% on average. The components that make up the water balance were well correlated with precipitation, especially in the annual data rather than the daily data. However, the amount of evapotranspiration seems to be more affected by other climatic factors such as temperature. Groundwater recharge in more detailed time scale rather than annual scale is expected to provide basic data that can be used for groundwater development and management if precipitation are severely varied by time, such as droughts or floods.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.87-95
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• 2012

This study was investigated to determine the contamination levels of total aerobic bacteria, coliform group, $E.$ $coli$ and food-borne pathogens of side dishes from 2 traditional markets (100 samples) and 2 super markets (100 samples) located on Ulsan. The levels (range) of total aerobic bacteria was 4.75 log CFU/g (1.60~6.92 log CFU/g) in traditional market and 4.62 log CFU/g (2.00~6.46 log CFU/g) in super market, respectively. Coliform was detected in 64 and 66 samples sold at traditional markets and super markets, respectively. $E.$ $coli$ was detected in 4 and 6 samples sold at traditional markets and super markets, respectively. The food-borne pathogens, namely $Bacillus$ $cereus$ and $Listeria$ $monocytogenes$ were detected in 1 sample sold at traditional markets, respectively, and $Bacillus$ $cereus$ was detected in 4 samples sold at super markets. However, other pathogens such as $Salmonella$ spp., $Shigella$ spp., $Vibrio$ $parahaemolyticus$, $Yersinia$ $enterocolitica$, $Clostridium$ $perfringens$, $Camphylobacter$ $jejuni$ and Pathogenic $E.$ $coli$ were not detected. The $Saengchae$ and $Seasoned$ $Jeotgal$ were relatively vulnerable compared to the others in the food-borne pathogens.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.65-65
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• 2018

갈바륨 도금강판은 알루미늄의 우수한 차폐 특성과 내열성, 열 반사성을 가지며 아연의 희생방식 특성을 겸비하여 동일 부착량의 용융 아연도금 및 알루미늄 도금강판에 비해 우수한 내식성을 나타낸다고 알려져 있다. 또한 이것은 표면이 미려하고 경제성이 높아 건자재 용도로 현재까지도 세계적으로 널리 이용되고 있다. 여기서 지칭하는 바륨 도금강판(galvalume steel)은 아연과 알루미늄 도금강판의 장점을 접목하기 위해 55 Al-43.4 Zn-1.6 Si (wt.%)로 구성되어 개발된 3원계 성분의 합금도금강판이다. 한편, 최근에는 강재의 내식성을 향상시키기 위한 다양한 연구 결과에 의해 Zn-Al-Mg의 3원계 합금도금강판도 개발되어 사용되고 있다. 이것은 기존의 아연도금 강판 보다 10배 정도의 우수한 내식성을 나타내는 것으로 보고되고 있다. 특히, 이것은 도금된 평판부의 내식성은 물론 절단된 도금 단면부의 내식성도 매우 우수하다고 알려져 있다. 그러나 상기한 갈바륨 도금강판의 경우에는 도금된 표면부에 비해 단면부의 내식성이 상대적으로 취약한 것으로 알려져 있다. 따라서 본 연구에서는 갈바륨 도금강판의 내식성을 종합적으로 향상시키기 위하여 이 갈바륨 도금강판 상에 PVD 스퍼터링법에 의해 Mg 코팅막의 제작을 시도하였다. 여기서 Mg 코팅막은 후처리 된 갈바륨 도금강판 상에 Ar 공정압력 2 및 20 mTorr 조건 중 1.5 및 $3{\mu}m$ 두께로 제작하였다. 또한 제작한 코팅막에 대해서는 모폴로지 관찰(SEM) 및 결정구조 분석(XRD)을 하였고, 분극측정, 염수분무 시험(SST) 및 복합부식 시험(CCT)에 의해 표면 및 단면부의 내식성평가를 수행하였다. 또한 여기서는 염수분무 및 복합부식 시험 후의 시험편도 채취 하여 표면 및 단면부위에 대한 원소조성 분석(EPMA)과 결정구조 분석(XRD)을 실시하였다. 이상의 실험 결과에 의하면, 본 실험에서 제작한 Mg 코팅막은 그 두께가 두꺼울수록 표면 Mg 결정립의 크기가 증가하였고, 그 부식속도가 증가하는 경향을 나타내었다. 또한 여기서는 공정압력이 높은 조건에서 제작한 막일수록 Mg(002)면 피크 강도가 감소하고 Mg(101)면 피크의 배향성이 증가하였다. 그때 그 막의 내식성은 향상되는 경향을 나타내었다. 그리고 종합적으로 염수분무 및 복합부식 시험 결과에 의하면 Mg이 코팅된 갈바륨 도금강판은 기존 갈바륨 도금강판 보다 내식성이 현저히 향상되었다. 특히, 단면부 내식성의 경우에는 기존 대비 5배 이상 향상되는 경향을 나타내었다. 여기서 단면부 내식특성 분석을 위한 EPMA 원소조성 분석 결과에 의거하면, 부식 초기에는 마그네슘의 부식생성물에 의해 단면부가 치밀하게 보호되고 있음을 확인할 수 있었다. 그 이후에는 부식이 지속적으로 진행됨에 따라 갈바륨 도금층에서 용출된 알루미늄 및 아연 성분이 마그네슘과 함께 치밀한 부식생성물을 형성하여 단면부를 차폐함에 따라 단면부의 내식성이 크게 향상된 것으로 생각된다. 이러한 부식생성물의 결정구조 분석 결과에 따르면, 염수분무와 복합부식 시험에서는 공통적으로 MgO, $Mg(OH)_2$ 이외에도 Simonkolleite상 등이 형성되었다. 또한 건-습 반복 부식시험인 복합부식시험 후에는 $Mg_5(CO_3)_4(OH)_24H_2O$(Hydromagnesite)상 등이 형성됨을 확인할 수 있었다. 즉, 본 실험에서 후처리된 갈바륨 도금강판 상에 제작한 마그네슘 코팅막의 경우에는 상기와 같은 다양한 부식반응에 의해 표면 및 단면부에 형성된 Mg계 부식생성물과 $Zn_5(OH)_8Cl_2H_2O$(Simonkolleite)상에 의해서 표면은 물론 단면부 내식성이 크게 향상된 것으로 사료된다.

• Journal of Nutrition and Health
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• v.48 no.3
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• pp.277-288
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• 2015

Purpose: As the rate of senior citizens living alone increases in the current aging society, there is much concern regarding the health and nutritional intake of solitary senior citizens. Therefore, this study compared the nutritional intake of senior citizens according to their family type. Methods: In July and August of 2011, two senior citizen welfare centers in Seoul were visited to survey 267 elderly women. Excluding 54 subjects for which the data were incomplete, information from 213 subjects was analyzed. The subjects were divided into three family types, living alone (LA, n = 74), living with spouse (LS, n = 78), and living with children (LC, n = 61). Results: The mean age of the LA group was the highest, while the mean age of the LS group was the lowest (p < 0.001), and WHR of the LC group was the highest (p = 0.049). Income was the highest in the LS group (p < 0.001). Frequency of eating out was the lowest in the LA group (p = 0.031). By Duncan's multiple analysis, the amounts of energy intake, vegetable protein, fat, calcium, phosphorus, potassium, selenium, Vit D, Vit E, $Vit\;B_2$, niacin, $Vit\;B_6$, $Vit\;B_{12}$, and cholesterol were significantly higher in the LS group compared with the LA or LC group (p < 0.05). The intakes of calcium, Vit D, $Vit\;B_{12}$, and cholesterol were still significantly different among the three groups, even after adjustment for age and monthly income. The LA group ate less fruit and fish than the LS or LC group (p < 0.05). The LA group showed the lowest dietary diversity and the LS group showed the highest diversity (p = 0.014), however, the significance of dietary diversity score among the three groups disappeared after adjustment for age and monthly income. Conclusion: Elderly women living with spouse were receiving better nutrition than elderly women living alone or living with children. Therefore, solitary elderly women who do not live with their spouse or children should be offered greater opportunities to receive a balanced meal at a congregational kitchen or welfare center. To ensure their healthy diet, it is essential to provide continuous nutrition education with these groups in mind.

• Korean Journal of Environment and Ecology
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• v.26 no.2
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• pp.210-218
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• 2012

This study was carried out to analyze the vegetation properties, soil characteristics and ordination of Bletilla striata population in South Korea. The $Bletilla$ $striata$ population was classified into $Juniperus$ $rigida$ dominant population, $Rhododendron$ $yedoense$ var. $poukhanense$ dominant population, $Rhus$ $javanica$ dominant population, $Bletilla$ $striata$ typical population. $Bletilla$ $striata$ were mainly distributed along the coast of south-western regions of the Korean penninsula and it's population was located at an elevation of 4m to 40m. In the study sites, soil organic matter, total nitrogen, available phosphate, exchangeable potassium, exchangeable calcium, exchangeable magnesium, cation exchange capacity and soil pH were 2.38-6.70%, 0.09-0.27%, 1.81-6.85mg/kg, 1.08-1.72$cmol^+/kg$, 3.56-7.71$cmol^+/kg$, 1.52-3.21$cmol^+/kg$, 5.28-16.95$cmol^+/kg$ and 4.60-6.01 respectively. $Rhododendron$ $yedoense$ var. $poukhanense$ dominant population was found in the steep sloped area that has high percentage of organic matter, total nitrogen, cation exchange capacity and pH than other populations. $Rhus$ $javanica$ dominant population was found in the gentle sloped area that has less percentage of organic matter, total nitrogen, cation exchange capacity and pH. $Juniperus$ $rigida$ dominant population and $Bletilla$ $striata$ typical population were found in the medium sloped area that has medium percentage of organic matter, total nitrogen, cation exchange capacity and pH. Current status of $Bletilla$ $striata$ habitats is very vulnerable with local development constantly threatening the species' survival. Thus, concrete conservation plans to protect natural habitats should be set up as soon as possible.

• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.30-36
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• 2012

This study was conducted to evaluate the microbiological hazard on nursery school children's hands and to investigate the reduction effect of hand washing education. A total of 59 nursery school children's hands were tested. The average number of total aerobic bacteria was $3.72{\pm}0.38log\;CFU/hand$. Five children's hands(2 male and 3 female) were positive(14.3%) for the coliform bacteria. These results showed that hand washing education are required repetitively. Among the pathogenic bacteria tested in this study, $Staphylococcus$ aureus and $Bacillus$ $cereus$ were detected in 9(25.7%) and 16(45.7%) out of 35 their hands, respectively. Twelve out of sixteen $B.$ $cereus$ isolates(70.0%) produced enterotoxin. The results indicate that the hand hygiene of nursery school children needs to be improved. Comparing before and after hand washing in educated and non-educated group, the reduction effect of total aerobic bacteria on their hands was 0.42 and 0.60 log CFU/hand, respectively. The educated group showed 0.18 log CFU/hand higher reduction effect than non-educated group but microorganism did not eliminate perfectly. From the results, using a hand sanitizer after washing with soap and the continuous hand washing education are required to control the contaminated bacteria on nursery school children's hands.

• Korean Journal of Environment and Ecology
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• v.34 no.2
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• pp.170-178
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• 2020

There are few landscape ecological analyses of Khingan fir (Abies nephrolepis) and other habitats of the sub-alpine zone in South Korea. In this study, we tried to quantitatively interpret and assess the habitat characteristics by analyzing 15 landscape indices according to the differences in tree layer coverage, in the Khingan fir habitat growing naturally in the sub-alpine zone of Seoraksan National Park. It was difficult to identify the tendency of landscape ecology to increase and decrease the tree layer coverage in the study site, which was the entire Khingan fir habitat in Seoraksan National Park. However, the Khingan fir habitat was found to be generally low in coverage, and population density as the tree layer coverage of less than 50 percent accounts for 85 percent of the total habitat. Moreover, the Khingan fir habitat in the 10 to 50 percent range was fragmented into a total of 286 patches, making it relatively less connected to the habitat. The total edge length and edge density, which could determine the edge effect of the main part according to the physical form, were the highest in the habitat of 26 to 50 percent coverage, indicating a relatively high impact from outside than habitats of other coverages. The shape with the tree layer coverage of between 10 and 50 percent was more complex even with patches of the same size, and it is believed that these characteristics make it more susceptible to habitat fragmentation and external confounding. We expect that the results of this study can be useful for time series analysis of spatial expansion or reduction of the Khingan fir habitat in Seoraksan National Park and provide the reference data for the morphological change and movement of patches and the connectivity and break-off between forests.

• Journal of the Korea institute for structural maintenance and inspection
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• v.27 no.6
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• pp.152-161
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• 2023

In general, large-capacity hydrogen storage vessels, typically in the form of vertical cylindrical vessels, are constructed using steel materials. These vessels are anchored to foundation slabs that are specially designed to suit the environmental conditions. This anchoring method involves pre-installed anchors on top of the concrete foundation slab. However, it's important to note that such a design can result in concentrated stresses at the anchoring points when external forces, such as seismic events, are at play. This may lead to potential structural damage due to anchor and concrete damage. For this reason, in this study, it selected an vertical hydrogen storage vessel based on site observations and created a 3D finite element model. Artificial seismic motions made following the procedures specified in ICC-ES AC 156, as well as domestic recorded earthquakes with a magnitude greater than 5.0, were applied to analyze the structural behavior and performance of the target structures. Conducting experiments on a structure built to actual scale would be ideal, but due to practical constraints, it proved challenging to execute. Therefore, it opted for an analytical approach to assess the safety of the target structure. Regarding the structural response characteristics, the acceleration induced by seismic motion was observed to amplify by approximately ten times compared to the input seismic motions. Additionally, there was a tendency for a decrease in amplification as the response acceleration was transmitted to the point where the centre of gravity is located. For the vulnerable components, specifically the sub-system (support columns and anchorages), the stress levels were found to satisfy the allowable stress criteria. However, the concrete's tensile strength exhibited only about a 5% margin of safety compared to the allowable stress. This indicates the need for mitigation strategies in addressing these concerns. Based on the research findings presented in this paper, it is anticipated that predictable load information for the design of storage vessels required for future shaking table tests will be provided.

• Journal of the Korean Society for Library and Information Science
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• v.58 no.2
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• pp.177-198
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• 2024

Article 22(1) of the Library Act, which was completely revised in December 2006, stipulated that regional representative libraries are statutory organizations, and Article 25(1) of the Library Act, which was revised again in late 2021, renamed them as metropolitan representative libraries and expanded their duties. The reason why cities and provinces are required to specify or establish and operate metropolitan representative libraries is that in addition to their role as public libraries for public information use, cultural activities, and lifelong learning as stipulated in Article 23 of the Act, they are also responsible for the legal works of metropolitan representative libraries as stipulated in Article 26, and lead the development of libraries and knowledge culture by serving as policy libraries, comprehensive knowledge information centers, support and cooperation centers, research centers, and joint preservation libraries for all public libraries in the city or province. Therefore, it is necessary to analyze and diagnose whether the metropolitan representative library has been faithfully fulfilling its legal works for the past 15 years(2009-2023), and whether it is properly providing the results of its statutory planning and implementation on its website to meet the digital and mobile era. Therefore, this study investigated and analyzed the performance of the metropolitan representative library for the last two years based on the current statutory tasks and evaluated the extent to which it provides them through its website, and suggested complementary measures to strengthen its web services. As a result, it was analyzed that the web services for legal works that the metropolitan representative library should perform are quite insufficient and inadequate, so it suggested complementary measures such as building a website for legal works on the homepage, enhancing accessibility and visibility through providing an independent website, providing various policy information and web services (portal search, inter-library loan, one-to-one consultation, joint DB construction, data transfer and preservation, etc.), and ensuring digital accessibility of knowledge information for the vulnerable.