• Journal of Environmental Health Sciences
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• v.30 no.3
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• pp.191-206
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• 2004

The present study investigated the hypothesis that a extremely low frequency magnetic field partially suppresses the synthesis of melatonin in a group of 28 primary schoolchildren living nearby and 60 primary schoolchildren aged 12 years living far away from overhead transmission power lines from December 2003 to April 2004 in Seoul, Korea. The mean personal exposure levels of the primary schoolchildren living nearby overhead transmission power line were 0.37 ${\mu}$T, whereas the value for the primary schoolchildren living away from overhead transmission power line 0.05 mT. From simple analyses, the mean melatonin levels in the primary schoolchildren living nearby were lower than away from overhead transmission power line, but not statistically significant differences in the levels of the melatonin (p=0.2421), whereas the statistically significant differences in the levels of the melatonin related to the distance from residence to power line less and more than 100 m by cut-off point (p=0.0139). In multiple linear regression analyses, distance from residence to power line (p=0.0146) and dietary habit about burned meat (p=0.0170) proved to be significant risk factors in the mean nocturnal melatonin levels in the primary schoolchildren. In conclusion, these results demonstrate that urinary levels of nocturnal melatonin are not altered in primary schoolchildren exposed to extremely low frequency magnetic field(ELF-MF) at overhead transmission power line.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.2
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• pp.196-207
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• 1999

The purpose of this study was to investigate the differences of the visual evaluation for the Picture image combination of Clothing and Ground. The major finding were as follows ; 1) For the visual evaluation of the Picture image as Clothing variation there were significant differences in all factors 2) For the visual evaluation of the Picture image as Ground variation there were significant differences in Attractiveness Hardness and softness Cuteness Attention Cool and Warm factor 3) For the visual evaluation of the Picture image as Percentage of Clothing there were significant differences in Attractiveness cool and Warm factor. It will Percentage of Clothing there were significant differences in Attractiveness Cool and Warm factor. It will aid in choosing the most beneficial background for any clothing brand. It will enhance the picture images to their full potential in any advertising medium 4) As a result of Regression analysis image effecting on " Preference" is refined-country like harmonious-inharmonious comfortable-uncomfortable beautiful-ugly splendid-dull stable-uneasy live-gentle 5) For the Image effecting on "Harmony" according to clothing image there were significant differences. the results analyzed according to the change of background are as follows. Mdern and strong images formed charming urban and cool visual images with urban and neat artificial backgrounds. Mature images were created with romantic and static artificial backgrounds. Mannish straight and conservative images created charming and rigid visual images in urban and formatted artificial background. Using a white natural background for the urban style created a cool visual image. The use of an interior background lead to warmer images and more defination lines Causal images created a rural and warm image which expressed charm and a soft visual while using a rural and natural background. A most unharmonious and hard image was created when using an urban and formatted artificial background. The coolest visual image was created with a cool and natural background. Feminine and flawless images created urban and neat visual image using an urban and formatted artificial background. The coolest visual image was fresh created with a cool and natural background. natural background.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.205-214
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• 2008

Blast disease caused by the fungal pathogen, Magnaporthe oryzae, is one of the most damaging diseases in rice. The use of resistant varieties is an effective measure to control the disease, however, many resistant varieties were broken down to their resistance effects by the differentiating of new virulent isolates. This study was done to analyze the haplotypes of 31 microsatellite markers linked to five major R genes and two QTLs and to identify the alleles for the putatively novel genes related to durable resistance to blast in 56 Korean japonica and four indica varieties. The 31 microsatellite markers produced 2 to 13 alleles(mean = 5.4) and had PICi values ranging from 0.065 to 0.860(mean=0.563) among the 60 rice accessions. Cluster analysis based on allele diversities of 31 microsatellite markers grouped into 60 haplotypes and ten major clusters in 0.810 genetic similarity. A subcluster IV-1 grouped of early flowering varieties harboring Piz and/or Pi9(t) on chromosome 6 and Pita/Pita-2 gene on chromosome 12. The other subcluster V-1 consisted of four stable resistance varieties Donghae, Seomjin, Palgong and Milyang20. The analysis of putative QTLs associated with seven blast resistance genes using ANOVA and linear regression showed high significance to blast resistance across regions and isolates in the markers of two genes Piz and/or Pi9(t) and Pita/Pita-2. These results illustrate the utility of microsatellite markers to identify rice varieties is likely carrying the same R genes and QTLs and rice lines with potentially novel resistant gene.

• Journal of Community Nutrition
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• v.7 no.4
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• pp.201-206
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• 2005

The purpose of this study was to examine the impact of offering brand-name fast food at schools on student participation in school lunch. Two studies were conducted in Indiana, USA. In the first study, daily participation rate of 42 Indiana schools were compared between the days when brand-name fast food were offered and when they were not offered. The impact of brand-name fast food service on school lunch participation differed depending on the types of service offering brand-name fast food. Offering brand-name fast food solely as part of reimbursable meals or a-la-carte items was shown to induce students to the lunch option where brand-name fast food was offered. The second study examined the relationship of brand-name fast food service to monthly participation rate by analyzing secondary data of 1,282 Indiana schools using multiple regression analysis. Offering brand-name fast food was associated with monthly participation rate in school lunch only when schools offered them solely a-la-carte. Based on the results of two studies, it was concluded that offering brand-name fast food induced students from other lunch options to the options where brand-name fast food was offered on the day of service. However, increased or decreased participation in school lunch only on a few days could have not impacted average school lunch participation over a month. It is recommended that schools planning to offer brand-name fast food should make it available as part of reimbursable school lunches so that usual school lunch eaters would not be distracted to a-la-carte lines. (J Community Nutrition 7(4): $201\～206$, 2005)

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.5
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• pp.159-169
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• 2008

The aim of this paper is to research the changes of social welfare by internalizing external cost, especially the maintenance cost. Main target of this paper is the Cheonan$\sim$Nonsan Line, where private capital highway, national highway and local road are competing against each other. Considering the realistic difficulties in applying the First Best pricing, this paper applied the Second Best pricing, applying the maintenance cost, in lieu of the already mentioned. The demand functions of the toll roads were built through regression analysis. By reflecting the maintenance cost to the toll fee, It was able to confirm the variation of social welfare deriving from the traffic assign change but also the aspects of toll revenue at the same time. Result of applying the Second Best pricing shows merely a small change in social welfare. However, in the aspect of finance, it is analyzed that there will be about 13 billion won worth of financial effectiveness which will contribute to the reduction of the national financial support.

• Safety and Health at Work
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• v.11 no.4
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• pp.491-499
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• 2020

Background: Assembly lines work is frequently associated to work-related upper limb musculoskeletal disorders. The related disability and absenteeism make it important to implement efficient health surveillance systems. The main objective of this study was to identify self-reported variables that can determine work-related upper limb musculoskeletal symptoms-discomfort/pain-during a 6-month follow-up. Methods: This was a prospective study with a 6-month follow-up period, performed in an assembly line. Upper limb musculoskeletal discomfort/pain was assessed through the presence of self-reported symptoms. Uni- and multivariate logistic regression analyses were used to evaluate which self-reported variables were associated to upper limb symptoms after 6 months at the present and to upper limbs symptoms in the past month. Results: Of the 200 workers at baseline, 145 replied to the survey after 6 months. For both outcomes, "having upper limb symptoms during the previous 6 months" and "education" were possible predictors. Conclusion: Our results suggest that having previous upper limb symptoms was related to its maintenance after 6 months, sustaining it as a specific determinant. It can be a hypothesis that this population had mainly workers with chronic symptoms, although our results give only limited support to self-reported indicators as determinants for upper limb symptoms. Nevertheless, the development of an efficient health surveillance system for high demanding jobs should implicate self-reported indicators, but also clinical and work conditions assessment should be accounted on the future.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.55-61
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• 2019

To improve bus service quality and passengers' safety at bus stops, it is necessary to analyze the relationship between bus stopping behaviors and bus stop conditions. Thus, this study investigated the proper stopping rate at 31 bus stops on Central Boulevard in Busan metropolitan city and analyzed the relationship between the proper stopping rate and bus stop operating conditions such as the length of berth, the distance from the front line of berth to bus shelter and so on. The analysis results show that the proper stopping rate is 45.82 % and the rates are closely related to each bus stop operating condition. Therefore, it is highly recommended that the front line of berth should be located parallel to bus shelter for improving the safety of bus passengers. In addition, it is suggested that the length of berth should be longer than 15m and the pavement marking of berth be redesigned with dash lines to take account of buses' entering and leaving the berth.

• Corrosion Science and Technology
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• v.20 no.6
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• pp.451-465
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• 2021

In this investigation, electrochemical characteristics and damage behavior of 316L stainless steel polymer electrolyte membrane fuel cell(PEMFC) were analyzed by potentiodynamic and potentiostatic tests in cathode operating condition of PEMFC. As the result of potentiodynamic polarization test, range of passive region was larger than range of active region. In the result of potentiostatic test, damage depth and width, pit volume, and surface roughness were increased 1.57, 1.27, 2.48, and 1.34 times, respectively, at 1.2 V compared to 0.6 V at 24 hours. Also, as a result of linear regression analysis of damage depth and width graph, trend lines of damage depth and width according to applied potentials were 16.6 and 14.3 times larger, respectively. This demonstrated that applied potential had a greater effect on pitting damage depth of 316L stainless steel. The damage tendency values were 0.329 at 6 hours and 0.633 at 24 hours with applied potentials, representing rapid growth in depth direction according to the test times and applied potentials. Scanning electron microscopy images revealed that surface of specimen exhibited clear pitting damage with test times and applied potentials, which was thought to be because a stable oxide film was formed by Cr and Mo.

• Ocean and Polar Research
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• v.44 no.4
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• pp.365-372
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• 2022

The present study measured the growth performance of juvenile hybrid of red-spotted grouper ♀ × giant grouper ♂ (RGGG) across four water temperatures (19, 23, 27, and 31℃) and compared it to those of maternal purebreds (red-spotted grouper ♀ × ♂, RG) for eight weeks. The specific growth rate (SGR) and weight gain (WG) of RGGG increased as temperature increased, with greater SGR and WG at higher temperatures (27 and 31℃) than RG. The condition factor of RGGG was higher than that of RG and there were no differences between temperature groups within breeding lines. Food consumption increased at higher temperatures for both RGGG and RG, and was the highest in the 31℃ group. Similar to the SGR and WG, the food conversion rate (FCR) in RGGG decreased with increasing water temperature, with the significantly lowest value at 31℃; in RG, however, FCR progressively decreased in the 27℃ group, then increased in the 31℃ group. Furthermore, the FCR of the 31℃ group of RGGG, which had the lowest value among the RGGG groups, was lower than that of the 27℃ group of RG, which had the lowest RG value. In the analysis of nonlinear regression curves within the range of experimental temperature, the optimum temperature for SGR and FCR in RGGG was 31℃, unlike in RG. In conclusion, the growth performance of juvenile RGGG seems to have largely improved from the influence of paternal traits, hybrid with giant grouper, and it is presumed to be more profitable for commercial production in tropics/subtropics.

• Economic Analysis
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• v.27 no.1
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• pp.37-66
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• 2021

This paper examines the potential impacts of COVID-19 on poverty in ASEAN countries. The first estimate, adopted from Summer et al. (2020) and Nonvide (2020), configures three scenarios of contractions in per capita household income or consumption; the impact of each scenario on poverty is calculated using poverty lines at different thresholds. In the second estimate, poverty impacts in 2020 and 2021 were projected using regression models controlling for unobserved country effects, unbalanced data, and endogeneity. COVID-19 has been shown to have negative impacts on poverty reduction in the ASEAN Member States. To reduce poverty, concerted efforts are needed to implement policies for reducing income inequality and promoting economic growth. Such efforts will not only speed up the countries' return to pre-pandemic poverty levels but also contribute to further accelerating poverty reduction.