• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.459-470
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• 2014

This study investigated the correlation between eating behavior patterns, including eating-habits, food preferences, snack intake levels, and eating-out frequency and stress levels in high school students (males 174 and females 122) in Seoul. Analysis of eating-habits showed that eating-irregularity and eating-speed increased with elevated stress levels in both males and females under stress. The size of meals decreased in males, whereas it increased in females under getting stress (P<0.01). Preferences for sugar, hamburgers, and pizza also increased in both males and females under stress. Eating-out frequency decreased in males with a high stress level (P<0.01), whereas it increased in females. As for eating-out partners, males did not show any changes, whereas females preferred friends to family when under stress. Eating-out expenses also increased in both males and females, particularly in females with a high stress level (P<0.05). Males under increased stress showed effective stress reduction by increasing food intake, whereas females under increased stress showed less effective results. Consequently, high school students under high stress, particularly females, showed negative changes in eating behavior patterns, including irregular eating-habits, increased instant food and snack intakes, and increased frequency of eating-out. Therefore, development of appropriate programs for reducing stress and persistent nutrition education to promote good dietary behaviors are required.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.6
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• pp.934-942
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• 2014

The purpose of this study was to investigate factors affecting problematic drinking by university students in the Chuncheon area. Lifelong drinking rate of subjects was 98.1%. Problematic drinking rates according to AUDIT (alcohol use disorders identification test) were as follows: 21.3% 'no problem', 58.0% 'at-risk drinking', 10.0% 'alcohol abuse' and 10.7% 'alcohol dependence'. Research has shown that problematic drinking is more prevalent among freshmen, early drinkers, those with hypochondria, and students who are less satisfied with their campus life or whose own parents are frequent drinkers. It has been shown that more serious problematic drinking is associated with higher 'positive alcohol outcome expectancies' and 'coping motives for drinking', and 'recognition level of drinking cultures' is considered less desirable. Multiple regression analysis revealed that 'coping motives for drinking' was the most significant variable affecting the problematic drinking of university students. Developing and fostering various alcohol-reducing programs that largely focus on 'coping motives for drinking' will greatly contribute to solving problematic drinking.

• Journal of Bio-Environment Control
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• v.18 no.1
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• pp.15-22
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• 2009

Adequate environment conditions with growth stage of potato were decided in a photoautotrophic micropropagation system using models. Total 20 day-period of growth were divided into three growth periods such as 6 (stage 1), 7(stage 2), and 7(stage 3) days. At the 1st stage, no significant differences were observed in the growth of potato plantlets at various photosynthetic photon flux density (PPFD) and $CO_2$ conditions. Considering damaged leaves, $80\;mmol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and ambient $CO_2$ level were adequate in this stage. At the 2nd stage, significant differences were partly observed in several growth characteristics including dry weight. Based on the dry matter model, over $240\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD was too high to cultivate potato plantlets at this stage due to the occurrence of damaged leaves. Considering both plant growth and energy efficiency, $160\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and $700\;mol{\cdot}mol^{-1}\;CO_2$ were selected for the adequate combination. At the 3rd stage, the biomass accumulation was significantly induced in potato plantlets under higher levels of PPFD and $CO_2$ concentration as suggested by increased fresh and dry weights. However, we could not find the saturated point with regard to dry matter due to continuous increase of dry mater even under maximum PPFD ($320\;mmol{\cdot}m^{-2}{\cdot}s^{-1})$. Thus, $320\;mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD and $1800\;mol{\cdot}mol^{-1}\;CO_2$ were considered as the best choice at final stage in this study. In conclusion, even though the growth period of micropropagated potato plantlets was quite a short, favorable environmental conditions required at each growth stage were different. This technique could improve the growth of micropropagated plantlets compared to the conventional micropropagation and apply to other agriculturally important crops as well as potato in the future.

• The Journal of the Korea Contents Association
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• v.12 no.1
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• pp.353-360
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• 2012

The purpose of this study was to evaluate tooth color and microhardness after 15% carbamide peroxide(CP) bleaching treatments with/without potassium nitrate and fluoride(PF), which were used home bleaching. Thirty tooth specimens were obtained from thirty premolar and were randomly divided into three groups: 1, untreated controls(Distilled water): 2, treatment with 15% CP bleaching agent; 3, treatment with 15% CP bleaching agent (contained 3% potassium nitrate and 0.11% fluoride). All groups were treated 6h per day for 14 days then immersed in distilled water. Changes in enamel color were evaluated on Baseline and Day 14. Microhardness were evaluated on Baseline, Days 7 and 14. All the bleached enamel specimens revealed increased whiteness without control group. Groups 2 and 3 showed significantly decreased enamel microhardness compared to control group. On Day 7, Groups 2-3 showed significantly decreased enamel microhardness compared to control group and respective baseline data. The percentage microhardness loss(PML) look at Day 7 and 14 for Group 1, respectively, there was little difference between 1.7 and 0.8. However, Group 2 was 21.9 and 3.5, Group 3 was 16.7 and 1.4 as a baseline and Day 7 were significantly different (p<0.05). The PML of group 2 was significantly highest than that of group 3 on Day 7. As a result, the data indicate that the addition of PF did not influence the whitening efficacy of the bleaching agent negatively. PF-containing bleaching agent reduce the percentage microhardness loss. PF-containing tooth bleaching your teeth with a whitening effect can be reduced by decreasing the hardness of enamel.

• Journal of Korean Society of Forest Science
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• v.82 no.3
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• pp.221-226
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• 1993

Methods for shoot proliferation via pulse treatment onto the microshoots of Quercus acutissima, and ex vitro root induction using peat plug systems of the microshoots of 4 oak trees were described. Pulsing solution was prepared by the addition of BA and/or BA plus zeatin onto the aqueous WPM and sterilized distilled water. Using the solution, pulsing time was adjusted at different levels(0. 1, 2, 5. 9, and 24 hours). Although the effect of pulsing solution prepared by the addition of cytokinins onto the sterilized distilled water was slightly lower in shoot proliferation rate, a little higher in shoot elongation was observed compared with that of aqueous WPM. One hour of pulse treatment revealed best in shoot proliferation and its elongation, whereas the increment of pulsing time slightly suppressed the response. In addition, prolonged pulse time resulted high frequency of hyperhydric shoot appearance. Single treatment of BA was better in shoot proliferation than that of BA combination with zeatin, whereas the latter treatment usually showed rapid and healthy shoot growth. For ex vitro root induction using peat plug systems, black oaks(Q. acutissima and Q. variabilis) revealed excellent rootability compared with white oaks(Q. serrata and Q. mongolica). Shoot-tip necrosis of white oaks eras one of the big problems for survival. In this study, we discribed the effect of pulse treatment, successful ex vitro rooting system by the incorporation of peat plug, and the possibilities for the overcoming the obstacles on micropropagation of oaks.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1491-1496
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• 2002

Purpose : This study was performed to investigate the level of obesity awareness and to help to prevent and to treat obesity by examining the relationship between knowledge of obesity and life style. Methods : Of the students who were surveyed, 1514 answered seriously and were accepted as subjects for the study. The questionaire was anonymous and was filled in by the students themselves. Body mass index was used to compare and analyze the subjects according to gender and age, with 85 percentiles or lower as group one, 86-94 percentiles as group two, and 95 percentiles or higher as group three. Results : Among the boys, level of obesity-awareness was significantly higher(P<0.01) in the obese group than in the normal-weight group. Among the girls, there was no difference in the level of obesity-awareness among the groups(P=0.332). The knowledge of obesity between the groups was not significantly different in either boys or girls. As for the relationship between healthy eating habits and knowledge of obesity, there were no significant differences in either boys or girls. There was no significant difference between the habit of regular exercise and the knowledge level of obesity in either boys or girls. Conclusion : Although this was a localized study and the students were aware of the seriousness of obesity to a certain extent, there was no difference in knowledge of obesity between normal-weight students and obese students. Also, there was no relationship between knowledge of obesity and healthy eating habits or the presence/absence of regular exercises.

• Environmental and Resource Economics Review
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• v.13 no.3
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• pp.519-547
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• 2004

This paper analyze problems about scope of specific trade obligations(STOs), principle of dispute settlement procedure, and non-parties in context of the Cartagena Protocol on Biosafety(POB), which based on sub-paragraph 31(i) of DDA WTO Ministrial Declaration. The implications based on result of this study are as follows. First, to accept the wider scope of STOs under POB in Korea, importing country, won't be harmful to LMOs and Bioindustry. Instead, it will ensure a high level of biosafety concerning the import of LMOs. Exporters can take different kinds of trade measures to countervail adverse effect on the export of LMOs in this case. Therefore importer will endure the aftereffect. However, if korea were in exporter's place, to accept the wider scope STOs under POB will not have a good influence on the export of LMOs. Korea, therefore, should devise scheme for responding to debate about the STOs in MEAs, which have to be based on cost-benefit analysis and scenarios taking into account of speed and level in biotechology progress, status and trend of LMOs R&D and production, and condition of other industries. Second, it is not easy to agree with applying to what's rule between the POB and WTO for settlement dispute. Because there is the incompatibility between the POB characterized according to social rationality and WTO's rules for safety and environmental protection characterized according to scientific rationality. This issue have to be discussed for long period due to gap like that. Accordingly Korea, one of major LMOs importing countries, should suggest continuously that the effort is needed to ensure an adequate level of protection in transboundary movements of LMOs and scientific, environmental and socio-economic study. Third, in case of dispute between party and non-party of the POB, the duties under the WTO of non-party of the POB(if WTO member country) is valid. The country, therefore, will try to settle dispute based on WTO's rules. However, international society have to ensure for sound and safe use of LMOs in the field of transboundary movements. Accordingly Korea should devise scheme for preventing the possibility of dispute between party and non-party of the POB(if WTO member country), which is supported by policy options under the POB.

• Survey Research
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• v.10 no.1
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• pp.1-32
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• 2009

This study examines the changes of income, everyday life and living condition of consumer in the aftermath of financial crisis. In this period financial crisis was the crucial factor behind various social problems such as the dissolution of families and individuals. This research explores the range and degree of impact on individuals and social groups after the financial crisis. We explore the social mobility in terns of maintaining middle class and falling into the lower class measured by middle class identification. The 60% of the middle class before the financial crisis maintained the middle class position and the rest of people left out of middle class and fell into lower class. The 60% of those who has been maintained and has just became the members of middle class were college - educated people. The great part of people whose income and assets has increased after financial crisis belongs to college - educated group. Many of those whose income have decreased belong to the high school educated group and blow, the older than 50 years old, self - employed without employee and unpaid family employee. Those whose income and assets decreased and those who experienced downward mobility have undergone changes in everyday life and living conditions as a consumer. Many of them experienced the unemployment, nonpayment or credit - delinquency, dissolution of family, worsening health condition, depression, feeling the impulse to commit suicide simultaneously. The poor consumer disposition, reduction of living expenses, sound consumer culture have expanded to people since economic crisis. The middle class reported that the cost of private education often goes beyond the family ability to pay. The lower class has suffered from the cost of living. In a meanwhile luxury goods preference, consumer consciousness for status symbol have continuously increased among all the classes since 1997. Thus fluctuations of one's income and social mobility during past 10 years were some of the major determinants which brought about the various damaging life events, changes of living conditions and everyday lives as a consumer.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.353-359
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• 2000

'Yumyeong' is one of the most popular peach varieties in Korea. This study was conducted to monitor the developments of cells and tissues, and the changes in sugar contents during fruit growth and development. At bloom, there were two rows of vascular tissues, and the number and the position of internal vascular bundles were consistent during the fruit growth, however, the number of vascular tissues were increased and the distribution was irregular in the flesh tissues. The tissues between the inner integument and the internal vascular bundles showed different development characteristics from other parenchyma cells which were consisted of small and dense cells containing tannins. Such observation suggested that the stone of peach was consisted of inner epidermis and cells in the internal vascular tissues. The outer epidermis consisted of single layer cells at bloom differrentiated into 1-2 layers by horizontal cell divisions on 14 days after full bloom. On 30 days after full bloom, the epidermis was consisted of 5-6 layers by vertical cell divisions. The cell layers consisting the outer epidermis were gradually decreased to 1-2 layers at maturity. The observations on the changes in the epidermis confirmed that some of the cells consisting the hypodermis of peach fruit were originated from the cells of outer epidermis. Tylosis was observed from 35 days after full bloom and the size and number of tylosis were increased until full fruit maturity. The sucrose content showed the tendency of sharp increase from 50 days to 120 days after full bloom then decrease slightly. After when stone hardening ended, other solids showed a gradual decrease tendency from 80 days after full bloom.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.343-356
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• 2016

The Korea Radioactive Waste Agency (KORAD) has developed a dual-purpose metal cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. The metal cask was designed in compliance with international and domestic technology standards, and safety was the most important consideration in developing the design. It was designed to maintain its integrity for 50 years in terms of major safety factors. The metal cask ensures the minimization of waste generated by maintenance activities during the storage period as well as the safe management of the waste. An activation evaluation of the main body, which includes internal and external components of metal casks whose design lifetime has expired, provides quantitative data on their radioactive inventory. The radioactive inventory of the main body and the components of the metal cask were calculated by applying the MCNP5 ORIGEN-2 evaluation system and by considering each component's chemical composition, neutron flux distribution, and reaction rate, as well as the duration of neutron irradiation during the storage period. The evaluation results revealed that 10 years after the end of the cask's design life, $^{60}Co$ had greater radioactivity than other nuclides among the metal materials. In the case of the neutron shield, nuclides that emit high-energy gamma rays such as $^{28}Al$ and $^{24}Na$ had greater radioactivity immediately after the design lifetime. However, their radioactivity level became negligible after six months due to their short half-life. The surface exposure dose rates of the canister and the main body of the metal cask from which the spent nuclear fuel had been removed with expiration of the design lifetime were determined to be at very low levels, and the radiation exposure doses to which radiation workers were subjected during the decommissioning process appeared to be at insignificant levels. The evaluations of this study strongly suggest that the nuclide inventory of a spent nuclear fuel metal cask can be utilized as basic data when decommissioning of a metal cask is planned, for example, for the development of a decommissioning plan, the determination of a decommissioning method, the estimation of radiation exposure to workers engaged in decommissioning operations, the management/reuse of radioactive wastes, etc.