• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.8
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• pp.1360-1366
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• 2007

In this paper, the load balancing which is one of the distribution power system's operation purposes was studied. Reconfiguration of Distribution power system presents that the configuration is changed by changing the switch on/off status which exists in the system according to the mentioned purpose. Through this method, the load of distribution power system is shown to be balanced. As a characteristic of complicated distribution power system, system is designed by being applied by OOP(Object Oriented Programming) method which connected more flexibly than existing Procedural Programming method, and the process of calculating the distflow and the loss of configurated system is shown. In addition, this paper suggests more efficient method compared by the results of reconfiguration on the purpose of the loss minimization and by the result of distribution power system reconfiguration on the purpose of load balancing. Moreover, it searches for the method to approach the global optimal solution more quickly.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1438-1440
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• 2005

A power control and distribution unit(PCDU) plays roles of protection of battery against overcharge by active control of solar array generated power, distribution of unregulated electrical power via controlled outlets to bus and instrument units, distribution of regulated electrical power to selected bus and instrument units, and provision of status monitoring and telecommand interface allowing the system and ground operate the power system, evaluate its performance and initiate appropriate countermeasures in case of abnormal conditions. In this work, we perform the preliminary design of a PCDU scheme for the small LEO Satellite applications. The main constitutes of the PCDU are the battery interface module, the auxiliary supply modules, solar array regulators with maximum power point tracking(MPPT) technology, heater power distribution modules, internal converter modules for regulated bus voltage generation. and instrument power distribution modules.

• Journal of Information Technology Services
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• v.18 no.1
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• pp.131-140
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• 2019

This study compares and analyzes the spatial distribution of people in two cities using location information in twitter data. The target cities were selected as Paris, a traditional tourist city, and Dubai, a tourist city that has recently attracted attention. The data was collected over 123 days in 2016 and 125 days in 2018. We compared the spatial distribution of two cities according to the two periods and residence status. In this study, we have found a hot place using a spatial statistical model called dart-shaped space division and estimated the urban area by reflecting the distribution of tweet population. And we visualized it as a CDF (cumulative distribution function) curve so that the distance between all the tweets' occurrence points and the city center point can be compared for different cities.

• Journal of the Korean Home Economics Association
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• v.38 no.9
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• pp.93-106
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• 2000

The Purpose of this study was to examine the adolescents'stress and social supports and the relationships of there two factors. Specifically, this study investigated the adolescents'stress and social supports depending on their sex, family status, socio-economic status. The subjects of this study were 467 middle school students in Pusan. Questionnaires were used consisting of adolescents'perceived stress and social supports for data analysis, Cronbach's $\alpha$-coefficient, frequency distribution, percentage, Oneway-ANOVA, t-test and Pearson's γ-coefficient were used. Major findings were as follows: Adolescents'stress were significantly different depending on their sex, father's educational level, family income and family intimacy The source of the adolescents'social support sources were different depending on their sex, family status, father's educational level, mother's educational level, family income and family intimacy. Adolescents'social support types were different depending on family status, lather educational level, mother educational level, father\`s job, family income and family intimacy. There were negative correlation between stress and social supports.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.393-400
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• 2001

We examined the relationship between plasma folate and total homocysteine(Hcy) levels and the distribution of plasma folate and Hcy levels from 204 Korean adults(113 men and 91 women aged between 20yr and 69yr). Plasma folate levels were significantly lower in men(12.2nmol/L) than in women(14.6nmol/L) after controlling for smoking and drinking(p<0.05). Plasma Hcy levels were significantly higher in men(13.9$\mu$mol/L) than in women(11.8$\mu$mol/L) after controlling and drinking. Plasma Hcy levels were more more strongly correlated with plasma folate in women(${\gamma}$=-0.321, p<0.05) than in men(${\gamma}$=-0.202, p<0.05), but the difference between men and women was no longer statistically significant controlling for plasma folate concentration. Prevalence of mild homocysteinemia(plama Hcy>15$\mu$mol/L) was greatest among subjects with lowest folate status. These results indicate a strong association between plasma Hcy concentration and folate status and the poor folate status is the strong causative factor of mild homocysteinemia. (Korean J Nutrition 34(4) : 393~400, 2001)

• Journal of the Korean Institute of Educational Facilities
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• v.20 no.6
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• pp.31-40
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• 2013

The purpose of this study is to understand the meaning of architectural history of designated cultural properties of modern educational facilities through the analysis of its status. This study considerate acceptance and evolution of modern educational facilities during the about seventy years from 1895 to 1965. Also, this study analyzes items that is distribution of construction and designation year, regional groups, and status of main structure material, status of conservation and utilization of facilities, its characteristics of architectural style. In this study, the result of analysis show that most analysis items of investment buildings are tend to biased and concentration to one direction. Accordingly, designated cultural properties of modern educational facilities are weakly express architectural representation and symbolism in the period of modern educational acceptance.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2010.04a
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• pp.55-58
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• 2010

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2010.04a
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• pp.52-54
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• 2010

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1998.06b
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• pp.113-121
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• 1998

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2008.04a
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• pp.80-82
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• 2008