• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.9
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• pp.528-535
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• 2020

Recently, the protection coordination method of DC systems has been presented because renewable energy and distributed resources are being installed and operated in distribution systems. On the other hand, it is difficult to detect ground faults because there is no significant difference compared to a steady-state current in ungrounded IT systems, such as DC load networks and urban railways. Therefore, this paper formulates the detection principle of IMD (Insulation Monitoring Device) to use it as a protection coordination device in a DC system. Based on the signal injection method of IMD, which is analyzed by a wavelet transform, this paper presents an algorithm of detecting ground faults in a DC system in a fast and accurate manner. In addition, this paper modeled an IMD and an ungrounded DC system using the PSCAD/EMTDC S/W and performed numerical analysis of a wavelet transform with the Matlab S/W. The simulation results of a ground fault case in an ungrounded DC system showed that the proposed algorithm and modeling are useful and practical tools for detecting a ground fault in a DC system.

• Journal of Distribution Science
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• v.13 no.10
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• pp.83-91
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• 2015

Purpose - The purpose of this study is to identify whether the operation of cultural centers in discount stores contributes to their profitability. Thus, this study is aimed at exploring how the lifestyles of customers who use the cultural centers influence their intention to use the discount stores. Specifically, the effect of shopping value on the correlation between the lifestyle types and usage intention of the customers were examined through a structured research model. To verify the effect, a survey on 139 customers of the Cultural Center of Nonghyup Hanaro Club's S branch was conducted and the valid questionnaires were used for analysis. Research design, data, and methodology - The findings are as follows. First, the lifestyles seeking self-realization had a positive effect on utilitarian value, and lifestyles seeking pop cultures had a positive effect on hedonic value. Second, the mediating effect of shopping value on the correlation between the lifestyle types and usage intention of the customers is as follows. Utilitarian value had a mediating effect only on the lifestyles seeking self-realization. In case of lifestyles seeking pop cultures, the use of Cultural Center had no effect on the intention to use the discount store. Third, an analysis of a revised research model revealed that the store usage intention of lifestyles seeking pop cultures can be enhanced by boosting the utilitarian value through hedonic value. Results - The findings suggest the following. Customers with lifestyles seeking self-realization, who value what is beneficial to them with little attention to the perceptions of others, are highly interested in the benefits they can gain from shopping. As for customers with lifestyles seeking pop cultures, they are highly likely to consume products popular in a particular culture such as new products and sports, based on financial stability they pursue. Thus, they prefer more subjective, personal experience, unlike consumers pursuing utilitarian value. Conclusions - As a result, the former pursues hedonic value gained in the process of shopping with fun and joy, rather than doing shopping with a particular purpose in mind. Therefore, Cultural Centers need to offer information that fits the lifestyles of the users so that they are more likely to use the discount stores. However, if the Cultural Centers offer unified, profit-driven products and information, just to increase their store sales, it can backfire, which occurred in the past. On the other hand, if they provide information that fits the lifestyles of the users, it can actually increase the sales. Also, the findings suggest that sophisticated marketing strategies that can boost the hedonic value of customers by linking the educational contents of Cultural Centers to actual shopping, which is beneficial to consumers, should be set and operated by discount stores. In particular, customers with lifestyles seeking self-realization can be encouraged to use the stores by making them recognize the utilitarian value. However, the use of Cultural Centers doesn't necessarily lead to higher sales among customers with lifestyles seeking pop cultures. As mentioned previously, unified marketing strategy is not as effective for Cultural Centers of large discount stores.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.1
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• pp.56-75
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• 2018

Korean Photochemical Assessment Monitoring Stations (PAMS) have been established since the late 2001 to monitor ambient air concentrations of VOC species, which would enhance understanding photo-chemical formation of ozone and subsequently contribute to developing efficient ozone control strategies. The present study aims at identifying major VOC species and examining their trends by analyzing PAMS monitoring data collected from the year 2006 to 2016. All the 18 PAMS sites operated by the Ministry of Environment were included in the study. PAMS monitored the 56 target VOC species, which are classified into four groups, alkenes, lower alkanes ($C{\leq}3$), higher alkanes ($C{\geq}4$), aromatics. The higher alkanes and aromatics dominated over the lower alkanes and alkenes in the type 2 and 3 PAMS sites except Joongheung site. N-butane was a major alkane species, toluene was a major aromatic species and most of VOCs showed decreasing trends in these sites. On the other hand, only the alkenes showed decreasing trends at the Joongheung site in Yeosu. Major sources of abundant species such as ethane, propane, n-butane, toluene were estimated by analyzing seasonal variations, correlation with other VOC species, and emission profiles. A major source of n-butane was identified as LPG cars, while major sources of toluene varied considerably from one site to another. The lower alkanes were composed of ethane and propane, both of which showed a strong seasonal variation, low in the summer and high in the winter, indicating that a major source might be the heating by gaseous fuels. Ozone formation potentials of VOC species were evaluated by applying MIR and POCP to the measured VOC species concentrations. Toluene contributed the most to total ozone forming potentials followed by m,p-xylene for all the type 2 and 3 PAMS sites except for two sites in Yeosu-Gwangyang. Ethylene and propylene were the first and second contributors to total ozone forming potentials at Joongheung site in Yeosu.

• Journal of Korea Technology Innovation Society
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• v.17 no.3
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• pp.604-628
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• 2014

We analyse the impact of R&D cooperation on Industrial R&D programs of Government (Ministry of Trade, Industry & Energy, MOTIE), specially performance differentiating between type of R&D partners, type of R&D project leader organizations. And considering five performance measures: paper, patent, technology transfer, commercialization, new employment. Using data on a large sample of post-performance survey of MOTIE in Korea (2013), we examine the impact of R&D cooperation in 2008-2012. The method of analysis is binary logistic regression models operated by SPSS. The results of this study are follows; the performance is statistically significantly different between type of R&D partners, type of R&D project leader organizations on R&D cooperation. Specially, when a private enterprise cooperate with non-profit institutions, performance has a greater success of paper, patent, new employment. On the other hand, when a private enterprise cooperate with a private enterprise cooperate, performance decrease success of paper, technology transfer. Lastly, when non-profit institutions cooperate with a private enterprise, performance has a greater success of patent, technology transfer.

• Journal of Animal Environmental Science
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• v.17 no.2
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• pp.61-70
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• 2011

This survey was conducted to investigate the current situation of ground condition of barn, moisture condition, feeding facilities, disinfection tool, etc. The data from a total of 305 farms were collected and analysed for establishment of managemental target in Hanwoo farm. The ground condition of barn was evaluated as a result of "moderate level" (46.4%). The moisture removal on the ground was conducted with the aid of electric fan (36.4%). The natural wind and sunlight should be used gradually for economic effect in farm. The exchange of floor straw was mostly conducted to remove the bad smell of barn (33.7%). 37.0% of farms had no the electric fan in internal barn, this instrument must be installed for control of body temperature and internal moisture in the future. Most of feeding facilities were operated by hand(88.2%). Modern farms should be installed with automatic feeding system. Farmer's skill of management was evaluated as a "2.80" of 5 points. Accordingly, farmers should be trained with high level of technical competitive skill. In conclusion, Hanwoo farms should be promoted and improved for enhancement of income through introduction to scientifically modern feeding skill.

• Journal of the Korean Society for Library and Information Science
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• v.6
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• pp.137-163
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• 1979

The Purpose of this study is analyzed that (l) How the public Libraries under the Japanese Rule since the end of the Yi-Dynasty were recepted and generated by the people and (2) How they were organiged and managed. (3) Also it examined that how they affected the development of the libraries of today. 1. The following are the analyzed results: Three types of the public Libraries under the Japanese Rule for a period of 36 years engaged busily in colonization were Private's Public Libraries, Local Self-Government's Libraries and the Central Governmental Libraries, and were in order established. 2. They were eatablished by individuals, Confucian School Foundation, Young Men's Clubs, School Associations, Korean brethren residing abroad, or The Press Centering around the Local Self-Governments and the Japanese Government-General. 3. In 1932 of the period of the Japanese Rule, the number of Libraies gained the summit and reached 80 Libraries. The Public Libraries including the Central Governmental Libraries remained in existence until the end of the War had been kept up the functions of the Libraries, but the Private Libraries operated by the Koreans were very small and poor. As a result, most of them were closed up and some Libraries transferred their controls to the public. Until the end of the war, only a little over 10 Private Libraries were Kept up. From the aspects of it's organization system, the most of their libraries replaced their chief librarians with non-professional county-headmen or Local supporters. From the aspect of collections, they wate mainly consists of Japanese books for the proper quidance of the public thought based on the ideology of Japanese Rule to Korea and on the industrial promotion rather than books about Koreanology or Western books. At that time, the Library users were with the jobless men and students as the central figures. And the next ranking by the social position of readers was children, farmers, merchants, industrialists, public servants, miscellaneous and educators. Their reading tendencies laid stress on linguistics and literature, physical sciences and medicine, While the reading trend of military sciences and medicine, while the reading trend of military sciences and engineering were very inactive. This was because the Japanese Government-General had not kept the military collections on file. Besides, they were reluctant to make Korean's learn the professional knowledge and so the main reference materials of technology not provited. Most of the Libraries put practiced in circulation services were very important circulation in withinder of the reading room rather than in outside of the Library building. On the other hand, their circulation services has above came with many limitations. As stated above, the public Libraries' managements and activitives under the period of Japanese Rule were the way and means to achive the colonial and imperialistic purpose of the Japanese Empire.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.464-473
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• 2016

The air temperatures of the coast and inland are rising due to an increase in carbon dioxide emissions and abnormal climate phenomena caused by global warming, El Nino, La Nina and so on. The sea levels of the Earth are rising by approximately 2.0 mm per year (global average value) due to the thermal expansion of sea water, melting of glaciers and other causes by global warming. On the other hand, when it comes to designing a hydraulic structure or coastal hydraulic structure, the standard of the design water level is decided by analyzing four largeness tide values and a harmonic constant with the observed tidal water level or simulating numerical model. Therefore, the design tidal water level needs to consider an increasing speed of the seawater level, which corresponds to the design frequency. In the present study, the observed tidal water levels targeting 46 tidal stations operated by the Korea Hydrographic and Oceanographic Administration (KHOA) from the beginning of observations to 2015 per hour were collected. The variation of the monthly and yearly and increasing ratio were performed and divided into 7 seas, such as east and west part of the Southern Sea, south part and middle of the East Sea, south part and middle of the Western Sea, and Jeju Sea. The current study could be used to determine the cause of local seawater rises and reflect the design tidal water level as basic data.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.4
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• pp.273-283
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• 2020

Numerical simulations of the storm surge and waves induced by the Typhoon Bolaven incident on the west sea of Korea in 2012 are performed using the JMA-MSM weather field provided by the Japan Meteorological Agency, and the calculated surge heights are compared with the time history observed at harbours along the various coasts of Korea. For the waves occurring coincidentally with the storm surges the calculated significant wave heights are compared with the data measured using the wave buoys operated by the Korea Hydrographic and Oceanographic Agency and the Korea Meteorological Administration. Additional simulations are also performed based on the pressure and wind fields obtained using the best track information provided by the Joint Typhoon Warning Center, and the calculated results are compared and analyzed. The waves and storm surges calculated using JMA-MSM wether field agree well with the observations because of the better reflection of the topography and the pre-background weather field. On the other hand, the calculated results based on the weather fields produced using the JTWC best track information show some limitations of the general trend of the variations of wave and surge heights. Based on the results of this study it is found that the reliable weather fields are essential for the accurate simulation of storm surges and waves.

• Journal of Korea Water Resources Association
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• v.31 no.4
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• pp.397-406
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• 1998

The Pyokkolche Reservoir was constructed as a major public project of the ancient agricultural society, 1600 years ago. From a hydraulic point of view, it is considered to have been carried out with a distinguished technology. It should be in particular noticed that for a consecutive banking the main stream was diverted and drained to the Yonpo stream and the dam with same sea levels on its top along the whole length was built in a nearly straight line in spite of the different sea levels between both ends on the bottom. These suggest that the carrying out artifice and surveying technigue of those days were considerably excellent. However, the insufficient plan and design at the time of the construction, the temporary management and the repeated repair works in the later ages caused the Pyokkolche to lose its function. The Changsaenggeo and Kyungjanggeo gate sites being the facilities for sluices composed of a simple span and a vertical lift hand-operated sing a pully. The advantage of the geographical characteristics at both ends of the main dam was scientifically taken to these sites which also functioned as a spillway against a flood. The gate site of Suyogeo must have been located in an entrance to Suwolri, the northern end of the Pyokkolche and Yutonggeo is presumed to have been located on the right of Sangsori, the southern end of the Pyokklche. Keywords : Pyokkolche Reservoir, construction technology, gate site location.

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.57-71
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• 2016

The development of ocean industries is an existing and important problem for South Korea, which is mostly surrounded by sea and has a long coastline along three seas. It is necessary for researchers to make efforts to enhance its cost and time competitiveness, because many ocean-based activities have been carried out in harsh physical conditions when compared with land-based ones. One of these efforts to improve efficiency is to operate an Offshore Supply Base (OSB), which is a basic infrastructure required to develop ocean industries effectively. For this reason, the construction and operation of OSBs have become an issue in Korea. The relevant research is limited. Nevertheless, there are a few reports published by Korean research institution. They focus on promoting ocean industries and only mention the necessity of OSB as a promotion tool for the industries. This study on the other hand, addresses various issues on the construction of OSBs in Korea and suggests implications for them. To examine the conditions on the construction of OSBs in Korea, we conduct case studies of Houston and Singapore, the representative regions where a massive OSB has been constructed and operated. In addition, we use Analytic Hierarchy Process (AHP) to evaluate the relative priorities of the services provided by OSBs if constructed in Korea.