• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.5
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• pp.463-467
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• 2003

This paper describes an AC voltage regulator using AC chopper and auxiliary transformer which is series connected with main input. It has many advantages such as fast voltage control, high efficiency and low THD. A detail study of step down AC voltage regulator is described and two kinds of novel step-up/down voltage regulator for AVR application are proposed. The operation principle and PWM method of the proposed regulator are described. Experimental results show that it can be used as AC voltage regulator for special purpose very efficiently.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.7 no.3
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• pp.65-75
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• 2017

This research studies the behavior patterns of a character in FIFA Online3, and the transaction patterns between the characters to present a character that acts like a real person and has social interaction with other characters. A character interacts with others mediated by balls in FIFA Online3, we analysis character's behavior and interactions more cleary. Providing the realistic behavior patterns of a character and the relation in the transaction patterns between the characters based on psychology theory, we can give a player the sense of reality. To define the behavior pattern of a character, this study applied the Ego-state as defined by Transactional Analysis(TA). Based on the Transactions in TA, this study then defined the transaction patterns between the characters, which are produced by the actions that a character in the game. This study also presented how to apply a character's transaction patterns with the examples. It showed that a character can act in the game like a real person by defining how a character acts and interacts in the game.

• The Journal of the Korea Contents Association
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• v.11 no.12
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• pp.950-957
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• 2011

With the convergence of disciplines in progress and Web 2.0 online collaborative environment, online knowledge exchange activities of researchers are increasing. Quickness of acquiring knowledge highly impacts on research productivity in the global era. Online knowledge exchange is critical service for researchers. In this study, knowledge exchange service model was presented from the perspective of activate participation, knowledge quality improvement, quickness of exchanges. A variety of domestic and international knowledge exchange services were analyzed, particularly Korean domestic service KOSEN What is? as for operational practice. It is confirmed that in order to stimulate researcher knowledge exchange the quality of the knowledges exchanged is essential and variety of operating activities are needed such as expert matching systems, enhancement of speed in knowledge exchange, ease of usability, and elements of fun.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.267-268
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• 2011

인터넷데이터센터는 현대 IT산업의 중심설비로서 수십 MW의 전력을 소비하는 집중부하형태를 취하고 있다. 인터넷데이터센터의 특성상 전원의 신뢰성을 높이기 위하여 무정전전원장치(UPS)를 사용하는 것이 필수사항이다. 따라서 기존의 교류방식은 (교류-직류), (직류-교류), (교류-직류)의 3단계 전력변환이 필요하여 전체 급전계통의 효율저하를 가져온다. 이에 비하여 직류급전방식은 기존 계통 망에 연결하기 위한 (교류-직류) 1단계의 전력변환만 필요하므로 효율을 크게 개선할 수 있을 뿐만 아니라 전원의 신뢰도를 높일 수 있다고 알려져 있다. 본 논문에서는 인터넷데이터센터 내에 220V교류방식과 300V직류방식의 시험용 급전계통을 구축하고 똑같은 부하운전 조건에서 실제의 급전효율을 측정하였다.

• Journal of Korea Water Resources Association
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• v.41 no.9
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• pp.919-927
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• 2008

Flow exchanges between stream and groundwater are assessed on urban streams in Daegu, Korea. Two rivers and 25 streams with the total length of 240 km run through the study area. The interaction between surface water and groundwater was estimated using Darcy's method. The study was conducted by dividing the basin into 16 smaller watersheds, and for comparison purposes. Groundwater level, surface water level, hydraulic conductivity, thickness of aquifer, and the distance between the well and the nearest stream were used for quantifying the interaction. To investigations the groundwater interaction in the watersheds, the amount of effluent seepage from groundwater to the stream, the amount of influent seepage from the stream to groundwater, and the amount of annual interaction between surface water and groundwater were computed. The total amount of effluent seepage from the groundwater to stream in the basin was approximately $72{\times}10^6m^3/year$. The total amount of influent seepage from the stream to groundwater was approximately $35{\times}10^6m^3/year$. It appeared that the total amount of annual interaction between surface water and groundwater was approximately $108{\times}10^6m^3/year$ and the total groundwater flow balance was approximately $37{\times}10^6m^3/year$. The annual amount of interaction between the surface water and groundwater was the largest in the Goryung Bridge Basin($29{\times}10^6m^3/year$) and the least in the Dalchang Dam Basin($0.2{\times}10^6m^3/year$). The results show that flow exchanges between stream and groundwater are very active and that there are significant difference among the smaller watersheds. Finally, the results indicate that it is necessary to further investigate to more precisely understand the interaction characteristics between surface water and groundwater in urban areas.

• Cartoon and Animation Studies
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• s.36
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• pp.619-641
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• 2014

Animation is an important tool to establish the identity of mutually related countries, as cultural contents with the economic value. That is, it is necessary that the Korean animation should extend the previous boundary of exchange, for the status of representative cultural industry in the 21st century global market. Especially, to overcome the regionally prejudiced and unbalanced cultural exchange, the possibility of extension with Czech animation, which has not had an active exchange with Korea, will be considered and the efficient method will be proposed. The Czech Republic is geopolitically located in the center of Europe and its infrastructure like industrial construction, investment environment, human resources is outstanding among Visegrad Group. The Czech Republic has a remarkable cultural border-crossing phenomenon, and as a complex country of cultural and religious characteristics of eastern and western European, it is a powerful nation leading Central Europe. Therefore, the animation exchange of Czech and Korea is valuable in culture and economy of both nations. Through such an animation exchange of both nations, not only Korean animation secures the diversity of exchange but also insignificant cultural exchange after formal establishment of diplomatic relations in 1990, will be revitalized and international firm relationship of both nations will be established. Therefore, as an activation plan or cultural exchange of Korea and the Czech Republic, concrete plan like Stop Motion Animation Workshop is proposed.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2055_2056
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• 2009

국가표준을 유지하기위한 표준기급의 교류저항은 상품화된 것이 외국에서 한 종류 있으나 고정된 기름 항온조에서 유지를 해야 하고, 정전차폐가 어렵고, 교류에서 측정단자의 호환성이 어렵고 가격도 대단히 비싸다. 또한 저항체가 지지대 역할을 하는 원형 보빈에 감겨져있는 선으로 구성되어서 국제비교시나 혹은 이동교정시에 기계적인 구조의 변화로 저항 값에 영향을 받기가 쉽다. 이러한 단점들을 극복한 교류저항 표준기가 개발이 되었다. 개발된 표준기는 저항체의 기계적 구조에 의한 변화를 막기 위해서 non-inductive 구조의 metal foil element로 제작된 것을 사용하였으며, 각각의 저항체에 개개의 항온조를 체택함으로서 온도의 안정성과 이동의 편리를 함께 만족되도록 하였다. 제작된 교류저항 표준기의 특성은 온도 안정도가 ${\pm}5$ mK/d, 저항값의 안정도가 ${\pm}0.01{\mu}{\Omega}/{\Omega}/d$, 1년간의 장기안정도가 $1{\mu}{\Omega}/{\Omega}$ 이하로 측정이 되었다. 개발된 교류저항 표준기는 교류저항분야 국가표준유지 및 소급에 사용이 된다.

• Journal of Korea Society of Industrial Information Systems
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• v.11 no.5
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• pp.216-224
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• 2006

Ten years have passed since the establishment of KOSHBA(Korea Small and medium enterprises Hybrid Business Association). KOSHBA is composed of over 400 regional groups; over 6,000 enterprises are participating in the association. To become a dynamic and vital association, it is necessary to share, learn, and discuss their managerial problems based on mutual trust and respect at the regular monthly meeting.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.95-107
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• 2012

Communication skill to maintain personal relationships is a crucial factor in our social life. However, even though a number of people are experiencing difficulty in communication owing to their poor interpersonal interchanges in real life, they are interacting with virtual characters in artificially created virtual space. In order to remedy such a lack of communication among game players, first, they need to search appropriate ways to communicate each other in real life, but not in virtual space, or to create a game space as a new place for interaction among them by utilizing advantages of the game world. To accomplish such an aim, it is necessary to precede the research on what kind of relations or characteristics for game players' interaction to others in the real life and game world. For the reason, in this paper, we investigate interaction patterns of game players in real life and in the virtual space. In order to perform this investigation, an ego-gram, which demonstrates the pattern of the ego states as a field-oriented approach is used as the research method. The result shows that there are differences between patterns in each spaces. so, we apply a factor analysis and analyse the relationship between the transaction pattern of players in two spaces using the ego-gram.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.555-558
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• 2017

In this paper, we designed a power supply AC LED driving device which can display uniform power consumption and light efficiency even when AC power of different size is applied. By setting input voltages and deviations of different sizes, it is confirmed that the electric light characteristics are the same at two input voltages. In addition, according to peak voltage of AC power, improper lighting caused in specific LED section is improved, and LED lighting of all sections is implemented in all commercial AC input voltage.