• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.153-154
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• 2015

Voltage Source Converter HVDC (VSC-HVDC) are a better alternative than conventional thyristor based HVDC systems. Unfortunately, VSC-HVDC's full potential cannot be utilized up till now due to absence of suitable HVDC protection. Recently, hybrid HVDC circuit breakers (HDCCB) have been developed and successfully lab tested. However, their application and feasibility in VSC-HVDC needs to be investigated. In this research paper we have modelled an existing HDCCB and evaluated its impact on fault reduction and interruption in VSC-HVDC systems. The HDCCB was applied in Korean Jeju-Haenam VSC-HVDC system model and its impact was analyzed for HVDC line-to-ground and line-to-line faults. HDCCB successfully interrupted the fault current and prevented the damages to costly IGBTs and converter transformers.

• Journal of Power System Engineering
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• v.7 no.3
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• pp.23-28
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• 2003

In heavy nuclear power plant, high energy through main steam line is provided to turbine that generate the electric power. Since plant had generated power, high noise has been occurred. Noise make equipments and work environment worse. For finding out the location and the cause of making noise, noise was measured along main steam line at open/close test of Main Steam Isolation Valve (MSIV hereafter). As the result, it was identified that the vortex shedding in the cavity of MSIV is main noise source. The profile change of MSIV seat ring was proposed as the method of noise reduction. After filletting MSIV seat ring, the noise level reduced $10{\sim}20dB$ compared before the change of profile.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1490-1493
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• 2009

In this work we present a new type of line plasma source using an internal-type ICP operated at 2MHz with a ferrite module, describe the effect of ferrite module on the enhancement of the plasma properties and the uniformity, and compare to those obtained with 13.56MHz discharge. Also the electrical characteristics of the antenna line and the characteristics of the plasma uniformity were studied.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.1 no.2
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• pp.21-25
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• 2008

A CCFL which commonly used in the back light units for the LCD, possess very high brightness hence, was widely used as a line light source. However, the use of CCFL, caused for several environmental concerns since it contain highly toxic mercury, gradually replaced into a LED. But the LED is a spot light source, the dark area occurs in the surface of the back light units. In this paper, we proposed the lens that can convert the spot light into the line light and it can remove the dark area in the surface of the back light units. The lens is composed with the light condensation part and the light guiding part. The conditions obtained will be helpful to plan an optimum structure for such preparation.

• Proceedings of the KIEE Conference
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• 1995.07a
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• pp.446-448
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• 1995

This paper dscribes a detail simulation model with EMTP (Electro-Magnetic Transients Program) which is very effective to analyze the interaction between the ac transmission line and STATCON (static condenser). The SATCON was represented by two voltage-source converters connected in parallel and sharing an energy storage dc capacitor bank. The voltage source converters was modeled with ideal gate turn-off switches. The power system was represented by a detail generator model and a distributed tramnsmission line model for detail performance analyses. Analysis results show that the conceived simulation model is very effective to analyze the interaction between the ac transmission line and STATCON, and to evaluate the performance of STATCON.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.551-560
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• 2008

The basic strategy of OSMU(One-source Multi-use) in digital image is a marketing that applying one source to other genres for leverage based on that cross-referencing in different genre enabled that one material(one-source) has synergy effect when reproduced to various products(multi-use) as cultural sources are available through on-line and digital format. Recently, according to the characteristics of culture industry with Window Effect, many culture contents such as movies, games, animations and characters are carefully planned at its design stage to get the maximum effect. Especially, the fact that one leading-trend source makes it easier to produce additional products with the least cost is observed and it enables organized management which resulted in low marketing and PR cost. This paper confirmed that OSMU strategy in Korea mainly get started from online to offline comparing to Japan and USA.

• Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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• 2004.08a
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• pp.73-84
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• 2004

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.1008-1011
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• 1998

Output of arc welding power source can be evaluated dynamically and also statically through an arc simulator. The arc simulator is developed to simulate the arc load of short circuit and arc and return power to the line.

• The Journal of the Acoustical Society of Korea
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• v.22 no.2E
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• pp.78-86
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• 2003

We analyzed the measured acoustic field to explore the characteristics of a horizontal coherence in shallow water. Signal spatial coherence data were obtained in the continental shelf off the east coast of Korea using a horizontal line array. The array was deployed on the bottom of 130 m water depth and a sound source was towed at 26 m depth in the source-receiver ranges of 1-13 ㎞. The source transmitted 200 ㎐ pure tone. Topography and temperature profiles along the source track were measured to investigate the relationship between the horizontal coherence and environment variations. The beam bearing disturbance and array signal gain degradation is examined as parameters of horizontal coherence. The results show that the bearing disturbance is about ± 8° and seems to be affected by temporal variations of temperature caused by internal waves. The array signal gains show degradation more than 5㏈ by the temporal and spatial variations of temperature and by the down-sloped topography.

• The Korean Journal of Food And Nutrition
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• v.24 no.2
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• pp.217-225
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• 2011

The current research identified the impacts of WOM(Word-of-Mouth) regarding dining experience and the factors which were likely to influence them. Specifically, this study is examined from the perspective of WOM recipient's in on-line settings. For the purpose of this research, online survey was used and a total 203 online questionnaires of respondents who had experienced restaurant reviews and recommendations via internet last 6 month were analyzed. Overall, the results indicated that in aspects of WOM recipients, the impacts of WOM were 'visit intention', 're-WOM intention' and 'source credibility' affected 'WOM acceptance' in this process. Additionally, 'online homophily' and 'message vividness' had a positive effects(p<0.001) on builiding source credibility. By clarifying the process between on-line WOM of restaurant consumers and their actual visit, this study intend to provide basis which can be used for restaurant industry's effective marketing activity.