• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.4
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• pp.1006-1011
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• 2008

In this paper, we developed a system for large scale on-line interactive game server based on Platform as a Service(PaaS). Small and medium sized game developing companies have various aspects of limitation to launch a large scale on line game site. By using the system proposed in this paper, small and medium sized game developing companies can easily publish their games into market.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.10-11
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• 2006

The fault location is obtained from the distance relay that detects the fault of the transmission line. In this time, transmission line crews track down the fault location and the reasons. However, because of having error at the fault location of the distance relay, there is a discordance between real and obtained fault location. As this reason, the inspection time for finding fault location can be longer. In this paper, we proposed the statistical (regression) analysis method based on each type of relay's the historical fault location data and the real fault distance data to improve the problems. With finding the regression equation based on the regression analysis, and putting the relay fault location into that equation, the real fault distance is calculated. As a result of the Prediction fault location, the inspection time of transmission line can be reduced.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.131-136
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• 1995

This paper presents a functional ability improvement of auto-reclosing relay in the power transmission line protection. When the high speed auto-reclosing is successful, Auto-reclosing is practically valuable to improve the transient stability limit of a power system, but it is fail due to surviving fault, both electrical and mechanical stresses can result on the transformers and turbine-generator. It is true that the longer dead time of the reclosing relay gives the higher rate of successful reclosing, On the other hand, the power system does not always need high speed reclosing because of enough stability margin. This paper proposed "stability margin based dead time reclosing" in order to decrease not only the rate of unsuccessful reclosing, but the possibility of the harmful stress also. On-line transient stability assessment using artificial neural network, for implementing the proposed scheme, has studied and tested with resonable results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.479-484
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• 2012

Geometric effect of landmarks to the navigation error is investigated in the two-dimensional line-of-sight measurement based vision navigation system. DOP is derived between line-of-sight measurement error and navigation solution error. For cases of three landmarks in an area, variations of the DOP were observed through computer simulations. Vision navigation system experiments were performed for the cases. Simulation and experimental results show that navigation solution errors have similar trend to DOP values of the simulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.7
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• pp.23-29
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• 2012

A single line diagram is a graphic user interface to represent electrical connectivity between power equipments in distribution automation systems. This paper proposes a new single line auto-drawing technique based on the service oriented architecture. Web service, CIM(Common Information Model) and SVG(Scalable Vector Graphics) are adopted to implement SOA concept. A web service demo system was established which is configured with the service provider, consumer and broker to verify the feasibility of this study.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.8
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• pp.1281-1286
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• 2003

A line search algorithm to increase a convergence in Newton's method is developed and applied to nonlinear finite element analysis. The algorithm is based on the slack line search theory which is an efficient algorithm to determine initial acceleration coefficient, variable backtracking algorithm proposed by some researchers, and convergence criterion based on residual norm. Also, it is capable of avoiding exceptional diverging conditions. Developed program is tested in metal forming simulation such as forging and ring rolling. Numerical result shows the validity of the algorithm for a highly nonlinear system .

• Journal of Engineering Education Research
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• v.13 no.2
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• pp.12-15
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• 2010

Learning community is one of the important pillars of the education in knowledge-based society. How to encourage students' spontaneous participation to the learning community is one of the actual problems to solve for the revolution of the education scheme. In this paper we introduce a strategy to boost the activity of the learning community, which works in the on-line space. The keys for the on-line supporting system for the learning community are to have communication space, trading space and connection with industry. To support activities of each space, we provide an on-line web site which includes a community module, a knowledge market module and an industrial commentary module. Students can start their self-leading study in the communication space, and they can also practice skills for the knowledge management in the knowledge trading space. Through the connection space, they can learn more from the real world critics with help of industry.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1014-1023
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• 2008

The K-AGT test line is managed similarly to revenue operation and operated automatically 120km per day, total 90,000km from August 2004 to December 2007. To enhance reliability of developed system, maintenance information system based on RCM is applied. The maintenance program applied in test line is based on RCM which prevent a fault before it happens and a fault made in test line is analysed by reliability growth test. Vehicle system, power supply system, signalling system, track and infrastructure are built in test line and it is reviewed enhancing system performance and changing designs to commercialize through reliability growth analysis method.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.953-954
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• 2006

Guaranteeing survivability is the most important issue in designing and operating optical transmission network. For dual system of optical transmission network, there should be two routes of the optical to prepare an error in one cable route. If a route is selected based on the standard of unused optical core when choosing an optical cable, dual optical cable routes could be installed in duplicated line. This paper simulates the installation of duplicated line when designing an optical transmission network, detects the status of duplicated line that could happen during transfer construction and switching and accomplishes a system that can confirm the location based on a map.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1035-1042
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• 2017

In this paper, we implement a public address system using power line communication in order to operate, extend, and expand the complicated public address devices and cables easily. Power line communication based public address system implemented consists of a public address control board and public address speaker boards which are suitable to digital streaming modulation. It can be noticed that we met satisfied results from performance measurement such as maximum audio output, audio channel response time, audio output SNR, and audio output THD+N.