• Journal of Advanced Marine Engineering and Technology
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• v.36 no.7
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• pp.942-947
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• 2012

As electricity has been used in ship's propulsion, it is necessary to increase the system voltage and current for the electrical distribution system. So it is required to improve the system safety and efficiency, the power stability, the efficiency of the generation through various analysis of ship's electric power system. In this paper, the electrical service reliability of the power distribution system of semi submersible drilling rigs has been analysed and discussed using ETAP.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.760-763
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• 2001

In this study, the graphical design system is developed and the digital mock-up is implemented for designing the spent fuel handling and disassembling processes. This system is used throughout the design stages from the conceptual design to the motion analysis. By using this system, all the processes involved in the spent fuel handling and disassembling precesses are analyzed and optimized. Also, this system is used in developing the on-line graphic simulator to enhance the reliability and safety of the spent fuel handling process by providing the remote monitoring function of the process. The graphical design system and the digital mock-up system can be effectively used for designing the process equipment, as well as the optimization of the main processes and maintenance processes of the spent fuel management.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.594-599
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• 2007

According to separation policy between rail infrastructure and operation, the National Railroad Administration was converted to Korea Railroad Cooperation on Jan, 2005. That makes railway service assessment regarded as essential. About this matter, Section 15 of the Framework Act on Rail Industry Development and section 26 of the Rail Business Act shows that the railway service assessment should be conducted every 2 years. The government can officially announce the result and give orders operation company to improve service level. In the first railway service assessment in 2006, the principal railroad lines and stations were investigated. Rail supply service index and customer satisfaction index are introduced. It includes service items of supply, reliability, convenience, safety and customer satisfaction. This study presents the contents of 2006 rail service assessment. Some points of assessment which should be improved are analyzed as well.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.5
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• pp.797-802
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• 2008

High Speed Rail Train Control System consists of CTC, IXL and ATC. IXL and ATC perform train control and command via interchanging relevant information between a signal room and CTC. However, it is proved that IXL and ATC are attributed to train delay error since those systems are highly sensitive to trackside conditions. Especially, network error on IXL blocks transmitting signal information to adjacent signal room so that its effects give rise to system overall problems. In order to figure out the measures for which minimizing the occurrence rate of train delay error due to HSR TCS, This paper is performed analysis on communication network structure, the length of SSI network roof and SSI-TFM distance by examining and analyzing the error cases related to IXL in a network aspect.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.2
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• pp.227-232
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• 2007

The autoreclosing is applied to power system for maintaining system stability and continuity of supply. Developments on distributed generation(DG) grows significantly by environmental issues and economical issues. If the DG is connected to distribution system, the DG influences the technical aspects such as power quality, protection and stability. It causes the challenges to protection, especially to reclosing. In order to achieve reliability and safety of the distribution system, the rules and guidelines suggest that the DG units should be rapidly disconnected from the network before the reclosing. If the DG is disconnected whenever the fault occurs, it cannot be utilized effectively. This paper presents the adaptive reclosing algorithm considering the DG. The algorithm consists of angle oscillation's judgment, EEEAC(Emergency Expanded Equal-Area Criterion), calculation of optimal reclosing time and re-connection algorithm. The simulation is implemented for the DG technology by using EMTP MODELS. The simulation results show that the transient stability is maintained and the DG is protected against disturbance.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.13-18
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• 2000

Nowadays, 60 percent of thermal power plants already have been operated over their own design life. These operations of old power plant over their design life have caused a fracture accident of degradation a loss of economic and human. Therefore, the new life assessment and prediction technology is necessary to improve the safety and reliability of high pressure and high temperature power plant facilities. In this paper, innovative electrochemical test method have been used and results have been compared to the conventional test. Finally, the electrochemical test is applied to the in-field HP turbine and a database is currently in progress for the development of the life assessment standard and procedure.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.576-580
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• 2008

Rubber material properties and useful life evaluation are very important in design procedure to assure the safety and reliability of the rubber components. In this paper, the evaluation of characteristics and useful life prediction of rubber component for elevator cabin were experimentally investigated. The material test and accelerated heat-aging test were carried. Rubber material constants were obtained by curve fittings of simple tension, pure shear and bi-axial tension test data. Heat aging test results changes as the threshold are used for assessment of the useful life and time to threshold value were plotted against reciprocal of absolute temperature to give the Arrhenius plot. By using the rubber material and component test several useful life prediction equations for rubber component were proposed. Predicted useful life of rubber component for elevator cabin agreed fairly with the experimental lives.

• Journal of Welding and Joining
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• v.19 no.2
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• pp.215-220
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• 2001

In the T-joint welding, the complete penetration joint which is obtained by groove welding with edge preparation is generally required thor the safety and reliability of structures but this way have the some defects such as increase of working time, consumed welding electrode quantity and large welding deformation. If there is no probrem, in the strength, T-joint welding without edge preparation will be profitably understood in the economical and welding deformation side. In this paper, we performed the finite element analysis to understand the characteristics of welding residual stresses on two models, complete penetration joint have the edge preparation and incomplete penetration joint without edge preparation, respectively. Especially, we observed the relation between welding residual stress distributed on the notch of gap in the root and external force in the incomplete penetration joint without edge preparation.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.731-736
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• 2011

In this study, the safety of the driving gear reducer of ESW traveling sea water screen was evaluated through seismic analysis. Mode analysis of gear reducer was performed for reliability of analysis. Seismic analysis was performed in Operating Basis Earthquake(OBE) and Safe Shutdown Earthquake(SSE), which was applied as design condition using Floor Respnse Spectrum(FRS). The maxsimum displacement of gear reducer under OBE and SSE were 0.0137 mm and 0.0241 mm, respectively. The maximum stress of gear reducer under OBE and SSE were 2.42 MPa and 4.36 MPa, respectively.

• Proceedings of the KSR Conference
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• 1999.05a
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• pp.315-321
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• 1999

The railway signaling system consists of microcomputerized vital devices on board and ground, which are connected to one another by track circuits, and interlocking equipment for route control, The software plays a major role in these microcomputer-based vital systems. Therefore it is important to design the software and validate the required levels of safety and reliability To verify the conditions and functions of signaling logic, the laboratory prototype test bench, which consists of personal computers, VME system and Ethernet LAN, will be developed. In this paper general design of signaling system test bench for high-speed rail is described and some developed subprogram is presented.