• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.566-572
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• 2005

The most crucial factor in membrane LNG ships to ensure sage operations, is how to effectively control tank pressure at the time of excessive generation of boil off gas (BOG). When the ships carry out tank cool down with her retaining heel prior to arrival at loading port, the vessel encounters the critical situation of excessive BOG and high tank pressure that can lead to high degree of risk. This is to provide one of the best ways to secure safe and effective LNG ship operations focusing on the detailed methods of tank cool down to achieve ATR(Arrival Temperature requirement) without building up high tank pressure and excessive BOG and calculating the appropriate heel quantity to be unutilized for tank cool down and fuel during ballast voyage.

• Journal of the Korean Institute of Navigation
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• v.22 no.1
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• pp.31-49
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• 1998

The technology of navigational instruments and the profession of going to sea have entered a time of dramatic change. A paradigm shift is taking place which will eventually make the industry unrecognizable to those who first went to sea only twenty years ago. This change is most emphatically seen in three areas: Automatic Identification System(AIS), Electronic Chart Display and Information System(ECDIS), and Voyage Data Recoreder(VDR). In order to make these new instruments to be fitted on board commerical ships, international requirements for enhacing the safety of navigation on the world's waterways, the Chapter V of International Convention for the Safety of Life at sea, 1974 as ameded(hereinafter referred to as "SOLAS"), are being also changed.o changed.

• Proceedings of KOSOMES biannual meeting
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• 2002.10a
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• pp.59-70
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• 2002

A heating cargo is solidified by several reasons during carnage. This study is to analyse a cargo accident which 811, 202 US barrels of Nile Blend crude oil reamined solid in the tanks after discharge. There are some possibilities that low temperature of loading cargo below cloud point and wax appearance temperature at loading time, heating interruption during voyage or discharging, and prohibition of crude oil washing during discharging might influence the cargo solidified. But we concluded that the defect of heating system would most affect the heating cargo solidified locally, and which blocked drain hole of bottom transverse and web frame and they obstruct flow of heating cargo in the tanks.

• Journal of the Korean Institute of Navigation
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• v.22 no.4
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• pp.45-50
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• 1998

A recently constructed commercial ship is a complexive integrated system like a small city in which has a generator, power distributing facilities, various radio equipments and high power circuit breakers are installed. Therfore it could make a malfunction of the microprocessor in the various control units which are so important during the ocean voyage of larger ship. This paper has studied whether is properly required or not on the view of the actual electro magnetic compatibility status on the electromagnetic interference and suceptibility test requirments listed on the IACS (International Association of the Classification Society). Through these results, we are looking forward to the new suggestions of the Electro Magnetic Compatibility test in order to reduce the malfunction in the ship regarding test item, test level, and test condition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.513-517
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• 1999

High voltage motor(rated 6.6kV and 448kw) has failed in the stator endwinding area during normal service. Experiments on microstructure property were conducted using the control and aged insulations, which were drawn out from stator windings of the high voltage motor. The analyses were characterized using stereozoom microscope(SM), scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy(EDS). SM result shows that large voids are present in the interface between turn insulation and groundwall insulation. SEM results indicated that the groundwall insulation is rarely thermal stress. EDS results showed that chemical elements in the high voltage motor stator insulations were Al, Si, O, K and Fe.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.621-625
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• 1999

Rosen type piezoelectric transformer for LCD backlight operated at high voltage and low current, may not be sucessfully used for illuminating general fluorescent lamps because low voltage and high current are required. In this study, the piezoelectric transformer with width vibration mode operated at low voyage and high current was designed for the application of fluorescent lasso ballast. The step-up ratio and efficiency as a function of the load resistance in the piezoelectric transformer indicated that the transformer can be effectively used for the electronic ballast for low profile fluorescent lamp.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.1448-1453
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• 2006

The Seoul Metro Line No.1 is a very complex service line which carries over 620 thousand passengers a day as a linked line to the satellites of the Seoul Metropolitan. Since the Line No.1 had its voyage service in 1974. it has been aged by the time, which resulted in the needs for the refurbishment to the new system, and as its system refurbishment was suggested to be implemented without any stop of the service, the signaling system interoperability was planned for this refurbishment, and finally it became a desirable reference of the metro signaling system overall refurbishment

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.130-132
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• 2001

We have investigated current-voltage(I-V) characteristics of organic light-emitting diodes based on TPD/Alq$_3$ organics depending on the application of forward-reverse bias voltage. Luminance-voltage characteristics and luminous efficiency were measured at the same time when the I-V characteristics were measured. We have observed that the I-V characteristics shows a current mxima at low voltage, which is possibly not related to the emission from Alq$_3$.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.106-111
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• 2004

A data communication should be carried out by a SSB(Single Side Band) to collect real time position data of fishery ship automatically, and a study on the protocol for exchanging the information with GPS should be made. A research about regional and concentrated maritime information should be first made to obtain ship's voyage data and also, research of the Modem and transmitter-receiver controller for sending voice and data simultaneously through a SSB and of the acquisition of data through a GPS also should be carried out.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.515-516
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• 2007

The marine power system is whole one system including power generation and distribution system. This systems have several power generators which are operated according to voyage situation in the vessel. Therefore, IEDs have to re-setting for changed marine power system. This paper is shown application of multi-setting protective IED in the marine power system.