• Journal of the Optical Society of Korea
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• 제20권2호
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• pp.300-304
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• 2016

A dual loop optoelectronic oscillator (OEO) based on an acousto-optic modulator (AOM) for single mode operation with an acousto-optic delay line is demonstrated in this paper. When the OEO operates, the free spectral range is a function of the total loop length of the OEO, which is mainly dependent on the propagation time of the acoustic wave in the AOM. Due to the huge difference in the magnitude between the speed of light and the acoustic velocity in the AOM, the effective loop length converted to light-propagation length of the OEO increases to 3.8 km. With 150 MHz oscillation frequency, phase noise of -118 dBc/Hz at 10 kHz frequency offset, and -140 dBc/Hz at 200 kHz frequency offset, is achieved.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1664-1666
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• 2001

This paper presents the development of electromagnetic wave detecting equipment for diagnosis of enclosed switchboard. High voltage power equipments are very important equipment of the key industries and the private enterprise. Power line accidents are national plans because of those set off casualties lose of power equipments and communication networks. Therefore the necessity of the development of detecting for power equipment diagnosis is demand for prevention of high voltage equipment accidents. This paper is the development of electromagnetic wave detecting equipment for diagnosis of high voltage equipment. This paper establishes the diagnosis method for high voltage power equipments, that secures original technique and possesses detecting technique for electromagnetic wave. By the study we developed electromagnetic wave detector, and we applied this equipment application tests at the place constructed high voltage equipments.

• 한국철도학회논문집
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• 제5권3호
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• pp.158-166
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• 2002

In this paper, we introduce the software and hardware of the measurement system for on-line testing and evaluation of high speed railway. The test items focus on the verification of the performance and acquirement of the technical data of the high speed railway system. The software controls the hardware of the measurement system, perform the analysis and calculation of measurement data and acts as interface between users and the system hardware. For this purpose, three programs a measuring program, a monitoring program and post-processing program are developed. The detailed test scenario is in the process of development to closely follow the process of development and design of the system.

• 전기학회논문지
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• 제63권2호
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• pp.313-318
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• 2014

In the last couple of decades industrialization and technological development has not only increase in the scale of electrical facilities and it has become more and more complicated and diversified. Furthermore, fires in the electrical transformers, like those that have knocked out power in the country in the past years, are likely to become more common as utility systems begin to show their age. The importance of preventing electrical accidents can never be overemphasized and for this reason, supply of on-line diagnosis system combining information and communication technology(ICT) for the customer's electrical facilities has been increasing recently. The major advantage of on-line diagnosis system is that the device's potential problems could be detected early before a serious deterioration or breakdown occurs. In this paper, We estimated the benefit from the investment in the right of present value of sales, success rate of commercialization regarding R&D investment for development and commercialization of on-line diagnosis technology targeting customer electrical facilities. As a result, the net value added of 29.7 billion won and the increased profit by roughly 7.52 precent are expected.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권2호
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• pp.117-126
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• 1999

The environmental impact of the KEPCO 765-kV transmission line was studied using a full scale test line in order to develop the design technology. Therefore this paper describes an environmental design summary of the audible noise, hum noise, wind noise, radio interference, TV interference and electric field measurement from the KEPRI 765-kV double circuit transmission test line with a bundle of $6-480mm^2$ conductors per phase. The analysis of the test results shows that 6-Rail and 6-Cardinal conductors bundle satisfy the audible noise criterion & TV interference under the stable rainy weather condition and the radio interference level under the fair weather. And the other items are also agreed with the design level criterion for KEPCO 765-kV transmission line.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2002년도 가을학술발표대회 디자인학 연구
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• pp.34-35
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• 2002

• 품질경영학회지
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• 제42권3호
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• pp.279-290
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• 2014

Purpose: The purpose of this study is to propose adoption of QFD and Stage-gate in order to analyze the quality of korea defense system. Methods: Drawing change data of initial production phase in korea defense system were anlayzed and a practical method was proposed. Results: The results of this study are as follows; Off line Quality Control should be introduced in development phase. Specially, in case of defense system, the best method is QFD(Quality Function Deployment) and Stage-gate process. At first, QFD 1 step defines product planning from VOC(Voice Of Customer), QFD 2 step specifies part planning from product planning, QFD 3 step defines process planning from part planning, QFD 4 step defines production planning from previous process planning. Secondly, Stage-gate process is adopted. This study is proposed 5 stage-gate in case of korea defense development. Gate 1 is located after SFR(System Function Review), Gate 2 is located after PDR(Preliminary Design Review), Gate 3 is located after CDR(Critical Design Review), Gate 4 is located after TRR(Test Readiness Review) and Gate 5 is located before specification documentation submission. Conclusion: Off line QC(Quality Control) in development phase is necessary prior to on line QC(Quality Control) in p roduction phase. For the purpose of off line quality control, QFD(Quality Function Deployment) and Stage-gate process can be adopted.

• 한국철도학회논문집
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• 제9권3호
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• pp.319-324
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• 2006

Studied was a strategy of technology development for railway system in terms of railway network. First, The successful launch of the Korean HST system has not only decreased logistics burden but also significantly transformed the Korean trunk-line railway network, revolutionizing the logistics and technology sectors and reinvigorating the Korean railway industry in one century. Korean railway industry sector is now investing to develop many different types of railway system(G7, Post G7, tilting train...) so that these kinds of various railway system development should be integrated with the National Inter-modal Transportation Network Plan. To secure sufficient capacity that is required by the National Railroad Plan, the railway industry needs to establish mid- and long-term train purchase and operation strategies in compliance with railway construction and operation policies. During a railway construction planning, train operators, based on their train operation strategies, should come up with measures to closely cooperate with project operators from the planning stage through to the opening of a railway system. To be more precise, train operators should establish long-term train procurement plans reflecting both long-term national railroad network plans and plans for each railway line in order to suggest appropriate roles and schedules for each line. Also, based on the long-term railway plan, directions should be decided concerning the research and development of trains in advance.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1039-1044
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• 2008

By the result of efforts for the technology development of G7 trainset, the technology of domestic high-speed train KTX-II has lately been put to practical use while a forward countries of railway, which have their own developing ability of high-speed train, are competing against each other for the development of faster high-speed train system. Japan has been commissioning of FASTECH 360 which was developed in June 2005. Also France and Germany have been commissioning of next generation high-speed train such as AGV and ICE-3, developed basing on technology of their existing high-speed train system(TGV and ICE), its maximum commercial running speed is 360kph, and adopted multiple unit system. For the development of technology of domestic high-speed train and enhancement of national technology competitive power, HEMU (High-speed Electrical Multiple Unit) development project has been carried out as a national R&D project from last August. For the executing of HEMU's maximum speed test, we have investigated the high speed line characteristics (i.e. radius of curvature, gradient, cant etc.) of Seoul-Pusan line and Honam line which is under construction. We'd like to examine a study of condition for the best HEMU T&C line considering HEMU's characteristics (i.e. acceleration, deceleration etc.) and its interface with infrastructure in this paper.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2002년도 추계학술대회 논문집
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• pp.155-160
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• 2002

In this paper, a compliant buoy mooring system of a floating cylindrical structure in shallow water depth is studied experimentally. The compliant buoy mooring system consists of four buoys, vertical mooring legs and horizontal mooring lines. A series of model test were carried out at KRISO ocean engineering basin for various mooring parameters; line length, pretension of mooring leg and mooring layouts and environmental conditions; regular and irregular waves combined with current and wind. The mooring line tensions and 6-DOF motions of the floating structure were measured using water-proof load cells and 3 CCD camera system. The results of a series of model tests were discussed on nonlinear motion behaviors of the floating structure and characterisitics of cumulative distributions of mooring line peak tensions.