• 전기학회논문지
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• 제64권9호
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• pp.1391-1397
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• 2015

Recently, various researches are conducted in the application of regenerative energy produced during the operation of an electric locomotive. Regenerative energy is produced by a generator in the brake procedure. The generator is operated by kinetic energy of an electric railroad using an electric motor. The process of producing regenerative energy varies with the current type of a railroad and its running condition. The quality of electric power can be improved and electric energy can be utilized effectively, especially in the use of an energy storage system (ESS). Thus, it is necessary to apply ESS into AC section and high speed railway. This study analyses the composition of the regenerative ESS equipment installed in Yong-Jeong sectioning post, operational principle, charge and discharge algorithm and energy efficiency. The analysis shows that CO2 emissions can be reduced about 0.5 ton per a day. In addition, ESS helps saving the energy and the compensation of the voltage drop caused by the operation of high speed train when it is installed at the end of the feeder section. The number of high speed train will be increased continuously related to the electrification rate. Therefore, applying the ESS to high speed railway is expected to solve the instability of the feeder voltage and the equipment capacity problem caused by the high speed trains.

• 한국철도학회논문집
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• 제14권3호
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• pp.285-294
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• 2011

R&D 투자로 인한 기술의 축적, 경제적 성과 및 파급효과에 대한 분석이 거시적인 측면과 타 부문에서는 다양하게 이루어지고 있으나 철도산업에 대한 분석은 미흡한 실정이다. 본 연구에서 성과목표 설정에 대해서는 선행연구에 대한 조사분석을 통하여 과학기술적 성과에 대한 공통지표로 지식재산권, 특허, 논문을 설정하고 성공적으로 종료된 철도 R&D 11개 사업의 과학기술적 성과에 대한 적정성을 검증하였다. 선행연구에서 투입요소로 투자금액에 의한 성과목표를 설정하였으나 정확도를 향상시키기 위해 투입요소로, 투자금액(RI), 자본적 투자금액(RCI), 인당 내부인건비(LCPM)를 적용하였으며 철도 R&D 11개 사업에 대한 횡단면 분석과 잔차 분석을 통하여 성과목표 모형을 설정하고 타 과제 분석을 통하여 실증분석과 타당성을 검증하였다.

• 대한교통학회지
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• 제33권5호
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• pp.431-440
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• 2015

본 연구는 국내 및 해외 국가의 철도물류 운영현황을 다양한 지표를 활용하여 비교 검토하여 국내 철도물류 경쟁력에 대한 시사점을 도출하고자 한다. 취득가능한 데이터들을 고려하여 국가간 비교가능한 검토항목과 철도물류회사간 비교가능한 검토항목으로 나누어 연구를 수행하였다. 국가별 화물열차 운행밀도, 화물 열차당 수송량, 화물의 평균 수송거리를 비교하였으며 철도화물회사별 단위수송당 매출액, 영업계수, 직원 1인당 매출액, 직원1인당 수송실적, 단위수송당 영업비용, 영업비용 중 인건비 비중 등을 비교검토 하였다. 분석 결과 우리나라는 다빈도 소량 수송을 하고 있는 상황으로 대량수송의 장점을 충분히 활용하고 있지 못하는 것으로 나타났으며 직원 1인당 수송실적 등 철도화물분야 생산성이 해외 철도화물회사 대비 낮은 것으로 분석되었다.

• 한국물환경학회지
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• 제35권4호
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• pp.370-378
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• 2019

In the recent years, various studies have presented stable and economic methods for increased regulations and compliance in sewage treatment plants. In some sewage treatment plants, the effluent concentration exceeded the regulations, or the effluent concentration was manipulated. This indicates that the process is currently inefficient to operate and control sewage treatment plants. The operation and control method of sewage treatment plant is mathematically dealing with a physical and chemical mechanism for the anticipated situation during operation. In addition, there are some limitations, such as situations that are different from the actual sewage treatment plant. Therefore, it is necessary to find a more stable and economical way to enhance the operational and control method. AI (Artificial Intelligence) technology is selected among various methods. There are very few cases of applying and utilizing AI technology in domestic sewage treatment plants. In addition, it failed to define specific definitions of applying AI technologies. The purpose of this study is to present the application of AI technology to domestic sewage treatment plants by comparing and analyzing various cases. This study presented the AI technology algorithm system, verification method, data collection, energy and operating costs as methods of applying AI technology.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2949-2951
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• 2011

It is expected that domestic railway vehicle operation companies may be subjected to GHG emission reduction when GHG emission system is enforced. This study aimed that reviewing on GHG emission system such as CDM, VCS and KCER, and analysing availability of GHG emission credit acquisition for railroad transportation sector. In order to estimate GHG emission credit, a GHG emission estimation methodology should be developed, which includes GHG emission baseline estimation and GHG emission monitoring method, MRV method and etc. Modal shift project, high speed train technology, straight lining project, mass transportation technology, operation optimization tehcnology and etc. may produce GHG emission credit.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.278-282
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• 2003

This paper presents TPS(Train Performance Simulation) which identified the condition of train operationing in short time. Using the program, the location of train, maximum current, metering power and regenerating of train, could be identified. This is an important part for Power Simulation. It is supposed that the grade, the curve, the limit speed and the current speed be constant within the time step in the conventional papers. In addition, the errors of the grade and the curve in each station interval are neglected. This paper will introduce improvement method the problem of TPS.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.179-182
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• 2005

In this paper, optical noise is reduced using a differential detector in an 1.3$\mu$m optical wireless system which is more safe for human eye than 0.8$\mu$m optical wireless systems. The differential detector is composed of a InGaAs photodiode and a Si photodiode. This is a very simple and cost effective method to reduce the noise interference from incandescent lamps.

• 한국안전학회지
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• 제27권4호
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• pp.115-120
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• 2012

In order to establish preventive maintenance standards through analysis & reliability prediction of about 60,000pcs of 20kindsof relays and contractors used for Seoul subway trains, several life prediction methodologies were applied. Firstly, Occurrence, Severity, Detection were defined and predicted by applying operation characteristic of EMU to the number of actions of relays & contactors which the manufacturers generally offer as the life cycle data. Secondly, failure distribution and average life of parts were analyzed through interpretation of field data based on a lot of experience which had built up in the field for a long time. Finally, using the 217PLUS standard as a reliability prediction program, comparative analysis of use reliability and inherent reliability was done through reliability prediction at the part level and system level.

• 시스템엔지니어링학술지
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• 제9권2호
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• pp.91-97
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• 2013

Recently, the Korean Railroad have been operating separately by Korea Rail Network and the Korail since 2005. In addition, because of the lack of government's social overhead capital, New railway projects have been built and operated by private investors which don't have railway operating experience. Therefore, systems engineering management is needed from the initial planning stage to the construction and the opening. In this paper, structural features were considered according to the separation of Daegok-Sosa-Wonsi Private Finance Initiative (Daegok-Sosa, Sosa-wonsi) and the operating agency's unification(Daegok - Sosa business operations). And based on the domestic system engineering applications, System-Engineering Implementation was studied.

• Tribology and Lubricants
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• 제23권1호
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• pp.19-28
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• 2007

Mechanical Brake system is inevitable equipment for stability of train and speed of the train. Especially brake disk and brake pads are core parts of mechanical brake system. It was investigated with tribological characteristics of brake discs for train by using lab-scale dynamometer. Gray cast iron disk was most attacked with sintered brake pad. Alloyed steel disk and NCM cast iron disk had suitable friction coefficient, high stability and low disk attack to the sintered brake pad. But at the view of economy, low alloyed cast iron will be most suitable choice.