• 대한기계학회논문집B
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• 제35권6호
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• pp.593-601
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• 2011

다양한 작동 조건에서 고분자 전해질형 연료전지의 성능 변화를 예측하기 위한 해석 프로그램을 구성하여 열관리가 시스템의 성능에 미치는 영향을 해석하였다. 전체 시스템은 연료전지 스택, 공기공급계, 연료공급계, 열 관리계로 구성 되었으며 각 구성부의 설계점을 고려하여 열역학적 모델링을 적용 하였다. 외기온 변화와 냉각 시스템의 성능 변화에 따라 연료전지 스택의 온도 및 출력 변화가 예상되므로 탈설계 해석을 하여 전체 시스템의 성능 변화를 예측하였다.

• 항공우주시스템공학회지
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• 제12권4호
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• pp.90-97
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• 2018

고속 비행체의 연료공급 및 냉각계통의 통합설계를 위한 프로그램을 개발하고 이를 이용하여 예비설계 및 검증을 수행하였다. 개발된 설계 도구는 상용 열유체 시스템 설계 프로그램을 프레임워크로 이용하여 모듈 통합과 입출력 처리 등이 개선되었다. 모델의 형상 및 열환경 변수를 입력하여 구성품의 상태량을 계산하고 모사를 통하여 설계 요구조건 충족을 확인할 수 있다. 이 프로그램을 사용하여 시스템의 세부 구성품 규격 선정에 적절하게 사용할 수 있음을 나타내었다.

• 한국자동차공학회논문집
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• 제21권1호
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• pp.43-50
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• 2013

The stringent emission regulation and future shortage of fossil fuel motivate the research of alternative powertrain. In this study, a system of proton exchange membrane fuel cell has been modeled to analyze the performance of the fuel cell system for automotive application. The model is composed of the fuel cell stack, air compressor, humidifier, and intercooler, and hydrogen supply which are implemented by using the Matlab/Simulink(R). Fuel cell stack model is empirical model but the water transport model is included so that the system performance can be predicted over various humidity conditions. On the other hand, the model of air compressor is composed of motor, static air compressor, and some manifolds so that the motor dynamics and manifold dynamics can be investigated. Since the model is concentrated on the strategic operation of compressor to reduce the power consumption, other balance of components (BOP) are modeled to be static components. Since the air compressor model is empirical model which is based on curve fitting of experiments, the stack model is validated with the commercial software and the experiments. The dynamics of air compressor is investigated over unit change of system load. The results shows that the power consumption of air compressor is about 12% to 25% of stack gross power and dynamic response should be reduced to optimize the system operation.

• 유통과학연구
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• 제21권5호
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• pp.43-51
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• 2023

Purpose: The current research investigates the beneficial impacts of supply chain innovation and risk management on the competitive advantage of organizations, based on the resource-based theory (RBT) framework. Research Design, Data, and Methodology: 14 survey items were included in the study's questionnaire, utilizing a random sampling technique to gather data from 239 leaders and managers employed by various steel trading firms in Vietnam. In order to validate the data and examine relationships, the collected data is analyzed using structural equation modeling, confirmatory factor analysis, and reliability analysis via SPSS 22.0 and AMOS 22.0 software. A fictitious system has been suggested. Results: According to the findings, the most positive influence on competitive advantage is supply chain innovation, followed by risk management capability, having the second greatest positive influence. Conclusions: Some conclusions are drawn based on the research's findings in order to assist managers in realizing the significance and necessity of giving attention to supply chain innovation and improving risk management capabilities, both of which are essential components for achieving the competitive advantage of an organization.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.266-266
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• 2009

현재 도시철도 전력설비의 진단시스템은 각 설비별로 산재되어 있어 종합적 상태를 실시간으로 모니터링 할 수 있는 시스템 구축이 필요하다. 특히 전력설비 고장을 사전에 검출하고 최적의 수명을 예측하기 위해서 표준화되고 객관적인 상태 판단을 위한 시스템 도입이 필요하다. 또한 도시철도 변전소가 무인으로 운영됨에 따라 전력실비 자체의 온라인 상시감시 및 자기진단을 수행할 수 있는 다양한 시스템을 도입이 필요하다. 본 연구에서는 도시철도 주요 전력설비 인 도시철도용 (AC/DC) 변압기, 단로기, 차단기, 정류기, GIS에 설치되는 각종 센서, 센서에서의 데이터를 측정하는 이상검출장치에서의 데이터를 수집하는 데이터취득장치, 데이터취득장치와 서버를 연결하는 통신제어장치, 모니터링 프로그램과 수명예측 프로그램이 설치된 서버를 포함하여 각종 부가 장치를 포함하는 변전기기 수명예측을 위한 전체 시스템의 개발에 대하여 기술 하였다. 또한 무선기반의 고장진단 검측 시스템을 구현하고 데이터 획득 기술에 대하여 나타내었다.

• 한국CDE학회논문집
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• 제21권3호
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• pp.353-362
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• 2016

As ships become larger and construction of offshore plants increases recently, the amount of outsourcing has increased accordingly in the shipyard. Consequently, the system integration in terms of SCM (Supply Chain Management) of information and material flows has become much more important. Especially, since the SCM in the shipbuilding industry is operated in accordance with the production planning in connection with design, purchasing and production process which are the main components of the supply chain, the best production plan has to be established over the whole scheduling activities from the long-term planning to the short-term planning. The paper analyzes the characteristics of the SCM and the production planning system and suggests the need and the direction of APS (Advanced Planning System) development specialized in the supply chain management only for shipbuilding industry. Furthermore, propose a new SCP-Matrix (Supply Chain Planning Matrix), which is the basis of the APS development, appropriate for the shipbuilding industry and draw the core function of the APS module for the practical production plan.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.44-50
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• 2002

The connecting rod big-end bearing is one of the most heavily loaded components of the lubrication system of high-speed combustion engines. The supply oil flow has to pass to the main bearing and the rotating crankshaft before entering the connecting rod bearing. It is common knowledge that the centrifugal forces due to the crankshaft rotation influence the oil flow to connecting rod bearing through the oil supply bore, especially, when the oil supply system to the connecting rod bearing has a 180$^{\circ}$circumferential groove via a single drilling in the crankshaft. In this case, it should be confirmed that the groove oil pressure in the main bearing is sufficient to overcome these centrifugal forces. For the purpose, the dynamic oil pressure before entering oil supply bore to the connecting rod bearing was measured instead of averaged oil pressure in main gallery. Experimental test results show that the dynamic oil pressure in the oil groove was more useful than that of main gallery. And it was also found that the oil pressure fluctuation in the groove was sensitively affected by the reduction of the main bearing clearance.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.501-504
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• 2000

In this paper the PC power supply is studied from the point of system stability. The power stage model of a multiple output forward converter with weighted voltage mode control is derived including all the major parasitic components and the small signal model is also derived. Determination of the weighting factors and a design procedure for the loop compensation are presented. Finally the model is verified through the simulation of three output forward converter with SABER.

• 한국전자거래학회:학술대회논문집
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• 한국전자거래학회 1999년도 학술대회지 vol.2
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• pp.431-445
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• 1999

This paper introduces a development of component based framework of supply-chain management. The existing legacy system, which is not designed for object-oriented paradigm, is re-modeled using unified modeling language. Components are extracted from the legacy application, and frameworks are also designed in order to increase productivities of software development. Design issues concerning component and framework development are discussed with real situation. Performance and development productivity issue are also discussed with discussing component size and scope. A real case is presented in connection with the discussed issues.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2012년도 추계학술대회
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• pp.909-910
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• 2012

선박을 건조하는 조선산업은 서로 다른 부품을 순서에 따라 하나씩 조립하여 생산하는 주문형 조립 산업이다. 선박 한척을 건조하는데 필요한 부품의 수는 십여 만개 이상으로 수천에서 수만톤의 강재가 필요하며 보통 선박의 수주에서 인도까지 2년이 소요된다. 조선산업에 쓰이는 부품 등은 국내 외 외주업체를 통해 주문형 생산방식으로 공급받기 때문에 건조과정에서 필요한 부품을 적기에 공급받지 못한다면 물류비용이 증가하고, 작업 및 공정관리의 혼란이 발생한다. 따라서 본 논문에서는 효율적인 선박부품의 관리를 위한 자재관리시스템의 구축 방안을 제안한다.