• 전기학회논문지
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• 제60권2호
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• pp.231-238
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• 2011

A role of Distribution Automation System(DAS) is required to be changed from observing and control to complex and various new system including functions which monitoring, control, prediction, operation and management of EMS type according to be gradually Smart Grid of distribution operation system for development of further power system industrial. IEC(International Electrotechnical Commission) published communication standards which interface and data model of distribution operation system to IEC 61968 and of host system like EMS(Energy Management System) to IEC 61970. So far, each standards are emphasizing themselves, but if they are applied by designed integration of the standards, it could be more efficiency system. So, in this paper, integration application of IEC standards and structure of further distribution operation system to use them are proposed by gradually increasing importance of communication protocols, functions and roles in further distribution management system considering Smart Grid.

• 감성과학
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• 제14권1호
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• pp.7-16
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• 2011

본 연구에서는 공공자전거 운영시스템을 도입하기 위해 국내외 사례조사와 대상지역인 나주시(NaJu City)의 현지조사를 통해 운영시스템 적용 방법에 대한 사례연구를 진행하였다. 1차 조사에서는 국내외 공공자전거 시스템 적용사례를 분석하여 이용시간, 도난과 파손 위험 등의 문제점을 조사하였다. 2차 조사에서는 공공자전거 시스템 도입 예정 지역인 나주시(NaJu City)의 조사결과 시민과 관광객이 쉽게 이용할 수 있는 운영시스템의 도입이 필요한 것으로 조사되었다. 3차 조사에서는 1, 2차 조사결과를 바탕으로 프랑스 밸리브(Velib) 시스템의 문제점을 해결할 수 있는 모바일 대여/반납 프로세스와 시스템 운영절차, 통신절차의 모듈을 정리하였다. 또한, 1차 조사와 2차 조사에서 나타난 문제점인 이용방법과 민원처리 방안에 대해서도 정리하였다. 위와 같이 본 연구에서는 국내외 사례조사, 현지조사, 그리고 대여/반납 프로그램의 모듈 개발을 통해 공공자전거의 운영시스템 도입 방법을 연구하였으며 현재 나주시에서 운영시스템이 시범운행 중에 있다. 따라서 앞으로 시험운행 결과를 종합하여 좀 더 효율적인 운영시스템이 도입될 수 있도록 연구를 진행하겠다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.400-408
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• 2009

Simulation applications for analyzing the productivity of construction operations at operation level and project schedules at project level are crucial methods in project management. The application at two different levels should be very tightly linked to each other in practice. However, appropriate integration at the levels is not achieved in that existing systems do not support to integrate operation models into a schedule model. This paper presents a new approach named to Discrete Event Simulation-Nesting modeling approach, which supports not only productivity analysis at operation level but also schedule management at a project level. The system developed by the authors allows creating operation models at the operation level, maintaining them in operation model library, executing sensitivity analysis to find the behaviors of the operation models when different combination of resources are used as existing DES systems do. On top of the conventional functions, the new system facilitates to find the optimum solution of resource combinations which satisfy the user's interest by computing the hourly productivity and the hourly cost of the operation. By drag-and-dropping an operation model kept in the operation model library, the operation models are integrated into an activity of the schedule model. When a complete schedule model is established by nesting operation models into the schedule model, stochastic simulation based scheduling is executed. A case study is presented to demonstrate the new simulation system and verify the validity of the system.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제48권7호
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• pp.363-368
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• 1999

The parallel operation system of multiple uninterruptible power supplies(UPSs) is used to increase power capacity of the system or to secure higher reliability at critical loads. In the parallel operation of the two UPSs, the load-sharing control to maintain the current balance between them is a key technique. Because a UPS has low output impedance and quick response characteristics, in case of an unbalanced load inverter output current changes very rapidly and thereby can instantaneously reach an overload condition. In this study, high precise load-sharing controller is proposed and implemented for the parallel operation system of two UPSs with low impedance characteristics and this controller controls the frequency and the voltage to minimize the active power component and the reactive power component which are gotten from the current difference between two UPSs. And then a good performance of the proposed method is verified by experiments in the parallel operation system with two 40KVA UPSs.

• 전기학회논문지
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• 제67권6호
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• pp.738-744
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• 2018

This paper proposes a low cost hot swap operation circuit of a parallel operation power supply for servers. Hot swap function for server power system is essential in 24 hour operation system such as internet data center, server, factory and etc. Server power supplies used in internet data centers have two or more parallel operations with the hot swap operation. However, the cost of the power supply is high because the controller IC for hot swap operation is very expensive. Therefore, this paper proposes a parallel-operated power supply with a low-cost hot swap controller for servers. The proposed system can operate hot swap function by using discrete devices and reduce the cost by more than 50%. A 1.2kW prototype system is implemented to verify the proposed low cost hot swap controller.

• 한국철도학회논문집
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• 제10권3호
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• pp.327-336
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• 2007

Operation a subway company requires high amount of early construction, operation and maintenance costs. Seoul Metro, one of the public subway companies in Seoul, Korea, has undergone operational deficit from its establishment, and the main reason is that the early construction and operation cost exceed the total revenue. Therefore, detailed researches on current operation system and possible alternatives are conducted to settle down finance trouble of the company. In particular, problems on operation and ticketing systems are analyzed, and based on that, necessity and detailed plan of railroad pass for one day are introduced and analyzed.

• 디지털산업정보학회논문지
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• 제5권3호
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• pp.155-173
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• 2009

Budget for the industry-university co-operation is expanded by the increasing of the importance of industry-university co-operation. Even though, industry and university do not co-operate voluntarily. Until now, there is no research about industry-university co-operation focusing on SMEs. This paper is about industry-university co-operation focusing on SMEs. In this paper, we introduce the status and structural problems of industry-university co-operation related with SMEs. And we derive the problems of industry-university co-operation in terms of co-operation purpose. Industry-university co-operation in terms of co-operation purpose can be categorized as R&D, technology transfer, infrastructure, and manpower training. And last, we suggest how we improve the industry-university co-operation system to benefit SMEs.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(II)
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• pp.929-936
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• 2002

This paper presents a Rotem's methodology for the establishment of train operation plan in Railway system. Train operation plan is the key prior plan to proceed the design of the civil and E&M relevant subsystem. But, due to the limitation of the environmental and project condition, common consensus to the key factors which make up the operation plan have not been accomplished. So, as a result of this comparative review for the general approaching method of train operation plan and application status of the major key factors being performed by Rotem, we will get the opportunities to improve the accuracy of the train operation plan.

• 한국항해항만학회지
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• 제30권9호
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• pp.741-748
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• 2006

Number of researches on efficient terminal operation system applying RFID(Radio Frequency Identification) are in progress. However, RFID has limitations on tracking and providing accurate positions of containers. In this paper, to enhance the performance of the integrated terminal operation system, an efficient loading management of yard is proposed by applying RFID based RTLS(Real Time Locating System) that provides real time accurate positions of containers. It was found that a group based sequence system is more efficient than the existing individual sequence number system in the container yard In the group based sequence system, the containers in the same group should have similar characteristics such as port of destination(POD), size, weight, etc. In order to run this system, we proposed the parameters to the unspecified N bytes of RFID tag which are specified in ISO 18000 7. And then, we developed an integrated operation system of container terminal using RFID. The proposed system reduces the ship turnaround time in ubiquitous port environments.

• 조명전기설비학회논문지
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• 제24권6호
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• pp.177-182
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• 2010

전력계통은 첨단기술과 함께 발전하고 있다. 최근 전력계통은 새로운 기술개발, 전기설비 및 운영 방법으로 전력계통 운영이 복잡해지고 있다. 전기설비가 발전함에 따라 전력계통의 사고비율이 감소하였지만, 그에 따라 새로운 운영방법이 필요하다. 계통 운영방법이 복잡해짐에 따라 효율적으로 전력계통 운영자들을 훈련시키고 교육시키는 전력계통 시뮬레이터가 필요하게 되었다. 본 논문에서는 LabVIEW 프로그램의 TCP/IP 통신을 이용하여 실시간 전력계통 교육용 시뮬레이터를 제작하였다. 제작한 시뮬레이터는 실제 전력계통에서 일어나는 예측하지 못한 다양한 사건으로 교육자를 지도할 수 있게 제작하였다.