• 전기의세계
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• 제24권5호
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• pp.21-30
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• 1975

These studies aim to support technically the National Rural Electrification Program now in progress by analyzing several engineering problems in regard to the program and then suggesting some appropriate solutions or measures. The contents of these studies are divided into three categories; (1)optimized distribution systems for the rural electrification, (2)optimized rural illumination and (3)single-phase operation of three-phase motors.

• 대한산업공학회지
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• 제37권4호
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• pp.390-399
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• 2011

Generally the life-cycle cost of complex systems composed of several sub systems or equipments such as train, aircraft weapon systems is spent much more during operation and maintenance phase than development phase. The maintenance cost for maintaining the availability and extending the life span of systems comprise a large proportion of systems operation cost. The cycle of preventive maintenance affects operation and maintenance cost a lot. In this study we introduce a way minimizing life-cycle cost of systems by calculating more reliable preventive maintenance period than the results of previous study using systems reliability data considered the reliability and failure effect ratio of sub-systems or components. We can solve the preventive maintenance period problem known as NP-Hard as quick as possible by using modified genetic algorithm than using other models introduced in previous study.

• 한국항해학회지
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• 제23권4호
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• pp.63-76
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• 1999

This paper aims at developing an integrated fleet management support system for industrial carriers who usually control the vessels of their own or on a time charter to minimize the cost of shipping their cargoes. The work is mainly concerned with the operational management problem of the fleet owned by a major oil company, a typical industrial carrier. The optimal fleet management problem for the major oil company can be divided into two phase problem. The front end corresponds to the production operation problem of the transportation of crude oil, the refinery operation, and the distribution of product oil to comply with the demand of the market. The back end is to tackle the fleet scheduling problem to meet the seaborne transportation demand derived from the front end. Relevant optimization models for each phase are proposed and described briefly. Then a user-friendly integrated fleet management support system is built based on the proposed optimization models for both ends under Windows environment. A case study reflecting the practices of fleet management problem for the major oil company is carried out by using the system.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1999년도 제14차 학술회의논문집
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• pp.29-32
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• 1999

Korea Multi-Purpose SATellite(KOMPSAT) is scheduled to be launched by TAURUS launch vehicle in November, 1999. Tracking, Telemetry and Command(TT&C) operation and the flight dynamics support should be performed for the successful Launch and Early Orbit Phase(LEOP) operation. After the first contact of the KOMPSAT spacecraft, initial orbit determination using ground based tracking data should be performed for the acquisition of the orbit. Although the KOMPSAT is planned to be directly inserted into the Sun- synchronous orbit of 685 km altitude, the orbit maneuvers are required fur the correction of the launch vehicle dispersion. Flight dynamics support such as orbit determination and maneuver planning will be performed by using KOMPSAT Mission Analysis and Planning Subsystem(MAPS) in KOMPSAT Mission Control Element(MCE). The KOMPSAT MAPS have been jointly developed by Electronics and Telecommunications Research Institute(ETRI) and Hyundai Space & Aircraft Company(HYSA). The KOMPSAT MCE was installed in Korea Aerospace Research Institute(KARI) site for the KOMPSAT operation. In this paper, the orbit determination and maneuver planning are introduced and simulated for the KOMPSAT spacecraft in LEOP operation. Initial orbit determination using short arc tracking data and definitive orbit determination using multiple passes tracking data are performed. Orbit maneuvers for the altitude correction and inclination correction are planned for achieving the final mission orbit of the KOMPSAT.

• 한국신뢰성학회지:신뢰성응용연구
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• 제7권3호
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• pp.101-110
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• 2007

The works of defence reliability have begun since the ILS team was organized in ROKA on March 2003. After that DAPA was opened at January 1st 2006 and those of defence reliability were reinforced. But the present of defence reliability is not enough. Many development and changes are required in the following area. The first is Master-plan making of defence reliability, and the second is making of the process of reliability. And then we have to enhance reliability of weapon system in the operation and support phase. The last is that policy is firmly executed among the defence organizations.

• Journal of Information Technology Applications and Management
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• 제12권4호
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• pp.59-70
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• 2005

Flash memories are one of best media to support portable computer's storages in mobile computing environment. The features of non-volatility, low power consumption, and fast access time for read operations are sufficient grounds to support flash memory as major database storage components of portable computers. However, we need to improve traditional transaction management scheme due to the relatively slow characteristics of flash operation as compared to RAM memory. in order to achieve this goal, we devise a new scheme called Flash Two Phase Locking (F2PL) scheme for efficient transaction processing. F2Pl improves transaction performance by allowing multi version reads and efficiently handling slow flash write/erase operation in lock management process. We also propose a simulation model to show the performance of F2PL. Based on the results of the performance evaluation, we conclude that F2PL scheme outperforms the traditional scheme.

• 천문학회보
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• 제24권2호
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• pp.83-83
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• 1999

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1996년도 추계학술대회발표논문집; 고려대학교, 서울; 26 Oct. 1996
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• pp.271-274
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• 1996

Since the primary purpose of information Engineering focuses on transaction or operation processing, various information needs acquired in Information Strategy Planning phase are not properly utilized from the viewpoint of decision support systems development. In this research, we suggest a case-based reasoning application that supports initial Data Warehouse Modeling by expanding the activities in Information Strategy Planning.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.191-193
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• 2005

Flash memories are one of best media to support portable computer's storages. However, we need to improve traditional data management scheme due to the relatively slow characteristics of flash operation as compared to RAM memory. In order to achieve this goal, we devise a new scheme called Flash Two Phase Locking (F2PL) scheme for efficient data processing. F2PL improves transaction performance by allowing multi version reads and efficiently handling slow flash write/erase operation in lock management process.

• 한국국방경영분석학회지
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• 제34권2호
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• pp.43-61
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• 2008

성과기반군수는 전투준비태세를 향상시키고 무기체계의 수법주기비용을 절감하기 위하여 연구되었다. 최근 미국 국방부는 성과기반군수를 연구하고 발전시켜서 이것을 미국 군수분야에 적용하고 있다. 따라서 본 연구논문에서는 미국의 군수기원 분야의 발전동향을 살펴보고 우리나라의 군수지원 분야의 실태를 분석한 후, 효율적인 군수지원을 위하여 성과기반군수를 활용한 군수지원 발전방안을 제시하였다.