• 한국항공운항학회지
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• 제23권1호
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• pp.120-125
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• 2015

Passengers and Airlines wish neither delay nor cancellation due to aircraft defects. However, about 1 delay or cancellation case occurs out of 100 departures worldwide whereas 1 quarter case does in Korean domestic industry. Independent LCC carriers in Korea have almost double case. Most cases are recovered by replacing aircraft components. Airlines have prepared the spare components based on the reliability data by manufacturers to rectify defects or perform preventive maintenances. The total value for initial spares including engine is 40% of the aircraft price when they operate less than 5 aircraft. The more airlines operate the aircraft, the less the ratio of the investment for spares reflecting the economy of scale. This study intends to suggest how to improve the efficiencies as well as the safety of LCC throughout parts pooling including engines.

• Journal of Korean Neurosurgical Society
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• 제42권2호
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• pp.135-140
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• 2007

It is not the best way to treat a hopeless patient with life-sustaining medical devices until the heart beats stop. Advanced medical technology may prolong the life for a significant period without recovery from the disease. However, it would give an unbearable economic burden to the family and the society. In 2006, we decided not to operate 9 patients with traumatic intracranial hematomas. We examined those patients with special references to possible legal and ethical problems. It is reasonable to withhold a treatment after documentation that the family never wants any life sustaining treatment when the treatment does not guarantee the meaningful life.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2009년도 춘계 종합학술대회 논문집
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• pp.693-698
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• 2009

컴퓨터 시스템을 중단 없이 정상적으로 동작 시키는 것은 중요한 문제 중의 하나이다. 이와 같이 컴퓨터 시스템이 중단 없이 동작하도록 하기 위하여 여러 가지 고장 감내 기법들이 개발 및 상용화되어 사용되고 있다. 대부분의 고장 감내 기법은 많은 경비가 소요된다. 본 논문은 리눅스 운영체제에서 동적 모듈(DLM)을 이용하여 USB 디바이스를 연결할 경우 USB 디바이스 사용에 대해 발생할 수 있는 커널 PANIC 현상을 줄이는 커널 하드닝 기법에 대해서 연구 한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.602-607
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• 2004

Several countries such as Japan, France and so on gradually operate double deck trains as efficient, reliable and comfortable mass transportation systems. However, the double deck trains have relatively big cross sectional areas and high mass centers that cause unsafe vehicle running performances and interface problems between the vehicles and infrastructures, and do not have enough spaces for electric equipments. Therefore, prior to operate double deck trains on the existing lines in Korea, careful investigations should be performed. In this study, we have roughly designed a double deck EMU train system for the existing lines around Seoul metropolitan area.

• 한국태양에너지학회 논문집
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• 제24권2호
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• pp.89-96
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• 2004

PV system is easy to operate and maintain than the other power generating system since it generally contains no moving parts, operates silently and requires very little maintenance. A solar cell generates DC power from sunlight whose power is different at any instance according to condition of irradiation and temperature variables. In order to improve the system utility factor and efficiency of energy conversion, it is desirable to operate the PV system at maximum power point of solar cell under different condition This paper describes the experimental results of the PV system contain solar modules and a DC-DC converter(boost type chopper) using fuzzy controller. The experimental results show that the PV system always operates at maximum power point of solar cells having stabilized output voltage waveform with relatively small ripple component.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1989년도 추계학술대회 논문집 학회본부
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• pp.240-244
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• 1989

This paper describes an electric vehicle DC-DC drive system capable of delivering motoring current and of generating braking current. The power transistor chopper Is adopted to operate a DC series motor. The transistor chopper adopted, a high chopping frequency and avoids additional inductance In series with the armature winding. The four-quadrant drive is applied to save the energy. The energy saving is critical in operating the Independent power source electric vehicle. Using software simulation, regeneration and braking characteristics are investigated. The microprocessor-based controller is used to operate the whole system.

• 한국통신학회논문지
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• 제18권5호
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• pp.757-772
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• 1993

본 논문에서는 영상 이해를 위한 지식 베이스 시스템에 있어서 핵심적 기능을 수행하게 되는 저급 지식원과 중급 지식원의 추출에 관한 것으로 화소 영역에 적용되는 저급 처리 과정으로 영역 분할 처리과정, 방향 영상 변환과정, 형태 정보 추출 과정, 영역 특징량 추출과정으로 구성되며 중급 처리 과정으로 특징 베이스 분류, 기하학적 토큰 관계성, 인지적 조직과 집단화 과정으로 구성되어 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.157-160
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• 2001

This paper presents A Design of WMR Controller that being composed of cooperative relation between PID controller and optimized neural network algorithm, it operate a variable control by velocity. Some proposed algorithm in the past just depended on PID controller for the control of position of WMR but for more efficient control we design a variable controller that operate control by PD controller using neural network if it is satisfied with any given condition. it adjust gain of PD controller for real time control using a fast feedforward algorithm which is different with Form of the standard backpropagation algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술대회 논문집 전문대학교육위원
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• pp.140-143
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• 2003

In order to improve the system utility efficiency of energy conversion, it is desirable to operate the PV system at maximum power point of solar cell under versable condition. This paper describes the experimental results of the PV system that contains a solar modules and DC-DC converter(boost type chopper). The Simulation results show that the PV system always operate at maximum power point of solar cells having stabilize output voltage waveform with relatively small ripple component.

• 전기학회논문지
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• 제64권1호
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• pp.23-28
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• 2015

Two old synchronous condensers in Jeju are being replaced by new machines to operate Jeju AC network with Haenam-Jeju HVDC system stably. Before new synchronous condensers operate on site, voltage stability analysis is conducted to verify stable operation of jeju AC network. Through impedance analysis of the synchronous machine, transformer and ac network, the equivalent circuit is constructed and the voltage drop during start-up is calculated. Then, PSS/E fault analysis is performed to acquire short-circuit capacity according to the generator operation scenarios. Voltage variation when starting synchronous condenser is simulated in PSCAD/EMTDC and satisfies the operating condition of jeju AC network and HVDC #1 system.