• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.417-420
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• 2006

FCEV uses electric energy generated from the reaction between Hydrogen and Oxygen in fuel cell stack as driving force. As fossil fuels are exhausted, fuel cell is regarded as a potent substitute for next generation energy source, and thus, most of car-makers make every efforts to develop fuel cell electric vehicle (FCEV). In addition, fuel cell is also beneficial in aspect of environment, because only clean water is produced during chemical reaction process instead of harmful exhausted gas. Generally, Hydrogen is supplied from high-pressured fuel tank, and air blower (or compressor) supplies Oxygen by pressurizing ambient air. Air blower which is driven by high speed motor consumes about $7{\sim}8%$ of energy generated from fuel cell stack. Therefore, the efficiency of an air blower is directly linked with the overall performance of FCEV. This study will present developing process of an air blower and its consisting parts respectively.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.403-406
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• 1996

Since most human activities in a nuclear power plant are perfirmed in the main control room (MCR), it is important to have its design well human-engineered, both physically and cognitively. Much research efforts have been given for better, operator-centered designs of human-machine interface in MCR capitalizing today's advanced information technology. Korea is among those who are actively expending such research for the next-generation nuclear plants. This paper analyzes two forerunners among the emerging MCR designs, namely Nuplex 80+ and N4, from the perspective of cognitive systems engineering. Since the two show some fundamental differences in their design concepts, the principles with their pros and cons must be enumerated to benefit our own design of new control rooms. This paper also lists many other decision-making points that emerged due to the new availability of cognitively based on cognitive engineering principles. The future scope and directions of related research are suggested.

• 한국연소학회지
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• 제4권2호
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• pp.43-50
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• 1999

Liquefied petroleum gas (LPG) has been used as motor fuel due to its low emissions and low cost. The fuel feeding system has been improved with stringent requirement for exhaust emissions. LPG carburetion system was first introduced, then the system has been changed to a precisely controlled gas injection system, but this gas feeding system has a limitation on improving power output. In order to improve an engine performance, a multi-point port injection system was introduced recently, and a liquid direct injection system into a cylinder was suggested as a next generation system to maximize a fuel economy as well as a power. This study addresses the analysis of the LPG spray from diesel injectors. The spray images are visualized and compared with diesel sprays in a wide injection pressure range. The photographs show much wider dispersion of LPG sprays.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1999년도 제19회 KOSCO SYMPOSIUM 논문집
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• pp.21-26
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• 1999

Liquefied petroleum gas(LPG) has been used as motor fuel due to its low emissions and low cost. The fuel feeding system has been improved with stringent requirement for exhaust emissions. LPG carburation system was firstly introduced, then the system changed into a gas injection system controlled precisely, but those gas feeding system has a limitation on improving power output. In order to improve an engine performance, a multi-point port injection system was introduced recently, and a liquid direct injection system into a cylinder was suggested as a next generation system to maximize a fuel economy as well as a power. This study addresses the analysis of the LPG spray from diesel injectors. The spray images are visualized and compared with diesel sprays in a wide injection pressure range. The photographs show much wider dispersion of LPG sprays.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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• pp.234-237
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• 2007

We report on our experience on utilization of collaborative tools for KISTI high energy physics group. Our main subject will be the new EVO (Enabling Virtual Organization) server that we hosted recently at KISTI. The EVO is a next generation collaborative tool from CalTech high energy physics group with several improvements from its predecessor VRVS (Virtual Room Videoconferencing System). EVO has the same baseline structure as in VRVS. The network of servers lies at the heart of EVO structure and one server called Panda communicates with local clients called Koala.

• 한국콘텐츠학회논문지
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• 제6권10호
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• pp.153-162
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• 2006

WDM/SCM FTTH는 가까운 미래에 WDM과 SCM 기술을 사용하여 액세스 네트워크의 다양한 요구 사항들을 충족시킬 수 있는 광 액세스 네트워크이다. 본 논문에서는 WDM FTTH(Fiber To The Home) 및 WDM/SCM (Wavelength Division Multiplexing/Sub-Carrier Multiplexing) FTTH의 새로운 네트워크 구조를 제안하고 네트워크의 광 특성들과 가입자 요구에 의한 대역폭의 동적인 할당에 대한 성능을 시뮬레이션 결과를 통해서 분석한다.

• 정보보호학회논문지
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• 제23권3호
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• pp.405-416
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• 2013

ZigBee는 WBAN이나 스마트 그리드를 위한 차세대 표준 인프라로 인정받는 무선네트워크 통신프로토콜이다. 보안은 몇몇의 ZigBee 어플리케이션에서 중요한 역할을 한다. 특히, ZigBee안에서 멤버가 가입이나 탈퇴를 하는 상황에서는 엄격한 멤버관리가 필요하다. 본 논문에서, 우리는 현재 ZigBee에서 사용 중인 탈퇴 과정의 보안 취약점에 대하여 조사하고, 문제 해결을 위한 새로운 보안 스키마를 제시하고 그것의 보안능력 및 성능을 분석한다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.311-318
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• 2003

Traffic management means the management of streams of people, vehicle and cargo. Its aim is to help creating an efficient, safe and environmentally friendly transport system. Traffic management can roughly be divided in traffic control and monitoring, traffic information and demand management. The main purpose of this thesis is providing the basis for developing the next generation train traffic management system by comparing domestic and abroad train traffic management system. The composition of this thesis has been discussed in the following order of the comparison of train traffic management system's function, the introduction of Autonomous Decentralized system, the comparison between CTC and ATOS. the comparison between the hierarchy system and Autonomous Decentralized system, the study of introduction plan of Autonomous Decentralized-type train traffic management system and conclusion.

• Current Optics and Photonics
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• 제2권1호
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• pp.39-46
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• 2018

Visible-light communication (VLC) combined with advanced illumination can be expected to become an integral part of next-generation communication networks. One of the major concerns in VLC implementation is developing resource-allocation schemes in a multi-user scenario. However, the scheduling for heterogeneous quality of service (QoS) traffic has not been studied so far, for the indoor VLC downlink system. In this paper, we creatively introduce effective-bandwidth and effective-capacity theory into the multi-user scheduling (MUS) problem, to guarantee the user's statistical delay QoS. We also take account of the aggregate interference (AI) in the indoor VLC downlink system, and analyze its impact on the user-centric MUS problem for the first time. Simulations show that the AI has a nonnegligible influence on the scheduling result, and that the proposed scheduling scheme could guarantee the user's QoS requirement under the premise of ensuring sum capacity.

• 전자통신동향분석
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• 제14권6호통권60호
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• pp.51-63
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• 1999

IPSEC (Internet Protocol Security) is a network layer security protocol that is designed to support secure TCP/IP environment over the Internet considering flexibility, scalability, and interoperability. IPSEC primarily supports security among hosts rather than users unlike the other security protocols. Recently, IPSEC is emphasized as one of the important security infrastructures in the NGI (Next Generation Internet). It also has suitable features to implement VPN (Virtual Private Network) efficiently and its application areas are expected to grow rapidly. In this paper, the basic concepts and related standard documents of IPSEC will be introduced.