• 대한토목학회논문집
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• 제28권5D호
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• pp.609-615
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• 2008

환승센터내 보행공간은 이용자들의 다양한 활동이 복합적으로 이루어지는 공간으로 이용자가 보행에 소모되는 통행비용이 증가하게 되면 환승센터로의 접근을 기피하게 되고 이는 환승센터의 이용 활성화를 저해하는 요소로서 작용될 수 있다. 이에 환승센터를 이용하는 보행자에게 실시간으로 의미있는 경로를 제공하고 보행 이동을 보조하여 환승을 목적으로 한 이용자의 혼란과 통행비용에 관한 경제적인 손실을 최소화시킬 수 있다면 연구의 가치를 기대할 수 있을 것이다. 이에 본 연구에서는 전 세계를 비롯하여 우리나라에서도 큰 이슈가 되고 있는 유비쿼터스 기술을 전제로 하여 환승센터내 보행자에게 의미있는 경로를 제공하는 방안과 이를 공간지도로 구축하는 방안을 제시하고자 한다.

• 대한토목학회논문집
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• 제31권2A호
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• pp.51-58
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• 2011

이 연구는 중소경간 교량상판의 구조적 효율성과 경제성을 향상시키고 시공시 환경오염이나 교통흐름을 방해할 수 있는 공정을 최소화하기 위한 새로운 형식의 Inverted-T형 거더(이하 IT거더)의 개발을 위한 시험연구이다. 이 공법은 기존의 교량형식보다 미관이 아름답고, 시야확보가 우수한 합성교량상판의 형식으로서 최근 국내 현장에서 당면하고 있는 기능 인력의 고령화로 인한 인력 수급의 어려움을 해결할 수 있는 방편의 하나이다. 따라서 중소경간 교량상판의 설계와 시공을 위한 새로운 IT거더 공법은 시공성 향상과 건설비용 절감을 위한 효과적인 방법으로 사료된다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
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• pp.215-217
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• 2004

In wireless sensor networks, fair allocation of bandwidth among different nodes is one of the critical problems that effects the serviceability of the entire system. Fair bandwidth allocation mechanisms, like fair queuing, usually need to maintain state, manage buffers, and perform packet scheduling on a per flow basis, and this complexity may prevent them from being cost-effectively implemented and widely deployed. It is a very important and difficult technical issue to provide packet scheduling architecture for fairness in wireless sensor networks. In this paper, we propose an packet scheduling architecture for sensor node, called FISN (Fairness Improvement Sensor Network), that significantly reduces this implementation complexity yet still achieves approximately fair bandwidth allocations. Sensor node for sensing estimate the incoming rate of each sensor device and insert a label into each transmission packet header based on this estimate. Sensor node for forwarding maintain no per flow state; they use FIFO packet scheduling augmented by a probabilistic dropping algorithm that uses the packet labels and an estimate of the aggregate traffic at the gathering node. We present the detailed design, implementation, and evaluation of FISN using simulation. We discuss the fairness improvement and practical engineering challenges of implementing FISN in an experimental sensor network test bed based on ns-2.

• Archives of Reconstructive Microsurgery
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• 제11권1호
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• pp.73-77
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• 2002

Medical application of leeches, by means of leech's blood suction, has advantages in not only directly removing blood congestion, but also preventing hindrance to venous drainage by inhibiting local thrombus formation and inducing continuous bleeding. Nevertheless, Aeromonas hydrophila infection secondary to such suction is most common and may develop into serious conditions from local inflammatory reaction to total necrosis of replanted parts and enterocolitis as well as sepsis. Once infected, it requires infection treatment, removal of necrotic tissues and reconstruction. Hence, duration and cost of treatment increase while functional recovery falls markedly. Accordingly, we present measures to reduce Aeromonas infections as follows: First, do not manipulate as much as possible while the leeches are sucking or moving. Second, the site which suction plates of the leeches are attached, should be selected away from the surgical wound site or open wound as much as possible. Third, contaminated or blood-wet gauze should be replaced often so that the skin of surgical areas would not swell. Furthermore, bleeding or oozing should be well-drained. Fourth, the areas other than the sites of leech attachment should be covered with sterilized gauzes in order to limit leech movement.

• 전기학회논문지P
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• 제64권4호
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• pp.212-219
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• 2015

Korea's first tram (so called "tram"), which was commenced the operation on May 4, 1899 of late Joseon Dynasty and run until 1968, played a pivotal role of public transportation. However, tram as new transportation mean is being recognized as traffic congestion problem becomes issue due to geometric automobile increase and reckless urban plan after stoppage of tram service. Tram has an advantage of inexpensive construction cost and eco-friendly means compared to existing and city railway, carrying more passengers rather than existing bus, excellent connectivity of existing transportation because of easy accessible to destination in the city center. Therefore, tram, what is called "Green Rvolution of Public Transportation", has a dreaming of revival and in the process of pushing. We suggest the accident type which might break out in the early stage of tram introduction and preventive measures by surveying the accident cases of tram advanced country, and study the crossing control measures.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.991-1001
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• 2013

Instead of building new substations or transmission lines, proper installation of flexible AC transmission systems (FACTS) devices can make the transmission networks accommodate more power transfers with less expansion cost. In this paper, the problem to maximize power system loadability by optimally installing two types of FACTS devices, namely static var compensator (SVC) and thyristor controlled series compensator (TCSC), is formulated as a mixed discrete-continuous nonlinear optimization problem (MDCP). To reduce the complexity of the problem, the locations suitable for SVC and TCSC installations are first investigated with tangent vector technique and real power flow performance index (PI) sensitivity factor and, with the specified locations for SVC and TCSC installations, a set of schemes is formed. For each scheme with the specific locations for SVC and TCSC installations, the MDCP is reduced to a continuous nonlinear optimization problem and the computing efficiency can be largely improved. Finally, to cope with the technical and economic concerns simultaneously, the scheme with the biggest utilization index value is recommended. The IEEE-14 bus system and a practical power system are used to validate the proposed method.

• 한국항행학회논문지
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• 제24권5호
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• pp.358-367
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• 2020

수도권 지역 직장인들의 평균 출퇴근 시간이 증가하고 도로의 교통혼잡비용이 증가함에 따라 새로운 교통수단의 필요성이 증가하고 있고, 도심항공 모빌리티(UAM)가 그 대안으로 떠오르고 있다. 따라서 본 논문에서는 인구, 교통량, 출퇴근 데이터를 이용하여 서울, 경기 지역에 UAM 수직 이착륙장 위치를 선정하고 운행 경로를 설정하였다. 전기 수직 이착륙 항공기(eVTOL)의 유형을 분석해 UAM에 적합한 추력편향형과 멀티콥터형 eVTOL을 선정하여 설정된 경로를 운행하였을 때 소요시간을 계산하였다. 또한 타 교통수단을 이용하였을 때 소요시간을 UAM 이용 시와 비교 분석하였다. 결과적으로 UAM을 이용한다면 출퇴근 시간이 대폭 줄어들 수 있음을 확인하였다.

• 시스템엔지니어링학술지
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• 제7권2호
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• pp.13-19
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• 2011

A LRT(Light Rail Transit) is one of the Future Urban Railway Development Project. The project's goal is to reduce a transportation congestion in the center of the city. New transportation is intensely required in order to overcome a limit of the ground transportation that is the existing public transportation, A LRT(Light Rail Transit) construction project to be based on an unmanned driving system is the large composition system that a vehicle, a signal, communication, electric, track etc. were organically integrated as echo-friendly urban transportation systems. It also put a huge budget, which is a large-scale infrastructure projects. It is international trend that Light Rail Transit projects apply a technique in System Engineering for a schedule, cost, quality elevations, and to approach in viewpoints of life-cycle from initial construction steps to operation, abolition. This paper intends to analyze RAM requirements taking into consideration ISO/IEC 15288 throughout life-cycle from concept, design, manufacture, operation and maintenance to the final phase, decommissioning, and the study seeks to suggest directions of efficient use to domestic LRT projects.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 춘계학술대회 논문집 전기설비전문위원
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• pp.195-197
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• 2009

It is a proven fact with the opening of the Seoul metro line number 1 in 1974 traffic congestion on the roads has decreased and the efficiency of people transportation in general has greatly been enhanced in the downtown and surrounding areas of Seoul. Even today construction of new subway lines are under way and many more are being planned due to the easy access to stations, short waiting and average travel times, compared with personal vehicles, contributing to the efficiency of the public transportation systems that are linking the downtown areas and also the intercity systems in moving passengers during rush hour and times of special event. Since the labour costs of the train operator in any large city based subway system accounts for a major part of the operating costs per kilometer and to ensure cost efficient operations, especially during non-peak hours, it is necessary to implement an unmanned(auto-driven) subway system. In order to implement such a system it is imperative that the on-board and wayside signalling control systems be fully automated as well. Only through proper examination of safety procedures not only by the AUGT(Automated Urban Guided Transport)system but also by ail the international standards organizations involved can safely and stability be ensured.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2010년도 춘계 학술대회 제22권1호
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• pp.99-100
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• 2010

이 연구는 Inverted-T형 거더 (이하 IT거더)를 이용하여 중소경간 교량의 구조적 효율성 및 경제성을 향상시키고 시공시 환경오염이나 교통흐름을 방해 할 수 있는 공정을 최소화하기 위한 시험연구이다. 특히, 이 공법은 기존의 교량형식보다 미관이 아름답고, 시야확보가 좋은 합성라멘교의 형식으로서 최근 국내 현장에서 당면하고 있는 기능 인력의 고령화로 인한 인력 수급의 어려움을 해결 할 수 있는 방편이다. 따라서 이 IT거더 공법은 시공성 향상 및 건설비용 절감을 위한 효과적인 방법이라 생각한다.