• 한국안전학회지
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• 제29권6호
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• pp.151-157
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• 2014

This study deals with the rear-end collision at roundabouts. The purpose of this study is to develop the accident models of rear-end collision in Korea. In pursuing the above, this study gives particular attention to developing the appropriate models using Poisson, negative binomial model, ZAM, multiple linear and nonlinear regression models, and statistical analysis tools. The main results are as follows. First, the Vuong statistics and overdispersion parameters indicate that ZIP is the most appropriate model among count data models. Second, RMSE, MPB, MAD and correlation coefficient tests show that the multiple nonlinear model is the most suitable to the rear-end collision data. Finally, such the independent variables as traffic volume, ratio of heavy vehicle, number of circulatory roadway lane, number of crosswalk and stop line are adopted in the optimal model.

• 한국콘텐츠학회논문지
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• 제7권1호
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• pp.32-39
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• 2007

다수 사용자용 온라인 게임은 온라인 서비스들 중에 중요한 부분을 차지하고 있다. 최근에는 네트워크를 통한 온라인 서비스를 이용하는 사용자들의 증가로 인해 서버에 부하가 가중되고 있다. 본 논문에서는 이와 같은 문제를 해결하는 2Layer-Cell 방식을 이용한 분산 MMORPG(Massively Multi-player Online Role Playing Game)게임 서버를 제안한다. 제안하는 방식은 많은 사용자들을 위한 MMORPG 분산 게임서버에 적합한 해결책을 제공한다. 성능평가는 제안하는 MMORPG 분산게임서버가 기존방법에 비해 메모리 사용량과 처리속도에서 성능이 우수함을 보인다.

• 해양환경안전학회지
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• 제2권S1호
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• pp.7-25
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• 1996

The amount of Sea Casualty is increased by heavy sea traffic, increasing sea-borne cargoes, and superannuated vessels. This study analyzed the circumstance of ship salvage in Korean Salvage Units and management of Salvage Divers in Korea and other countries in order to make establishment of Ship Salvage Divers. This paper reputed the object, the necessity and the character of Ship Salvage Divers. For the purpose of study two parts are considered in order to analyze the environment of salvage divers(the circumstance of Sea Casulties and Ship Salvage). Under the present circumstance in Korea this development planning study may be restricted, but the effective planning to activate Korean Ship Salvage Diver is abstracted as follows; First, the political assistance of concerned government authority is needed. Second, establishment of new course, grade, certificate and licence for Salvage Diver is a Pre-requisite factor for the successful enactment. Third, establishment of Korean Ship Salvage Diving Center or School is strongly required.

• 한국항해학회지
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• 제17권4호
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• pp.53-71
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• 1993

The amount and quantity of sea casualities are increased by both an increasing sea-borne cargoes and heavy sea traffic. This paper analyzed the situation of Korean salvage company in order to activate on civilbasis, compared with the nature of common enterprises, and reported the object, the necessity, and the cha-racter of salvage company. For the purpose of this study, three parts are considered in order to analyze the environment of salvage company(the trend of sea casualties, sea-borne cargoes-passengers, ship tonnage/age) the effective planning to activate Korean salvage company are abstracted as follows : 1.the political assistance of concerned government authority. 2.the cooperation system of concerned business field. 3.the self-developing management of salvage company.

• 한국통신학회논문지
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• 제29권11B
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• pp.974-979
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• 2004

IEEE 802.l1b에서는 기본서비스인 DCF와 QoS를 제공하기 위한 무경쟁 서비스인 PCF가 제공된다. DCF는 CSMA/CA(충돌을 회피하는 매체 접속 기법) 접속 프로토콜을 사용한다. 본 논문에서는 PCF를 수정하여 트래픽의 부하가 많아진 채널에 가충치를 두어 서비스하는 기법을 제시하였다. 스테이션 측으로부터 부분적인 큐의 정보를 받아 가중치를 계산하였으며 NS-2 시뮬레이터를 사용하여 PCF 기법을 수정한 기법의 우수성을 검증하였다.

• 한국통신학회논문지
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• 제35권5B호
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• pp.734-740
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• 2010

본 논문에서는 에너지를 기존의 기법보다 더 효율적으로 관리하기 위해 다중 라우팅 경로 설정 및 중계노드교체 기법을 제안하였다. 제안된 방법은 게임이론중의 하나인 샤플리 밸류 (Shapley Value)를 이용하여 에너지 효율적인 다중 라우팅 경로를 설정하여 데이터를 전송한다. 시뮬레이션 결과 제안된 기법이 기존의 기법보다 전체 무선 네트워크의 성능을 향상시킨 것을 확인할 수 있었다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.177-182
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• 2004

Railroad car is one of major public transportation because of an increase in population and heavy traffic problems. We design the concept with air filtration of HVAC system using CFD, select environment-friendly components and compose intellectual HVAC system. For this object, the research to connect HVAC system which control temperature, humidity, air flow with pollutant controlling system which can deal with particular dust, nasty smell. In case of train, fresh air should be provided continuously for pleasant environment of the cabin every season. The air will control outer dust, inner particular dust, $CO_2$ density by air conditioning, heating, humidity regulating, air filtering and ventilating. Ventilation system on passenger cars should be designed for the health and comfort of the passengers.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(II)
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• pp.516-521
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• 2003

The presentation and development of LRT(light rail transit) is one of the effective solution to reduce the heavy traffic problems of urban area The metropolitan cities and operation companies of urban transit railway are driving to. construct the LRT system because of the advantage of construction cost and environmental serviceability. Up to now, the design criteria of structures for LRT is not established. Therefore, this paper presents the structural design criteria for LRT with rubber wheels. The proposed code provides a means of establishing minimum standards for acceptance of design and construction of LRT. In order to improve the proposed design criteria, some details will be tested and evaluated in test line.

• 전자공학회논문지A
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• 제29A권10호
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• pp.1-7
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• 1992

This paper proposes reservation-based multiple access with variable frame length (RMAV) which is a new multiple access scheme for indoor and outdoor wireless data communications. RMAV is based on the slot reservation scheme and adopts a frame structure with variable frame length. The frame length increases as the number of active terminals and/or the system load increases. As a result, RMAV is adapted to the changes in the traffic pattern, and it offers short delay in light load conditions and high throughput in heavy load conditions. The performance of RMAV is evaluated by simulations. In addition, it is compared with the performance of PRMA(packet reservation multiple access).

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.485-490
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• 2000

Because of occuring easily the crack, debond, lutting on asphalts pavement of bredge decks under traffic's heavy weigt load. We investigated the application of latex modified concrete to resurface and repaire bridge decks for preventing the above problems. Here, Using the ordinary portland cement and high early cement, We rested mix design, workability, compressive strength, adhesive power, drying shrinkage, carbonation, and economic estimation etc. We selected the condition of application to resurface and repaire bridge decks and detected high early cement is superior to ordinary portland cement in results of analyzing the application of the repairing bridge decks and economic estimations.