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제4차 철도 패키지에 의한 유럽철도 운송시장개방 모델 분석
김상암(Sangahm Kim),조영남(Young-Nam Cho),김창환(Chang-Hwan Kim) 한국철도학회 2013 한국철도학회 학술발표대회논문집 Vol.2013 No.5
최근 유럽연합 집행위원회는 네 번째 철도 패키지를 통해 단일 유럽철도권역 구축 및 철도운영부문 시장개방 강화정책을 발표하였다. 유럽철도는 철도산업의 약화, 수송분담율 저하 등을 타개하기 위하여 1980년 중반부터 상하분리, 국제철도 및 화물철도 시장개방 등을 추진하여 왔으며, 일부 국가에서 성공적인 지표들을 보이고 있다. 유럽은 ‘하나의 시장’, ‘지속가능한 성장"이라는 목표를 가지고 철도교통의 비전을 설정하였으며, 철도부분은 시장개방이라는 수단을 통해 유럽연합의 목표와 일치시키고 있다. 유럽철도의 구조개혁과 발전전략은 현재 우리나라 철도 정책방향 설정에 시사하는 바가 크므로 본 논문에서 제4차 철도 패키지를 분석하고 구조개혁 모델에 대하여 살펴보고자 한다. Recently the EC announced a comprehensive package of measures to deliver better quality and more choice in railway services in Europe. Rail is a vital part of EU transport, with a key role in addressing rising traffic demand, congestion and de-carbonization. Since 2000, these principles have been progressively translated into reality, not least through the adoption of three successive packages of EU legislation. But many European rail markets are currently facing stagnation or decline. Faced with this reality, the Commission is proposing far reaching measures to encourage more innovation in EU railways by opening EU domestic passenger markets to competition, as well as substantial accompanying technical and structural reforms. In this paper the detailed targets, strategic plans and market opening models are presented by reviewing several documents such as communication and working documents.
김상암(Sangahm Kim),조연옥(Yunok Cho) 한국철도학회 2011 한국철도학회 학술발표대회논문집 Vol.2011 No.10
As technologies are developed and systems are complicated hazards embedded in the system are also increasing. proving safety and managing the safety is more scientific and organizational domain so that safety management system is pursuing to be active formation detecting the factors of hazard and managing them beyond passive-way. In the future in aorder to establish and manage national safety management system it is important to have effective system and manage it and also more important that all the people related to target system has to change their recognition and to play roles in it.
김상암(Sangahm Kim),조연옥(Yunok Cho) 한국철도학회 2011 한국철도학회 학술발표대회논문집 Vol.2011 No.10
The railway safety in Koreaisthreatenedduetotherestructuring of the railway industries introduction of the Korea Train eXpress (KTX) and electrification of the conventional lines. Many technical backgrounds are required to control railway accidents as low as reasonably practicable such as a railway safety act safety standards and safety assessment infrastructures. Korean government and the Korea Railroad Research Institute (KRRI) are conducting an integrated R&D program for improvement of the railway safety where the target is to reduce the accident fatalities by half. The program is composed of three parts; the safety system engineering and the program management the establishment of a safety management system and the development of techniques for assessing and preventing major railway accidents. Details of the research programs are explained in this paper where risk is used as the major control measure.
조병호,염병수,김상암,Cho, Byeong Ho,Yum, Byeoungsoo,Kim, Sangahm 한국정보통신학회 2016 한국정보통신학회논문지 Vol.20 No.3
사고수목을 이루는 게이트나 기본사상이 많아질수록 정상사상 확률의 정확한 계산이 어려워진다. 이를 극복하기 위해 BDD 방법을 적용하면 중소형 사고수목의 경우 짧은 시간에 근사계산 없이 정확한 값을 구할 수 있다. CUDD 함수를 이용하여 사고수목을 BDD로 변환하고 그로부터 정상사상의 발생확률을 구하는 고장경로 탐색 알고리즘을 고안하였다. 후방탐색 알고리즘은 전방탐색 알고리즘보다 고장경로의 탐색과 확률계산 시간에서 효과적이다. 이 탐색 알고리즘은 BDD에서 고장경로를 찾는데 있어서 탐색시간을 줄일 수 있고, 해당 사고수목의 단절집합과 최소단절집합을 찾는 유용한 방법이다. As the number of gates and basic events in fault trees increases, it becomes difficult to calculate the exact probability of the top event. In order to overcome this difficulty the BDD methodology can be used to calculate the exact top event probability for small and medium size fault trees in short time. Fault trees are converted to BDD by using CUDD library functions and a failure path search algorithm is proposed to calculate the exact top event probability. The backward search algorithm is more efficient than the forward one in finding failure paths and in the calculation of the top event probability. This backward search algorithm can reduce searching time in the identification of disjoint failure paths from BDD and can be considered as an effective tool to find the cut sets and the minimal cut sets for the given fault trees.
대규모 고장수목 계산에서 빠른 BDD 생성을 위한 고장수목 축소
조병호(Byeong Ho Cho),이우준(Woojune Yi),김상암(Sangahm Kim) 한국도시철도학회 2016 한국도시철도학회논문집 Vol.4 No.4
It is known that the size of fault tree affects the BDD(Binary Decision Diagram) structure and as the fault tree size decreases, the number of BDD nodes also decreases in general and the BDD generation time is shorter than the other. For two given fault trees which are logically the same each other, the BDD generation time for the smaller fault tree is shorter. Contraction, absorption and extraction rule can be applied for the logically same, but smaller fault tree transformation. As the BDD conversion of fault tree is performed per gate, the aim of fault tree reduction is to reduce the number of gates and to simplify the repeated events. Formulation of fault tree reduction is obtained and three forms of fault tree reduction are recommended before the BDD conversion of fault trees in order to reduce the runtime. The fault tree of an derailment accident is calculated and it is shown that the reduction strategy can be used for huge fault trees in order to reduce conversion runtime in BDD generation.