• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1345-1352
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• 2008

An inventory with constant demand is studied. We adopt a renewal argument to obtain the transient and stationary distribution of the level of the inventory. We show that the stationary distribution can be also derived by making use of either the level crossing technique or the renewal reward theorem. After assigning several managing costs to the inventory, we calculate the long-run average cost per unit time. A numerical example is illustrated to show how we optimize the inventory.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1524-1530
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• 2008

Generally a road vehicle's wrong entry into level crossing gives rise to hazardous events, the eventual collision with a approaching train depends on the effective operation of safety barriers such a abnormal condition detecting or emergency braking. In this paper, the risk assessment models developed for the level-crossing accidents will be introduced. The definition of hazardous events and the related hazardous factors are identified by the review of the accident history and engineering interpretation of the accident behavior. A probability of the hazardous events will be evaluated by the FTA, which is based on the accident scenario. For the severity estimation, the critical factors which can effect on the consequence will be reviewed during the ETA. Finally, the number of casualty for the public(vehicle drivers) and the train passengers are converted into an equivalent fatality.

• 한국전자통신학회논문지
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• 제5권2호
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• pp.138-144
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• 2010

철도건널목에서 SIFT 기반의 알고리즘을 사용한 영상 안전감시 시스템을 구축하고 실험을 수행하여 실제 상황에의 적용가능성을 판별하고 테스트하였다. 이를 위해 영상 획득 이후의 관심 지역과 관심 영역 구분, 특징점의 추출에 따른 데이터 매칭을 단계적으로 진행하였다. 또한 실시간 상황에서 동작이 가능하도록 헤시안 방법을 사용한 특징점 추출 방법을 사용한 SIFT와 다른 알고리즘과의 성능을 시험하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.315-317
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• 2001

In this paper, the relationship between system engineering lifecycle and safety lifecycle is investigated. V diagram and IEC 61508 model are represented in the lifecycle model. V diagram easily shows the flow of information between phases. But it does not show the amount of work involved in each stage. IEC 61508 model describes the activities to be performed during each phase of the lifecycle. And also the causal-consequence analysis for the level crossing is presented Representing this analysis procedure, we are try to establish safety of level crossing.

• KEPCO Journal on Electric Power and Energy
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• 제2권1호
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• pp.43-47
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• 2016

This system is a diagnosis system that checks whether it causes a partial discharge of a power cable or not. It is to classify normal from abnormal-normal, PD (Partial Discharge) sound through analysis of RLCR (Relative Level Crossing Rate) and spectrogram energy algorithm. Partial discharge diagnostic system has a function that stores PD sound and analyzes the data. The wave shape of PD sound is similar to noise and is systematically generated by partial discharge. Therefore, in this paper, we could discreminate between normal and abnormal case using relative level crossing rate (RLCR) and spectrogram of frequency energy rate.

• 한국철도학회논문집
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• 제9권2호
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• pp.230-236
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• 2006

For a short-term measurement to reduce an accident on a railroad crossing, it is necessary to find out the weakness and problems of existing equipment in the railroad transportation system. The analysis of railroad crossing accidents shows that main causes of accidents (24.9%) are the careless driving including an engine problem, damage on the safety equipment, slide on the snow, and an engine stop on the railroad crossing. Therefore, it is required to install a sensor, or to make a crossing gate at the exist for detecting obstacles on a railroad to prevent collisions among trains. This paper suggests 'a panel sensor using the strain gauge' to make up the weaknesses of the sensing Dead Zone, which are caused by using a laser method, and to detect any small objects passing railroads in order to reduce the errors, which are occurred in the earth magnetic field for controlling Exit Slide Crossing Arm Detector. The device, suggested in this paper, is verified with detecting any small objects passing the railroad, with judging entry decision clearly, and with controlling passing gate and obstruction warnings/cautions obstacles at the same time, through an experimental test.

• 한국경영과학회지
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• 제29권3호
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• pp.1-7
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• 2004

We demonstrate in this paper that the level crossing technique can be applied to such a system that not only the state vector is two-dimensional but Its two components are heterogeneous. As an example system, we use the GI-G/c/K queue whose state vector consists of the number of customers in the system and the total unfinished work.

• Journal of the Korean Statistical Society
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• 제31권3호
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• pp.405-413
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• 2002

We consider a finite dam with general inputs and adopt the level crossing approach to obtain explicit formulas of the expected wet period, the expected loss of water due to overflows in a wet period, and the long-run proportion of loss in inputed water.

• 조명전기설비학회논문지
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• 제24권1호
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• pp.160-166
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• 2010

철도와 도로가 평면 교차하는 개소에서 열차의 진입을 통행자에게 알려 사고를 방지하는 운전보안설비를 건널목 보안장치라 하며, 이 장치는 레일을 전기회로의 일부로 사용하여 회로를 구성하고 철도차량의 차축에 의해 레일사이를 단락함에 따라 열차의 유무를 검지하는 궤도회로장치에 의한 것이 대부분이다. 그 만큼 건널목보안장치에서 궤도회로장치가 중요한 역할을 하지만, 열차운행 횟수 감소로 눈, 비, 습기 등에 의하여 레일에 녹이 발생하여 열차가 궤도회로를 점유하여도 단락감도 불량으로 궤도회로가 낙하되지 않아 건널목보안장치 무경보 발생으로 도로차량과 충돌하는 사고발생이 우려된다. 본 논문에서는 이와 같은 문제점을 보완하기 위하여 열차에 의해 궤도를 단락하는 열차검지방식에서 적외선 센서에 의해 열차접근을 확인하여 건널목보안장치를 제어하는 방식으로 변경하여 열차안전운행을 확보하는 효율적인 안전장치로서의 역할을 수행할 수 있도록 설계 방법을 제안한다.

• 문화기술의 융합
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• 제5권2호
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• pp.355-360
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• 2019

본 연구에서는 고속열차 주행 중 발생하는 풍하중 안정성 검토조건을 준용하여, 열차속도 300km/h와 360km/h에 대한 고속선로용 고무보판 패널 구조의 열차 풍하중에 대한 구조적 안정성을 검토하였다. 이를 위해 고무보판 패널 시스템이 가장 복잡한 구성으로 설치될 수 있는 현장조건을 적용하여 3차원 해석모델링을 이용한 정밀 수치해석을 수행하였으며, 이를 통해 고속열차 풍하중에 대한 고무보판 패널 시스템의 구조적 안정성을 해석적으로 입증하였다.