• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.125-130
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• 2001

It is vary importance that stopping distance for the freight train and need to design parameter of the brake force and friction coefficient. Acoording to the brake force between shoe and wheel less than the adhesion between wheel and rail. Because of vary difference between empty and weight car of 0∼500kN, this solution was made to application for variable loaded brake system. When the V=110km/h. the emergency stopping distance of freight train is about 700m, so this study was considered on the two condition, one of the increse brake force and to be different of the increse friction coefficient on the brake shoe. It was useful increse friction coefficient. Result of study, analyze effect of the brake shoe on the brake force of the freight car and high friction coefficient were proposed. To do this, ${\mu}$=0.155${\pm}$10% when S=600m on the V=110km/h of the train, 2 groove of friction surface on the temperature distribution were considered.

• Smart Structures and Systems
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• 제21권5호
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• pp.669-675
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• 2018

Under braking forces of a freight train, there are great longitudinal structural responses of a large freight railway cable-stayed bridge. To alleviate such adverse reactions, viscous dampers are required, whose parametric selection is one of important and arduous researches. Based on the longitudinal dynamics vehicle model, responses of a cable-stayed bridge are investigated under various cases. It shows that there is a notable effect of initial braking speeds and locations of a freight train on the structural responses. Under the most unfavorable braking condition, the parameter sensitivity analyses of viscous dampers are systematically performed. Meanwhile, a mixing method called BPNN-NSGA-II, combining the Back Propagation neural network (BPNN) and Non-Dominated Sorting Genetic Algorithm With Elitist Strategy (NSGA-II), is employed to optimize parameters of viscous dampers. The result shows that: 1. the relationships between the parameters of viscous dampers and the key longitudinal responses of the bridge are high nonlinear, which are completely different from each other; 2. the longitudinal displacement of the bridge main girder significantly decreases by the optimized viscous dampers.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.351-354
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• 2005

Research purpose of this project is intending Maintenance Free of freight car and speed up of freight train. At goods transport as heightening traveling by ship speed of freight train shortening raise railway share of physical distribution and stand on tiptoe to Northeast Asia physical distribution main country to contribute expect. This paper is the performance elevation methods of next generation railway freight vehicles.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.110-115
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• 1999

Experimental study is conducted to clarify the pneumatic characteristics of brake system for freight car. KNR(Korean National Railroad)'s freight cars have the laden-tare type control valve of brake system. But, laden-tare type control valve has some shortcomings to match the high speed freight car. Newly developed diaphragm type control valve is introduced to adopt freight car for speed-up. The test using the formated train set consisted of 21 cars is conducted to estimate the pneumatic braking efficiency of the mixed train set. From the results of experiment, the pressure characteristics of each brake cylinder show similar patterns qualitatively. But, in the case of release and brake application, quantitative pressure values of brake cylinder are different.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2001년도 추계학술대회 논문집
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• pp.62-73
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• 2001

The scope of this study is focused on the survey of new logistics transportation systems in railroad and case studies of new systems such as piggyback system, bi-modal system swapbody, and double stack train(DST). Piggyback system, bi-modal system, swapbody, and double stack train are reviewed in term of technological validity and economic validity in Korea. Piggyback - trailer does pass loaded weight limits but does not pass train limits and can not utilize the existing freight cars. Piggyback - cargo trunk does pass all the criteria and could be developed by a domestic technology. But this study suggests to expand the length of train cars to 18.300mm for accommodation of two cargo trucks. Bi-modal system and swapbody do also pass. Double stack train could only pass the loaded weights and does not meet the train limit and the possibility of using existing freight cars. Domestic technology could not development DST, due to civil engineering construction limits and low standard height of electric line, which could not afford to operate DST.

• 한국철도학회논문집
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• 제17권4호
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• pp.313-319
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• 2014

여객 증편열차 운영은 수송력 보강이나 관광열차 운행을 위해 증편된다. 화물열차의 경우는 철도화물수요를 위해 주로 증편된다. 기존 연구들에서는 증편열차 스케줄 작성을 위해 추가 열차의 운행시각을 지정한 후에 운행가능성을 판단한다. 그러나 국내에서 이러한 방법의 경우 추가열차의 증편이 불가능한 경우가 많다. 왜냐하면 한국철도 네트워크는 운행밀도가 높고 여러 차종이 있기 때문이다. 특히 화물열차의 경우 여객열차와의 경합이 발생할 때마다 지연이 증가되거나 운행이 불가능하다. 본 논문에서는 출발시각이 지정된 요청열차 스케줄과 시간범위 내에 운행 가능한 스케줄을 찾을 수 있는 열차 증편모형을 제시한다. 제시된 모형은 혼합정수 계획법으로 모델링하고 열 생성기법을 사용하였다.

• 한국철도학회논문집
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• 제15권2호
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• pp.185-192
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• 2012

노선 계획이란 수요를 만족시키면서 열차 운행 비용(operation cost)을 최소화하는 시종착별 열차 운행횟수를 결정하는 과정을 말한다. 그러나 화물 수송의 경우 화물 취급역에서 발생하는 화물의 연결 혹은 해방 작업은 상당한 시간을 필요로 하여, 잦은 중간 화물역에서의 연결 해방 작업은 수송 서비스의 품질을 저하시킬 수 있으므로, 여객 열차의 노선 계획과 달리, 화물 열차 노선 계획에서는 각 열차의 도중 입환역을 어떻게 설정할 것인가가 매우 중요한 문제이다. 본 연구는 열차의 운행 경로, 운행 횟수뿐만 아니라 열차별 도중 입환역를 포함하는 노선계획을 작성하기 위한 최적화 모형을 제시하고, 이 모형에 대한 열생성 기반 해법 및 실험결과를 제시할 것이다.

• 한국산학기술학회논문지
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• 제21권1호
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• pp.61-69
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• 2020

본 논문은 국내 고속형 화물열차에 적용되는 P4a 분배밸브를 갖는 화물열차의 장대 편성시 제동특성에 관한 것이다. 제동신호가 열차의 끝단까지 연결된 제동관을 통해 공기압력으로 전달되는 화차의 제동은 열차 길이와 사용된 밸브 등에 따라 영향을 받기 때문에 실험적 방법으로 확인한다. 장대화물 열차의 제동 특성은 평상시 운영의 약 2배인 50량으로 구성한 화물열차의 비상제동과 상용제동의 시험을 이용하였다. 1, 10, 20, 30, 50번째 차량에서 제동 실린더 압력이 측정되었다. 열차의 길이가 길어질수록 후방의 차량은 제동이 늦게 체결되는 제동지연 현상을 확인하였으며 특히 비상제동시 차량간 충격이 클 것을 예상할 수 있었다. 제한된 시험의 결과를 보완하고 향후 제동거리 계산을 위해 열차를 구성하는 모든 차량에서의 제동 압력을 예측할 필요가 있다. 제동시 각 차량에서의 압력은 계산시간의 단축과 신뢰성 있는 정보를 제공하는 것으로 알려진 선형보간, 단계형, 지수함수형의 경험적 모델들을 이용하여 예측하였다. 경험적 모델들의 예측결과는 실측한 결과들과 비교하였으며 지수함수형 모델이 비교적 정확하게 예측하고 있음을 확인하였다. 본 연구의 결과는 장대화물열차의 안전한 운용에 기여하고 화물열차의 제동거리 예측과 제동시 차량간 충격량 계산 등에 활용될 수 있을 것으로 예상된다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.1691-1694
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• 2004

This paper is aiming to study of the speed-up of the railway freight services. Recently investment in freight continues to support the growth both traditional and intermodal markets, and will begin to influence newer markets. Railways offer the highest speeds in ground-based transport systems and therefore offer competitive transport times on routes between large cities. In freight transport, top speeds of 100$\∼%$150km/h are competitive with the road transport. The speed of freight railway can be increased in particular by the creation of a network of freight corridors, the speed-up of freight train, and efficient transhipment installations.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.732-741
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• 2008

After freight train line opening between Munsan of South Korea and Bongdong of North Korea last December 2007, people's expectation and interest about trans North-South and continental railways have been increasing. However, the commercial traffic of freight by train has not been increased as much as we expected in the mean time road traffic is more increased. This study examined the Kaesong industrial complex which has a high rail accessibility. Especially, we interviewed the owners of enterprises in Kaesong to integrate their opinions for deriving the problems and improving the business conditions. Also, this study embodied the methods for improving rail freight traffic between North and South Korea. Based on this study, we expect more research will carry out on this field to reform the operation system of trans Korea railways by Kaesong industrial complex development project and the commercial reconversion from road to rail.