• Journal of Korean Society of Transportation
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• v.13 no.1
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• pp.113-123
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• 1995

버스의 크기에 따른 운행시격과 승객 대기시간의 Trade-off 는 대중교통 운영정책의 중요한 기본개념의 하나로서 여태까지 선진 구미의 여러 교통공학작들에 많은 연구가 수행되어져 왔다. 본 논문에서는 시스템 전체의 최적화(System Optimization )라는 측면에서 차량비를 포함한 버스회사의 총 운행경비와 버스 승객들의 대기시간과 주행시간을 금전으로 호나산한 사용자 경비를 합산한 총비용을 최소화 사키는 적정 버스크기(=좌석수)를 산정할 수 있는 모델식을 개발코자 하였다. 이를 위해 우선 수집된 자료들의 회귀분석을 통해 버스 운행경비와 버스크기와의 관계를 규명하였으며 이를 토대로 하여 버스 좌석수를 결정변수(Optimizable Variable)로 하는 총비용에 관한 목적함수식을 도출하였다. 또한 개발된 모형의 적절성을 검증하기 위해 미국 수도 워싱턴 지역에서의 교통자료를 인용하여 사례조사를 하였으며 이를 통해 본 연구에서 도출된 모형식의 실용성을 확인할 수 있었다. 추후 본 연구에서 개발된 수식들은 국내의 버스운행 여건과 실태를 잘 반영할 수 있도록 광범위한 자료조사를 통해 수정되어야 할 것이다.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.8
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• pp.953-958
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• 2015

Generally, Urban railway have special characteristics with short distance journey and minimum headway intercity transportation. These days, urban railway operators choose the driverless operation system without driver. On the contrary, Conventional & high speed railway utilize for long distance and high speed running. Because of special conditions of freight railway operation compared with urban railway, operation of conventional & high speed railway is showed very different characteristics. In this paper, We compares different operation scheme of urban railway and conventional & high speed railway and then present condition for train control system based on radio.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.953-960
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• 2009

In the major operation section of urban railway, there has been occurred habitual delay, and delay propagation and spread to consecutive trains. Therefore, this delay cause the increase of operation time and irregular operation, also the increase of crowd and inconvenience to passengers. The railway operation plan is a promise to passengers and must have reliability. In the case of high frequency urban operation, dwell time have considerable influence on operational headway, so it is very important to efficiently plan and control the dwell time at stations. In this paper, the survey of the research on dwell time for urban railways is presented. The practical estimation model for minimum required dwell time, and the numerical example and validity are proposed.

• Journal of the Korean Society for Railway
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• v.13 no.1
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• pp.65-70
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• 2010

AC traction power supply system has adopted autotransformer (AT) feeding method. This system has an advantage as long feeding distance. However, the countermeasure for voltage drop should be considered, because load capacity grows larger and headway grows shorter in recent electric railway system. This paper proposes the improved system configuration to enhance voltage drop in ac railway system without additional power electronic device. That is to increase turn ratio between contact wire and rail of AT. By modifying turn ratio of AT at SSP or SP, collecting voltage on train will be enhanced.

• Journal of the Korean Society for Railway
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• v.17 no.2
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• pp.140-147
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• 2014

Line planning is an important step to determine the optimal frequencies of trains given the forecasted demand for each train type. The main input data for line planning is the leg traffic demand which can be derived using suitable traffic assignment models. However most assignment models require a line plan, in other words, train frequencies or headways, so that inconsistent results just by the procedural approach to find an optimal line plan after determining leg traffic can be avoided. This paper suggests a unified model that can consider the traffic assignment and line planning, simultaneously. We further provide an elaborated approximation algorithm and, finally, provide experimental results determined for the Korean railway network.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.634-639
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• 2015

In order to understand phenomenon of the electric railway power feeding system in the construction planning step, analysis of the overall system including electric characteristic of electric railway power feeding system, train running characteristic and power consumption pattern and train operation plan and gradients of railroad and curve radius is required. This paper study the feeder system by analysis of comprehensive system according to train operation plans, line impedance, running characteristic of train, electrical properties of the feeder system. In order to understand phenomenon to the feeder system of tram exactly regarding export of the field railroad preceeding actively recently.

• Journal of the Korean Society for Railway
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• v.20 no.1
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• pp.142-155
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• 2017

It is anticipated that, in cases in which different train operators share railway network, conflicts may occur among train operators with regard to train operation rate, train priorities, and arrival and departure time; besides this, during times when there is high demand for trains, operators will request train operations intensively, steadily increasing train conflict phenomena. In the present study, train operation sequence, minimum headway, arrival and departure time, train priorities, etc., were analyzed, and while using train departure times as decision variables in variably given train schedules, by adjusting train time requested by train operators, and finally rejecting the train times in cases in which conflict resolution is impossible, so that various constraints can be satisfied, a train slot allocation model was suggested to find the objective function, that is, the maximum number of train slots that can be practically applicable to railway operation.

• Journal of Korean Society of Transportation
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• v.17 no.4
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• pp.47-58
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• 1999

The Purpose of this Paper is to develop a multi-period bus scheduling model, in which a decomposition technique is applied. In general a bus scheduling requires a vast amount of calculation. Thus, a bus scheduling is a very complicated problem even with a single depot and is almost unable to obtain the optimal solution theoretically with many depots. In this paper in order to simplify the problem, the whole operating hours of a day are partitioned into several time periods. In one period, the same headways are maintained. For one period, the bus scheduling is simple and the solution applying the FIFO(First-In, First-Out) Principle is the optimal. However, connection between Periods remains as another scheduling Problem with a reduced problem size. This paper suggests how to connect bus schedules of consecutive periods efficiently, minimizing the operating cost. Through case studies for multiple routes with a single depot, this decomposition technique is proved to be effective practically.

• Journal of the Korea Society of Computer and Information
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• v.19 no.12
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• pp.187-196
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• 2014

In this paper, Minimize driving energy for operation within a defined distance yeokgan fixed time-resolved and determine the nature of the train is traveling, and to model mathematically. Urban rail car cruise in general by the PID controller is used instead of automatically tracking a target value while traveling in energy consumption to be minimized by using optimal control model railroad charyangreul was designed under real operating conditions the same. The actual track conditions apply to the minimum value or a separate listing of cars around the track facility without a driving energy of the automatic operation and to reduce the driving energy. Therefore, actual route chosen straight line 8 / gradient segment / curve for the measured data analysis, such as sections within the city-minute drive each section and presented how the trains to save energy, depending on the pattern of the train station in the region.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.67-72
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• 2010

In this paper, we verify the driverless operation possibility of MBS, which could overcome the defects of conventional track-circuit-based FBS, such as additional needs of maintenance and others problems according to short-circuit sensibility and, and which could allow the minimal interval between trains. With MBS, we can expect the reduction of headway, then the increase of transportation demand, and the protection of unnecessary speed variation because it allows the real time detection of train position from central office, and direct transmission of data between preceding trains and the following ones. In addition, it is possible to reduce the number of wayside-equipment substantially, to improve the passenger service, and to the achieve the positive economic effects by comfortable ride.