• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• v.4B no.1
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• pp.29-35
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• 2004

Locomotive scheduling in railway systems experiences many difficulties because of the complex interrelations among resources, knowledge and various constraints. Artificial intelligence technology has been applied to solve these scheduling problems. These technologies have proved to be efficient in representing knowledge and rules for complex scheduling problems. In this paper, we have applied the CSP (Constraints Satisfaction Problems) programming technique, one of the AI techniques, to solve the problems associated with locomotive scheduling. This method is more effective at solving complex scheduling problems than available mathematical programming techniques. The advanced locomotive scheduling system using the CSP programming technique is realized based on the actual timetable of the Saemaul type train on the Kyong-bu line. In this paper, an overview of the CSP programming technique is described, the modeling of domain and constraints is represented and the experimental results are compared with the real-world existing schedule. It is verified that the scheduling results by CSP programming are superior to existing scheduling performed by human experts. The executing time for locomotive scheduling is remarkably reduced to within several decade seconds, something requiring several days in the case of locomotive scheduling by human experts.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3706-3714
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• 2011

This study deals with the algorithm to finding the maximum capacity and their schedule of extra freight while honoring planned timetable of trains on railway network. Time-expanded network, a kind of space-time graph, can be shown both planned train timetable and dynamic features of given problem. Pre-processing procedure is a series of infeasible arcs removal from time-expanded network honoring planned timetable. In the result, this preprocessing transforms dynamic features of given problem into static maximal flow problem which can be easily solved.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.940-947
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• 2011

Load capacity varies according to a day of the week in traction power supply system, because time schedule in railway is changed as demand for passengers and freights. Therefore, Voltage drop also varies as load capacity. In Korea railway, Voltage collected from catenary in train is decreased, as load supplied traction power supply system is increased. Therefore, investigation about voltage drop should be performed, before development of countermeasure against voltage drop. The investigation can be performed by simulation or field test. Naturally, field test is more precise than simulation. In addition, field test should be carried out at peak load. This paper presents test and analysis about voltage drop in railway. The test is performed in both a day of the week and weekend. The analysis is figured out comparison load capacity between two days and voltage drop across terminal.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2210-2211
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• 2011

Load capacity varies according to a day of the week in traction power supply system, because time schedule in railway is changed as demand for passengers and freights. Therefore, Voltage drop also varies as load capacity. In Korea railway, Voltage collected from catenary in train is decreased, as load supplied traction power supply system is increased. Therefore, investigation about voltage drop should be performed, before development of countermeasure against voltage drop. The investigation can be performed by simulation or field test. Naturally, field test is more precise than simulation. In addition, field test should be carried out at peak load. This paper presents test and analysis about voltage drop in railway. The test is performed in both a day of the week and weekend. The analysis is figured out comparison load capacity between two days and voltage drop across terminal.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.102-105
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• 1991

In recognition of the transportation problems of the present and to prepare for the ever increasing demands of the future, government decided to develop the magnetically levitated train domestically and started R&D program office in Korea Institute of Machinery and Metals(KIMM). This office since has established three step by step goals : first to develop a 40 passenger exhibition vehicle for Daejon EXPO'93, second to develop the low to mid-speed maglev system for urban public transportation by 1997 and finally the high speed inter-city maglev train by year 2001. The first two maglev systems will use attractive levitation-LIM driven technologies and these technologies are the ones currently being developed by this office and others. The maglev train system is a product of wide range of technologies from electro-technologies to civil engineering technologies. Some of the technologies are currently available but more have to be developed in the near future and these technologies are owned by or to be developed by various institutions within the science & technology community. The level of the technologies available at the present time are still very rudimentary and their basis are very narrow. Recently we have made a few successes in terms of levitation and propulsion but they are only with small scale modules and results are very qualitative at best. A great deal of development work has yet to be done to refine the technologies and to gain confidence. Full scale levitation/propulsion modules will be tested on the curved guideway within 6 months by this office and another institution. This paper reviews the current status of the maglev technologies in Korea and discuss the development strategies. The Korean maglev program is very ambitious and the schedule is even more so. A steady financial support and strong system engineering and integration are essential to the success of this program.

• Journal of Korean Society of Transportation
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• v.31 no.2
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• pp.80-89
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• 2013

The purpose of this research is to optimize the line planning of the intercity passenger railway. In this study, the line planning problem has been formulated into a mixed integer programming by minimizing both user costs (passenger's total travel time) and operator costs (operation, maintenance and vehicle costs) with multiple train types. As a solution algorithm, the branch-and-bound method is used to solve this problem. The change of travel demand, train speed and the number of schedules have been tested through sensitivity analysis. The optimal stop-schedules and frequency as well as system split with respect to each train type have been found in the case study of Kyoung-bu railway line in Korea. The model and results of this research are useful to make a decision for railway operation strategy, to analyze the efficiency of new railway systems and to evaluate the social costs of users and operators.

• Journal of Korea Multimedia Society
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• v.23 no.10
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• pp.1270-1285
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• 2020

As a representative concept of the fourth industrial revolution era where everything is digitized, digital twin means analyzing and optimizing a complex system using a simulation model synchronized with the system. In this paper, we propose a digital twin simulation model for the efficient operation of urban railways in Busan. Due to the geopolitical nature of Busan, where there are many mountains and narrow roads, the railways are more useful than other public transportation. However, this inversely results in a high level of congestion, which is an inconvenience to citizens and may be fatal to the spread of the virus, such as COVID19. Considering these characteristics, the proposed model analyzes the congestion level of the railways in Busan. The model is developed based on a mathematical formalism called discrete-event system specification and deduces the congestion level and the average waiting time of passengers depending on the train schedule. In addition, a new schedule to reduce the congestion level is derived through particle swarm optimization, which helps the efficient operation of the railways. Although the model is developed for the railways in Busan, it can also be used for railways in other cities where a high level of congestion is a problem.

• Journal of the Korean Society for Railway
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• v.9 no.4 s.35
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• pp.441-448
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• 2006

Following the recent privatization of the UK railway system there has been an increase in the volume of rail freight. It. Influential factors include the problem of road congestion, and policies towards increasing grants. With a focus on grants (government subsidies), this paper examines changes in rail freight, and the tasks facing the UK railway. I attempt to explain recent trends in rail freight grants and changes that have positively influenced the rail freight. In particular, I demonstrate the trends in rail freight and scheme which link the government and industry. Moreover, I explain the grants scheme and method of calculation, concisely. Finally I reveal the characteristics of UK rail grants scheme. In this paper, I argue that grants have played an important role of in the development of freight and that rail freight is more environment friendly than road transport. This paper have a many important aspects. Namely, an account of the introduction of the grant scheme of UK. Also, I explore the method of calculation of these grants. It will give some lessons for Korea rail. In conclusion, I note some suggestions and those problems which impede the freight transport. In future, the problems of some of these problems should be addressed, For example, the lack of infrastructure and development of an adequate train time schedule in case of rail freight have to be improved.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.118-121
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• 2008

Bimodal tram is a transit with no-step floor for wheel-chaired persons, with docking to the station precisely and moving on schedule like train. Because of the automatic traveling of bimodal tram to search and follow the magnet embedded in roadway, bimodal tram should be careful about rainfall, snow and wind like a car driving on roadway in respect to natural disasters. Though response procedures in emergency are different according to the passengers' boarding, emergency mobilization is needed if any emergency situation happens. Emergency mobilization is the act of preparing for major catastrophic events, which may affect public transportation systems or their service areas, by assembling and organizing resources, including people, equipment, facilities, communications systems, expert technical support, and public information systems and protocols. Mobilization is the process that ensures that the right people will deploy appropriate resources at the correct time. Effective mobilization requires a partnership of local and state agencies. Public transportation operators and systems play vital roles in response to and recovery from emergencies and other unexpected catastrophic events. These systems, and their capabilities to mobilize resources, are profoundly affected by the decisions and directives of others during these activities. In this study, we focused on the emergency management for bimodal tram and reviewed the considerations about infrastructures under natural disasters, especially heavy rainfall.

• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2006.03a
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• pp.195-203
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• 2006

The crossing construction under railroad have two methods which are cut and cover and trenchless method. first, cut and cover method is an extremely limited method concerning non-running time. Whereas, trenchless method is free from restriction such as train speed and running time, and has the strong points of safe and rapid construction. Front Jacking method, one of the trenchless methods, is frequently applied recently due to its stability during construction and vantage of assuring schedule reliability. The procedure is that after minimizing interlocking friction with structure and earth pressure due to jacking the small steel tube, pulling the precast box manufactured at the field in the ground using PC strand and hydraulic Jack. This method is able to be applied regardless of section size and length of box and condition of ground. And that is also pro-environmental. This paper presents the case of Daejeon E. W. perforate Road Project applied with the Front Jacking method.