• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.5
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• pp.688-694
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• 2018

The transition section of the overhead rigid conductor rail (ORCR) consists of a direct induction device and a limit point to prevent the power supply failure and failure of the electric railway vehicle pantograph due to the difference of the uplift in the catenary line. In T-Bar transition section, a twin simple catenary is mostly installed between the overhead catenary system (OCS) in the ground section and the ORCR in the underground section. In this paper, we compare and analyze the possibility of replacing the twin simple catenary with heavy simple catenary. The reliability of numerical analysis results was confirmed by comparing field test with numerical results. Comparing the numerical results of the twin simple catenary with the heavy simple catenary in the transition section, the difference uplift is 5.9[mm] on average. When applying heavy simple catenary instead of twin simple catenary, the slight difference of uplift can be compensated by adjusting the height of hanger-ear or support bracket.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.4
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• pp.733-739
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• 2017

Research on fuel cell systems attracting attention as an environmentally friendly energy source has been actively conducted. And research is being conducted on railway vehicles that use direct current power generated by a fuel cell as an energy source. In this paper, a two-phase interleaved bidirectional DC-DC converter has been proposed which can supply electric energy of a battery to a traction motor during powering and charge the battery with regenerative energy during braking. Therefore, the topology of the energy storage system applied to the railway vehicle was analyzed, and the simulation was performed by constructing the power conversion system by this topology. Experiments were also conducted through hardware design and fabrication based on the simulation analysis results, and the validity of the hardware implementation was verified.

• The Journal of Industrial Distribution & Business
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• v.13 no.3
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• pp.13-24
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• 2022

Purpose: The purpose of this paper is to investigate key factors that affect customer dissatisfaction on public transportation system by highlighting the necessity of citizen participation and improved management of advanced technology for sustainability. Research questions applied in this study include following; i) how are factors on dissatisfaction related to types of transportation modes; ii) how do perceived proposed factors affect citizen dissatisfaction; iii) how do the improvement of public transportation service affect the level of expected satisfaction; and iv) how do expected satisfaction affect policy agreement and government trust. Research design, data and methodology: For qualitative research, civil opinions were collected and chi-square analysis was applied using keywords. For quantitative research, online survey was collected and factor and multiple regression analyses were applied. 3) Results: This study found that efficiency of operation system and safety on dissatisfaction showed significant in all three public transportation modes. This study found that perception of government policy and trust on government will increase as expected satisfaction increases. Conclusions: This study provides managerial and policy implications on society and policy makers by addressing necessity of improving strategies for public transportation system with the consideration of citizen relationship management and sustainable development.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.1 s.24
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• pp.61-66
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• 2006

It have been known that the probability of occidental happening in towing-barge is higher than that of other merchant vessels. Bemuse the towing-barge is restricted in thier manoeuvring ability due to its towingline. A report from ministry maritime affairs and fisheries said that the rate of collision occident for towing-barge is 40% high than other transport system in sea A number of researches have been carried out to improve the safety policy in the towing-barge sea transportation system by the gorvenment. This study examined the safety status in domestic towing-barge sea transportation system The registration status, safety operational policy and past occidental data were also examined A survey research of experts relating to towing-barge operation also was carried out to fine the detailed of safety status. This study would be applicable to set up safety policy for towing-barge marine transportation system.

• Journal of Korean Society of Transportation
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• v.28 no.2
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• pp.161-169
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• 2010

The amount of energy consumed by a transportation system in a city is influenced not just by a transportation system itself but also by city's spatial character. Yet there have been very limited studies on this subject. This study investigates the factors that influence the energy consumption by a transportation system and city's spatial character. The model of an urban area confined within a definite boundary is assumed in order to develop the relationships between the energy consumption and the transportation system. Various assumptions on the character of a city and activities are made. An equation for computation of the energy consumption is derived with such factors as modal split, densities of residents and workers, as well as technological development. Using the equation, sensitivity analyses are performed in order to identify the relationships between energy consumption and influencing factors. It is found that the modal split is the most powerful factor that determines the energy consumption by the transportation system. Yet it is also found that the densities of residents and workers and the technological factors are very important in determining the amount of energy consumption as well.

• Journal of Korean Society of Transportation
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• v.5 no.1
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• pp.47-58
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• 1987

A commodity distribution problem with intertemporal storage facilities and dynamic transportation networks is proposed. mathematical integer programming methods and multiobjective programming techniques are used in the model formulation. Dynamic characteristics of commodity distribution problems are taken into account in the model formulation. storage facility location problems and transportation link addition problems are incorporated into the intertemporal multicommodity distribution problem. The model is capable of generating the most efficient and rational commodity distribution system. Therefore it can be utilized to provided the most effective investment plan for the transportation infrastructure development as well as to evaluate the existing commodity distribution system. The model determines simultaneously the most efficient locations, sizes, and activity levels of storage facilities as well as new highway links. It is extended to multiobjective planning situations for the purpose of generating alternative investment plans in accordance to planning situations. sine the investment in transportation network improvement yields w\several external benefits for a regional economy, the induced benefit maximization objective is incorporated into the cost minimization objective. The multiobjective model generates explicitly the trade-off between cost savings and induced benefits of the investment in transportation network improvement.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.775-789
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• 2011

Centering on KTX stations, Korea is implementing specialized development of metropolitan business zones nationwide and is in the process of building the transfer link system of transportation in order to actualize intermodalism nationwide. Daejeon station, hub of high-speed railway requires the effective transportation transfer system considering Daejeon station area reorganization plan and opening of second phase high-speed railway. Based on the analysis of the possibility and validity of building a transit center under the Transportation System Efficiency Act, it is necessary to make a mutual benefit in a regional development by installing the resonable transfer system between railway and other transportation services. Through analysis of current situations and technical, economic and environmental feasibility evaluation, design plan of effective transportation transfer system in Daejeon station is proposed.

• Proceedings of the KIPE Conference
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• 1998.07a
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• pp.95-98
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• 1998

Applying the magnetically levitated transportation system, which is noncontact bearing system, to solve the problems such as transformation of original form or flaw of iron plate caused by transportation of thin iron plate which required high quality as body of motor vehicle, materials of electronic devices etc.. Magnetic saturation phenomena caused by thickness of iron plate and gap size between magnets. In case of iron plate, the vibration mode will be considered since vibration occurs during transportation. In order to solve the problems caused by vibration, choose the levitation system method using numbers of magnet, magnetic saturation for thickness and length of iron plate with parameters in location and gap of magnet. In this paper, we will suggest the whole design technique of magnetically levitated transportation system, namely method of magnetic attraction and transportation system

• Smart Structures and Systems
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• v.32 no.1
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• pp.49-59
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• 2023

A bridge transportation network supplies products from various source nodes to destination nodes through bridge structures in a target region. However, recent frequent earthquakes have caused damage to bridge structures, resulting in extreme direct damage to the target area as well as indirect damage to other lifeline structures. Therefore, in this study, a surrogate model-based comprehensive framework to estimate the seismic resilience of bridge transportation networks is proposed. For this purpose, total system travel time (TSTT) is introduced for accurate performance indicator of the bridge transportation network, and an artificial neural network (ANN)-based surrogate model is constructed to reduce traffic analysis time for high-dimensional TSTT computation. The proposed framework includes procedures for constructing an ANN-based surrogate model to accelerate network performance computation, as well as conventional procedures such as direct Monte Carlo simulation (MCS) calculation and bridge restoration calculation. To demonstrate the proposed framework, Pohang bridge transportation network is reconstructed based on geographic information system (GIS) data, and an ANN model is constructed with the damage states of the transportation network and TSTT using the representative earthquake epicenter in the target area. For obtaining the seismic resilience curve of the Pohang region, five epicenters are considered, with earthquake magnitudes 6.0 to 8.0, and the direct and indirect damages of the bridge transportation network are evaluated. Thus, it is concluded that the proposed surrogate model-based framework can efficiently evaluate the seismic resilience of a high-dimensional bridge transportation network, and also it can be used for decision-making to minimize damage.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.114-122
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• 2001

As of these, the exterior design of the public transportation systems, especially electric multiple, tends to mimic advanced country's design rather than design of car shape reflecting cultural and spiritual background. However, in the new transportation system, the design which satisfies the transportation demand must be changed into the design which creates transportation demand. In this respect, this research focuses on the factor's embodiment which is perceived by Korean passenger sympathetic to cultural and spiritual needs. The results of this research are Korean AGT design on rubber tire AGT, steel wheel AGT, LM AGT system and environmental design related to AGT systems.