• Journal of Information Technology Services
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• v.19 no.2
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• pp.125-138
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• 2020

Currently, subway crowding is estimated by observing a specific point at specific hours once or twice every 1 or 2 years. Given the extensive subway network in Seoul Metropolitan Area covering 588 stations, 11 lines and 80 transfer stations as of 2017, implementing crowding mitigation policy may have its limitations due to data uncertainty. A proposal has recently been made to effectively use smart card data, which generates big data on the overall subway traffic related to an estimated 8 million passengers per day. To mitigate subway crowding, this study proposes two viable options based on data related to smart card used in Seoul Metropolitan Area. One is to create a subway passenger pattern model to accurately estimate subway crowding, while the other is to prove effectiveness of early bird policy to distribute subway demand that is concentrated at certain stations and certain time. A subway passenger pattern model was created to estimate the passenger routes based on subway terminal ID at the entrance and exit and data by hours. To that end, we propose assigning passengers at the routes similar to the shortest routes based on an assumption that passengers choose the fastest routes. In the model, passenger flow is simulated every minute, and subway crowding level by station and line at every hour is analyzed while station usage pattern is identified by depending on passenger paths. For early bird policy, highly crowded stations will be categorized based on congestion level extracted from subway passenger pattern model and viability of a policy which transfers certain traveling demands to early commuting hours in those stations will be reviewed. In particular, review will be conducted on the impact of policy implemented at certain stations on other stations and lines from subway network as a whole. Lastly, we proposed that smart card based subway passenger pattern model established through this study used in decision making process to ensure effective implementation of public transport policy.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.3
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• pp.316-323
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• 2010

We propose a method to find flows of transit users in the subway transportation network of the metropolitan Seoul and analyze the passenger flows on some central links of the network. The transportation network consists of vertices for subway stops, edges for links between two adjacent subway stops, and flows on the edges' Each subway transit user makes a passenger flow along edges of the shortest path from the origin stop to the destination stop in his trip. In this paper, we have developed a new algorithm to find the passenger flow of each link in the subway network from a large trip-transaction database of subway transit users. We have applied the algorithm to find the passenger flows from one day database of about 5 million transactions by the subway transit users. As results of the experiments, the travel behavior on 4 central subway links is analyzed in passenger flows and top 10 flows among all subway links are explained in a table.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.142-147
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• 2009

In the present study, a numerical simulation of passenger evacuation in a subway station was performed. Algorithm for passenger flow analysis based on DEM(Discrete Element Method) has been improved to simulate passenger flow in detailed geometry. The effect of grid density was assessed in the present study to show the advantage of using finer grid in the simulation. The method of coupling passenger flow and fire simulation has also been investigated to analyze passenger evacuation flow under fire. In this method the CO distributions in the subway station was used to assess fire hazards of passenger by means of FED(Fractional Effective Dose) model. Using the coupled algorithm a simulation for passenger evacuation flow and fire analysis were performed simultaneously in the simplified subway station. This algorithm could be used in the design of subway station for the purpose of passengers' safety in case of fire.

• The Journal of the Korea Contents Association
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• v.10 no.4
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• pp.397-405
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• 2010

This study proposes visualization methods of the diurnal passenger flows on the Metropolitan Seoul Subway system (MSSs) and examines the passenger trip behaviors of major central business districts (CBDs). We mine the MSS passenger flow information from a single day T-card passenger trip transaction database. It is practically intractable to analyze such flows, involving huge, complex space-time data, by means of general statistical analysis. On the other hand, dynamic visualizations of the passenger flows make it possible to analyze intuitively and to grasp effectively characteristics of the passenger flows. We thus propose several methods to visualize the passenger flow information. In particular, we visualize dynamic passenger flows of each link on the subway network and analyze the time-space characteristics of passenger ridership for the three major CBDs. As the result, we can ascertain the strong association between CBD and subway line and clarify the distinction among three major CBDs in the diurnal patterns of subway passenger flow.

• Information Systems Review
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• v.7 no.1
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• pp.65-80
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• 2005

The Seoul Metropolitan Subway Corporation (SMS) and the Seoul Metropolitan Rapid Transit Corporation (SMRT), which manage the city's eight subway lines, are intending to overcome their operational inefficiencies. The two investigators of the paper realize with emphasis that it is essential for the two subway authorities to analyze subway transit data prior to put policies and plans into practice. In this paper, the investigators propose a new, and an intuitive, way of analyzing subway passenger transit patterns. To achieve this goal, they have implemented a data mart by blending the "Pass Card" log data into the multidimensional model. The subway passenger's transit patterns and the practical implications of this system are also investigated.

• Proceedings of the KSR Conference
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• 1998.05a
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• pp.160-171
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• 1998

Express subway system is one of the effective systems adapting to improve service level. Express trains make fewer passenger stop, using a double track or a bypass track, than local trains which served all stations, Express service has been very popular with passengers who travel uninterrupted between terminals, but is has generated some dissatisfaction among passengers who experience longer waiting time on stations. This study aims at proposing the methodology to analyze changes of travel pattern in subway system adapting the express service and to estimate the time saving effects resulting from the installation of the express system. This methodology is evaluated in the fifth line under an assumpt ion that express subway system are adapted. Based on the results of the case study, the following conclusions are made: First, express system reduce a total travel time of 13% or above. Second, shorter headway of express trains increases the time saving effects on subway system. although it requests more waiting time to local train passenger. Third, an installation of Express system to Seoul subway system can augment subway demand in seoul metropolitan area.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.2
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• pp.95-104
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• 2018

Using network betweenness centrality we attempt to analyze the characteristics of Seoul metropolitan subway lines. Betweenness centrality highlights the importance of a node as a transfer point between any pairs of nodes. This 'transfer' characteristic is obviously of paramount importance in transit systems. For betweenness centrality, both traditional betweenness centrality measure and weighted betweenness centrality measure which uses monthly passenger flow amount between two stations are used. By comparing traditional and weighted betweenness centrality measures of lines characteristics of passenger flow can be identified. We also investigated factors which affect betweenness centrality. It is the number of passenger who get on or get off that significantly affects betweenness centrality measures. Through correlation analysis of the number of passenger and betweenness centrality, it is found out that Seoul metropolitan subway system is well designed in terms of regional distribution of population. Four measures are proposed which represent the passenger flow characteristics. It is shown they do not follow Power-law distribution, which means passenger flow is relatively evenly distributed among stations. It has been shown that the passenger flow characteristics of subway networks in other foreign cities such as Beijing, Boston and San Franciso do follow power-law distribution, that is, pretty much biased passenger flow traffic characteristics. In this study we have also tried to answer why passenger traffic flow of Seoul metropolitan subway network is more homogeneous compared to that of Beijing.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.543-546
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• 2015

There have been subway conflagrations such as Daegu subway conflagration at 2003, Washington D.C conflagration last month and so on. Compared to that, proper evacuation route is far from satisfactory. So this paper suggests optimized route when subway's passengers evacuate from passenger cars. For conducting our experiment, We made temporarily a model of subway station which is made up with 8 passengers cars and 3 exits. Using genetic algorithm, we found the optimized route that first and second passenger cars are optimized to first exit and third, fourth, fifth and sixth passengers cars are optimized to second exit and finally seventh, eighth passengers cars are optimized to third exit. It is expected that real subway station is applied to our experiment by developing passenger distribution algorithm.

• Journal of the Economic Geographical Society of Korea
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• v.14 no.2
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• pp.116-128
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• 2011

Some subway passengers may want to have their fresh vegetables purchased through internet at a service facility within the subway station of the Metropolitan Seoul subway system on the way to home, which raises further questions about which stations are chosen to locate service facilities and how many passengers can use the facilities. This problem is well known as the pickup problem, and it can be solved on a traffic network with traffic flows which should be identified from origin stations to destination stations. Since flows of the subway passengers can be found from the smart card transaction database of the Metropolitan Seoul smart card system, the pickup problem in the Metropolitan Seoul subway system is to select subway stations for the service facilities such that captured passenger flows are maximized. In this paper, we have formulated a model of the pickup problem on the Metropolitan Seoul subway system with subway passenger flows, and have proposed a fast heuristic algorithm to select pickup stations which can capture the most passenger flows in each step from an origin-destination matrix which represents the passenger flows. We have applied the heuristic algorithm to select the pickup stations from a large volume of traffic network, the Metropolitan Seoul subway system, with about 400 subway stations and five millions passenger transactions daily. We have obtained not only the experimental results in fast response time, but also displayed the top 10 pickup stations in a subway guide map. In addition, we have shown that the resulting solution is nearly optimal by a few more supplementary experiments.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.8
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• pp.509-514
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• 2010

A numerical simulation of passenger evacuation in a subway station was performed by coupling the passenger flow analysis and the fire simulation. The algorithm of the passenger flow analysis was based on a DEM (Discrete Element Method) using the potential map of the direction vector for each passenger. This algorithm was improved in the present study as to use finer grid smaller than a passenger in order to resolve detailed geometry of the station and to resolve the behavior of passengers in the bottleneck at the ticket gate considering the collision of passengers to a wall or with other passengers. In the fire simulation, the CO distribution predicted by using CFD was used to take into account the effect of toxic gases on the passengers' mobility. The methodology proposed in the present study could be used in designing safer subway station in case of fire occurrence.