• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.144-151
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• 2017

In this paper, the antenna for parking management using wireless communication in outdoor parking environment was proposed. The proposed antenna was miniaturized by using parasitic element to reduce the size of the radiating element of the basic ${\lambda}/2$ microstrip antenna. The dimensions of the proposed antenna are $35mm{\times}35mm{\times}20.1mm$ that is 98.7% smaller than $309.1mm(0.46{\lambda}){\times}296.1mm(0.441{\lambda}){\times}20.1mm(0.029{\lambda})$ of the basic ${\lambda}/2$ microstrip antenna. The electrical characteristics of the antenna are 1.1 dBi at the center frequency of 447 MHz, an omni-directional radiation pattern on the E-plane, and $87.5^{\circ}$ of HPBW on the H-plane. The miniaturized ${\lambda}/4$ folded microstrip antenna using parasitic element has proved to be easy to mount on the wireless repeater, the sensor node installed on the ground, and the strop bar in the outdoor parking environment.

• Journal of Korean Society of Transportation
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• v.33 no.2
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• pp.204-213
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• 2015

The congestion of pedestrians impedes the utilization efficiency of a subway station. Conflicts among pedestrians due to unseparated pedestrian flows not only increase the impedance of pedestrian mobility but also negatively affect on pedestrian safety. This paper analyzes the travel characteristics of bi-directional pedestrian flow based on microscopic movements, and evaluates the operation efficiency on separating the traffic line. The subway station was simulated in a 2-D grid structure by applying Discrete Element Method, and the movement is organized in each cell of the grid. As a result, the model explicates that separating the traffic line and encouraging the 'Keep right rule' would be mostly effective for the conflicting flows. Therefore, applying the 'Walking Guidance System' would be efficient to improve the pedestrian convenience and mobility.

• Journal of Korean Society of Transportation
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• v.34 no.2
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• pp.168-179
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• 2016

This study describes an improved model for estimating pedestrian LOS (Level of Service) by utilizing the space occupied by pedestrians. The method introduced the concept of conflict along the bi-directional pedestrian flow which enables calculating conflict area and average travel time in walking. Especially, the method incorporates the idea of generalized density concept which can consider effective walking area and pedestrian flow rates that might vary during the analysis period. After establishing methodology, adjustments of pedestrian LOS criteria in term of walking space occupied by pedestrians were performed. As a result, walking-occupied space at capacity level is 0.68 and corresponding pedestrian flow rate was calculated as 80 persons/min/m, while different pedestrian-occupied spaces were ordered to classify LOS at the points where the gradient changes. Furthermore, the statistical verification of service levels has shown that there is significant difference among all LOS categories at 5% significance level.

• Journal of Korean Society of Transportation
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• v.33 no.2
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• pp.170-181
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• 2015

This study explores passengers' travel characteristics at six bus stops on the Seoul Ring Expressway using smart traffic card data. Based on the characteristics, political strategies to improve bus facilities on expressway are suggested. Firstly, among them two bus stops of Guri and Uiwang-Cheonggye have higher transfer rate of passengers, 37.56% and 36.9% of the total intercity (red) bus passengers on the expressway, respectively. Secondly, Uiwang-Cheonggye bus stop has the highest transfer rate, and Guri bus stop has also higher transfer rate and the highest on-and-off passengers. It implies that both bus stops need to be prioritized for improving bus stop facility, access roads, and connection facility between the bi-directional stops. Thirdly, Guri (down) bus stop has relatively longer waiting time for transfer, thus shorter bus headways running the bus stop should be considered. Lastly, most passengers using both stops come to and from Bundang-gu in Geongnam City. Overall, the results of this study would be helpful for transport planners to develop effective bus route policies and bus operation.