• ETRI Journal
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• v.45 no.5
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• pp.836-846
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• 2023

Mobile robots are used in modern life; however, object recognition is still insufficient to realize robot navigation in crowded environments. Mobile robots must rapidly and accurately recognize the movements and shapes of pedestrians to navigate safely in pedestrian-rich spaces. This study proposes real-time, accurate, three-dimensional (3D) multi-pedestrian detection and tracking using a 3D light detection and ranging (LiDAR) point cloud in crowded environments. The pedestrian detection quickly segments a sparse 3D point cloud into individual pedestrians using a lightweight convolutional autoencoder and connected-component algorithm. The multi-pedestrian tracking identifies the same pedestrians considering motion and appearance cues in continuing frames. In addition, it estimates pedestrians' dynamic movements with various patterns by adaptively mixing heterogeneous motion models. We evaluate the computational speed and accuracy of each module using the KITTI dataset. We demonstrate that our integrated system, which rapidly and accurately recognizes pedestrian movement and appearance using a sparse 3D LiDAR, is applicable for robot navigation in crowded spaces.

• International Journal of Highway Engineering
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• v.19 no.4
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• pp.69-78
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• 2017

PURPOSES : In this study, we analyzed the road crossing behavior of older pedestrians on a mid-block signalized crosswalk, and compared it to that of younger pedestrians. In addition, we analyzed the correlation between accidents involving older pedestrians while crossing roads and their behavioral characteristics. Finally, we confirmed the reasons for an increase in accidents involving older pedestrians. METHODS : First, 30 areas with the highest incidence of accidents involving older pedestrians while crossing roads were selected as target areas for analysis. Next, we measured the start-up delay (the time elapsed from the moment the signal turns green to the moment the pedestrian starts walking) and head movement (the number of head turns during crossing a road) of 900 (450 older and 450 younger) pedestrians. The next step was to conduct a survey and confirm the differences in judgment between older and younger pedestrians about approaching vehicles. Finally, we analyzed the correlation between the survey results and traffic accidents. RESULTS : The average start-up delay and head movement of the older pedestrians was 1.58 seconds and 3.15 times, respectively. A definite correlation was obtained between head movement and the frequency of pedestrian traffic accidents. The results of our survey indicate that 17.3% of the older pedestrians and 7.8% of the younger pedestrians have a high crash risk. CONCLUSIONS : Behavioral characteristics of older pedestrians were closely correlated with accidents involving older pedestrians while crossing roads in mid-block signalized crosswalks. Our study indicates that in order to reduce the number of accidents involving older pedestrians, it is necessary to develop an improvement plan including measures such as installation of safety facilities taking the behavioral characteristics of older pedestrians into consideration and their safety education.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.69-77
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• 2008

This article proposes new method for estimating pedestrian quality of service(QOS) that is useful to changing pedestrian environment by examining pedestrian quality of service as well as developing new method that integrate qualitative variables into the estimating indicators for the pedestrian movement right. Based on survey questionnaire addressed to experts group, the obtained data for the indicators were analyzed through Analytic Hierarchy Process(AHP). The results show that pedestrian traffic flow(quantitative figure: 52%), sidewalk geometric(quantitative figure: 16%), sidewalk usage behavior(qualitative figure: 11%) in commercial and business zone pointed out the importance of quantitative indicators such as pedestrian traffic flow, and sidewalk geometric. In addition, the results also show that pedestrian traffic flow(quantitative figure: 30%), sidewalk geometric(quantitative figure : 22%), sidewalk usage behavior(qualitative figure: 20%) indicate the significance of qualitative indicators such as pedestrian's sidewalk usage.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.36-49
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• 2016

A subway system is one of the major transportation modes at a metropolitan area. When it meets the other lines, the metro station, so-called transferring station, is usually threatened by severe pedestrian congestion and safety issue of transit users including the transportation vulnerable. Although transportation planners forecast travel demand at the beginning, it is not easy to predict pedestrian flows precisely for a long term if land use plans have dramatically changed. Due to expensive costs, structural extension of metro stations is limited. Therefore, it requires efficient and technical improvements as meeting the demand of pedestrian and physical characteristics. In this study, the core mechanism of pedestrian movement-based simulation model was introduced and evacuation scenarios were analyzed with the developed model. As a result, the multiple optimal routes for unexpected events at the solid space of the multiple stories are easily searched through the simulator and in the case of Sadang Station, travel time can be reduced by 60% when the evacuation information and intuitive design are provided.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.6
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• pp.37-49
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• 2015

In Space Syntax, the greater the degree of integration between separate links, the greater the links' accessibility from the target network. As such, planning pedestrian walks so that links with high degrees of integration are connected, or else inducing high integration value land use are both valid options. The travel distribution model reflects how walking demand, or more specifically, the pedestrian, partakes in route choosing behavior that minimizes select criteria, notably level of discomfort, as measured using travel distance and time. The model thus demonstrates travel patterns associated with demand pertaining to minimization of discomfort experienced by the pedestrian. This research introduces a method that integrates Space Syntax and the pedestrian travel distribution model. The integrated model will determine whether regions with high degrees of integration are actually being used as pivots for pedestrian demand movement, as well as to explain whether the degree of integration is sustained at an appropriate level while considering actual movement demand. As a means to develop the integrated model, a method that combines display of the visibility of the space syntax network and road-divided links is proposed. The pedestrian travel distribution model also includes an alternative path finding mechanism between origin and destination, which allows for uniform allocation of demand.

• Spatial Information Research
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• v.20 no.5
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• pp.77-89
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• 2012

Walking is the most basic personal mobility and its importance and concern is ever increasing with the highlighting of a new paradigm, such as transit oriented development, sustainable development and revitalization of green transport. The existing analytical research on pedestrian network is using a pedestrian's moving distance to a destination and integration in space syntax theory as its representative accessibility factors. However, the uniplanar network moving distance fails to reflect topographic characteristics, so the moving distance could show a similar result value in case of the regions for analysis that have a similar network structure to each other. Accordingly, the aim of this study is to suggest a new analytical methodology on pedestrian network accessibility in consideration of the grade in pedestrian sections and a pedestrian's size. this study, in its analysis of a uniplanar pedestrian network moving distance, analyzed the pedestrian network moving distance in consideration of the grade in pedestrian sections, and even the pedestrian network moving distance in consideration of a pedestrian's size, and suggested the methodology on pedestrian network accessibility analysis in consideration of a more substantive pedestrian's characteristics. It is hoped that the methodology used by this study will be used as the methodology on pedestrian network analysis which can reflect topographic characteristics in the pedestrian network analysis, and take a more substantive pedestrian's movement into account.

• 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.

• Transportation Technology and Policy
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• v.13 no.5
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• pp.48-55
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• 2016

• Journal of Korean Society of Transportation
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• v.26 no.1
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• pp.137-144
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• 2008

It is important to know pedestrian volume to carry out pedestrian safety analysis and pedestrian friendly design. However, it is too difficult to come across research work related to pedestrian volume analysis in the field of transport, due to lack of interests on pedestrian movement. Most transport research has been focused on vehicles and highways rather than pedestrian. On the other hand, in the field of urban studies, there comes an effective tool to estimate pedestrian volumes using Space Syntax theory. This theory twins out to be effective and economic because it only requires network information, which is easy to acquire from maps and field survey. However, this method is different in the way representing networks from the way that is common in the field of transport. To make up for this point, this paper develops a novel measure for estimating pedestrian volume using Dial's algorithm, and applies the model in the two test networks; Insadong and Soongryemoon networks. The application results reveals that developed measure is an effective tool to explain pedestrian volume; a correlation coefficient between the measure and pedestrian volume is 0.713 in Insadong and 0.492 in Soongryemoon, and the goodness of fit($R^2$) of regression models are 0.893 in Insadong and 0.671 in Soongryemoon. This estimation method is significantly less complicated to estimate the effect of a pedestrian network change than Space Syntax theory, which requires special softwares not readily available.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.6
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• pp.14-24
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• 2018

Pedestrian movement of passengers using smart card within stations can be divided into three types of activities - straight ride and alight, line transfer, and station transfer. Straight ride and alight is transfer activity for which the card terminal and embarking line are identical. In this case, straight ride occurs at the origin station and straight alight occurs at the destination station. Line transfer refers to activity in which the subway line embarked on by the passenger is different from that which is disembarked. Succinctly, line transfer is transfer at a middle station, rather than at origin or destination stations. Station transfer occurs when the card terminal line and embarking line are different. It appears when station transfer happens at the origin station as starting transfer, and at the destination station as destination transfer. In the case of Metropolitan smart card data, origin and destination station card terminal line number data is recorded, but subway line data does not exist. Consequently, transportation card data, as it exists, cannot adequately be used to analyze pedestrian movement as a whole in subway stations. This research uses the smart card data, with its constraints, to propose an analysis model for passenger pedestrian movement within subway stations. To achieve this, a path selection model is constructed, which links origin and destination stations, and then applied for analysis. Finally, a case study of the metropolitan subway is undertaken and pedestrian volume analyzed.