• Journal of Korean Society of Transportation
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• v.34 no.6
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• pp.499-509
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• 2016

The pedestrian traffic flow has more complicated microscopic features than vehicular traffic flow. Without any designated lanes or any guidance, pedestrians naturally move and change their routes in two dimensional domain with ease. Thus the assessment of pedestrian comfort level should be considering the microscopic features of pedestrian flow. This study is aimed at developing pedestrian comfort criteria based upon pedestrian flow simulation model. This study suggests three criteria to determine pedestrian comfort level; the deviation of route, the acceleration of walk, and the number of collision. Each criterion, which can address the unique walking patterns of pedestrian flow, is represented as each different function with respect to traffic flow rate. The criteria can be the additional indicators to determine the level of service of pedestrian flow together with traffic flow rate and walking speed.

• Wind and Structures
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• v.11 no.1
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• pp.51-70
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• 2008

CFD is applied to evaluate pedestrian wind comfort at outdoor platforms in a high-rise apartment building. Model validation is focused on generic building sub-configurations that are obtained by decomposition of the actual complex building geometry. The comfort study is performed during the design stage, which allows structural design changes to be made for wind comfort improvement. Preliminary simulations are performed to determine the effect of different design modifications. A full wind comfort assessment study is conducted for the final design. Structural remedial measures for this building, aimed at reducing pressure short-circuiting, appear to be successful in bringing the discomfort probability estimates down to acceptable levels. Finally, the importance of one of the main sources of uncertainty in this type of wind comfort studies is illustrated. It is shown that the uncertainty about the terrain roughness classification can strongly influence the outcome of wind comfort studies and can lead to wrong decisions. This problem is present to the same extent in both wind tunnel and CFD wind comfort studies when applying the same particular procedure for terrain relation contributions as used in this paper.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.315-320
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• 2022

With the rapid development of urbanization the problems of pedestrian-level wind comfort and natural ventilation of tall buildings are becoming increasingly prominent. The velocity at the pedestrian level ($\overline{MVR}$) and variation of wind pressure coefficients $\overline{{\Delta}C_p}$ between windward and leeward surfaces of tall buildings were investigated systematically through numerical simulations. The examined parameters included building density ρ, height ratio of building α_H, width ratio of building α_B, and wind direction θ. The linear and quadratic regression analyses of $\overline{MVR}$ and $\overline{{\Delta}C_p}$ were conducted. The quadratic regression had better performance in predicting $\overline{MVR}$ and $\overline{{\Delta}C_p}$ than the linear regression. $\overline{MVR}$ and $\overline{{\Delta}C_p}$ were optimized by the NSGA-II algorithm. The LINMAP and TOPSIS decision-making methods demonstrated better capability than the Shannon's entropy approach. The final optimal design parameters of buildings were ρ = 20%, α_H = 4.5, and α_B = 1, and the wind direction was θ = 10°. The proposed method could be used for the optimization of pedestrian-level wind comfort and natural ventilation in a residential area.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1308-1317
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• 2009

The mass transit networks in Korea, such as buses, metro and subway, are co-related and the number of transfer points, in which a lot of pedestrian movement is generated, are rising. The functions of the transfer centers, in which several travel modes cross at a point, have to include convenience and comfort for pedestrians using the transfer centers, and such functions can make transit a more attractive travel option and thus eventually contribute to increases in ridership. However, the guidelines for station layouts and their assessments in transfer stations are not suggested so far. So the pedestrian pattern data (pedestrian walking distances and times, pedestrian approaching distances and times, pedestrian walking paths in the inside of stations) was collected and analyzed. Based on the results of the analysis, the ways to measure the quality of comfort for those who using transfer facilities were suggested using the times that pedestrians consume to transfer from a travel mode to another. The walking time of pedestrians at the inside of stations was also measured by pre-selected pedestrian pathways as the guidelines for station layout assessment in transfer facilities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5D
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• pp.597-604
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• 2009

The mass transit networks in Korea, such as buses, metro and subway, are co-related and the number of transfer points, in which a lot of pedestrian movement is generated, are rising. The functions of the transfer centers, in which several travel modes cross at a point, have to include convenience and comfort for pedestrians using the transfer centers, and such functions can make transit a more attractive travel option and thus eventually contribute to increases in ridership. However, the guidelines for station layouts and their assessments in transfer stations are not suggested so far. So the pedestrian pattern data (pedestrian walking distances and times, pedestrian approaching distances and times, pedestrian walking paths in the inside of stations) was collected and analyzed. Based on the results of the analysis, the ways to measure the quality of comfort for those who using transfer facilities were suggested using the times that pedestrians consume to transfer from a travel mode to another. The walking time of pedestrians at the inside of stations was also measured by pre-selected pedestrian pathways as the guidelines for station layout assessment in transfer facilities.

• Journal of Information Technology Services
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• v.16 no.4
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• pp.223-234
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• 2017

The audible pedestrian signal (APS) is an add-on device which connects to the pedestrian signaling device and informs the contents and changes of the signaling by sound. It provides walking direction information of the pedestrian crossing so that the blind people can safely cross the pedestrian crossing. In an intersection where a plurality of audible pedestrian signal (APS) are installed at an intersection crosswalk, existing audible pedestrian signal (APS) operate simultaneously in the communication radius of a wireless remote controller, which may cause confusion for the blind people and the public may complain about the noise. In this paper, we developed a BLE (Bluetooth Low Energy)-based audible pedestrian signal (APS) system capable of supporting two-way communications with a smart-phone that can cross the intersection safely and improve the walking comfort and traffic safety for the blind people. The proposed method is a method in which the BLE beacon communication based audible pedestrian signal (APS) presents active service to the blind people, and the existing audible pedestrian signal (APS) is a way of requesting the passive service by the blind people with the wireless remote control by the unidirectional communication based on 358Mhz. The developed system is installed in the crossroad of Doma-dong, Seo-gu, Daejeon, and it is tested and operated by the blind people. The satisfaction evaluation and analysis of the audible pedestrian signal (APS) for the blind people have good results and are planned to be expanded in the future.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.8
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• pp.169-176
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• 2019

The purpose of this study was to analyze outdoor thermal comfort of apartments planning characteristic of pedestrian height in Beijing, China. Selecting 322 apartment complexes with more than 1000 households and more than 10 buildings(including 10 buildings), mainly in Chaoyang District and Tongzhou District to select 32 basic layout types and then 12 typical layout types were select in 32 basic layout types. Finally, the simulation was conducted for the 12 typical layout types using the micro-climate model ENVI-met to evaluate the wind environment, the thermal environment and the comfort. The results of this study as follows: In the parallel arrangement, it has the best outdoor thermal comfort of Slab-East-Parallel(S/E/P). Next is Slab-South-Parallel(S/S/P), Tower-South-Parallel(T/S/P) in turn. In the stagger arrangement, Mixture-South-North and South Stagger-1(M/S/NSS-1) has the best outdoor thermal comfort and Slab-South-North and South Stagger(S/S/NSS), Tower-South-North and South Stagger(T/S/NSS), Mixture-South-North and South Stagger-3(M/S/NSS-3), Mixture-South-North and South Stagger-4(M/S/NSS-4), Mixture-South-North and South Stagger-2(M/S/NSS-2) in turn. In the cluster arrangement, Mixture-Mixture-Cluster-2(M/M/C-2) has the best outdoor thermal comfort and Mixture-Mixture-Cluster-3(M/M/C-3), Mixture-Mixture-Cluster-1(M/M/C-1) in turn. Due to the low wind speed and high air temperature, it is necessary to consider the layout types that can form the wind road at first, such as Mixture-South-North and South Stagger-1(M/S/NSS-1), Slab-South-North and South Stagger(S/S/NSS) and so on.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.3
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• pp.59-66
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• 2019

In recent years, urban regeneration is focused on smart and pedestrian oriented development utilizing various mobility technology. The characteristics of walkways needs to reflect such development orientations. This research is the first step to find an adequate slope for ramp replacing stairs and shared by pedestrians, personal mobilities and powered wheelchairs. It aims to check if ramps on a recommended degree of angle by general guidelines are more preferred than stairs and find out what make difference of such preferences. Two surveys were conducted at $9^{\circ}$ and $9.6^{\circ}$ ramps coexisted with stairs at sequential and parallel location. The study on the survey result found that the general evaluation of $9^{\circ}$ ramp was better than $9.6^{\circ}$ ramp but $9^{\circ}$ ramp was not preferred than stairs while $9.6^{\circ}$ ramps was preferred. The difference of preferences was related to characteristics of stairs. The stair with shorter tread and riser next to $9^{\circ}$ ramp was evaluated much better than stairs next to $9.6^{\circ}$ ramp. Therefore the research concludes that $10.0^{\circ}$ which many guidelines recommend for the maximum slop of a ramp was not adequate for a ramp to replace stairs as a preferred means of vertical circulation. In addition the research found that the preference was sensitive to moving direction and gender especially in regards to comfort of stairs and safety of ramp. Most pedestrians chose a means of vertical circulation based on its comfort but pedestrian's evaluation of safety was most different based on moving direction.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2008.04a
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• pp.402-409
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• 2008

Wind loads and environments in realistic situations surrounded by neighboring buildings may be considerably different from those in idealized or simplified situations such as codes and standards. Interference effects of change in wind passage of a building group on wind loads and wind environments are reviewed. Wind-induced interference effects depend mainly on the building geometry and arrangement of these structures, their orientation and upstream terrain conditions. The most important factor among them may be the arrangement of building structures which can change the wind direction directly. Interference effects regarding wind loads are discussed with examples of window damages by typhoon and of pressure measurements in the boundary layer wind tunnel. Wind environment problems are also discussed, specially underlined on pedestrian comfort and safety. Various evaluation techniques or standards of wind environment are introduced. The change of wind velocity between the panel-type apartment buildings is examined, depending on the distance each other.

• International Journal of High-Rise Buildings
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• v.5 no.2
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• pp.87-94
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• 2016

High-rise as a building typology is gaining popularity in Asian mega-cities, due to its advantages in increasing volumetric density with limited land resources. Numerous factors contribute to the formation of high-rise urban form, from economical and institutional, environmental to socio-political. Environmental concerns over the impact of rapid urbanization in developing economies demand new thought on the link between urban environment and urban form. Outdoor and indoor climate, pedestrian comfort, and building energy consumption are all related to and impacted by urban form and building morphology. There are many studies and practices on designing individual "green" high-rise buildings, but far fewer studies on designing high-rise building clusters from the perspective of environmental performance optimization.. This paper focuses on the environmental perspective, and its correlation with the evolution of the high-rise urban form. Previous studies on urban morphology in terms of environmental and energy performance are reviewed. Studies on "parameterizing" urban morphology to estimate its environmental performance are reviewed, and the possible urban design implications of the study are demonstrated in by the author, by way of a microclimate map of the iconic Shanghai Xiao Lujiazui CBD. The study formulates the best-practice design guidelines for creating walkable and comfortable outdoor space in a high-rise urban setting, including proper sizing of street blocks and building footprint, provision of shading, and facilitating urban ventilation.