• KSCE Journal of Civil and Environmental Engineering Research
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• v.35 no.2
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• pp.437-445
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• 2015

The layout of facilities, in relation to information and navigational displays, has great influence on subway satisfaction, and tend to vary depending on the types of subway platform and transit station. However, until now, few studies have covered such aspects as of yet. Starting from this viewpoint, the purpose of this study was to use an IPA analysis technique to analyze that satisfaction on the importance of facilities to aid in accessibility, such as elevators and escalators, transit amenities and information and navigational displays depending on the types of platform and transit station. To do so, we've classified 15 metropolitan stations according to types of platform and transit station and analyzed differences in user importance and satisfaction as well as improvements for platforms and transit stations of similar type. By the analysis results of this study, we've concluded that the proper selection and positioning of elevator and escalator facilities and information and navigational displays was important when designing the subway station according to platform type (separate platform) and or according to the transit station type (cross, L, T types) where pedestrian flow heavily intersected. We considered that such analysis results would be helpful in the design of new stations and the enhancement of existing stations pursuant to a new direction that minimizes user inconvenience, and that improvement items should be developed first according to the platform and transit station types, which would be helpful in enhancing the efficiency of the subway improvement cost.

• Particle and aerosol research
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• v.18 no.3
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• pp.51-59
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• 2022

In this work, virion concentration and its dose changes by HVAC and air cleaners were estimated in a subway station platform to control airborne infection of SARS-CoV-2. Collection efficiencies with particle size were measured for the air filter equipped in a HVAC in one subway station in Daejeon. Indoor PM_2.5 changes according to outdoor PM_2.5 with time were also measured to estimate air infiltration rate in the subway station platform. When infected persons generate virions by 10⁴, 10⁵, 10⁶, 3 × 10⁶ and 5 × 10⁶ h^-1 in a 2,400 m³ volume platform, the concentration and dose were estimated as 9, 92, 275 and 458 virions/m³ and 4, 43, 130 and 217 virions after 1 hour exposure, respectively. The concentration and dose were reduced by 70%, and 64%, respectively by operations of both HVAC (with a flow rate of 16,000 m³/h, MERV 11) and ten air cleaners(with total CADR 10,740 m³/h) compared to those without operation of both HVAC and air cleaners. However, virion dose in the platform was estimated to be too low at the general conditions due to a large space, a high air infiltration (3 h^-1) and a short residence time (usually < 10 mins) in the platform irrespective of the operations of HVAC or air cleaners. HVAC with filters and air cleaners would be more necessary in the concourse or shopping areas in the subway stations to reduce the infection dose from a few hundred to several tens virions in a hour.

• Journal of environmental and Sanitary engineering
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• v.24 no.4
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• pp.60-68
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• 2009

The most principal approach to improve indoor air quality(IAQ) of subway was to examine the fine particulate(PM-10) from the emission sources. Therefore, this study was carried on the investigation the fine particulate for comparison with the removal efficiency of PM-10 in divided the PSD(Platform Screen Door) and Non-PSD subway station from July, 2007 to May 2008. In the monitoring results, the range of PM-10 concentration of Non-PSD station was $44.6{\sim}116.5{\mu}g/m^3$ and the range of PM-10 concentration of PSD station was $23.9{\sim}81.1{\mu}g/m^3$. And then the range of PM-2.5 concentration of Non-PSD station was $17.4-56.6{\mu}g/m^3$, and then the range of PM-2.5 concentration of PSD station was $17.9{\sim}34.4{\mu}g/m^3$. In comparison with the results of the PSD and Non-PSD subway station, we found that the PM-10 removal efficiency of PSD was 30-40%. In conclusion, the PSD will be applied the effective facilities of decreasing PM-10 in subway station in Korea.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.1
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• pp.59-67
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• 2012

Platform screen doors (PSD) installed at 289 stations in Seoul metropolitan subway from November 2005 to December 2009, are expected to prevent death from a fall and improve air quality. In this study, we systematically surveyed changes in radon concentrations before and after PSD installation in Seoul metropolitan subway stations. By solid-state nuclear track detectors (SSNTD), the radon concentrations before and after the PSD installation were measured at 54 stations of 6 lines from 2 to 7 reported to have relatively high radon concentrations. Mean radon concentrations at platforms were decreased by approximately 56% from 121.7 Bq/$m^3$ to 54.0 Bq/$m^3$. Before PSD installation, mean radon concentrations were in the decreasing order for subway lines 7, 5, 6, 3, 4 and 2. On the other hand, after PSD installation the order was changed to 5, 6, 7, 3, 4 and 2. According to a radon map of Seoul metropolitan subway, the number of platforms where radon concentration over was 74 Bq/$m^3$ decreased from 38 to 12 after PSD installation.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.1984-1989
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• 2008

In this study, fire simulations were performed to analyze the characteristics of the fire driven flow and the effects of the platform screen door on the smoke flow in the station, when the fire occurred in the center of the platform. Soongsil Univ. station (line number 7, 47m in depth underground) was chosen which was the one of the deepest underground subway stations in the Seoul metro, SMRT. The parallel computational method was employed to compute the heat and mass transfer eqn's with 6 CPUs of the linux clustering machine. The fire driven flow was simulated with using FDS code in which LES method was applied. The Heat release rate was 10MW and The Ultrafast model was applied for the growing model of the fire source. The 10,000,000 structured grids were used.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.366-370
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• 2007

This paper discusses a most suitable wireless communications system for subway trains on condition that a geo-spatial video system is implemented in subway trains. Geo-spatial video system for subway trains refers to the device that can transfers the images captured by cameras within a subway station building or in and around a subway track to on coming trains wirelessly, which allows the operator in operating room to monitor the state of a platform and a subway track, the flow of passengers, and the condition of passengers getting on and off. To minimize the problem, secure civil safety and prevent accidents and calamity from occurring, a geo-spatial video system for subway trains has been increasingly introduced. The wireless communications systems for GVS for subway trains involve HF(High Frequency), IR(Infra Red), M/W(Micro Wave), wireless LAN approaches. Each has its own strengths/weaknesses, and different vendors have different technology.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.588-595
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• 2006

Indoor radon($^{222}Rn$) concentrations of subway stations in Seoul area were measured to survey the environmental indoor radon levels and to identify sources of radon. The radon concentration of indoor air by method of long-term measuring with a-track detector were surveyed at 232 subway stations from 1998 to 2004. And the radon concentration in ground-water was measured with a method of alpha particle counting. To trace main source of radon, 8 out of 232 stations were selected and their radon concentrations in tunnel and on platform were analyzed. Total geometric mean and arithmetic mean of radon concentrations in all stations from 1998 to 2004 were $1.40{\pm}1.94pCi/L,\;1.65{\pm}1.07$ respectively. Geometric means of radon concentrations on platform and concourse were $1.54{\pm}1.96pCi/L,\;1.23{\pm}1.88pCi/L$ respectively, with higher concentration at the platform than at the concourse. The geological structure was significantly correlated to the indoor radon concentration in subway stations region. Radon concentrations of adjacent tunnel and ground-water of subway station was significantly correlated to the indoor radon concentration in subway stations. And There was a significant difference in radon concentration, depending on the depth levels in platform of subway stations(p<0.05).

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.4
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• pp.374-383
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• 2012

In this study, we have observed the airborne radon levels in the subway cabins before and after platform screen doors (PSD) installation. The measurements have been conducted at Seoul metropolitan subway lines in 2008, 2009 and 2010. The mean concentration of the radon inside subway cabins were increased by approximately 53% from $20.1Bq/m^3$ to $30.8Bq/m^3$ by installing PSD. After PSD installation, measured values for the different lines were rather different, and varied between 8.2 and $76.5Bq/m^3$. And mean radon concentrations were in the decreasing order for subway lines 5, 6, 7, 8, 3, 4, 2, 9 and 1. It was also found that the indoor radon concentrations in the subway cabins were highly dependent on the management approach of a ventilation system at the subway stations. By assuming an average of $720\;h\;year^{-1}$ and $2,880\;h\;year^{-1}$ spent in subway cabin, effective doses to passengers and employee were estimated. The expected annual effective dose, in case of an equilibrium factor of 0.4, were $0.07mSv\;y^{-1}$ and $0.26mSv\;y^{-1}$, respectively.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.4
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• pp.504-516
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• 1997

Recently scientists and engineers are developing a system to get waste heat of low-temperature level with advanced heat pump, which have not been used up to now. As the reason, it is necessary to examine capability of using waste heat which is raised up in the tunnel of subway out of widely distributed low-temperature waste heat in large cities. Therefore we surveyed thermal environment of the tunnel of subway in $S\check{o}my\check{o}n$, downtown of Pusan, from November 1995 to December 1996 and developed a program to predict the thermal environment of subway on the basis of experimental data and the geometries of tunnels. This paper has proved availability of waste heat of subway when the measured results obtained in subway in the winter time and the simulated results of thermal environment prediction program are compared, as well as has reported results of estimating reliability of the simulation program. As the result, the charateristics of thermal environment in the tunnel of subway in $S\check{o}my\check{o}n$ station in the winter time are to be followed; 1) temperature in the tunnel is about $10^{\circ}C$ higher than outside air temperature, 2) temperature change in the tunnel is less than that in the platform so that we may obtain stable heat source, 3) and when the measured results obtained in subway in the winter time and the simulated results of thermal environment prodiction program is compared, both results show similar tendency. Therefore, we confirm estimating reliability of the simulation program.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.325-330
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• 2014

In order to operate trains both mainline railroad platform and metropolitan subway line platform, it is necessary to develop the door step equipment of the rolling stock regardless of low(500mm, mainline) and high level platforms(1,135mm, metropolitan subway line) because of the requisite door safety system. In this study, TMS-DCU interface is studied for low and high level railway platforms. As a result, Design circuit of TMS(Train Management System)-DCU(Door Control Unit) interface is suitable for telescopic sliding type doorstep unit to minimize damage to the carbody underframe of railway vehicles.