• Journal of the Korean Society of Safety
• /
• v.27 no.1
• /
• pp.1-6
• /
• 2012

In crowded subway stations indoor air quality (IAQ) is a key factor for ensuring the safety and health of passengers. Since physical variables that describing IAQ such as the concentration of particulate, $CO_2$, VOCs and biological agents need to be closely monitored and controlled in multiple locations within subway stations and in remote sites, concept of web-based monitoring and control network using both wireless and wired media needs to be implemented. Connecting remote wireless sensor network and device (LonWorks) networks to the IP network based on the concept of VDN can provide a powerful, integrated, distributed monitoring and control performance. In this study, performance of wireless and wired network in VDN for monitoring and control of IAQ in subway stations is evaluated. Specifically, delay induced in wireless and wired networks, and data transmission rate are evaluated. A key parameter is identified in assuring safety and health of passengers in subway stations.

• Journal of Environmental Health Sciences
• /
• v.24 no.2
• /
• pp.134-144
• /
• 1998

A comprehensive air quality monitoring was carried out to investigate the criteria concentration of air pollutant in indoor of subway stations of Seoul City. The samples were collected twice per year (the first and the second half of the year) at each sampling point from February to September in 1997. Sampling point of subway stations was ticket office and platform. The measurement of indoor air pollutants such as sulfur dioxide(SO$_2$), nitrogen dioxide(NO$_2$), carbon monoxide(CO), carbon dioxide(CO$_2$), total suspended particulate(TSP) was performed to determine the indoor air quality. Heavy metals(Pb, Cd, Cu, Cr, As, Hg) were also measured together with those air pollutants. The annual average concentration of CO$_2$ and TSP in subway stations were relatively high while those of heavy metals were within 10% of environmental recommended standard concentration in all stations. As results of regression analysis between line and line of air factors, the concentrations of CO, CO$_2$, TSP, Pb, Cd, Cr and Cu were highly correlated, but those of $SO_2, NO_2$ and Hg were not correlated. As results of regression analysis between ticket office and platform, the concentrations of heavy metals such as Cr and Cu were highly correlated. Results of oneway analysis of variance between the first and the second half of the year air factors also indicated that CO, CO$_2$, Cd, Cu, Hg were significant($\alpha$=0.01), respectively. The average contration of total suspended particulate(TSP) in subway line No. 1 was shown high concentration(200 $\mu g/m^3\cdot$ day) level.

• Journal of Environmental Science International
• /
• v.28 no.7
• /
• pp.595-606
• /
• 2019

This research investigated the characteristics of CO, $CO_2$, and $NO_2$ concentrations at main subway stations in Busan. The annual mean CO concentrations at the Suyeong and Nampo stations were 0.75 ppm and 0.48 ppm, respectively. Annual $CO_2$ concentration at the Seomyeon 1- platform was 649 ppm. The $NO_2$ concentrations at the Seomyeon 2- waiting room and the Yeonsan station were 0.048 ppm and 0.037 ppm, respectively. CO concentration was highest at two times of the day, and was proportional to the number of passengers commuting to and from work. The CO and $CO_2$ concentrations were highest in winter, but $NO_2$ concentration was highest in spring. CO and $CO_2$ concentrations were highest on Saturday and lowest on Sunday. The correlation of CO and $NO_2$ concentrations measured at the subway stations with those at the ambient air quality station were highest at the Seomyeon 1 and 2- waiting room and Jeonpodong. The correlation was lowest at the Yeonsan and Yeonsandong station. The number of days when $CO_2$ concentration exceeded 700 ppm over the last three years at the Seomyeon 1- platform was 174. The findings of this research are expected to deepen understanding of the fine particle characteristics at subway stations in Busan and be useful for developing a strategy for controlling urban indoor air quality.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.50 no.6
• /
• pp.294-301
• /
• 2013

The particle matter concentrations in the subway stations should be monitored and controlled for the health of commuters on the subway system. Seoul Metro and Seoul Metropolitan Rapid Transit Corporation are measuring several air pollutants regularly. In this paper, the reliability of the cheap instruments using light scattering method is improved with the help of a linear regression analysis technique to measure the $PM_{10}$ concentrations continuously in the subway stations. In addition, a monitoring system is implemented to display and record the data of $PM_{10}$, $CO_2$, humidity, and temperature. To transmit and receive these measured sensor data, CDMA M2M wireless communication method is applied.

• Journal of Fisheries and Marine Sciences Education
• /
• v.22 no.4
• /
• pp.604-610
• /
• 2010

Busan subway transportation system has been established a key role in the society last 20 years. However many people are suffering from hot and humid environment at subway station and platform due to deteriorated ventilation system as well as insufficient air conditioning system in existing stations and platforms. As a result, these systems require revitalization. There is about 5400tons of low temperature underground water is generated from subway stations every day. By using this method and air washer we are trying to lower the temperature. Air washer is commonly used for removing humidity but in this experiment it will be used as air precooling. This research offers result of experiment using air washer system to lower the temperature in large spaces like subway station. The experiment result has shown when L/G was the same, at condition which water spray temperature at $18^{\circ}C$ resulting inlet and outlet temperature difference larger. Also, in the same water spray temperature conditions, larger L/G condition showed a greater temperature difference. LCC evaluation of both system were shown that air washer system of using underground water will save 53% of the initial cost than refrigeration system, and save 75% of operating cost.

• Asian Journal of Atmospheric Environment
• /
• v.4 no.2
• /
• pp.97-105
• /
• 2010

A quantitative single particle analytical technique, denoted low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA), was applied to characterize particulate matters collected at two underground subway stations, Jegidong and Yangje stations, in Seoul, Korea. To clearly identify the source of the indoor aerosols in the subway stations, four sets of samples were collected at four different locations within the subway stations: in the tunnel; at the platform; near the ticket office; nearby outdoors. Aerosol samples collected on stages 2 and 3 ($D_p$: $10-2.5\;{\mu}m$ and $2.5-1.0\;{\mu}m$, respectively) in a 3-stage Dekati $PM_{10}$ impactor were investigated. Samples were collected during summertime in 2009. The major chemical species observed in the subway particle samples were Fe-containing, carbonaceous, and soil-derived particles, and secondary aerosols such as nitrates and sulfates. Among them, Fe-containing particles were the most popular. The tunnel samples contained 85-88% of Fe-containing particles, with the abundance of Fe-containing particles decreasing as the distances of sampling locations from the tunnel increased. The Fe-containing subway particles were generated mainly from mechanical wear and friction processes at rail-wheel-brake interfaces. Carbonaceous, soil-derived, and secondary nitrate and/or sulfate particles observed in the underground subway particles likely flowed in from the outdoor environment by human activities and the air-exchange between the subway system and the outdoors. In addition, since the platform screen doors (PSDs) limit air-mixing between the tunnel and the platform, samples collected at the platform at the Yangjae station (with PSDs) showed a marked decrease in the relative abundances of Fe-containing particles compared to the Jegidong station (without PSDs).

• Korean Management Science Review
• /
• v.14 no.2
• /
• pp.81-90
• /
• 1997

Network approach is used to find the shortest paths and transportation time between the subway stations in Seoul, Korea. Because of transfer stations, we reconstruct the subway network to compute the shortest routes and corresponding transportation times. The reconstructed network is useful to obtain desired information because it can handle the transfer time between tracks. Time and route information about the subway system is obtained and it will be displayed in the subway guide board at each station. Then, all passengers can have the information of shortest route to a destination and corresponding transportation time.

• KIEAE Journal
• /
• v.15 no.4
• /
• pp.53-60
• /
• 2015

Purpose: Subway in Seoul, Korea is an important urban mass transportation system as it carries more than 4 million people a day. To support this important mission, subway entrances were designed and installed to maximize accessibility to the stations. However, a uniform plan by the national government guided quantity and layout of the subway entrances. Therefore, the plan did not consider unique characteristics of each station area and reorganization of the subway entrance system is required to improve pedestrian environment. Method: This study grouped the subway entrances into specific patterns to propose reorganizing schemes. The authors conducted field surveys, examined case studies and proposed an entrance reorganizing plan for each type. Result: The study recommends subway entrances be installed inside adjacent building when large commercial or office complexes are nearby. The authors proposed installing a bridge connecting the stations and adjacent buildings for elevated entrances. This would be only possible when there are commercial or office facilities nearby with enough floor space. The study summarizes the pros and cons of each solution. To translate our proposals into realities, various incentives should be given to building or land owners. This study made suggestions as to which kinds of incentives exist and be effective in a range of situations.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.439-441
• /
• 2007

The seoul metropolitan subway has installed 8 lines and about 500 stations to transport 5 million passengers everyday. The underground air pollution level in the subway stations is very severe status, which is very harmful to the commutators and its personals. Although subway roles as such a massive and huge transportation system, the subway doesn't adapt yet any real-time air monitoring system. They have only some hand-held type detector equipments for monitoring air pollution. Therefore subway passengers are exposed to the harmful air pollution environment. The most harmful environmental parameters among the air pollution are known as the dust and sound noise dB level in the subway station. Because the dust is consisted of very small particles, we can't see them easily in dark condition on the platform, but it is very harmful. The monitoring system for air pollution is developed using embedded system attached with 6 different environmental sensors. This system monitors air pollution of dust sound noise, gas, temperature, humidity, inflammable gas, toxic gas in the subway ?station. The sensor unit of the ARM-CPU board and sensor transmits real time environmental data to the main server using Zigbee wireless communication module and TCP/IP network. The main control server receives and displays the real-time environmental data, and it send alarms to the personals when high level value.

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