• Journal of Korean Society for Atmospheric Environment
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• v.29 no.5
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• pp.625-633
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• 2013

This study attempted to find an alternative method for fine dust control in the pre-exiting facilities of metro-subway stations. A new double-layer design was proposed for the MVAC (mechanical ventilation and air control) system. Several filter lay-outs were combined a pre-filter with electret filter (EF), electret bundle filter (EBF), or electret pleated filter (EPF), and were then examined focusing on the collection efficiency of particulate matters and pressure drop across the filter layers. The experimental results from the lab and field tests showed the best collection efficiency with EPF, which achieved 85% for $PM_{10}$ and 55% for $PM_{2.5}$. It was also found from the long term field test that the new filter lay-out could provide quite consistent dust level particularly in underground platform regardless of external condition.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.5
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• pp.103-109
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• 2008

Precipitation on slope is separated into infiltration and outflow according to physical properties of soil and slope. However, the slope analysis is assumed that all precipitation are percolated. So, groundwater level is excessive tend to be calculated. In this paper, NRCS model and Horton models that have a suitability were used for agro-type analysis of Seoul station after precipitation was separated into infiltration and outflow. Also, gradient of slope was analyzed about seepage behavior and underground water level aspect through numerical analysis. After inclination correction, the estimated infiltration was compose of slopes much applied by domestic design standard. The change of groundwater level is appeared greatly as agro-type goes from D type to A type in the analysis results.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.8
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• pp.620-626
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• 2006

Recently, indoor air quality (IAQ) is one of the greatest problems in our modern societies. Although research for IAQ is made rapid progress but IAQ problems concerning in door microorganism contamination is required to be studied still more. So we have investigated the indoor microorganism concentration of a variety of department store, subway station, underground shopping center, kindergartens, library where people complain about the in-door air quality. The experiment on microorganism concentration of indoor air was carried out and the average of total microorganisms was measured. Comparing the experimental results with existing foreign criterion, the experimental results show that the ministry of environment recommendation microorganism concentration value ($800 CFU/m^3$) is in need of revision in the near future.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.698-705
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• 2005

This study contains actual scaled site experiments on mediation factors affecting ultimate pulling force of the buoyancy resisting anchor which is installed underground water level suffering buoyancy force and breaking mechanism. Site buoyancy test selected the buoyancy acting site where acting buoyancy to the station structure since the stream and reservoir is neighboured to the vicinity ground and executed site experiments leading to variation of anchoring length, drilling diameter and tendon diameter at the weathered rock ground. The test result showed that pulling force getting increased more and more proportionate to increase of anchoring length, drilling diameter and tendon diameter, and as a result of analysis for correlations between anchoring length-ultimate limited load and drilling diameter-ultimate load (on the basis of 254mm settlement), modulus of correlation showed very high relation 0.9 and 0.99 respectively and correlation formular showed the limited load is increasing proportionate to cubic meters of anchoring length as well as the ultimate load proportionate to alignment of drilling diameter. It is also showed that limited load increased about 42.5% from 392kN to 559kN as a result of change the tendon diameter to 36mm and 50mm.

• Asian Journal of Atmospheric Environment
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• v.5 no.2
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• pp.113-120
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• 2011

Adsorbent combination studies have been carried out to remove nitrogen dioxide ($NO_2$) and volatile organic compounds (VOCs: BTEX) out of a subway environment characterized by high flow and low concentration. Optimal conditions for the high removal efficiency of the concerned target compounds were obtained through testing a series of control factors such as adsorbent sorts, thicknesses, and superficial velocity. It was found that the efficiencies increased as the specific surface area of activated carbon and its thickness increased, and external void fraction decreased. Furthermore, mixed activated carbon with granular and constructed contents was extensively tested to reduce pressure drop through the carbon bed. It was found that the performance of higher contents of granular activated carbon was better than that of higher contents of the constructed carbon. When the mixed carbon was applied to the subway ventilation system in order to eliminate $NO_2$ and VOC simultaneously, the removal efficiencies were found to be 75% and 85%, respectively.

• Asian Journal of Atmospheric Environment
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• v.4 no.3
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• pp.115-140
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• 2010

Great concerns about atmospheric aerosols are attributed to their multiple roles to atmospheric processes. For example, atmospheric aerosols influence global climate, directly by scattering or absorbing solar radiations and indirectly by serving as cloud condensation nuclei. They also have a significant impact on human health and visibility. Many of these effects depend on the size and composition of atmospheric aerosols, and thus detailed information on the physicochemical properties and the distribution of airborne particles is critical to accurately predict their impact on the Earth's climate as well as human health. A single particle analysis technique, named low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA) that can determine the concentration of low-Z elements such as carbon, nitrogen and oxygen in a microscopic volume has been developed. The capability of quantitative analysis of low-Z elements in individual particle allows the characterization of especially important atmospheric particles such as sulfates, nitrates, ammonium, and carbonaceous particles. Furthermore, the diversity and the complicated heterogeneity of atmospheric particles in chemical compositions can be investigated in detail. In this review, the development and methodology of low-Z particle EPMA for the analysis of atmospheric aerosols are introduced. Also, its typical applications for the characterization of various atmospheric particles, i.e., on the chemical compositions, morphologies, the size segregated distributions, and the origins of Asian dust, urban aerosols, indoor aerosols in underground subway station, and Arctic aerosols, are illustrated.

• 한국지구물리탐사학회:학술대회논문집
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• 2003.11a
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• pp.214-220
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• 2003

Pipe jacking is a name for a method to excavate a tunnel by pushing pipe into the ground from an especial pit. Size of tunnels in this method is different from under 900mm (microtunneling) to more than 3,000mm. Method of excavation is also different from hand digging to use of any kind of tunnel boring machines such as slurry and earth pressure balance (EPB) machines. Slurry pipe jacking was firmly established as a special method for the nondisruptive construction of the underground tunnels in urban area. During the pipe jacking and microtunneling process, the jacking load is an important parameter, controlling the pipe wall thickness, need to and location of intermediate jacking station, selection of jacking frame and lubrication requirements. The main component of the jacking load is due to frictional resistance. In this paper the skin friction between pipe surface and surrounding condition also lubricant quality based on a few fundamental tests, were considered. During this study unconfined compressive strength test, dynamic friction measurement test and direct shear box test were raised for one of the largest diameter slurry pipe jacking project in Fujisawa city in Japan. It could be concluded that in slurry pipe jacking, prediction of frictional forces are mainly dependent on successful lubrication, its quality and lubricant strength parameters. Conclusions from this study can be used for the same experiences.

• Journal of the Korean housing association
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• v.26 no.5
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• pp.45-52
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• 2015

Following natural disasters, there is a need to develop temporary housing through the rapid installation of mass-produced prefabricated housing. This study has developed a model construction manual for prefabricated temporary housing installable in underground spaces. First, the temporary housing prototype was drawn based on opinion poll results from earlier studies. $4.32m^2$ was calculated as the basic unit of the temporary housing living space for one person. Units included panel type, box type and mixed-type, for a variety of field conditions and scales. In order to enable space expansion and movement desirable to the user, the prototype was combination of panel and box types. The drawn prototype was utilized as the basic design template for producing prototypes and for the manual. Second, the possibility of utilizing subway stations as temporary housing was verified through the production of the prototype, and the construction process was summarized in the manual. The manual was developed in the form of a checklist to provide a guideline for users to build with prefab materials.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.40-47
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• 2004

Recently, the utilization of subway stations for varied working spaces is beginning to receive more attention. However, due to feeling of closeness and rejection to the underground, a daylighting is useful to alleviate the complaints of subway environments. This paper aims to investigate and evaluate the luminous environments of subway stations with and without daylighting in Seoul. At the first stages, the field experiments are performed to estimate the illuminance levels of chosen three subway stations. And then, the interview and questionnaire surveys are conducted to evaluate the luminous atmospheres of them. As results, the daylighting effects to subway visual environments are analyzed. Also, the basic data for a daylighting design are suggested.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2010.04a
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• pp.367-369
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• 2010

The purpose of this study is to develop a campus facility management system, construct 3D graphic data and attribute data of facilities on the Kumoh National Institute of Technology and then verificate the developed system's practicability. Utilized the existing campus facility data from the existing drawings, images, cadastre records and so forth, 3D position data of underground facilities surveyed with a total station and high-resolution aerial photos, 3D realistic models were produced by means of a XD2D software and a XDWORLD Builder Professional software of GIS engines. We intend to embody not only campus guide service in virtual reality space but visualization of 3D virtual campus by providing 2D and 3D data to web space using XDWORLD server soon after. It is expected that the campus facility management system is able to contribute to the integrated management of 3D facility data service, the support of prompt decision-making related to spatial affairs, the work simplification through data holding in common between the members of the staff and so forth.