• Journal of the Korea Safety Management & Science
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• v.21 no.3
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• pp.17-21
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• 2019

With the development of public transportation, the use of subways as a means of transportation in the city center is increasing, so that vibrations and structural noises are emerging as a new environmental issues. This study can be used as a basis for research on subway safety and shock mitigation by applying vibration-proof mat.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.1345-1351
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• 2010

First, In this essay we research about secondary source unit(SIV)180KVA is install on VVVF direct subways for using Filter Capacitor(FC) maintenance & limit of use. Vehicle's extendly use and congestly at load for Catenary voltage and load change about output change and in SIV unit there are important device named GTO Thyristor, Power Transistor Module device become short and it often happen. We analysis the fault cause and there are effects and we know the secondary source unit in filter capacitor FC1~4 input harmonic distortion component's filtering don't do correctly so we study the capacitor extend use for the component change and the outside condition by slow property changed happen and we check before and when its fault, its difficult to measure. Finally, In this research we care for this reason and we study about capacitor maintenance through control and measure ways improvement and capacitor's life spans limit of use.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.1131-1137
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• 2004

With the recent continuous expansion of subways, newly created subways tend to have lower locations and wider sections. Furthermore. since box structures and evacuating tunnels are classified into a category of mass-concrete. the thermal-stress, emitted from the inside. causes cracks to structures from the inception of constructing. In this paper, thermal-stress analysis and durability evaluation of box structure were carried out to investigate relationship between durability and parameter causing the heat of hydration. Through the examination, this paper tries to find out satisfactory solutions to regulated thermal crack and ensure the required duration period. The results of this paper showed that to control thermal crack and guarantee the required duration period it was more effective to use low-heat-portland cement and moderateheat-portland cement. As cement volume due to reduction of water-cement ratio increased, the possibility of thermal cracks occurrence increased but results of durability evaluation was different depending on evaluation method. The results showed that the appropriate water-cement ratio to control the heat of hydration and satisfy the required durability was $45\∼55\%$. And it was showed that during placement of concrete blocks ambient temperature affect the heat of hydration. thermal crack and long-term durability largely and when concrete was placed at low temperature to control thermal crack. it need to try to guarantee the required duration period. Henceforth, by studying not only internal and external conditions, such as the relative humidity and the unit weight. but also methods, to evaluate durability, in accordance with domestic situations, more reasonable design of durability should be achieved.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.4
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• pp.323-330
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• 2003

GIS-based applications for route guidance are increasingly developed recently, but most of them are for self$.$driven cars. Although some of them are intended for public transportation, they show limitations in dealing with time constraints problems taken place in transfer areas. Developing a public transportation guidance system requires the fallowing aspects: (i) people may change transportation means not only within the same type but also among different modes such as between buses and subways, and (ii) the system should take into account the time taken in transfer from one mode to the other. This study suggests the framework for developing a public transportation guidance system that generates optimized paths in the transportation network of mixed means including buses, subways and other modes. For this study, the Genetic Algorithms are used to find the best routes that take into account transfer time and other service-time constraints. The method for constructing the data structure in the GIS was also suggested.

• Korea Real Estate Review
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• v.24 no.1
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• pp.63-76
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• 2014

This study utilizes FGLS (Feasible Generalized Least Squares) to determine the impact of Jeju Olle trekking courses on nearby land prices. Official 2010 land price data for 7 areas surrounding different Jeju Olle Trails was examined with a GIS program to determine the exact distance of land parcels from nearby trekking courses. Distance and various other pricing factors were used as explanatory variables for increases in land prices. The dependent variable was the rate of change in land prices from 2002 to 2010. Unlike existing studies which have examined the effect of highways, subways and other transportation facilities on land prices, this paper examines the effect of Korea's first-ever trekking courses on nearby land prices. This study concludes that 7 different Olle Trails exert a significant influence on nearby land prices and that land prices decrease by 0.03% per meter as plots get further and further from Olle Trails. This result shows that not only transport infrastructure (highways, subways, etc.) but also non-traffic infrastructure such as Jeju Olle Trails and trekking courses can have positive effects on local real estate markets.

• Journal of the Korea Safety Management & Science
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• v.21 no.1
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• pp.1-7
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• 2019

Along with industrial development, various architectural structures have become bigger and higher, leading to an expansion in the size and capacity of construction equipment. And with the development of public transportation, the use of subways as a means of transportation in the city center is increasing, so that vibrations and structural noises are emerging as a new environmental issue. Considering that architectural structures may be used from several decades to hundreds of years after the time of construction, they can be seen as semi-permanent. Due to changes in the vibration-proof polyurethane mats installed in the foundation of these structures, settling may occur and vibration reduction may become inadequate. Therefore, in view of service life, it is necessary to have a high-level standard of reliability and stability. In accordance with this, the Floating Floor System, which uses soft polyurethane foam and can be constructed within a relatively short period of time, has excellent vibration resistant characteristics. It is presented as a great alternative solution to the issue of vibrations caused by subways, railways and building structures. At present, vibration-proof polyurethane mats have been developed up to the same product level as in other advanced countries. However, in the construction of structure foundations, the physical properties of this product and its shape incur changes. If they are installed as such in the structure of a building, it may cause significant impact on stability, requiring that this cause be urgently identified and improved.

• Tunnel and Underground Space
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• v.34 no.4
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• pp.283-300
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• 2024

Due to the revitalization of urban development, the number of cases of excavating tunnels adjacent to existing subways is increasing. This may affect the structure and track of the existing subway, resulting in reduced stability and usability. In this study, we verified the adequacy of the proximity evaluation range to ensure the stability of new tunnels and existing subways when excavating adjacent to tunnels, and proposed a quantitative correction rate considering various conditions. Conditions for applying the correction rate considered rock grade, geologically weak section, structurally weak section, and structural deterioration section. It is hoped that a more accurate proximity evaluation will be performed by applying a quantitative correction rate that considers rock and geological conditions, structure status, etc. to the proximity evaluation standard.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.904-909
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• 2011

The development of train control system shall operate a series of processes like system designing, system production and system performance evaluation as a result of various requirements analysis presented in operation rules, operating guidelines for railway organizations etc, notified by the nation. Therefore, considering operation conditions, operation plan, linkage to railway network etc, the major document like system functional specifications, system development specifications, system test plans etc must be drawn up. In this paper we classify system operating scenarios required to prepare for system standard specification and system performance evaluation report of CBTC system for urban subways supporting unmanned automatic operation, and adjust each of the operating status.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1996.10a
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• pp.89-94
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• 1996

The use of shield is increasing day by day, because it's method is advantageous tunneling method to soft and collapsible ground. In case of analyzing shield tunnel by FEM, short term behavior of ground by initial heaving and tail void closure and long terms of it because of consolidation by changes of pore pressures in clay must be considered. In this paper, the shield tunneling construction stages was analyzed from 2 dimensional elasto - viscoplastic finite element program used Mohr - Coulomb yield criterion but not considered the changes of pore pressures. The object of investigation was N - 2 Tunnel. Since the good results of analysis compared to the measured behavior of ground for heaving, tail void closure and liner installation, this results can be applied to design and construction of shield tunneling for the subways, sewage lines etc.

• Journal of Korean Association for Spatial Structures
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• v.7 no.4
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• pp.97-104
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• 2007

This paper is concerned with the vibration characteristics of medium-rise building, which severely vibrated by vehicles. The field vibration measurement was employed for finding the vibration source and vibration reducing method. Time domain data from measurements were also utilized for vibration characteristics, such as effect of buses and subways-induced vibration on the floor vibration of the building. effectiveness of the vibration reducing method was also demonstrated.