• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.360-363
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• 1999

• Smart Structures and Systems
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• v.33 no.1
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• pp.17-26
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• 2024

The new metro crossing the existing metro will cause the settlement or floating of the existing structures, which will have safety problems for the operation of the existing metro and the construction of the new metro. Therefore, it is necessary to monitor and predict the settlement of the existing metro caused by the construction of the new metro in real time. Considering the complexity and uncertainty of metro settlement, a Gaussian Prior Bayesian Emulator (GPBE) probability prediction model based on Bayesian optimization (BO) is proposed, that is, BO-GPBE. Firstly, the settlement monitoring data are analyzed to get the influence of the new metro on the settlement of the existing metro. Then, five different acquisition functions, that is, expected improvement (EI), expected improvement per second (EIPS), expected improvement per second plus (EIPSP), lower confidence bound (LCB), probability of improvement (PI) are selected to construct BO model, and then BO-GPBE model is established. Finally, three years settlement monitoring data were collected by structural health monitoring (SHM) system installed on Nanjing Metro Line 10 are employed to demonstrate the effectiveness of BO-GPBE for forecasting the settlement.

• Journal of Service Research and Studies
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• v.12 no.2
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• pp.48-64
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• 2022

The metro played a role in improving and alleviating the problems of urban ground transportation, promoting rational development of the city and at the same time leading the development of metro-related industries. There is no doubt that it had a double effect of enormous economic and social benefits on the development of the country as a whole. The purpose of this study is to apply the concept of servicescape to the metro and establish the definition of the Metro Servicescape(MSS). To this end, the service space and service facilities of the metro were analyzed, and the existing domestic and foreign literature related to servicescape was studied. First, this study defined the concept of servicescape of metro. Second, 10 elements suitable for the metro service landscape were derived through domestic and foreign service landscape studies. Third, through field surveys and analysis of metros in five cities in Seoul, Busan, Daegu, Daejeon, and Gwangju, the ranking of the current status of the domestic metro servicescapes was 203 Seoul metro, 197 Busan metro, 192 Daegu metro, 178 Gwangju metro, There were 172 metro lines in Daejeon. Among them, the four elements of comfort, sociality, cleanliness, and safety are the same, and accordingly, it seems that each city metro is the same standard. However, the six elements of aesthetics, spatiality, convenience, entertainment, openness and information were found to be different for each city metro. It is expected that the results of this study can provide a reference value for future metro service landscape research.

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.275-277
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• 1999

• Proceedings of the KSR Conference
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• 2008.06b
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• pp.27-41
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• 2008

Construction of metro transportation infra is a large-scale project requiring tremendous financial resources. This study suggests operation method to use for rapid transit line existing infra such as Gyeongbu line and spare line capacity following second phase KTX construction. Reviewing various constraints of metro rapid transit operation, we found that the conditions for metro rapid transit operation are already satisfied in Daegu area, just like the case of Gyeongbu line in Seoul Metro area. Also, the evaluation of the economic feasibility of metro rapid transit operation in Daegu area shows that B/C is about 2.4, which implies that there is sufficient economic feasibility. According to the result of sensitivity analysis, the project is economically feasible unless the passenger demand decreases 15% and construction costs increases more than 70%. B/C is evaluated large because the utilization of already exiting infra lowers the initial cost. As one of mass transportation system of large capacity, metro rapid transit can generate significant spillover effect: It will strengthen competitiveness of metro area by connecting cities within the area and by extending one-day life zone of the area, to say nothing of the benefit of improving traffic condition. The construction of metro rapid transit network is necessary for the mass transportation system of Yeongnam area as well as Daegu area, and it may work as a starting point for uniting Daegu and Gyeongbuk and strengthening regional competitiveness.

• Structural Engineering and Mechanics
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• v.76 no.2
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• pp.207-222
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• 2020

Due to the rugged terrain, metro lines in mountain city across numerous wide rivers and deep valleys, resulting in instability of high-pier bridge and insecurity of metro train subjected to fluctuating crosswind. To ensure the safe operation in metro lines in mountain cities, running safety of the metro train over the high-pier bridge under crosswind is analyzed in this paper. Firstly, the dynamic model of the wind-train-bridge (WTB) system is built, in which the speed-up effect of crosswind is fully considered. On the basis of time domain analysis, the basic characteristics of the WTB system with high-pier are analyzed. Afterwards, the dynamic responses varies with train speed and wind speed are calculated, and the safety zone of metro train over a high-pier bridge subjected to fluctuating crosswind in mountain city is determined. The results indicate that, fluctuating crosswind triggers drastic vibration to the metro train and high-pier bridges, which in turn causes running instability of the train. For this reason, the corresponding safety zone for metro train running on the high-pier is proposed, and the metro traffic on the high-pier bridge should be closed as the mean wind speed of standard height reaches 9 m/s (15.6 m/s for the train).

• Wind and Structures
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• v.29 no.5
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• pp.299-312
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• 2019

Due to the rugged terrain, metro lines in mountain city across numerous wide rivers and deep valleys, resulting in instability of high-pier bridge and insecurity of metro train under crosswind. Compared with the conditions of no-wind, crosswind triggers severer vibration of the dynamic system; compared with the short-pier viaduct, the high-pier viaduct has worse stability under crosswind. For these reasons, the running safety of the metro vehicle traveling on a high-pier viaduct under crosswind is analyzed to ensure the safe operation in metro lines in mountain cities. In this paper, a dynamic model of the metro vehicle-track-bridge system under crosswind is established, in which crosswind loads model considering the condition of wind zone are built. After that, the evaluation indices and the calculation parameters have been selected, moreover, the basic characteristics of the dynamic system with high-pier under crosswind are analyzed. On this basis, the response varies with vehicle speed and wind speed are calculated, then the corresponding safety zone is determined. The results indicate that, crosswind triggers drastic vibration to the metro vehicle and high-pier viaduct, which in turn causes running instability of the vehicle. The corresponding safety zone for metro vehicle traveling on the high-pier is proposed, and the metro traffic on the high-pier bridge under crosswind should not exceed the corresponding limited vehicle speed to ensure the running safety.

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.108-111
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• 1999

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2005.10a
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• pp.128-128
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• 2005

• International Journal of High-Rise Buildings
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• v.5 no.2
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• pp.105-115
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• 2016

In the process of exploring sustainable development, major cities in China are expanding metro systems as a strategy to reduce the negative environmental and social consequences of fast-paced motorization. A metro station is not only a transportation node, but also a place where diverse activities can be performed. Therefore, the realization of the spatial potential for human interaction is the essence of the strategy for integrated development in metro station areas. For this paper, 10 well-developed metro stations in Central Shanghai were selected to investigate the correlation between accessibility and spatial performance in station areas. The spatial performance in station areas is significantly affected by metro configuration. However, both vehicle and pedestrian accessibility show weak influence on spatial performance. A synergistic model was then developed to provide quantitative support for transit-oriented development in metro station areas.