• Geomechanics and Engineering
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• v.32 no.4
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• pp.427-443
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• 2023

Across the globe, rapid urbanization demands the construction of basements for car parking and sub way station within the vicinity of high-rise buildings supported on piled raft foundations. As a consequence, ground movements caused by such excavations could interfere with the serviceability of the building and the piled raft as well. Hence, the prediction of the building responses to the adjacent excavations is of utmost importance. This study used three-dimensional numerical modelling to capture the effects of twin excavations (final depth of each excavation, H_e=24 m) on a 20-storey building resting on (4×4) piled raft. Because the considered structure, pile foundation, and soil deposit are three-dimensional in nature, the adopted three-dimensional numerical modelling can provide a more realistic simulation to capture responses of the system. The hypoplastic constitutive model was used to capture soil behaviour. The concrete damaged plasticity (CDP) model was used to capture the cracking behaviour in the concrete beams, columns and piles. The computed results revealed that the first excavation- induced substantial differential settlement (i.e., tilting) in the adjacent high-rise building while second excavation caused the building tilt back with smaller rate. As a result, the building remains tilted towards the first excavation with final value of tilting of 0.28%. Consequently, the most severe tensile cracking damage at the bottom of two middle columns. At the end of twin excavations, the building load resisted by the raft reduced to half of that the load before the excavations. The reduced load transferred to the piles resulting in increment of the axial load along the entire length of piles.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.14 no.4
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• pp.257-268
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• 2021

As the variety and scale of facilities increase due to industrialization and urbanization, blind spots for facility safety management have occurred, resulting in numerous casualties.To meet safety and security needs of citizens living in smart cities, we present a procedure for establishing an integrated platform for facility safety management by combining 5G and digital twin technologies. It can be used to perform inspection according to risk factors and aging of facilities. In this paper, the current status of facility management and application directions of new 5G digital twin-based smart city technologies are reviewed and digital twin implementation procedures are presented. Five cities were selected as target areas: Osan, Gwangmyeong, Guri, Uijeongbu, and Anyang. Old and emergency facilities of each local government were selected. A total of 33 digital twin facilities reflecting policy directions of each city were selected. Focusing on facilities determined by each city, the purpose of this study was to define information technology infrastructure elements for the application of the 5G digital twin facility safety management integrated platform, define categories of implementation services, and suggest a concrete integrated platform configuration plan.

• Journal of the Korean Geographical Society
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• v.32 no.2
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• pp.155-174
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• 1997

This paper's main objective is to present an assessment of the impact of NAFTA on the economic structure of the Mexican northem borderlands. The NAFTA is the strategy of a free trade agreement with the United States and Canada, first mentioned by Salinas in June 1990 and established since January 1994. Mexican govemment permitted factories called maquiladoras at the northem borderlands for the first time in 1965. in the early 1980s Mexico was in a deep economic crisis and the international environment was adverse to Mexico. Mexico began to move toward an open economy and abandoned the import-substitution industrialization model that characterized Mexico since the 1930s. Through the new economic reform, the market system was preferred to the regulation; the private ownership, to the public ownership; and the competition, to the protection. The most phenomenal urbanization in northem Mexico has occurred around the major crossing points along the Mexico-U.S. border. The rapid urbanization in northern Mexico has been much due to the industrialization, brought about bv the maquiladora programs and, recently, by the NAFTA.