• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.41-44
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• 2005

Three precast concrete beam-column connectors for the high-rise office buildings were considered to investigate the prestressing effects of the DDC(Dywidag Ductile Connectors) of Germany and of the modified DDC. The specimens of DDC, DDC with post-tensioning and modified DDC with post-tensioning were constructed and tested to verify the safety. The DDC with and without post-tensioning showed reliable joint strength and ductility but failed in critical x-shape crackings at the column. The modified one showed better behaviors in tests because they did not show critical column crackings at failure. The use of prestressing did not helpful significantly to increase the strength and ductility of connectors but helpful only to develop self-centering behavior for stability.

• International Journal of High-Rise Buildings
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• v.7 no.1
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• pp.65-73
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• 2018

Increasingly, mixed-use, multi-program complexes are emerging as the standard development model around the world. As their prominence grows, these projects are becoming increasingly complex. Program adjacencies are ever more intertwined as developers (and the architects who support them) are becoming more comfortable blurring the traditional boundaries between office, retail, residential and hospitality. This article discusses a second generation of mixed-use projects that embrace this hybridization, honing in on supertall architecture, their hybrid program offerings, and innovative sky lobbies. It concludes that programmatic advancements will continue to expand and find integration within single structures, both repositioned and built from the ground up.

• International Journal of High-Rise Buildings
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• v.6 no.4
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• pp.323-326
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• 2017

Sustainability is becoming more and more important in our everyday lives. Thus, it is apparent that more sustainable initiatives are incorporated in a building design concept to reduce operation costs and environmental impacts. However, will the construction cost go up if the building is going green - especially if it is a tall building? This is the question on everyone's mind. In the following paragraphs, we will look into a case study of a skyscraper in Nanning, China. That 411-metre skyscraper, Nanning China Resources Centre East Office Tower, is currently under construction. Designed to LEED-CS Gold standards, the building has adopted a number of sustainable design elements and operation practice, which indeed only accounts for a small percentage of the total construction cost.

• Journal of architectural history
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• v.27 no.2
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• pp.51-62
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• 2018

This study examines the site and erection of the Government Complex Seoul which was a project attempted to assemble dispersed government buildings in a certain place. The study focuses on the fact that the project is situated between the 1960s' making of capital Seoul and Seoul urban planning, and the way how the project achieved symbolism in capital Seoul. The project, one of the 1960s' Major Government Buildings, led both plan of capital Seoul and transforming city Seoul. The 1960s' Major Government Building Plan had identical drive with the 1950's Major Government Building Plan, however the 1960s' had additional layer: Seoul urban planning. After restoration of the Capital building, Sejongro the capital street was planned to the site arranging government offices. The Government Complex Seoul was set to be a modern building on a site with historical context according to the plan. Because of the site, the Government Complex Seoul was constructed in aware of other buildings that represented a competitive high-rise atmosphere in the late 1960s, including the Capital building nearby. PAE International's plan was completed through a series of design modification, and it boasted a vertical aspect, unlike the horizontal-looking plan that was already won after the design competition. The Government Complex Seoul tried to acquire the symbolism in the central space of the capital Seoul and high-rised city Seoul. "The new construction method" was a requirement to achieve the height.

• International Journal of High-Rise Buildings
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• v.8 no.3
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• pp.177-183
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• 2019

This paper describes the structural design of a 212 m tall building currently under construction in the Tokiwabashi District Redevelopment Project facing Tokyo Station. In this project there was a requirement to rationally solve many issues arising from the conditions of the redevelopment project. In particular, the following two points were considered to be important from the point of view of structural design. 1) To provide an overhang frame with the perimeter columns on the lower stories inclined, in order to enable a typical floor area that greatly exceeded the limitations of the underground structure shape. 2) To provide high grade seismic performance for the office buildings to be constructed on prime city center land. LSCVCS (Lower Stories Concentrated Vibration Control System) was proposed as the method of rationally designing the overhang frame, which is an extremely disadvantageous element in the structural scheme of the tall building with a large slenderness ratio. LSCVCS is a system to provide effective damping by arranging vibration control devices in a concentrated manner in a lower story with large story height, that produces large deformation in an earthquake. Also, the vibration control devices arranged in the lower story are limited to viscous devices, to take into consideration the residual deformation of the overhang frame after an earthquake. The results of investigations into the specific effects of the system for the seismic design are reported, including Performance-based seismic design.

• International Journal of High-Rise Buildings
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• v.6 no.3
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• pp.227-235
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• 2017

This paper describes some of the challenges for structural design of a mid-story seismic isolated high-rise building, which is located near Tokyo station, completed in 2015. The building is a mixed-use complex and encompasses three volumes: one substructure including basement and lower floors, and a pair of seismic isolated superstructures on the substructure. One is a 136.5m high Main Tower (office use), and the other is a 98.5 m high South Tower (hotel use). The seismic isolation systems are arranged in the $3^{rd}$ floor of the Main Tower and $5^{th}$ floor of the South Tower, so that we call this isolation system as the mid-story seismic isolation. The primary goal of the structural design of this building was to secure high seismic safety against the largest earthquake expected in Tokyo. We adopted optimal seismic isolation equipment simulated by dynamic analysis to minimize building damage. On the other hand, wind-induced vibration of a seismic isolated high-rise building tends to be excited. To reduce the vibration, the following strategies were adopted respectively. In the Main Tower with a large wind receiving area, we adopted a mechanism that locks oil dampers at the isolation level during strong wind. In the South Tower, two tuned mass dampers (TMDs) are installed at the top of the building to control the vibration. In addition, our paper will also report the building performance evaluated for wind and seismic observation after completion of the building. In 2016, an earthquake of seismic intensity 3 (JMA scale) occurred twice in Tokyo. The acceleration reduction rate of the seismic isolation level due to these earthquakes was approximately 30 to 60%. These are also verified by dynamic analysis using observed acceleration data. Also, in April 2016, a strong wind exceeding the speed of 25m/s occurred in Tokyo. On the basis of the record at the strong wind, we confirmed that the locking mechanism of oil damper worked as designed.

• Atmosphere
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• v.29 no.2
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• pp.183-196
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• 2019

High-quality and high-resolution meteorological information is essential to reduce damages due to disastrous weather phenomena such as flash flood, strong wind, and heat/cold waves. There are many meteorological observation stations operated by Korea Meteorological Administration (KMA) in Seoul Metropolitan Area (SMA). Nonetheless, they are still not enough to represent small-scale weather phenomena like convective storm cells due to its poor resolution, especially over urban areas with high-rise buildings and complex land use. In this study, feasibilities to use additional pre-existing networks (e.g., operated by local government and private company) are tested by investigating the effects of network density on the gridded horizontal distribution of two meteorological variables (temperature and precipitation). Two heat wave event days and two precipitation events are chosen, respectively. And the automatic weather station (AWS) networks operated by KMA, local-government, and SKTechX in Incheon area are used. It is found that as network density increases, correlation coefficients between the interpolated values with a horizontal resolution of 350 m and observed data also become large. The range of correlation coefficients with respect to the network density shows large in nighttime rather than in daytime for temperature. While, the range does not depend on the time of day, but on the precipitation type and horizontal distribution of convection cells. This study suggests that temperature and precipitation sensors should be added at points with large horizontal inhomogeneity of land use or topography to represent the horizontal features with a resolution higher than 350 m.

• International Journal of High-Rise Buildings
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• v.4 no.1
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• pp.9-25
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• 2015

Field measurements of various structures have been conducted for many purposes. Measurement data obtained by field measurement is very useful to determine vibration characteristics including dynamic characteristics such as the damping ratio, natural frequency, and mode shape of a structure. In addition, results of field measurements and modal identification can be used for modal updating of FEM analysis, for checking the efficiency of damping devices and so on. This paper shows some examples of field measurements and modal identification for structural health monitoring. As the first example, changes of dynamic characteristics of a 15-story office building in four construction stages from the foundation stage to completion are described. The dynamic characteristics of each construction stage were modeled as accurately as possible by FEM, and the stiffness of the main structural frame was evaluated and the FEM results were compared with measurements performed on non-load-bearing elements. Simple FEM modal updating was also applied. As the next example, full-scale measurements were also carried out on a high-rise chimney, and the efficiency of the tuned mass damper was investigated by using two kinds of modal identification techniques. Good correspondence was shown with vibration characteristics obtained by the 2DOF-RD technique and the Frequency Domain Decomposition method. As the last example, the wind-induced response using RTK-GPS and the feasibility of hybrid use of FEM analysis and RTK-GPS for confirming the integrity of structures during strong typhoons were shown. The member stresses obtained by hybrid use of FEM analysis and RTK-GPS were close to the member stresses measured by strain gauges.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.103-111
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• 2007

Since the 1980's the school of Busan metropolitan city has been converted into the other land-use such as high-rise apartment houses, commercial and office buildings. School facilities are available to locate in green area due to not restricted by land use zone. And the location of school facilities were closely related with the school district, distribution of neighborhood unit, safety of students, and so on. The purpose of this study is to understand the location characteristic of school - moved sites in Busan metropolitan city.

• International Journal of High-Rise Buildings
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• v.9 no.2
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• pp.197-212
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• 2020

In this study, POE(Post Occupancy Evaluation) evaluation indexes were selected into six categories through the consideration of theories and prior research. Therefore, qualitative supply can be achieved through POE according to the aspect of residential environment after the quantitative supply of mixed-use apartment complex by the population concentration in Seoul due to industrialization and urbanization. As the evaluation elements, detailed survey contents were selected for livability, convenience, comfort, safety, economy, and sociality. Based on the survey contents, six elements were evaluated and analyzed using Data coding and Likert scale after surveying 12 complexes (Urban areas and non-urban areas) in Seoul. As a result of the study, six categories selected as the POE showed that importance of quality of life and safety was developed in high recognition according to high satisfaction with convenience and safety. Sociality showed the lowest satisfaction in the following order : livability, comfort, economy and sociality. Residents' sense of community, interaction with neighborhood, etc., showed low satisfaction, and it seems that it is necessary to improve and supplement the system for the development of mixed-use apartment complex in the future. The detailed characteristics of livability showed high satisfaction of the living room, the front door and the main room which are main uses of housing, and low satisfaction in storage size. The analysis of convenience is that convenient public transportation was the highest, and educational environment and additional facilities were the lowest, showing the advantages and disadvantages of location characteristics. As a result of the analysis of comfort, satisfaction with the landscape area was low and it seems that green space is needed for the development of mixed-use apartment complex in the future. Lastly, regarding the safety, the satisfaction of the access control, the location of security office, etc. were high, however separation of circulation was low. Therefore, it is necessary to clearly separate the circulation between the residence and other facilities in the mixed-use apartment complex.