• Journal of the Korean Professional Engineers Association
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• v.10 no.1
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• pp.10-14
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• 1977

In accordance with introducing extra high voltage system, system power plants have to be operated in underexcited condition, which causes temperature rise at the stator end portion of turbine generator. This Paper deals with (1) various elements affecting temperature rise and (2) methods of pre-estimating temperature rise.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.4
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• pp.73-79
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• 2007

In order to analyze the potential rise of grounding systems installed in buildings, a hemispherical grounding simulation system was studied. Potential rise was measured and analyzed regarding the shape and distance of the grounding electrodes by using this system. The system was composed of a hemispherical water tank, AC power supply, a movable potentiometer, and test grounding electrodes. The potential rise was measured in real time by the horizontal moving probe of be potentiometer. The test grounding electrodes were fabricated through reducing the grounding electrode installed in real buildings such as the ground rod, grounding grid and so on. The potential rise was displayed in a two-dimensional profile and was analyzed regarding the shapes of the ground electrodes. The potential rise of the grounding grid combined with a ground rod was the lowest of every grounding electrode tested. The proposed results can be applicable to evaluating ground potential rise in grounding systems, and the analytical data can be used to stabilize the electrical installations and prevent electrical disasters.

• Architectural research
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• v.17 no.2
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• pp.49-56
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• 2015

For more than 100 years, American skyscrapers got along with the change of Modern architecture. However, high-rise building can not be regarded anymore as a monopoly of America. The purpose of this study is to clarify the aesthetic characteristics of Asian high-rise buildings. Basic concepts on the aesthetic and artistic expression of high-rise building have been discussed, emphasizing the importance of artistic characteristic. A brief introduction on the rise of Asian high-rise buildings also summarized in terms of changing trends for decades from 1970s. Among the 75 buildings in Asian countries out of 100 tallest buildings in the world, 10 buildings are selected to clarify the artistic characteristics which can be presented as an Asian trend in 21st century. The results can be summarized as follows; It was from 1990s that the Asian high-rise buildings began to express a specific regional aesthetics as a trend of post-modernism. Conventional ideas, traditional objects, and regional shapes and patterns are good instruments to successfully represent their national prides. Religions in Chinese and Islamic culture are popular motifs in Asian countries as well as feng shui and conventional idea of five primary elements. Traditional objects like pagoda and minaret are good precedents that can provide friendly recognized vertical objects. Many other interesting cases can be found referring to the traditional shapes and patterns like Chinese character, geometric pattern, Islamic sign, etc.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.4
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• pp.121-129
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• 2001

The semi-adiabatic temperature rise and the losses of temperature of cement paste, mortar and concrete were measured by an apparatus of semi-adiabatic temperature. Heat of hydration was measured by a conduction calorimeter and adiabatic temperature rise of concrete was measured by an adiabatic calorimeter. The derived equation which can assume the adiabatic temperature was proposed by measuring the semi-adiabatic temperature of concrete. The maximum adiabatic temperature rise of concrete obtained by the derived equation of adiabatic temperature, $T_{ad}(t)=T_{sad}(t)+T_{dis}(t)$, showed $55^{\circ}C$ approximately and it had good relation with the other one obtained by the heat of hydration of cement paste and with maximum value which was measured by the adiabatic calorimeter. The adiabatic temperature rise obtained by derived equation was a different information in comparison with the value obtained by adiabatic temperature rise equations by Hell and et. al. in early age, but it showed similar tendencies with the other one according to elapsed time. Adiabatic temperature rise of lich mix concrete with highly cement content was predicted. The adiabatic temperature rise of cement paste and mortar obtained by derived equation from us showed comparatively matching results to compared with that of obtained by adiabatic temperature equation from concrete standard specification.

• Smart Structures and Systems
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• v.29 no.4
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• pp.641-652
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• 2022

High-rise structures prone to large vibrations under the action of strong winds, resulting in fatigue damage of the structural components and the foundation. A novel compound damping cable system (CDCS) is proposed to suppress the excessive vibrations. CDCS uses tailored double cable system with increased tensile stiffness as the connecting device, and makes use of the relative motion between the high-rise structure and the ground to drive the damper to move back-and-forth, dissipating the vibration mechanical energy of the high-rise structure so as to decaying the excessive vibration. Firstly, a third-order differential equation for the free vibration of high-rise structure with CDCS is established, and its closed form solution is obtained by the root formulas of cubic equation (Shengjin's formulas). Secondly, the analytical solution is validated by a laboratory model experiment. Thirdly, parametric analysis is conducted to investigate how the parameters affect the vibration control performance. Finally, the dynamic responses of the high-rise structure with CDCS under harmonic and stochastic excitations are calculated and its vibration mitigation performance is further evaluated. The results show that the CDCS can provide a large equivalent additional damping ratio for the vibrating structures, thus suppressing the excessive vibration effectively. It is anticipated that the CDCS can be used as a good alternative energy dissipation system for vibration control of high-rise structures.

• International Journal of High-Rise Buildings
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• v.11 no.2
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• pp.75-86
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• 2022

High-rise buildings often can accommodate the population of small horizontal cities. The investment in high-rise buildings is considerable and therefore a rapid return on investment is necessary. The immediate availability of high-rise buildings can be achieved by automated prefabrication of highly finished modules and their instant on-site assembly by robotic and automated construction sites. A high-rise building as a vertical city can be considered as a sophisticated organism that can constantly change throughout its lifecycle in response to economic growth, demographic change, and environmental pressures. To date, many new urban high-rise developments claim to be "vertical cities", yet few represent this important characteristic. This article analyzed the technological readiness and innovations in the field of construction automation and robotics including single-task construction robots, automated on-site construction factories, and ambient assisted living. These technological advances enable the realization of future vertical cities that are able to continuously grow and transform in terms of form and function. Finally, the article proposes a visionary archetype of vertical city in the name of "dynamic vertical urbanism" that is easy to expand vertically and horizontally in order to achieve instant availability and full life cycle resilience thanks to advanced building technologies.

• International Journal of High-Rise Buildings
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• v.12 no.2
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• pp.163-168
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• 2023

Today 55 percent of the population in the world lives in urban areas which is expected to increase to 68 percent by the year 2050. In the cities, high-rise buildings as symbols of the modern cityscape are dominating the skylines, but the data to demonstrate their embodied energy and environmental impacts are scarce, compared to low- or mid-rise buildings. Reducing the embodied energy and environmental impacts of buildings is critical as about 42 percent of primary energy use and 39 percent of the global greenhouse gas (GHG) emissions come from the building sector. However, it is an overlooked area in embodied energy and environmental impacts of high-rise buildings. Life cycle assessment (LCA) is a widely used tool to quantify the embodied energy and environmental impacts of the building sector. LCA combined with Building Information Modeling (BIM) can simplify data acquisition of the building as well as provide both tools with feedback. Several studies recognize that the integration of BIM and LCA can simplify data acquisition of the building as well as provide tools with feedback. This article provides an overview of literature on BIM-based of embodied energy and environmental impacts of high-rise buildings. It also compares with different LCA methodologies. Finally, major strategies to reduce embodied energy and environmental impacts of high-rise buildings, research limitations and trends in the field are covered.

• Wind and Structures
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• v.36 no.6
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• pp.379-392
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• 2023

Structural health monitoring is used to ensure the well-being of civil structures by detecting damage and estimating deterioration. Wind flow applies external loads to high-rise buildings, with the horizontal force component of the wind causing structural displacements in high-rise buildings. This study proposes a deep learning-based predictive model for measuring lateral displacement response in high-rise buildings. The proposed long short-term memory model functions as a sequence generator to generate displacements on building floors depending on the displacement statistics collected on the top floor. The model was trained with wind-induced displacement data for the top floor of a high-rise building as input. The outcomes demonstrate that the model can forecast wind-induced displacement on the remaining floors of a building. Further, displacement was predicted for each floor of the high-rise buildings at wind flow angles of 0° and 45°. The proposed model accurately predicted a high-rise building model's story drift and lateral displacement. The outcomes of this proposed work are anticipated to serve as a guide for assessing the overall lateral displacement of high-rise buildings.

• Journal of Korean Association for Spatial Structures
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• v.23 no.1
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• pp.35-43
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• 2023

Microclimate analysis was conducted through actual measurement according to land use status in urban, and CFD analysis was conducted to analyze and predict the microclimate characteristics of urban, and compared and analyzed with the actual measurement results. It was measured in high-rise areas and parks, and the temperature of the park area was 0.4 to 0.6℃ lower, and the relative humidity was 1.0 to 3.0% higher. The correlation coefficient was obtained by comparing the results of the computational fluid analysis with the results of the computational fluid analysis at the actual location located within the CFD analysis area for validation. The seasonal correlation coefficients are all higher than 0.8, so it is judged that they can be applied to microclimate analysis in urban area. The computational fluid analysis was divided into three areas (low-rise, low and high-rise, and high-rise) centered on the A2 point. On average, the low-rise area was 0.1 to 0.4% higher than the high-rise area. In the low and high-rise area and high-rise area, the pith of buildings are wide, so the airflow is smooth, so it is judged that the temperature is relatively low.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2006.11a
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• pp.306-309
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• 2006

The architectural difference between the existing residence and high-rise residential building causes changes on environmental conditions such as ventilation and insulation. The object of this study is to present the improvement on envelop of high-rise residential buildings to reduce heating and cooling load. To improve the environmental performance of envelop, it is necessary to modify envelop vent system and ensure intermediate space. In this study, the shape of vents in high-rise residential buildings has been inspected, and the survey about the interior environmental conditions related to the envelop of high-rise residential building has been conducted. Environmental measurement has been done to examine out door air quality for natural ventilation.