• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.401-408
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• 2019

This study numerically examined the maximum wind pressure distribution of a billboard on the roof of a middle-rise building. The deformation caused by the maximum wind pressure was examined. For the numerical analysis, the signboard was assumed to be installed on $(b)20m{\times}(d)10m{\times}(h)$ buildings. The maximum wind pressure was measured using four models with the standard model and different sizes of the signboard. The numerical analysis showed that the horizontal deformation predominantly occurs as the shape of the signboard becomes closer to a rectangle, and high wind pressure and deformation occur at the corners of both ends. As the height of the signboard increases, vertical deformation predominantly occurs, and static pressure forms on the backside. When the height is lower than the width of the signboard, the wind pressure is concentrated on the center of the roof. Therefore, the distribution of the maximum wind pressure is stable, and the effect of the wind pressure is relatively low as the height-to-width ratio approaches 1.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.11
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• pp.1474-1480
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• 2018

When fires occur in high-rise buildings, it is difficult to determine whether each escape route is safe because of complex structure. Therefore, it is necessary to provide residents with escape routes quickly after determining their safety. We propose a method to measure the visibility of the escape route due to the smoke generated in the fire by analyzing the images. The visibility can be easily measured if the density of smoke detected in the input image is known. However, this approach is difficult to use because there are no suitable methods for measuring smoke density. In this paper, we use principal component analysis by extracting a background image from input images and making it training data. Background images and smoke images are extracted from images given as inputs, and then the learned principal component analysis is applied to map of as a new feature space, and the change is calculated and the visibility due to the smoke is measured.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.2
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• pp.3-11
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• 2018

Korea has achieved a rapid economic development and with the increase in population and national income and the expansion of social and economic activities, energy consumption has rapidly increased too. Energy consumption per head has constantly increased and currently, power consumption per head is 7.5 times bigger than in 1985. Buildings occupy 25% of total energy consumption and especially, 50% of total energy is consumed for heating and cooling. In this situation, multi-family housing, which has constantly been increased, has an energy saving rate of 1.9%, which is the lowest level and this makes the government's energy policy for sustainable energy system development useless. Besides, energy consumption leads to secondary problems, such as air, water and marine pollution and heat pollution and wastewater/drainage and the increased use of fossil fuel is a fundamental reason for ozone layer destruction and global warming. Therefore, efficient energy consumption plans are required. This study aims to analyze energy performance in each block type of high-rise and diversified multi-family housing that accounts for 60% of all the housing forms, depending on the variations in stories through BIM-based energy simulation. For this study, four representative block types were selected, based on the multi-family floor plan, which is certified for energy performance evaluation and they were applied to the floor plan of a multi-family house that is scheduled to be built. Then BIM modeling was conducted from the fifth story to the 40th story at an intervals of 5 stories and based on the finding, energy characteristics of each block type and energy performance depending on the variations in stories were analyzed. It is considered that this would serve as objective data for block type and block story decision of energy performance-based multi-family housing.

• Journal of the Korea Institute of Building Construction
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• v.21 no.1
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• pp.41-49
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• 2021

This study was to solve the lift problem of the existing unit curtain wall type by using the vertical material mullion as a rail in curtain wall, which is recently used as an external finishing material for high-rise buildings. It has been shown that the application of the curtain wall mullion's rail can be quantified even at 20m/sec wind speed through the Mock-Up test. Based on the sites selected for comparison of construction methods, it was analyzed that the construction period could be shortened by 48 days, or about 20 percent. It was analyzed that the number of construction workers could be reduced by about 33 percent from the previous nine to six. Based on these results, assuming the installation of curtain wall units of 10,000㎡, it is judged that construction cost can be reduced by 80% or more.

• Current Photovoltaic Research
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• v.11 no.2
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• pp.49-53
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• 2023

Expanding the supply of BIPV is crucial to strengthening the competitiveness of the photovoltaic industry and achieving Nationally Determined Contributions through the zero-energy building mandatory policy. BIPV is a technology that integrates into the building envelope to generate electricity and provide functions as a building material. It is suitable for domestic environments with many high-rise buildings due to the narrow land area and urbanization. To expand the supply of BIPV, economics, safety, and aesthetics must be ensured. In this study, a color BIPV module with a color PET film applied as a front material was manufactured for aesthetic and economic feasibility. The relationship between power output and transmittance according to color was analyzed. By analyzing the power output of the module and the transmittance of the film, the wavelength band (transmittance reduction band) that has the greatest effect on efficiency was analyzed regarding the color of the film. The red film showed the narrowest transmittance reduction band and the lowest degree of decrease in transmittance, making it ideal for minimizing the efficiency decrease rate compared to existing ones.

• Geomechanics and Engineering
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• v.35 no.6
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• pp.603-615
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• 2023

Population growth and urbanization prompted engineers to propose more sophisticated and efficient transportation methods, such as underground transit systems. However, due to limited urban space, it is necessary to construct these tunnels in close proximity to existing infrastructure like high-rise buildings and bridges. Battered piles have been widely used for their higher stiffness and bearing capacity compared to vertical piles, making them effective in resisting lateral loads from winds, soil pressures, and impacts. Considerable prior research has been concerned with understanding the vertical pile response to tunnel excavation. However, the three-dimensional effects of tunnelling on adjacent battered piled foundations are still not investigated. This study investigates the response of a single battered pile to tunnelling at three critical depths along the pile: near the pile shaft (S), next to the pile (T), and below the pile toe (B). An advanced hypoplastic model capable of capturing small strain stiffness is used to simulate clay behaviour. The computed results reveal that settlement and load transfer mechanisms along the battered pile, resulting from tunnelling, depend significantly on the tunnel's location relative the length of the pile. The largest settlement of the battered pile occurs in the case of T. Conversely, the greatest pile head deflection is caused by tunnelling near the pile shaft. The battered pile experiences "dragload" due to negative skin friction mobilization resulting from tunnel excavation in the case of S. The battered pile is susceptible to induced bending moments when tunnelling occurs near the pile shaft S whereas the magnitude of induced bending moment is minimal in the case of B.

• Journal of the Korean Wood Science and Technology
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• v.52 no.4
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• pp.375-382
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• 2024

The study focuses on evaluating the bending creep performance of laminated veneer lumber (LVL) formwork in timber concrete composite (TCC) structures. Timber-framed construction is highlighted for its environmental benefits and seismic resistance, but limitations such as poor tensile strength and brittle failure in bending hinder its use in high-rise buildings. Wood-concrete hybrid structures, particularly those using reinforced concrete slabs with TCC floors, emerge as a potential solution. The research aims to understand the time-dependent behavior of TCC components, considering factors like wood and concrete shrinkage and connection creep. The experiment was conducted in western Japan on the TCC floor designed for use in the Kama-city Inatsuki-higashi compulsory education school. The LVL formwork, measuring 9,000 mm by 900 mm, and concrete is loaded onto it for testing. The creep test periods are examined using concrete loading. It employs a comprehensive creep analysis, adhering to Japanese standards, involving deflection measurements and regression analysis to estimate the creep coefficient. Results indicate substantial deformation after shoring removal, suggesting potential reinforcement needs. The study recommends extending test periods for improved accuracy and recognizing regional climate impacts. Overall, the research provides valuable insights into the potential of LVL formwork in TCC structures, emphasizing safety considerations and paving the way for further experimentation under varied conditions to validate structural integrity.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.145-154
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• 2007

As buildings are built higher and their service life made longer, face brick walls are also required to be constructed in an easy and systematic manner, and to ensure their satisfying structural performance, inspectingly, against lateral load. Therefore this study aims to investigate the structural performance of face brick walls constructed by a new method using screwed stainless steel connectors and provide fundamental experiment data for field application of this method. The results of this study indicated that the face brick wall tied with screw connectors had better shear capacity against rocking motion than that of the wall constructed with ordinary tie bars when their tie spacing was the same. Based on the good performance of the wall tied with the screw connector, it is also expected that the spiral anchors developed in this study can possibly applied to high-rise by adjusting the spacing of the anchors considering the difference of dimensions.

• Wind and Structures
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• v.39 no.3
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• pp.223-242
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• 2024

Wind comfort in cold climates is one of the most essential factors for urban planners. This issue is particularly important for sidewalks that are in line with the prevailing wind flow and surrounded by high-rise buildings. Imam Street near the University Square in Tabriz is one of the passages that struggle with uncomfortable wind speeds. The aim of this study is to investigate the role of sidewalk walls on pedestrian wind comfort. These multifunctional walls not only serve as street furniture, but also reduce wind speed at pedestrian level. In this work, all simulations are performed using the RWIND tool and validated by wind tunnel experiments at the Architectural Institute of Japan. The main objective of this study is to evaluate the effects of the angle, height and spacing of the walls on wind attenuation at pedestrian level. The results show the effect of multifunctional walls on pedestrian-level wind mitigation. By rotating the windbreak walls from 0 to 60 degrees along the street, the average wind speed decreases by 30% to 46% compared to a situation without this type of wall. Increasing the wall height from 1.5 to 2 meters reduces the urban wind speed by 39-46%. However, increasing the distance between the sidewalk walls from 3.5-9.5 meters reduces the speed in the models from 46% to 32.7%. Finally, it has been demonstrated that sidewalk walls with a height of 2 meters, a rotation angle of 60° and a distance of 3.5 meters are the optimal choice for wind attenuation at pedestrian level.

• Korean Journal of Construction Engineering and Management
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• v.12 no.1
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• pp.43-52
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• 2011

Unnecessary transportation of resources are one of the major causes that adversely affect construction site work productivity. Therefore, layout related studies have been conducted with efforts to develop management technologies and techniques to minimize the resource transportation made at site-level. However, although the necessity for floor-level layout planning studies has been increasing as buildings have become larger and floors have become more complicated, studies to optimize the transportation of materials inside buildings are currently not being actively conducted. Therefore, in this study, a model was developed using genetic algorithms(GA) that will enable the optimization of the locations of finishing materials on the work-floor. With the established model, the arrangement of diverse materials on complicated floors can be planned and the optimized material layout planning derived from the model can minimize the total material transportation time spent by laborers during their working day. In addition, to calculate travel distances between work sites and materials realistically, the concept of actual travel distances was applied. To identify the applicability of the developed model and compare it with existing methodologies and analyze it, the model was applied to actual high-rise residential complexes.