• Journal of the Korea Concrete Institute
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• v.23 no.3
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• pp.385-392
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• 2011

In this study, experimental research was carried out to evaluate and improve the seismic performance of reinforced concrete beam-column joint regions using strengthening materials (steel plate, carbon fiber sheet, and embedded carbon fiber rod) in existing reinforced concrete buildings. Six specimens of retrofitted beam-column joints are constructed using various retrofitting materials and tested for their retrofit performances. Specimens designed by retrofitting the beam-column joint regions (LBCJ series) of existing reinforced concrete building showed a stable mode of failure and an increase in load-carrying capacity due to the effect of crack control at the time of initial loading and confinement from retrofitting materials during testing. Specimens of LBCJ series, designed by the retrofitting of FRP in reinforecd beam-column joint regions increased its maximum load carrying capacity by 26~50% and its energy dissipation capacity by 13.0~14.4% when compared to standard specimen of LBCJC with a displacement ductility of 4.

• Fire Science and Engineering
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• v.33 no.6
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• pp.53-62
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• 2019

A recent trend shows that more buildings are being constructed as mixed-use (residential and commercial) properties for efficient land use. This has led to an increased frequency in the occurrence of fires and the associated potential risks. In particular, in case of high-rise apartments, at least one of the elevators in each building is installed for evacuation purposes separately from the emergency elevator; therefore, for a combined ancillary room and emergency elevator platform situation, the structure is inevitably in series with the evacuation elevator platform. Thus, a proposal for a new type of ventilation zone based on existing national fire safety codes is required to achieve smoke control performance. To this end, the air egress velocity and differential pressure of each ventilation zone are checked using the "CONTAM" software; further, an alternative is proposed to secure smoke control performance for series structures.

• Korean Institute of Interior Design Journal
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• no.14
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• pp.82-89
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• 1998

During the boom of museum building in the 1970s-80s two museum wee erected in Germany. They are James Stirling's Neue Stattsgalerie Stuttgart and hans Hollein's Stadtisches Museum Abteiberg Monchengladbach, These two museums share the folowing point of similarity : Stirling's Neue Stattsgalerie Stuttgart and Hollein's Staditisches Museum Abetiberg Monchenbladbach both manifest the conditions of the times in light of their respective cities' local characters and historical contexts without being bound to traditional formality. Stirling and Hollein attempted to grasp the meaning of the 기nuseum as a city in miniature." Taking into account the t two museums’s territorial characteristics of being situated on a slope, both Stirling and Hollein made the walker to pass t through their building complex and introduced the concept of a public square within them. As a result, the museums are not j just two large buildings but are architecture composed of a collage of various structures. S Stirling’s architecture employs the method of attaching additional elements on top of basic constituents, which is suggestive '||'&'||'#61551; of the historical fragment from Shinkel's Altes Museum. On the other hand, Hollein applies a collage-style method as if he w were doing urban planning, maintaining the distinctiveness of each of the various forms and materials of buildings. T The object style buildings of the two museums actively demonstrate the contrast of double meaning to represent the a ambiguous and multifarious characteristics of the modern times. Stirling explores the theme of opposition and coexistence in h his Neue Stattsgalerie Stuttgart by placing a series of opposing concepts, such as the past and present and histor${\gamma}$ and t technology, in one space. Thereby, the contradiction and its appeal are manifested. Hollein made use of the visual illusion and c contradiction in alluding to the irony of the modern reality induced by nature and culture and history and technology. F For the above reasons and methods, James Stirling ’ s Neue Stattsgalerie Stuttgart allowed the penetration of art into daily l life and became the general public’s favored museum for its free and unrestrained environment. Likewise, Hans Hollein’s S Stadtisches Museum Abteiberg Moncbengladbach contribute to the development of museum function as it an expression of art i in the form of a complex piece of scupture on its own.ts own.

• Journal of the Korea Convergence Society
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• v.11 no.10
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• pp.9-18
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• 2020

The purpose of this study is to suggest a method of predicting seismic vulnerability and safety conditions of each building in a targeted area. The scope of this study includes 'developing a simulation model for precaution activities,' 'testing the validity of the developed model', From the facility point of view, target of this study is a local building system. According to the literature review, the number of earthquake prediction modeling and cases with GIS applied is extremely few and the results are not proficient. This study is conducted as a way to improve the previous researches. Statistic analyses are conducted using 348 domestic and international data. Finally, as a result of the series of statistical analyses, an adequate model is developed using optimization scale method. The ratio of correct expectation is estimated as 87%. In order to apply the developed model to predict the vulnerability of the several chosen local building systems, spatial analysis technique is applied. Gangnam-gu and Jongro-gu are selected as the target areas to represent the characteristics of the old and the new downtown in Seoul. As a result of the analysis, it is discovered that buildings in Gangnam-gu are relatively more dangerous comparing to those of Jongro-gu and Eunpyeong-gu.

• Journal of the Korea Concrete Institute
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• v.24 no.6
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• pp.667-675
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• 2012

Flat plate are being used more in buildings requiring a high level of technical installations or in buildings needing changeable room arrangements during their life time such as office buildings. The main problem in flat plate is its weak resistance against a punching failure at its slab-column connections. Therefore, in this research, an experimental study on full-scale interior slab-column connection was performed. Three types of shear reinforcements were tested to prevent brittle punching shear failure that could lead to collapse of the structure. A series of four flat plate specimens including a specimen without shear reinforcement and three specimens with shear reinforcements were tested. The slabs were tested up to failure using monotonic vertical shear loading. The presences of the shear reinforcements substantially increased punching shear capacity and ductility of the interior slabcolumn connections. The test results showed that a slab that did not have enough bond length failed before shear reinforcement yielded due to anchorage slip. Also, FEM analyses were performed to study an effect of slab thickness and concrete compressive strength on the flat plate slab. The analytical study results were used to propose a method to calculate performance capacity of shear reinforcement in slab-column connection.

• Smart Media Journal
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• v.13 no.7
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• pp.9-17
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• 2024

Due to the increase in energy consumption, and eco-friendly policies, there is a need for efficient energy consumption in buildings. Anomaly power detection based on deep learning are being used. Because of the difficulty in collecting anomaly data, anomaly detection is performed using reconstruction error with a Recurrent Neural Network(RNN) based autoencoder. However, there are some limitations such as the long time required to fully learn temporal features and its sensitivity to noise in the train data. To overcome these limitations, this paper proposes the TCN-USAD, combined with Temporal Convolution Network(TCN) and UnSupervised Anomaly Detection for multivariate data(USAD). The proposed model using TCN-based autoencoder and the USAD structure, which uses two decoders and adversarial training, to quickly learn temporal features and enable robust anomaly detection. To validate the performance of TCN-USAD, comparative experiments were performed using two building energy datasets. The results showed that the TCN-based autoencoder can perform faster and better reconstruction than RNN-based autoencoder. Furthermore, TCN-USAD achieved 20% improved F1-Score over other anomaly detection models, demonstrating excellent anomaly detection performance.

• Earthquakes and Structures
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• v.1 no.3
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• pp.269-287
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• 2010

High-strength concrete (HSC) is becoming more popular in the construction of beams and columns of tall buildings because of its higher stiffness and strength-to-weight ratio. However, as HSC is more brittle than normal-strength concrete (NSC), it may adversely affect the flexural ductility and deformability of concrete members. Extended from a series of theoretical study conducted on flexural ductility of concrete beams, the authors would in this paper investigate the effects of some critical factors including the degree of reinforcement, confining pressure, concrete and steel yield strength on the flexural deformability of NSC and HSC beams. The deformability, expressed herein in terms of normalised rotation capacity defined as the product of ultimate curvature and effective depth, is investigated by a parametric study using nonlinear moment-curvature analysis. From the results, it is evident that the deformability of concrete beams increases as the degree of reinforcement decreases and/or confining pressure increases. However, the effects of concrete and steel yield strength are more complicated and dependent on other factors. Quantitative analysis of all these effects on deformability of beams has been carried out and formulas for direct deformability evaluation are developed. Lastly, the proposed formulas are compared with available test results to verify its applicability.

• Geomechanics and Engineering
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• v.23 no.2
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• pp.103-113
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• 2020

Gypsiferous soils classified as problematic soils due to the dissolution of gypsum. Presence of gypsum in the soils texture subjected to steady flow can cause serious damages for the buildings, roads and water transmission canals. Therefore, researchers have conducted a series of physical, mechanical and microstructural laboratory tests to study the effect of gypsum leaching on the geotechnical properties of a lean clay containing 0%, 3%, 6%, 9%, 12%, and 15% raw gypsum. In addition, a combination of two nano-chemical stabilizers named Terrasil and Zycobond was used in equal proportions to stabilize the gypsiferous clayey samples. The results indicated that gypsum leaching considerably changed the physical and mechanical properties of gypsiferous soils. Further, adding the combination of Terrasil and Zycobond nano-polymeric stabilizers to the gypsiferous soil led to a remarkable reduction in the settlement drop, compressibility, and electrical conductivity (EC) of the water passing through the specimens, resulting in improving the engineering properties of the soil samples. The X-ray diffraction patterns indicate that stabilization by terrasil and zycobond causes formation of new peaks such as CSH and alteration of pure soil structure by adding raw gypsum. Scanning electron microscope (SEM) images show the denser texture of the soil samples due to chemical stabilization and decrease of Si/Al ratio which indicates by Energy dispersive X-ray (EDS) interpretation, proved the enhance of shear strength in stabilized samples.

• International Journal of Air-Conditioning and Refrigeration
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• v.16 no.1
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• pp.15-21
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• 2008

Air-cooled split-type air conditioners (AC) are very popular in high-rise residential and commercial buildings in Korea. The performance of such AC systems varies significantly with system characteristics and environmental conditions. Particularly, the outdoor condensing unit of the system, if poorly cooled due to high density of AC distribution and restricted outdoor space, will result in large decrease of cooling efficiency and increase of electrical energy consumption and may further jeopardize the system reliability. This paper presents a numerical analysis on the thermal and energy performance of a group of air-cooled air conditioners installed at a courtyard of a high-rise building. The study introduces a series of new energy performance indices to assess the group performance of the AC condensers with different outdoor unit layouts. The results not only indicate the COP of the systems, but also quantify the system capacity and energy consumption. The evaluation method and indices developed are useful for guiding the design of the distribution plan of the AC units at building re-entrants.

• Wind and Structures
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• v.24 no.2
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• pp.145-169
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• 2017

The auxiliary structures of a high-rise building, such as balconies, ribs, and grids, are usually much smaller than the whole building; therefore, it is difficult to simulate them on a scaled model during wind tunnel tests, and they are often ignored. However, they may have notable effects on the local or overall wind loads of the building. In the present study, a series of wind pressure wind tunnel tests and high-frequency force balance (HFFB) wind tunnel tests were conducted on rigid models of an actual super high-rise building with vertical ribs protruding from its facades. The effects of the depth and spacing of vertical ribs on the mean values, fluctuating values and the most unfavorable values of the local wind pressure coefficients were investigated by analyzing the distribution of wind pressure coefficients on the facades and the variations of the wind pressure coefficients at the cross section at 2/3 of the building height versus wind direction angle. In addition, the effects of the depth and spacing of vertical ribs on the mean values, fluctuating values and power spectra of the overall aerodynamic force coefficients were studied by analyzing the aerodynamic base moment coefficients. The results show that vertical ribs significantly decrease the most unfavorable suction coefficients in the corner recession regions and edge regions of facades and increase the mean and fluctuating along-wind overall aerodynamic forces.