• International Journal of High-Rise Buildings
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• v.10 no.4
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• pp.335-344
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• 2021

In structural engineering practice, understanding the performance of composite columns under extreme loading conditions such as high-rise bulding, long span and heavy loads is essential to accuratly predicting of material responses under severe loads such as fires or earthquakes. Hitherto, the combined effect of partial axial loads and subsequent elevated temperatures on the performance of hollow steel column filled fly ash concrete have not been widely investigated. Comprehensive test was carried out to investigate the effect of elevated temperatures on partial axially loaded square hollow steel column filled fly ash concrete as reported in this paper. Four batches of hollow steel column filled fly ash concrete ( 30 percent replacement of fly ash), (HySC) and normal concrete (CFHS) were subjected to four different load levels, n_f of 20%, 30%, 40% and 50% based on ultimate column strength. Subsequently, all batches of the partially damage composite columns were exposed to transient elevated temperature up to 250℃, 450℃ and 650℃ for one hour. The overall stress - strain relationship for both types of composited columns with different concrete fillers were presented for each different partial load levels and elevated temperature exposure. Results show that CFHS column has better performance than HySC at ambient temperature with 1.03 relative difference. However, the residual ultimate compressive strength of HySC subjected to partial axial load and elevated temperature exposure present an improvement compared to CFHS column with percentage difference in range 1.9% to 18.3%. Most of HySC and CFHS column specimens failed due to local buckling at the top and middle section of the column caused by concrete crushing. The columns failed due to global buckling after prolong compression load. After the compression load was lengthened, the columns were found to fail due to global buckling except for HySC02.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.3
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• pp.45-52
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• 2018

Currently, apartments have become an important research subject for the overall area of politics, economics, and culture as well as urban architectural study. However, there are few analyses of the research trends related to the current interest in the apartment research and prediction of the future changes of an apartment in politics and industry. In this study, the research information related to the apartment has classified, and the changes in the research trends have analyzed. Based on the classified data, the first thesis and dissertation related to the apartment and changes of academic notation have discovered. In addition, future interests and future research directions through Frequency of Appearance, Degree Centrality Analysis, and Betweenness Centrality Analysis of author keywords were predicted. As a result of the analysis, 'Space,' 'Residential Mobility' and 'Apartment Complex' studies were found to be important research topics throughout the entire period. 'Han Gang Apartment,' 'Small Size Apartment,' 'Civic Apartments,' 'Jamsil,' and 'Child' were newly interested topics until 70's era. '(Super) High-rise Apartment,' 'Perception,' 'Jugong Apartment,' 'Housing Environment,' 'Housewife,' 'Apartment Layout,' and 'Busan' were newly interested topics during the 80's and 90's era. 'Apartment Price,' 'Energy,' 'Remodeling,' 'Noise,' 'Resident Satisfaction,' 'Community,' and 'Apartment Lotting-out' were newly interested topics after the year 2000. New concerns for last decade are found to be 'Super High-rise Apartment', 'Remodeling', 'Indoor'(2007), 'Apartment Reconstruction Project', 'Brand', 'AHP', 'Housing Environment'(2008), 'Ventilation'(2009), 'Apartment Lotting-out'(2010), 'Economic Assessment'(2011), 'Cost'(2012), 'Green Building', 'Apartment Sales', 'Law', 'Society'(2013), 'Floor Impact Noise', 'Seoul'(2014), 'Noise'(2015), 'Hedonic Model'(2016). In addition, following research topics are expected to be active in the future: In maturity stage of the research development is going to be 'Apartment Price', 'Space', 'Management of Apartment Housing'; the hedonic model, which is research growth and development stage, is going to be '(Floor Impact) Noise', 'Community', 'Energy.

• Fire Science and Engineering
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• v.30 no.2
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• pp.1-6
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• 2016

We are living in the 21st century, a new era of high-technology. Due to movements in population towards certain preferred areas, caused by material and technological advancement, growth has occurredn beyond the metropolis, leading to the development of the so-calleda "megalopolis." This development has changed the culture of housing, notably the characteristics of high-rise buildings, and underground facilities (such as subways and shopping centers), and has generally enlarged the scale of the facilities. Due to the increase in the number of single-family households, - notably ones including only the nuclear family, there has been a growing overpopulation problem, with apartments and urban housing developments expanding at rates beyond institutional safety regulations. In this study, we analyze the phenomenon of fire spreading in apartment buildings through actual apartment fire case studies, including that of the MunjonPonpuri apartment building. It was found that the speed at which the fire spreads is lower in apartments without than in those with an extended balcony. Based on the findings from case studies and the test results, we propose a series of safety countermeasures and responses for apartment fires.

• Korean Institute of Interior Design Journal
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• v.14 no.2 s.49
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• pp.112-119
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• 2005

This study attempts to suggest new directions of urban multi-family housing design in the recent era of information, in which the representation of publicity and privacy of the housing reflects new meanings and relationships of the current digital society. The study examines cases of Dutch multi-family housing and investigates the meanings and relationships of publicity and privacy in the building as well as unit design of the housings. Borneo-Sporenburg housing development is a good example that suggests new interpretation and design solution for low-rise, high-density multi-family housing. Thus, this study analyzes street patterns, facade design, and ways of housing unit combination in Borneo-Sporenburg housing and concludes as follows. First, public space in Borneo-Sporenburg housing, which was designed differently from hierarchical and centripetal organization of modern architecture, is divided into small units and spread into the inside, which provides high potential for personal control of space and personal programming of space by space choices. Second, street pattern and facade design of Borneo-Sporenburg housing provide visual publicity and privacy simultaneously as they maintain unity as a whole as well as articulate individual unit in many different ways and provide clues to neighboring. Streets as a public domain have self-controlled boundaries for residents and introduce voluntary use-programs for residents. Third, facades of the housing have no inter-mediate space or common space, and confront streets directly. Space in-between is composed inside the facade and extends into the streets by residents' own choices. Fourth, privacy and individuality of the housing is strengthened. Units of the housing have individual entrances, unique plan type and complicated combination of space that all together emphasize individuality of units, however they are not often notified from the outside.

• Korean Journal of Construction Engineering and Management
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• v.13 no.2
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• pp.25-36
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• 2012

As the international construction market is rapidly expanding, Korean contractors have the need for having new leading businesses for their sustainable growth and high performance. Thus, this research tried to explore new leading businesses with two questions: 'What can be the new leading businesses?' and 'How can Korean contractors implement new leading businesses?' To this end, based on Porter's five forces framework and the resource-based view (RBV), we first derive three evaluation criteria (possibility of market entry, possibility of profit earning, and possibility of value-added earning). Next, we developed a framework for business evaluation which considers external market condition, internal competitiveness, and spin-off effects toward domestic market. Based on the framework, we defined green-energy plant, environmental plant, desalination plant, nuclear power plant, new urban development, and high-rise building as new leading business. Then, we selected green energy plant, environmental plant, and new urban development for the purpose of prior occupation of the market, consolidation of the competitiveness, and expansion of the ripple effect, respectively. Finally, we deduced market entry strategies for each business by investigating experts' opinions.

• Architectural research
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• v.14 no.4
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• pp.125-132
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• 2012

In contemporary Korean society, urban community environment is often associated with high-density and high-rise residences that make people's relationships superficial, instrumental and impersonal. Furthermore, urban community consistently interplays with neighboring residents and childhood emotional experience are influential on their unconscious images and attitude about their current neighborhood environment, while affecting the environmental attitude and the formation of community sense. Previous research found evidences that increased level of community sense is fostering more feeling of living in so-called "real neighborhood environment." This study aimed to cross-culturally examine what the respondents' emotional perception and their attitude were about the community environment in their childhood through environmental autobiography method and to examine the effects of the results on adults' formation of sense of community for their current community environment. Extensive literature review explored a few important theoretical framework which are closely related to sense of community (SOC) as a result of emotional experience: membership, influence, integration and fulfillment of needs, shared emotional connection and community satisfaction. Chi-square and GLM analysis revealed that there were no demographic, and socio-economic differences between two groups of Korean and US residents. Correlation analysis indicated that childhood emotional experience of Koreans and US citizens was statistically significant on sense of community for their current living community. Multi-regression analysis also found that the degree of influence were the main predictors for building strong sense of current community throughout a cross-cultural group. Furthermore, the relationship between various emotional experience of each factor in previous and current community environment were statistically significantly related. It is concluded that as the positive childhood experience of influence in their past community was going up, the level of sense of community for their current community was strengthened across their cross-cultural background.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.645-648
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• 2008

Due to the rapid increase super high-rise buildings and multi-complex spaces, the space of a staged a very complex and variety of situations occur in the space of the building. The management is still based on limited information obtained by the administrator depends on the decision is made. However, the ability of human beings during a limited time, analysis limited information, and there is a limit to take the appropriate action and situation. To overcome these limitations high information technology that can be fused to take advantage of ubiquitous system is to offer. The aim of this study is on object-oriented 3D data and collected information about the status of the 3D data extraction, to exchange data between systems, the use of object-oriented 3D data, and I studied common space information of a multi-use facilities extracted from 3D CAD information to send to the GIS system.

• International Journal of High-Rise Buildings
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• v.3 no.2
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• pp.155-165
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• 2014

This study measured and compared the variation of ventilation rate and fan energy consumption according to various control strategies after installing wireless sensor-based pilot ventilation system in order to verify the applicability of demand-controlled ventilation (DCV) strategy that was efficient ventilation control strategy for underground parking lot. The underground parking lot pilot ventilation system controlled the ventilation rate by directly or indirectly tracking the traffic load in real-time after sensing data, using vehicle detection sensors and carbon monoxide (CO) and carbon dioxide ($CO_2$) sensor. The ventilation system has operated for 9 hours per a day. It responded real-time data every 10 minutes, providing ventilation rate in conformance with the input traffic load or contaminant level at that time. A ventilation rate of pilot ventilation system can be controlled at 8 levels. The reason is that a ventilation unit consists of 8 high-speed nozzle jet fans. This study proposed vehicle detection sensor based demand-controlled ventilation (VDS-DCV) strategy that would accurately trace direct traffic load and CO sensor based demand-controlled ventilation (CO-DCV) strategy that would indirectly estimate traffic load through the concentration of contaminants. In order to apply DCV strategy based on real-time traffic load, the minimum required ventilation rate per a single vehicle was applied. It was derived through the design ventilation rate and total parking capacity in the underground parking lot. This is because current ventilation standard established per unit floor area or unit volume of the space made it difficult to apply DCV strategy according to the real-time variation of traffic load. According to the results in this study, two DCV strategies in the underground parking lot are considered to be a good alternative approach that satisfies both energy saving and healthy indoor environment in comparison with the conventional control strategies.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.3
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• pp.297-311
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• 1998

Landscaping on artificial ground is currently served as a means to imposing a greenery benefit on high-density and high-rise apartment sites. It functions as a sub-hierarchy in apartment planning such as ornamental element from the past. Major parking space tends to be allocated on the basement area in response to the required parking regulation. Therefore, competitive relatioinship between the parking and greenery space I limited outdoor of apartments leads to the development planning strategy and technology of artificial ground. This study aims at evaluating landscape planning on artificial ground of apartment complex through several approaches such as site survey, plan drawing analysis, and interview with related field experts. 15 survey apartment sites including Bundang Model, Shindaebang-dong, Pyoungchon Hyundai Apartments have been selected for conducting the research. Main results of this study are summarized below : First, scattering allocation of artificial ground between apartment building units is a dominant plan layout type among the survey sites. Even though unifying allocation type has an advantage to maximize underground parking space, it has a difficulty in maintaining proper soil ground base for nurturing plants. Therefore, underground parking space should be planned by unifying allocation type placed separately from apartment units. This plan type can provide a balanced planting between soil and artificial ground on surface level. Second, It is strongly recommended to integrate the whole planting base which involves architectural structure, drainage, and water proofing above the planting design. When considering that process as a professional subject dealing with natural material such as trees and shrubs, those tasks should be directed by landscape architectural divison and landscape architect. And planting area for artificial ground has to be specified in initial phase of architectural design. This step provides an opportunity to make a proper decision on structural load, drainage, and water proof design as an integrated part of the management.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.1
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• pp.21-28
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• 2008

The CFT (Concrete Filled Steel Tube) columns became popular in high rise building construction due to not only its composite effect but also economic advantage. However, it has been pointed out in various previous researches that the current practice in CFT columns may lead the steel tube to probable local buckling at critical sections of the columns right after yielding. To resolve such a problem, the TR-CFT (Transversely Reinforced Concrete Filled Steel Tube) column is proposed to control or at least delay the local buckling state at the critical section by wrapping the CFT columns with carbon fiber sheet. The validity of the proposed column system is validated through the present paper by observing the experimental performance and comparing it with the analytical prediction of the TR-CFT columns with hish strength concrete. It is also shown that the current design code provisions such as ACI-318, in which the contribution of concrete confining effect filled in steel tube is not appropriately accounted for, may contain too much conservatism.