• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.490-498
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• 2020

In this study, the seismic performance of low-rise piloti buildings with eccentric core (shear wall) positions was analyzed and reviewed. A prototype was selected among constructed low-rise piloti buildings with eccentric cores designed based on KBC2005. The seismic performance of the building showed plastic behavior in the X-direction and elastic behavior in the Y-direction. The inter-story drift is larger than that of a concentric core case and has the maximum allowed drift ratio. The displacement ratio of the first story is much larger than that of upper stories, and the frame structure in the first story is vulnerable to lateral force. Therefore, low-rise piloti buildings with eccentric cores need to have less lateral displacement, as well as reinforcement of the lateral resistance capacity in seismic design and seismic retrofit.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.5
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• pp.61-69
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• 2007

The main purpose of this study is to provide a basic information for the seismic capacity evaluation and the seismic design of low-rise reinforced concrete (RC) shear wall buildings, which are comprised of a pilotis in the first story. In this study, relationships between strengths and ductilities of each story of RC buildings with pilotis are investigated based on the nonlinear seismic response analysis. The characteristics of low-rise RC buildings with pilotis are assumed as the double degree of freedom structural systems. In order to simulate these systems, the pilotis is idealized as a degrading trilinear hysteretic model that fails in flexure and the upper story of shear wall system is idealized as a origin-oriented hysteretic model that fails in shear, respectively. Stiffness properties of both models are varied in terms of story shear coefficients and structures are subjected to various ground motion components. By analyzing these systems, interaction curves of required strengths for various levels of ductility factors are finally derived for practical purposes. The result indicates that the required strength levels derived can be used as a basic information for seismic evaluation and design criteria of low-rise reinforced concrete shear wall buildings having pilotis structure.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05b
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• pp.97-98
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• 2011

The number of high-rise buildings has increased year after year, with there currently being 5 projects in progress to construct buildings higher than 100 stories in Seoul alone. The construction cost for such high-rise buildings is significantly higher than the cost for a conventional low-rise building, while maintenance costs are expected to be two to three times higher. To reduce the maintenance cost of a high-rise building, there is the need for a guide rail to be used for maintenance, which is why there is the need for research on the guide rail system. For this reason, as preliminary research to develop a guide rail, this study aims to derive the factors increasing construction cost by taking the installation of a guide rail into account. This is expected to lay the groundwork for the design and construction of guide rails for high-rise building maintenance.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.8
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• pp.57-64
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• 2019

This study attempts to analyse the effects of high-rise living on suicide rates. All the apartments in the City A and every suicide were examined in detail. Research methods are as follows. First, a database including tenure type and number of residents in all apartment complexes was created. Second, apartments were categorized into two income groups of private apartments and social housing, and spatial configuration characteristics of a typical apartment were analysed. Third, differences in suicide rates were analysed for lower and upper levels in both apartment categories. Finally, the relationship between high and lower levels of apartments with their spatial configuration characteristics and suicide rates was compared. The analysis shows significant differences between lower and upper floors living residents' suicide rates. It can be stated that the low-income residents are more sensitive to living in high-rise environment. Also, it suggests the need to improve the high-rise living environment of vulnerable social groups. In addition, spatial integration decrease in upper floors of high-rise buildings, and it can be interpreted that spatial configuration may affect residents' pathological disorders or even suicidal behaviors.

• Earthquakes and Structures
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• v.18 no.5
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• pp.649-665
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• 2020

One of the most important issues in structural systems is evaluation of the margin of safety in low and mid-rise buildings against the progressive collapse mechanism due to the earthquake loads. In this paper, modeling of collapse propagation in structural elements of RC frame buildings is evaluated by tracing down the collapse points in beam and column structural elements, one after another, under earthquake loads and the influence of column removal is investigated on how the collapse expansion in beam and column structural members. For this reason, progressive collapse phenomenon is studied in 3-story and 5-story intermediate moment resisting frame buildings due to the corner and edge column removal in presence of the earthquake loads. In this way, distribution and propagation of the collapse in progressive collapse mechanism is studied, from the first element of the structure to the collapse of a large part of the building with investigating and comparing the results of nonlinear time history analyses (NLTHA) in presence of two-component accelograms proposed by FEMA_P695. Evaluation of the results, including the statistical survey of the number and sequence of the collapsed points in process of the collapse distribution in structural system, show that the progressive collapse distribution are special and similar in low-rise and mid-rise RC buildings due to the simultaneous effects of the column removal and the earthquake loads and various patterns of the progressive collapse distribution are proposed and presented to predict the collapse propagation in structural elements of similar buildings. So, the results of collapse distribution patterns and comparing the values of collapse can be utilized to provide practical methods in codes and guidelines to enhance the structural resistance against the progressive collapse mechanism and eventually, the value of damage can be controlled and minimized in similar buildings.

• Earthquakes and Structures
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• v.18 no.6
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• pp.691-707
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• 2020

One of the most important issues in structural systems is evaluation of the margin of safety in low and mid-rise buildings against the progressive collapse mechanism due to the earthquake loads. In this paper, modeling of collapse propagation in structural elements of RC frame buildings is evaluated by tracing down the collapse points in beam and column structural elements, one after another, under earthquake loads and the influence of column removal is investigated on how the collapse expansion in beam and column structural members. For this reason, progressive collapse phenomenon is studied in 3-story and 5-story intermediate moment resisting frame buildings due to the corner and edge column removal in presence of the earthquake loads. In this way, distribution and propagation of the collapse in progressive collapse mechanism is studied, from the first element of the structure to the collapse of a large part of the building with investigating and comparing the results of nonlinear time history analyses (NLTHA) in presence of two-component accelograms proposed by FEMA_P695. Evaluation of the results, including the statistical survey of the number and sequence of the collapsed points in process of the collapse distribution in structural system, show that the progressive collapse distribution are special and similar in low-rise and mid-rise RC buildings due to the simultaneous effects of the column removal and the earthquake loads and various patterns of the progressive collapse distribution are proposed and presented to predict the collapse propagation in structural elements of similar buildings. So, the results of collapse distribution patterns and comparing the values of collapse can be utilized to provide practical methods in codes and guidelines to enhance the structural resistance against the progressive collapse mechanism and eventually, the value of damage can be controlled and minimized in similar buildings.

• Journal of the Korean Home Economics Association
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• v.42 no.6
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• pp.1-12
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• 2004

This study investigates residents' living satisfaction with high-rise, mixed-use apartments built in the structures of reinforced concrete construction(RC) and with steel framed, reinforced concrete construction(SRC). The following study results were obtained: 1) Residents expressed below average satisfaction (below 3.0) with the common-area landscape and environmentally-friendly factors, children's playground and its facilities, community service for residents' by the management offices and utility plan. 2) According to the satisfaction of sound environment, residents of the SRC group expressed above average satisfaction. It can be concluded that noise problems around the residential area of the SRC group was well solved in this study. However, the residents of the SRC group expressed low satisfaction with the freshness of indoor air, humidity, and smell in the living quarters. 3) High-rise, mixed-use apartments should accommodate a familial life cycle, be designed as an environmentally friendly resting place in harmony with city life, and provide various communal programs for residents.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2003.11a
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• pp.145-149
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• 2003

This study is to investigate residents' living satisfaction with high-rise mixed-use apartment complexes built in the structures of the reinforced concrete constructing and the steel framed reinforced concrete construction. The results of this study were obtained as follows: 1. Residents expressed below average satisfaction (below 3.0) with the common-area landscape and environmentally-friendly factors, children's playground and its facilities, community service for residents' by the management offices and the plan of utility. 2.According to the satisfaction of sound environment, residents of SRC group expressed above average satisfaction; it can be concluded that problems of causing noise around the residential area of the SRC and S groups were well solved in this study. However, satisfaction with the freshness of indoor air, humidity, and smell in the living quarters was rated low by the residents of SRC group. 3. High-rise mixed-use apartment complexes should accomodate families's life cycle, design an environmentally-friendly resting place in harmony with city life, and provide various communal programs for residents.

• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.114-120
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• 2014

In this paper, a method for multi-physics analysis of the temperature-dependent properties of an oil-immersed transformer is discussed. To couple thermal fields with electromagnetic and fluid fields, an algorithm employing a user defined function (UDF) is proposed. Using electromagnetic analysis, electric power loss dependent on temperature rise is calculated; these are used as input data for multi-physics analysis in order to predict the temperature rise. A heat transfer coefficient is applied only at the outermost boundary between transformer and the atmosphere in order to reduce the analysis region. To verify the validity of the proposed method, the predicted temperature rises in high-voltage (HV) and low-voltage (LV) windings and radiators were compared with the experimental values.

• Journal of Power System Engineering
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• v.11 no.1
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• pp.51-55
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• 2007

A study on combustion characteristics using emulsified fuel in a diesel engine were performed experimentally. In this paper, the experiments were performed at engine speed 1800rpm, emulsion ratios were 0%, 10%, 20%, and main measured items were specific fuel consumption, cylinder pressure, rate of pressure rise, rate of heat release etc. The obtained conclusions were as follows. 1) Specific fuel consumption increased maximum by 19.8% at low load, but was not affected at full load. 2) Rate of pressure rise and rate of heat release were about the same in the case of 10% and 20% of emulsion ratio. 3) Cylinder Pressure increased 9.6%, rate of pressure rise increased 53.4% in case of emulsion ratio 20% at full load. 4) Rate of heat release increased 72.4% in case of emulsion ratio 20% at full load.