• 전기학회논문지
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• 제62권12호
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• pp.1647-1656
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• 2013

Although the demand for electricity has been increasing these days, it becomes more difficult to find new sites for large-scale power generation plants near urban areas due to environmental and economic issues. Therefore, new power plants are forced off to rural or desolate coastal areas. As a result, there is significant regional imbalance in power generation and consumption between urban and rural areas in South Korea. This paper investigates the feasibility of high-voltage DC (HVDC) system as a candidate for electric power transmission system from east-coastal sites to metropolitan area. To this end, this paper analyzes transient stability and dynamic impact of a HVDC transmission system and compares the results to conventional high-voltage AC (HVAC) transmission systems via PSS/E simulation. This paper also examines the effect of HVDC system to voltage variation and low-frequency resonance in the neighboring buses in the grid using ESCR(Effective Short Circuit Ratio)과 UIF(Unit Interaction Factor) indices.

• 한국농촌건축학회논문집
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• 제12권2호
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• pp.13-22
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• 2010

This study is to analyze women's power in family to be related to Anbang, kitchen, dining room, and utility room planning in a unit plan of condominium apartment housing in rural area Data were collected 194 unit plans from 9 eastern regions of Kungi-Do. The results are as followed: 1) Anbang reflects the women's power on changing its space character into mater bedroom, the highest hierarchy in private zone, and planning a dress room in it. 2) Dining room and kitchen is openly centered on the unit plan, but kitchen is still only women's working space for family and agriculture depended on literature review. Dining space is not activated family interaction, so it is not different from urban apartment housing. However, its location and character are changed, and its hierarchy is relatively higher with women. Dining room and kitchen tend to plan visually separated after 2001, so its trend seems to establish women's territory at home. 3) Whole family can't be easy to access utility and back balcony close to kitchen, and these spaces are functionally separated for women's house work. This design trend seems to establish for women's area. 4) Finally, women's power seems to be effective in house working area including kitchen space depended on results. Also, these results from rural condominium apartment are similar to urban ones in previous study.

• 한국주거학회논문집
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• 제14권6호
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• pp.15-22
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• 2003

The regeneration of built-up areas is considered as one of the necessary measures for the effectiveness of urban growth management. In this vein, this study explores how to limit the number of people who leaves the built-up areas and to restore the area with the resident. For this, a residential area of the built-up area is analyzed in terms of why people in that area are moving out of the area and who fills in it after all. This study founds that narrow roads in a residential area and the changes in land use from residential purposes to commercial are major forces that push the people in the built-up area. In addition, the lack of welfare facilities, the pavement of roads, and pedestrian roads. education. crime. the lack of interaction between neighbors, and the quality of housing are all emerged contributing the loss of people in the built-up areas. It is recommended that all the factors here should be restored in an appropriate way. Another finding is that those who fill in the built-up area are largely over 50, self-employed, comparably wealthy, and having their own families. Hence, it is advised that the built-up area would be rearranged in order to attract those type of people in there.

• 도시과학
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• 제8권1호
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• pp.25-31
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• 2019

Infiltration affects indoor environmental and air quality and energy consumptions in buildings. Especially, airflow and the infiltration are more remarkable in high-rise buildings due to the air-driving forces (stack and wind effects). Thus, it is important to understand infiltration distributions in high-rise residential buildings. In this study, the weather-driven infiltration is characterized from the viewpoint of interactions between external wind and stack effect in high-rise residential buildings. To calculate accurately the annual infiltration distributions, this study also suggests an airflow and thermal simulation method with a two-step calibration of air-leakage data. The simulated results show (1) how the interaction between stack and wind effects induce infiltration types (outdoor and interzone air infiltration) and (2) how much the interzone air infiltration (being ignored in previous studies) occurs due to the stack effect, as well as the outdoor air infiltration rates.

• 한국지진공학회논문집
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• 제23권4호
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• pp.221-229
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• 2019

Several water tanks installed in the building were damaged during the Gyeongju earthquake (2016) and the Pohang earthquake (2017). Since a water tank for fire protection is very important component, seismic safety should be ensured. In this study, an interaction between a water tank and a building was studied by the dynamic analysis of the RC building with the water tank. In case the water tank was installed on the roof of the RC building, it was confirmed that it did not significantly affect the response of the building. Based on the result, dynamic response characteristics of the water tank in the building were studied using two SDOF models represented dynamic behavior of the water tanks under earthquake. An earthquake time-history analysis was carried out with variables of aspect ratio of the tank, story of the building, and installed location in the building using three kinds of earthquakes.

• Journal of Information Technology Applications and Management
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• 제26권1호
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• pp.95-102
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• 2019

Public transportation systems play key roles in supporting dynamic activities and interaction between urban places. Especially, high efficient public transportation systems are required in order to support large traffic demands in urban areas. In this paper, we define a new metric, structural activation level (SAL), to replace the conventional transportation share ratio (TSR) measuring efficiency of public transportation systems. First of all, we access the Korea Transport Database (KTDB) and download origin-destination data by transport types to construct traffic networks with respect to transport types for each city. Then, we calculate the QAP (Quadratic Assignment Procedure) correlation between each traffic network and the total traffic network for each city to investigate SAL by comparing cities one another. The results of our investigation reveal inconsistency between TSR and SAL. In Daegu, TSR of public transportation systems is relatively low while SAL is high. In Deajeon, however, SAL is low while TSR is high. Therefore, we suggest to take into consideration SAL as well as TSR in order to investigate the degree of activation of public transportation.

• 지역사회간호학회지
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• 제32권4호
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• pp.506-517
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• 2021

Purpose: The purpose of this study was to explore the health management experience of Vietnamese Married Immigrant Women living in the city. Methods: The study participants were 11 Vietnamese immigrant women residing in the urban area who felt bad about their health. Data collection was conducted in depth through individual interviews, and the collected data were analyzed through Strauss & Corbin data analysis. Results: The core category was "health is not a necessity but a choice in a strange land called Korea". The contextual conditions were, "The hard thing-exposing "myself" to the world", and "Hurts hidden, to be away from people's eyes". For the causal condition, the categories of "Unfamiliar life to live alone", "Unfamiliar life different from expectation", and "Symptoms of body suddenly suffering alone", were derived. Through action-interaction, the immigrant women revealed that in their Korean social-structural context, they tended to follow "Health pushed away in turbulent life". The intervening conditions were "a person who is able to help me", "places that can give a helping hand nearby", and "Vietnamese women's grit". A Vietnamese married immigrant woman had her own "Health in the chain with life". As a result, they gained "Health, which is a top priority in life" or "Health oppressed by the weight of life". Conclusion: This study enhanced the understanding of the healthcare process of Vietnamese married immigrant women living in urban areas.

• Architectural research
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• 제24권2호
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• pp.41-52
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• 2022

The purpose of this study is to grasp the understanding of smart cities and to review whether the common perception of smart cities, as people understand it, is changing over time. This study analyzes keywords related to smart cities used in social network services (SNSs) in 2011, 2016, and 2020 respectively through semantic network analysis. Smart city discussions appearing on SNS in 2011 mainly focused on technology, and the results of 2016 were generally similar to those of 2011. We can also find policy or business-oriented characteristics in emerging countries in 2020. We highlight that all the results of 2011, 2016, and 2020 have some correlation with each other through QAP(Quadratic Assignment Procedure) correlation analysis, and among them, the correlation between 2011 and 2016 is analyzed the most. The results of the frequency analysis, centrality analysis, and CONCOR(CONvergence of interaction CORrelation) analysis support these results. The results of this study help establish policies that reflect the needs and opinions of citizens in planning smart cities by identifying trends and paradigm transitions expressed by people in SNS. Furthermore, it is expected to help emerging countries by enhancing the understanding of the essence and trend of smart cities and to contribute by suggesting the direction of more sustainable technology development in future smart city policies for leading countries.

• Earthquakes and Structures
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• 제24권1호
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• pp.65-79
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• 2023

A simplified analytical solution for seismic response of tunnel cross section in horizontally layered ground subjected to oblique incidence of SH wave is deduced in this paper. The proposed analytical solution consists of two main steps: free-field response in layered field and tunnel response. The free field responses of the layered ground are obtained by one-dimensional finite element method in time domain. The tunnel lining is treated as a thick-wall cylinder to calculate the tunnel response, which subject to free field stress. The analytical solutions are verified by comparing with the dynamic numerical results of two-dimensional ground-lining interaction analysis under earthquake in some common situations, which have a good agreement. Then, the appropriate range of the proposed analytical solution is analyzed, considering the height of the layered ground, the wavelength and incident angle of SH wave. Finally, by using the analytical solutions, the effects of the ground material, burial depth of the tunnel, and lining thickness and the slippage effect at the ground-lining interface on the seismic response of tunnels are investigated. The proposed solution could serve as a useful tool for seismic analysis and design of tunnels in layered ground.

• 국제초고층학회논문집
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• 제13권1호
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• pp.85-95
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• 2024

A composite member made of concrete-filled steel tubes (CFT columns) has been recognized for its fire resistance due to the thermal mass effect of concrete inside the steel tube, as shown in various studies. In this study, the fire resistance performance of reinforced CFT columns under constant axial load was evaluated using finite element analysis with ABAQUS. For this purpose, the variables including cross-section size, steel tube thickness, and concrete cover thickness were set, and the temperature distribution in the column cross-section exposed to a standard fire was investigated using heat transfer analysis. Ultimately, a P-M interaction curve was obtained by evaluating the overall residual strength of columns, and the fire resistance time was determined by evaluating axial displacement-time responses due to the reduction in load capacity during fire through stress analysis.