• Smart Structures and Systems
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• 제9권1호
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• pp.35-53
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• 2012

Mechanical dampers have been proved to be one of the most effective countermeasures for vibration mitigation of stay cables in various cable-stayed bridges over the world. However, for long stay cables, as the installation height of the damper is restricted due to the aesthetic concern, using passive dampers alone may not satisfy the control requirement of the stay cables. In this connection, semi-active MR dampers have been proposed for the vibration mitigation of long stay cables. Although various studies have been carried out on the implementation of MR dampers on stay cables, the optimal damping performance of the cable-MR damper system has yet to be evaluated. Therefore, this paper aims to investigate the effectiveness of MR damper as a semi-active control device for the vibration mitigation of stay cable. The mathematical model of the MR damper will first be established through a performance test. Then, an efficient semi-active control strategy will be derived, where the damping of MR damper will be tuned according to the dynamic characteristics of stay cable, in order to achieve optimal damping of cable-damper system. Simulation study will be carried out to verify the proposed semi-active control algorithm for suppressing the cable vibrations induced by different loading patterns using optimally tuned MR damper. Finally, the effectiveness of MR damper in mitigating multi modes of cable vibration will be examined theoretically.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.1197-1200
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• 2003

Urban subways usually make environmental problems because subway vibrations are transmitted to building structures. However, when the buildings are designed, vibrations due to subway are not usually considered in advance. This results in many environmental vibration problems after buildings are constructed. This study was carried out to set up and evaluate a pre-assessment technique for the environmental impact of urban subway vibration on newly planned buildings near a subway line. for this purpose, semi-emperical method was set up and vibration measurements were made on site in accordance with construction schedule. Computer simulation was also performed using ANSYS software to predict the building vibration and compared with the measured results for evaluation of the pre-assessment technique.

• 대한가정학회지
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• 제32권2호
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• pp.129-144
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• 1994

This research is to examine the homogeneity in premarital resources that is exchanged in mate selection and its effect on marital satisfaction among the urban couples in the early period of marriage. Structured questionnaires from 310 urban couples who had been married less than three years were analyzed in this study. First the urban couples tended to seek homogamous selection in age educational level in socioeconomic status of the parents and themselves, Second those who had a spouse from his(her) own religious parental socioeconomic status showed higher level of marital satisfaction than those who had not. The rewards from personal traits such as physical attractiveness gender-role identity personality role-expectation value orientation and perceived reward found to have strong and positive associations with marital satisfaction. Parental approval and semi-arranged marriage were associated with marital satisfaction. Third perceived rewards from these resources and parental approval had significant effects on marital satisfaction; almost half of marital satisfaction was explained by these premarital factors.

• 인간식물환경학회지
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• 제21권6호
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• pp.565-574
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• 2018

Previous studies have shown that forest therapy program can help prevent dementia. However, few studies have focused on low-income elderly people living alone. The current study examined the meanings that the elderly living alone receiving medical care assigned to the urban forest therapy program, as a way to understand the pathways that nature-based intervention affect preventing dementia. Twenty-one participants were recruited and they participated in a five-week urban forest therapy program. Semi-structured interviews were carried out with 21 participants who experienced the urban forest therapy program, and analyzed qualitative data using thematic analysis. Results showed that all themes identified were related to connectedness with oneself, neighbors and nature. Awarenesses of change were consisted of positive and negative themes. The themes of positive awareness were improvements of mental and emotional condition, feelings of isolation and loneliness, and health-related lifestyle. The negative themes were terminations of short-term programs and inconvenient access to the urban forest. Based on these data, we suggest an urban green welfare framework for future research and interventions for preventing dementia of underprivileged elderly group.

• 한국물환경학회지
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• 제26권6호
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• pp.986-993
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• 2010

Spatially distributed on-site devices such as bioretentions and bioboxfilters are becoming more common as a means of controlling urban stormwater quality. One approach to modeling the cumulative catchment-scale effects of such devices is to resolve the catchment down to the scale of a land parcel or finer, and then to model each device separately. The focus of this study is to propose a semi-distributed model for simulating urban stormwater quantity and identifying best sites for spatially distributed on-site stormwater control devices in an urban drainage system. A detailed model for urban stormwater improvement conceptualization simulation is set up for a $0.9342km^2$.

• KIEAE Journal
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• 제16권4호
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• pp.31-39
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• 2016

Purpose: Urban heat island and Heat wave raise urban temperature and create damage of human life. Growing up as quantitative supply to solve shortage of housing, Urban residential area in Korea have a low rate of nature surface and heavily population makes temperature rise. Most houses in the declined residential area are multi-family rental housing and have many factors congesting housing environment such as narrow in-between space, outdoor staircases, walls and semi-basement floor, which make thermal environment getting worse. Most of the residents in this area are small tenants vulnerable to climate change adaptation, This damage is expected to be even greater. This study focus on multiple dwelling in urban residential area prone to temperature rise and draw temperature adaption method that can apply to multiple dwelling.

• 대한토목학회논문집
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• 제31권1D호
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• pp.141-148
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• 2011

인천광역시는 도시 전체의 심각한 교통체증 경감을 위하여 도시철도 1호선(총연장 31.1km)을 1999년 10월 개통하였다. 본 연구는 인천광역시의 도시철도 1호선 개통이 역세권 도시공간에 어떠한 영향을 미치는가에 대한 규명을 통하여 바람직한 역세권 개발방향을 제시하는데 목적이 있으며 이를 위해 국가에서 발간된 통계 자료에 근거하여 분산분석(Analysis of Variance)을 수행하였다. 연구결과 도심형 및 농촌형 역세권은 철도개통에 따라 뚜렷하게 도시공간 변화에 영향을 미쳐 역세권을 형성함에 따라 지역발전을 도모하고 도시기능을 분담하였으나 주거형, 준주거형, 교외형 역세권은 철도개통 후 도시공간 변화에 큰 변화가 없어 역세권이 형성되지 못했다. 따라서 향후 도시철도 개통시 주거형 및 준주거지형 역세권에서는 역세권 입지 특성을 고려하여 주민 및 산업인구를 유인하고 다양한 시설 수요를 창출할 수 있는 계획적 역세권 개발이 요구된다. 한편 교외형 역세권에서는 역사개발 후 자연 발생적 역세권 개발이 현실적으로 어렵기 때문에 도시철도 역사 개발시 역세권 개발을 동시에 추진하여 지역 주민의 삶의 질 향상 및 양호한 생활여건 조성에 앞장서야겠다.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2006년도 춘계학술대회 논문집
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• pp.336-338
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• 2006

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.117-125
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• 2017

Research on Maglev (Magnetic Levitation) train is currently being conducted in Korea, concerning Urban Transit (110 km/h of maximum speed), semi-high-speed (200 km/h of maximum speed), and high-speed (550 km/h of maximum speed) trains. This paper presents a research study on the levitation and guidance systems for the Korean semi-high-speed maglev train. A levitation electromagnet was designed, and the need for a separate guidance system was analyzed. A guidance electromagnet to control the lateral displacement of the train and ensure its stable operation was then also designed, and its characteristics were analyzed. The dynamic performance of the designed levitation and guidance electromagnets was modeled and analyzed, using a linearized modeling of the system equations of motion. Lastly, a test setup was prepared, including manufactured prototypes of the designed system, and the validity of the design was verified and examined with performance evaluation tests.

• 대한가정학회지
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• 제28권4호
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• pp.87-101
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• 1990

This study was undertaken to test to fit forms of the Engel curves to data. The comparisons were confined to the linear, semi-logarithmic and double-logarithmic forms. Data from the 1970-1987 Urban Household Economy Survey were used to estimate the Engel curves. The twelve categories of consumption expenditure were considered for investigation. Parameters of the Engel curves were derived from OLS and TSLS. In this paper the size of the family was used as the deflater. The results could be summarized as follows: 1. Comparing with the R2 of three foms, it could be concluded that, the linear form generally gave a better fit to data than the other forms did. Only for housing and clothing and foot wear, did the semi-logarithmic form give a better fit. Only for meals outside the home, fuel, light and water charges, and miscellaneous, did the double-logarithmic form give a better fit. 2. Comping with the income elasticities based on the alternative forms, it could be concluded that the differences between the estimates were since each form made different assumption as to the way in which elasticity varied. In general, the semi-logarithmic form gave the highest estimate and double-logarithmic form did the lowest estimate. The difference between semi-logarithmic and the other forms were greater than the those of linear and double-logarithmic form. 3. It was found that the income elasticity varied with the difinition of income used as an explanatory variable in Engel curves.