• Journal of the Earthquake Engineering Society of Korea
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• v.14 no.4
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• pp.61-71
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• 2010

Five half-scale beam-to-column connections in a precast concrete frame were tested with cyclic loading that simulated earthquake-type motions. Five half -scale interior beam-column assemblies representing a portion of a frame subjected to simulated seismic loading were tested, including one monolithic specimen and four precast specimens. Variables included the detailing used at the joint to achieve a structural continuity of the beam reinforcement, and the type of special reinforcement in the connection (whether ECC or transverse reinforcement). The specimen design followed the strong-column-weak-beam concept. The beam reinforcement was purposely designed and detailed to develop plastic hinges at the beam and to impose large inelastic shear force demands into the joint. The joint performance was evaluated on the basis of connection strength, stiffness, energy dissipation, and drift capacity. From the test results, the plastic hinges at the beam controlled the specimen failure. In general, the performance of the beam-to-column connections was satisfactory. The joint strength was 1.15 times of that expected for monolithic reinforced concrete construction. The specimen behavior was ductile due to tensile deformability by ECC and the yielding steel plate, while the strength was nearly constant up to a drift of 3.5 percent.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.447-456
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• 2013

This study was carried out for the establishment of theory and foundational data for breeding, on variegated foliage plants using for potted plants, based on examination and analysis for shape, color, and area ratio of variegated leaves and chlorophyll contents. Six families, 18 genus, and 54 species of variegated plants domestically distributed in Korea were used as the plant materials. Patterns based on chlorophyll-deficient part in variegated leaves were divided into 20 types, such as steps, border, collapsed border, sandy border, half, silk, stars, vein, firewood, border and firewood, center, entirety, leaf, irregular, net, watermelon, melon, and so on. There were 10 kinds of colors including dark green, red, dark red, reddish white, reddish yellow, white, silver, silvery white, yellowish white, and yellow. The ratio of variegated area was ranged from 5.8% to 100% and it was diverse depending on species or cultivar. The ratios by patterns were highest in entirety (98.6%) and relatively high in step (60.8%), whereas, low in boarder, star and firewood (33.6-36.4%), and relatively low in half and vein (43%). Chlorophyll content of variegated leaf was rather lower compared to normal plants and chlorophyll b tended to be higher in ratio of chlorophyll a to b. Particularly content of chlorophyll b in Stromanthe sanguinea 'Triostar', Dracaena fragrans 'Massangeana Compacta', D. reflexa 'Song of India', and Tradescantia spathacea was higher than chlorophyll a in comparison with that of normal plants.

• Journal of the Korean Institute of Landscape Architecture
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• v.33 no.6 s.113
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• pp.98-108
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• 2006

The climate of urban area is an unstable type with considerable seasonal variation in precipitation wind speed, and temperature and it grows worse. Besides, ozone is a serious air pollutant in most of large cities. So worldwide, some of large cities are investing in forestry options to offset their climate problems, but lack of information has hindered comparisons of urban un cost effectiveness to other options. This research intends to study the economic benefits of tree shading of 19 parking lots in UCD campus. The economic benefits of tree shading are air conditioning savings, air quality, stormwater run-off, and other benefits. Especially, this study focuses how much the economic benefit of parking lot shading has been increased from 1995 to 2003 year by aerophoto. Some data on dimensions of parking lots and the number, size, tree species, and location of trees around each parking lot was inventoried. Two aerophotos(1995,2003) were used in order to analyze the increasement of tree canopy in 19 parking lots for 8 years. However, increasing coverage of trees and managing them for healthy growth would not be sufficient for avoiding adverse impacts by future climate change. Additional measures should be followed such as an increase of energy use efficiency and development of substitute energy. For example, coverage of trees help to save cooling energy by blocking solar radiation reaching parking cars and building structures through shading, and creating cool micro-climates through evapotranspiration. They also reduce heating demand by decreasing air infiltration and heat conduction out of the interior of buildings. Proper arrangement of vegetation over the parking lots can reduce cooling and heating costs. So proper planting design around hard space paving including species selection and location can significantly save cooling and heating energy. And a reduction in car and building's heating and cooling costs results in the reduction in energy demand which causes to emissions of air pollutants. Total increased tree canopy from 1995 to 2003 is $8,470.45m^2$ and the economic benefits is US$ 5,282.10. The economic benefit of one tree has been US$ 7.21 for 8 years. And an annually increased benefit is US$ 0.9 per a tree. If this kind of study is applied to studying the economic benefits of tree canopy in parking lots of Korea, it could result in guidelines of tree planting of parking lots. Because the trees selected for planting in parking lots were not suitable for an environment, the guidelines should contain a recommended list of trees. The guidelines should propose the shading percentage of parking lot when we plan a parking lot and contain the maintenance of trees in order to maximize the economic benefits of tree canopy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.745-755
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• 2017

University campuses try to satisfy students' demands. Therefore, the physical environment of university campuses keeps changing. Due to the increasing the number of students and shortage of school building facilities, it is necessary to improve the facilities and create new space in the campus, in order to solve this problem and improve the universities. At the moment, the learning method of university students is evolving toward discussion sessions involving fellow students and presentations utilizing multimedia facilities. In response to these changes, a new type of independent space has appeared, which is called the Group Study Room. In this study, we analyze the spatial characteristics of the Group Study Room. Also, through an IPA(Importance Performance Analysis), this study tries to examine the relationship between the spatial characteristics and users' satisfaction. This analysis is expected to reveal the importance of the spatial characteristics of the group study rooms from the users' point of view. This research can be used for facility planning in universities in the future. The primary aim of this study is to analyze the physical environment of the Group Study Rooms of K university. The secondary aim of this study is to manifest the characteristics of these new learning spaces and to check the space elements of the group study rooms for the sake of efficient planning and management.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.785-793
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• 2017

The guidelines for the district unit planning(DUP) of detached houses in the area of Misagangbyeon-City (MISA) do not consider the characteristics of the region. Therefore, this study was conducted to analyze the relationship between the blocks and parking lots of the detached houses area. The research results can be summarized as follows: 1) Detailed design guidelines are provided for apartment homes in MISA, but not for detached houses. 2) Apartment home and multi-family house parking lot equivaluation calculations exist in the DUP guidelines, however there are no regulations related to detached houses and the problem of parking for these residents is worsening which causes tension. 3) The DUP guidelines stipulate that the outer wall material of multi-family houses must be glass, however this is a dangerous material for use on the first floor, because cars that park close to this wall. 4) There is a significant risk to elementary and kindergarten students who must walk along the road in the inner blocks where cars are driving quickly. 5) There are a number of issues involved when planning parking lots without considering the characteristics of the area. The local government uses the traditional parking lot codes without considering the current regional characteristics, whereas the number of cars has dramatically increased. 6) The pedestrian mall is not currently being used for pedestrians, because it is full of parked cars due to the lack of parking space.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.4
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• pp.155-161
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• 2016

This research is to explore resident's assessment of the Automated Vacuum Waste Collection System (AVWCS), which is devised to attain sustainability of residential environment. A number of AVWCS has been installed in Gyeonggi Province, so 283 households in 11 new public housing estates of 5 cities participated in a self-administered questionnaire survey. The data collected from 133 respondents in for-sale housing estates and 150 participants in rental housing estates, and the primary findings were as follows: a vast majority of both owners and renters had neither been aware of nor used the system before moving to their current housing estate. Also, most of the respondents learned how to use the AVWCS from on-site housing management staff, and the learning among renters was greatly delayed. Renters were in stronger favor of the system than owners, and their satisfaction was greater than the counterpart. Although few items were unsatisfactory, many emphasized that AVWCS should be augmented with user-centered, environmentally friendly features, and also they viewed that the system would substantially contribute to sustainable urban environment.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.12
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• pp.674-681
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• 2015

This research conducts both experimental evaluation and resident's assessment of zero food waste system (ZFWS) in multifamily housing estates in order to explore the feasibility of ZFWS embedded in fermentation and extinction technology utilizing wood chips turned into fertilizer. Having been established in a multifamily housing estate, ZEFWS was proved to be functional and effective. During the 3-month experimental period, the weight between infused food waste and its reactor was reduced significantly enough, and the chemical analysis showed that the concentration of organic compounds went from 87.9% to 75.8%, $H_2O$ decreased from 69.7% to 45.5%, NaCl rose from 0.2% to 0.5%, pH increased from 4.6 to 7.8, and ATP escalated from 505.3 nmol/L to 723.5 nmol/L. Also, the chemical analysis of the output in the experimentation indicated adequacy of the organic fertilizer. In the self-administered questionnaire survey for residents participating in the field project, almost all the respondents viewed that ZFWS can compete with conventional food waste disposal methods and an idealistic way to upcycling food waste into fertilizer.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.568-574
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• 2007

Crack-free dried gel monoliths of the composition $Li_2O1{\cdot}7Al_2O_3{\cdot}8.6SiO_2$ have been prepared as a precursor of transparent glass-ceramic by the hydrolysis and polycondensation of mixed metal alkoxides in solutions containing N,N-dimethylformamide as the drying control chemical additive, alcohols, and water. It was investigated that activation energy for gelation according to the variation of water concentration ranged from 13 to 14 kcal/mol. Only when the amount of water for gelation was 3 times higher than the stoichiometric amount, monolithic dry gels were successfully prepared after drying at $70{\sim}75^{\circ}C$ and at a rate of 0.1~0.3%/h. The specific surface area, the pore volume, the average pore diameters of dried gel at $180^{\circ}C$ were about $239.40m^2/g$, 0.001~0.03 mL/g, and $145.62{\AA}$, respectively. It showed that the dried monolithic gel had a porous body. The DTA curve had the first exothermic peak around $800^{\circ}C$ and the 2nd peak around $980^{\circ}C$, which may correspond to crystallization of the gel.

• Journal of Korea Society of Industrial Information Systems
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• v.24 no.6
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• pp.43-53
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• 2019

In recent years, there have been many cases of damage to indoor air hazardous materials, and major damage due to the lack of quick action. In this regard, the system is intended to establish for sending push messages to the user's mobile when the concentration of hazardous substances is exceeded. This system extracts data with IoT system such as Arduino and Raspberry Pi and then constructs database through MongoDB and MySQL in cloud computing system. The database is imported through the application server using NodeJS and sent to the application for visualization. Also, when receiving signals about a dangerous situation in IoT system, push message is sent using Google FCM library. Mobile application is developed using Android Web view, and page to enter Web view is developed using HTML5 (HTML, Javascript CSS). The application of this system enables real-time monitoring of indoor air-dangerous substances. In addition, real-time information on indoor/outdoor detection location and concentration can be sent to the user's mobile in case of a risk situation, which can be expected to help the user respond quickly.

• Journal of Families and Better Life
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• v.26 no.3
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• pp.37-52
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• 2008

The purpose of this study was to provide the valid data about residential-linked pension insurance development. The development was a part of national housing projects, which was an incentive for rural living of retired people, in order to relieve residential issues of elderly and revitalize rural communities by residents moving from cities. The insuring intent, decisive insuring factors and the residential service demand degree of people preparing retirement were analyzed. Data was collected in October, 2007. 364 Sample Subjects lived in Seoul Metropolitan area. Firstly, more than 90% of respondents had intention to purchase a residential-linked pension insurance and about 50% of them necessarily desired receiving premium for moving in. This indicated that it could be developed as an insurance which helped to meet housing expenses by housing-linked system, and in the mean time, it met the original purpose of pension insurance as the pension benefit could be guaranteed for all the insurance subscribers. Secondly, the respondents, whose income and private assets were higher, were able to pay more for insurance compared to average. Therefore, It was necessary to regulate monthly insurance bill and the payment period according to asset states of insurance subscribers after establishing certain amount of total insurance payment. Thirdly, by and large, it indicated the tendency that the less they prepare for older age the later they wanted to move into the pension insurance residence. It was inferred that in the case of insufficient preparation for older age, people preferred preparing behind time by postponing move in to moving in early to enjoy retired life, due to uncertainties. lastly, the respondents understood the significance of health, medical treatment and emergency management service and these two services were preferred as essential provided services. Because of the necessity of developing residential-linked pension insurance was found to be positive, further research to find the real cost, directives for operation and institutional support for this type of pension insurance might be needed.