• Journal of Labour Economics
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• v.24 no.1
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• pp.97-124
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• 2001

Co-residence is a type of intergenerational private transfers of resources: money, time and space. Adult daughters and their elderly parents decide to co-reside, depending on their utility levels before and after co-residence that mainly depend on the health status of the elderly. Therefore, co-residence implies positive net benefits to both parties in the sense that, when they co-reside, elderly parents share childcare and adult daughter provide elderly care. In other words, formal (paid) care can be substituted with informal (unpaid) one. Both marriage and giving births are considered as the major obstacles to labor market attachment of women who bear burdens of home production and childcare. Co-residence can be a solution for married women to avoid career interruption by sharing burdens with their elderly parents. However, most previous studies using the U.S. data on intergenerational private transfers focused on elderly care and have concluded that they reduce government expenditures associated with public subsidies to the elderly. This study focuses on adult daughters and it examines effects of co-residence on labor supply of married women in Korea, who face limited formal childcare programs in terms of both quantity and quality. It applies the Tobit model of married women's labor supply to the data from the Second Wave of the Korean Labor and Income Panel Survey( 1999), in order to investigate effects of co-residence and the work and health status of the co-residing elderly as well as their own health status. Four specifications of the empirical model are tested that each includes co-residence with elderly parents, their gender, or their work and health status. Estimation results show that co-residence, co-residence with female elderly, and co-residence with not-working female elderly have significant positive effects on labor supply of married women while poor health status of co-residing female elderly does not bring about any negative effects. However, co-residence with male elderly, regardless of their work and health status, has no significant effect The results indicate that co-residence is closely related to sharing of home production among female elderly and adult daughters who are married and, through intergenerational private transfers of resources in terms of time, it helps women avoid career interruption.

• Proceedings of the KIPE Conference
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• 2008.10a
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• pp.190-192
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• 2008

The government plans to deploy 100,000 photovoltaic system in residential houses by 2012. In this paper, I described how to design the Residence PV System and how to simulated which predict the efficiency of its electrical generation. AS comparing the simulated data and actual installed 3kW photovoltaic power generation system. I analyze the condition of the Residence PV system and suggest the best way to design in best condition.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.1 s.244
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• pp.32-41
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• 2006

We analyzed the non-Newtonian and non-isothermal flow in the melt conveying zone in co-rotating and counter-rotating screw extruder system with the commercial code, STAR-CD, and compared the mixing performance with respect to screw speed and rotating direction. The viscosity of fluid was described by power-law model. The dynamics of mixing was studied numerically by tracking the motion of particles in a twin screw extruder system. The extent of mixing was characterized in terms of the residence time distribution and average strain. The results showed that high screw speed decreases the residence time but increases the shear rate. Therefore higher screw speed increases the strain and has better mixing performance. Counter-rotating screw extruder system and co-rotating screw extruder has the similar shear rate with the same screw speed in spite of different rotating direction. However, the counter-rotating screw has good mixing performance, which is resulted from longer residence time than that of co-rotating screw extruder.

• Korea-Australia Rheology Journal
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• v.18 no.3
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• pp.153-160
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• 2006

We analyzed the non-Newtonian and non-isothermal flow with Carreau-Yasuda viscosity model in co-rotating and counter-rotating twin screw extruder systems. The mixing performances with respect to the screw speed, the screw pitch, and the rotating direction have been investigated. The dynamics of mixing was studied numerically by tracking the motions of particles. The extent of mixing was characterized in terms of the deformation rate, the residence time distribution, and the average strain. The results showed that the high screw speed decreases the residence time but increases the deformation rate. Small screw pitch increases the residence time. It is concluded that the high screw speed increases the dispersive mixing performance, while the small screw pitch increases the distributive mixing performance. Co-rotating screw extruder has the better conveying performance and the distributive mixing performance than counter-rotating screw extruder with the same screw speed and pitch. Co-rotating screw extruder developed faster transport velocity and it is advantageous the flow characteristics to the mixing that transfers polymer melt from one barrel to the other barrel.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.2
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• pp.173-182
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• 2012

Effects of temperature, pressure, and gas residence time on methane combustion characteristics of mass produced oxygen carrier particle (OCN706-1100) were investigated in a pressurized fluidized bed reactor using methane and air as reactants for reduction and oxidation, respectively. The oxygen carrier showed high fuel conversion, high $CO_2$ selectivity, and low CO concentration at reduction condition and very low NO emission at oxidation condition. Moreover OCN706-1100 particle showed good regeneration ability during successive reduction-oxidation cyclic tests up to the 10th cycle. Fuel conversion and $CO_2$ selectivity decreased and CO emission increased as temperature increased. These results can be explained by trend of calculated equilibrium CO concentration. However, $CO_2$ selectivity increased as pressure increased and fuel conversion increased as gas residence time increased.

• Journal of the Korean Society of Combustion
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• v.17 no.4
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• pp.30-37
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• 2012

The flame lengths and NOx emission characteristics of syngas $H_2$/CO turbulent non-premixed jet flames were investigated. The flame length which is the main parameter governs NOx emission was studied for various syngas compositions. The flame length was compared with previous correlation between Froude number and flame height and it shows that they have good agreements. It was confirmed that the turbulent jet flames herein investigated are in the region of buoyancy-momentum transition. NOx emission was reduced with increased Reynolds number and CO contents in syngas fuel and with decreased fuel nozzle diameter which is attributed by decreased flame residence time. Previous EINOx scaling based on flame residence time of $L_f^3/(d_f^2U_f)$ satisfies only the jet flame in momentum-dominated region, not buoyancy-momentum transition region. The simplified flame residence time ($L_f/U_f$) was adopted in modified EINOx scaling. The modified scaling satisfies the jet flames not only in momentum-dominated region but in buoyancy-momentum transition region. The scaling is also satisfied with $H_2$/CO syngas jet flames.

• Korean Journal of Family Social Work
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• no.53
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• pp.161-198
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• 2016

This study examined how previous financial and time transfers from mothers to their adult children affect co-residence of elderly mothers and their adult children in South Korea. This study employed multi-level logistic analysis considering hierarchical relationship structures between mothers and their adult children. A sample of 1,925 elderly mothers and 7,460 adult children was extracted from data which were from the first wave (in 2006) to the forth wave (in 2012) of Korean Longitudinal Study of Ageing (KLoSA). The result of the analysis suggested that past financial transfer from mothers to their adult children was not significantly associated with co-residence between elderly mothers and their adult children. However, likelihood of co-residence increased with the amount of time transfer, which was measured by unit of time for elderly mothers' caring for their grandchildren. This study discussed that long-term reciprocal relationships between elderly mothers and their adult children are built by intergenerational support relationships. However, the result that showed only grandmaternal child care affected intergenerational co-residence implies that intergenerational care may play an important role in intergenerational reciprocal relationships. Through these findings, this study suggested theoretical, practical, and policy implications.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.748-753
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• 2005

In a super-highrise residence project, a project manager needs to form the long-term risk management plan which covers the problems from the beginning of project to the time of demolition. The cause and responsibility for a risk are clarified and quantitatively evaluated through the life cycle of a project. Development of the system which supports a risk strategy effectively is needed as a project becomes complex. In this paper, through the life cycle of a specific super-highrise residence project, a risk phenomenon is specified from a viewpoint of each participant, and the mathematical model is formulated choosing the combination of the optimal strategy against a risk quantitatively within a fixed risk strategy budget.

• Journal of Soil and Groundwater Environment
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• v.8 no.1
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• pp.42-47
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• 2003

A biofilter study was performed in order to remove mixed benzene and ethylene emitted from soil and groundwater remediation. In particular, more than 96% of ethylene was removed at residence times of 10～15 min, and the possibility of use of the biofilter was obtained. The benzene removal efficiency was achieved as much as 100% at residence times of 2～15 min. With a residence time of 15 min, the maximum elimination capacity of benzene and ethylene was 4.3 g/$\textrm{m}^3$hr and 1.4 g/$\textrm{m}^3$hr, respectively. The maximum elimination capacity of benzene was 3 times higher than that of ethylene. Carbon dioxide concentration decreased as residence times were lowered due to low ethylene degradation rate. The maximum carbon dioxide production rate of 3,169 [mg-$CO_2$/(g-${C_2}{H_4}$＋${C_6}{H_6$)] was investigated when benzene and ethylene were completely removed. It was found that dominant bacteria in the benzene-degrading microorganisms were identified as Bacillus mycoides and Pseudomonas fluorescens. Dominant bacteria in the ethylene-degrading microorganisms were identified as Pseudomonas putida and Pseudomonas fluorescens.

• Journal of the Korean housing association
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• v.21 no.4
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• pp.51-58
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• 2010

In the modernization process of the city, urbanization raised a variety of social issues. Urbanization brought noticeable changes in dwelling patterns, such as drastic changes in the housing lifestyle, that revolved around the metropolitan areas of Seoul and Busan etc. before and after the expansion of economic growth. Especially in 1985, when 23.8% of the country's population was concentrated in Seoul, the imbalance of housing supply and demand caused a vast range of housing shortage. The shortage, that resulted from public sector mishandling of natural housing demand, lead to the occurrence of private sector rental housing. The occurrence of this abnormal rental housing supply, became a major cause of Korea's typical lease system called 'Co-dwelling', where the leaseholder and tenant physically lives in the same residence. The leaseholder and tenant's 'Co-dwelling' started from partial renting of traditional Korean-style housing and transformed with the transition of dwelling form and time. However, after 1985, legalization of multi-family housing, Korean rental housing started to be planned in the beginning of it's housing construction and to be produced as an independent space with separate circulation. Also in terms of facility, it changed from partial renting of a space within the residence to an assembly of small individual spaces. However, the background of this deep-rooted 'Co-dwelling' lease system, in different forms and periods of residence, is still based on the lack of public sector rental housing supply and private sector supply of rental space to utilize extra space, 'Jeonsei' payment.