• Bulletin of the Korean Chemical Society
• /
• v.30 no.11
• /
• pp.2589-2594
• /
• 2009

Aging phenomena of plasma polymer films were studied by using the surface analysis techniques of contact angle measurement, X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOFSIMS), and atomic force microscopy (AFM). The polymer films were grown on an aluminum substrate by using a plasma polymerization method from a gas mixture of acetylene and helium, and the films were subsequently modified to have a hydrophilic surface by oxygen plasma treatment. Aging of the polymer films was examined by exposing the samples to water and air environments. The aging process increased the hydrophobicity of the surface, as revealed by an increase in the advancing contact angle of water. XPS analysis showed that the population of oxygen-containing polar groups increased due to the uptake of oxygen during the aging, whereas TOF-SIMS analysis revealed a decrease in the polar group population in the uppermost surface layer. The results suggest that the change in surface property from hydrophilic to hydrophobic nature results from the restructuring of polymer chains near the surface, rather than compositional change of the surface. Oxidative degradation may enhance the mobility and the restructuring process of polymer chains.

• Korea journal of population studies
• /
• v.8 no.2
• /
• pp.93-99
• /
• 1985

There have been numerous studies in Korea and other countries of which the major hypotheses are identifying and dearibing the conditions under which the value of children has been formed. The present study proposes to view the formation of the value of children as a correlate of family's consumption-saving and work4eisure behavior pattern. The objectives of the proposed study are to identify the socio-economic and demographic factors determining the family's consumption-saving and work-leisure behavior pattern and to analyse the relationship between the value of children and this behavior pattern. The conceptual framwork of the analysis is that an individual family's socio-economic and demographic factors influence and shape the consumption-saving and work-leisure behaviors and these behaviors in turn influence and reflect the correlates and proximate determinants of the family'sfertility. In this paper, regression model is used to analyse the hypothesized relationship among the various variables. The regression methods used are first and second stage multiple regressions. In addition, MONOVA has been used to show the interactions. Data used are collected from the government publicactions. The major findings from this study are as follows: As the living Standard improves, n individual family's consumption of necessities and its working hours decline, while savings and leisure activities increase. The phenomena result in the fertility reduction as can be seen in the more developed conntries. Child-bearing and rearing activities are found to be the important component to determine the condumption-saving and work-leisure activies. The married women's labor participation, and the investment in education and health are also found to be the factors reducing fertility rate.

• Journal of Korean Society of Disaster and Security
• /
• v.14 no.4
• /
• pp.1-7
• /
• 2021

Although the working environment has changed significantly compared to the past, such as the implementation of the five-day work week and the aging of the population, it is not reflected in the current industrial accident index calculation such as frequency rate, severity rate, and safe T-score. In this study, statistical data were used to understand time-series trends such as increase in life expectancy, working age, shortening of working hours, and average age of death by accident. As a result of time series trend analysis of statistical data, life expectancy increased to 83.3 years, and the legal working age was raised to 65 years due to the aging of the population. Also, with the advent of the 5-day work week since 2001, the average annual working hours decreased to 2008.1 hours. It can be confirmed through statistical data that these phenomena are applied to the current working environment due to a complex action, and these environmental changes affect the calculation results of the industrial accident index.

• Korea journal of population studies
• /
• v.16 no.2
• /
• pp.84-110
• /
• 1993

This study aims at identifying the recent change in marriage behaviors in Korea. The data used here is the vital statistics compiled from the vital registration system of which registration form is put on one from together with the civil registration form. According to the results of this analysis, since 1970 the number of marriages has steadily increased from about 300, 000 in the former of 1970s to about 400, 000 in the latter of 1980s, appproximately coincided with the change in population size at the marriageable age span. The few exceptions that can be seen in the 1970s seem to result from the impact of social upheavals during 1950s; since the birth cohorts affected by the low fertility during the Korean war and the post-war baby-boom generations chracterized by the high fertility entered the marriage market in the 1970s. However, the marriage rate shows a little increase from around 7 in the former of 1970s to around 9 in the latter of 1980s, indicating that the marriage prevalence has been more or less inconsiderably changed during this period. It is also found that the proportion of remarriage to the total marriages has increased to around 10 per cent in 1989, while decreasing that of first marriage. This fact can be attributable to the higher prevalence of divorces and the collapsing of the Confucianism ethic which contributed to expediting the remarriage of widows. Although this proportion is insignificant compared with that of the of more developed countries, it is not difficult to say that the proportion of remarriages will continue to increase in future. The age first at first marriage(AFM) which directly affects the span exposed to the risks pregnancy has increased to the age about 28 for male and about 25 for female in recent years. However, big difference in AFM between urban and rural areas has narrowed, resultant from the increasing involuntary postponement of marriage of rural young population who have met difficulties in seeking their bride or bridegroom in rural areas characterized by the heavy out-migration of young, particularly female, population. The present study shows the reverse relationship between AFM and educational attainment; i.e, the higher the educational attainment the lower the AFM. The conditions which are taken into considerations were the class and the family in the past time but which are, educational attainment, job and personal characteristics. With regard to the age condition, in recent years the male prefers the female younger than himself on the average by 3 years and vice versa, which is reduced form 4-5 years in beginning of 1970s. The age difference bride and bridegroom tends to decrease with the educational attainment increase. This may be attributable to the fact that the persons with the higher educational attainment prefer the love marriage and hence are more likely to choose their counterparts in the about same age. The education condition is characterized by the bridegroom having the higher educational level than bride. It is also significant to note that the proportion of love marriage has increased, whereas that of traditional arranged marriage has decreased. This is true in the urban areas than the rural areas, indicating that rights as well as responsibilities for marriage have been handed over the young population from their parents. In conclusion, the change in the marriage behaviors in Korea are characterized by increasing tendency for the postponement of first marriage, higher prevalences of divorces and a result remarriages, increase of love marriages, narrowing age difference between bride and bridegroom, etc. which are the main results of rapid industrization, increase in educational and economic activity opportunities and change in the ideals of marriages during the past decades. These phenomena prevailing in Korean society would affect not only the family structure that will become less proliferiated but the population size and structure. The most important is that the changes in marriage behaviors of Koreans and their impact on the society with respect to norms, values, morals, of individual and family in the social aspect, change in population size and structure in the demograpic aspects, and economic development in the economic aspects should be integrated into the plannings towards to the future.

• Korean Chemical Engineering Research
• /
• v.60 no.1
• /
• pp.116-124
• /
• 2022

In this study, waste air containing ethanol and hydrogen sulfide, was treated by an integrated hybrid system composed of two alternatively-operating UV/photocatalytic reactor-process and biofilter processes of a biofilter system having two units with an improved design (R reactor) and a conventional biofilter (L reactor). Both a pressure drop (△p) per unit process of the integrated hybrid system and a microbe-population-distribution of each biofilter process were observed. The △p of the UV/photocatalytic reactor process turned out very negligible. The △p of the L reactor was observed to increase continuously to 4.0~5.0 mmH₂O (i.e., 5.0~6.25 mmH₂O/m). In case of R reactor, its △p showed the one below ca. 16~20% of the △p of the L reactor. Adopting such microbes-carrying biofilter media with high porosity as waste-tire crumb media, and the improved biofilter design, contributed to △p of this study, reduced by ca. 37~50% and 40~53%, respectively, from the reported △p of conventional biofilter packed with biofilter media of the mixture (50:50) of wood chip and wood bark. In addition, the △p of R reactor in this study, reduced by ca. 80% from the reported △p of conventional biofilter packed with biofilter media of the mixture (75:25) of scoria with high porosity and compost, was mainly attributed to adopting the improved biofilter design. On the other hand, in case of L reactor, the CFU counts in its lowest column was analyzed double as much as those in any other columns. However, in case of R reactor, its CFU counts were bigger by 50% than the one of L reactor and its microbes were evenly distributed at its higher and lower columns of R_dn reactor and R_up reactor. This phenomena was attributed to an even moisture distribution of 50~55% of R reactor at its higher and lower columns. Therefore, R reactor showed superb characteristics in terms of both △p and microbe-population-distribution, compared to L reactor.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.25 no.4
• /
• pp.284-290
• /
• 2015

Road traffic noise is closely related with urban forms and urban components, such as population, building, traffic and land-use, etc. Hence, it is possible to minimize the noise exposure problem depending on how to plan new town or urban planning alteration. This paper provides ways to apply for urban planning in consideration of noise exposure through road traffic noise estimation for alteration of small-scale urban form. Spatial autoregressive model from the former study is used as statistical model for noise simulation. The simulation results by the spatial statistical model are compared with those by the engineering program-based modeling for 5 scenarios of small-scale urban form alteration. The error from the limitation of containing informations inside the grid cell and the difficulties of reflecting acoustic phenomena exists. Nevertheless, in the stage of preliminary design, the use of the statistical models that have been estimated well could be useful in time and economically.

• Journal of the Korean Institute of Rural Architecture
• /
• v.13 no.4
• /
• pp.1-8
• /
• 2011

Korea is moving toward an aging society faster than the other advance countries such as the U.S. and France. Such aging phenomena are posing greater problems in rural areas than in urban areas, and particularly, decrease in productivity caused by aging population leads to economic difficulties and hinders the improvement of housing life. The purpose of this research is to examine and identify the housing conditions of the vulnerable in rural areas and to present ways to improve the elderly housing and the housing environment in rural areas and to provide basic data for materializing the policies to enhance the quality of life. The results of this research are as follows. First, the elderly in rural areas were found to receive relatively smooth supports for services related to clothing and food through the government and social organizations. But for the housing problems, it was found that there were not any supports. Second, the poor housing environment may cause diseases to the elderly with weak immunity, so ways to remedy these problems are urgently needed. Third, the vulnerable in rural areas can hardly bear the burden of improving the housing environment, so supports from the government and social organizations are needed. Fourth, ways to support the vulnerable such as households receiving basic living subsidies and to support the poor who are not receiving such subsidies should be explored.

• Korean Institute of Interior Design Journal
• /
• v.25 no.5
• /
• pp.63-70
• /
• 2016

Modern society is suffering from the phenomena of low-fertile, ultra-aging, and low-growth. On this social flow, most social classes undergo vulnerable situation and their overall housing and living condition have difficulties. So far many housing guidelines for diverse population were developed, recently, inclusive 'Customized Housing Design Guideline for Childcare Families' in terms of maintaining family and society has been completed. The purpose of this study is to analyze User Benefit Characteristics of 'Customized Housing Design Guideline for Childcare Families'. The research subjects are essential 140 guidelines appropriate to children's development and parents' care. The research method is contents analysis and the analysis criterion are 4 concepts of the User Benefit Criteria- 'Behavioral Facilitation (BF)', 'Physiological Maintenance (PhM)', 'Perceptual Maintenance (PM)', 'Social Facilitation (SF)'. 3 people inter-raters reliability was established. Altogether, the guidelines were rated in the order of PhM>PM>BF>SF, and these characteristics are similar as common universal design guidelines. This showed the supportability of spatial characteristics in the guidelines related to user's special behaviors. Also, the results show the importance of outdoor space planning for safe social interactions. The supportable characteristics of 'Customized Housing Design Guideline for Childcare Families' could be expected to efficiently apply for new housing development in the future.

• Journal of Ecology and Environment
• /
• v.29 no.2
• /
• pp.175-183
• /
• 2006

The discovery of deep-sea hydrothermal vents and their ecosystems is a monumental landmark in the history of Ocean Sciences. Deep-sea hydrothermal vents are scattered along the global mid-ocean ridges and back-arc basins. Under sea volcanic phenomena related to underlying magma activities along mid-ocean ridges generate extreme habitats for highly specialized communities of animals. Multidisciplinary research efforts during past three decades since the first discovery of hydrothermal vents along the Galapagos Rift in 1977 revealed fundamental components of physiology, ecology, and evolution of specialized vent communities of micro and macro fauna. Heterogeneous regional geological settings and tectonic plate history have been considered as important geophysical and evolutionary factors for current patterns of taxonomic composition and distribution of vent faunas among venting sites in the World Ocean basins. It was found that these communities are based on primary production of chemosynthetic bacteria which directly utilize reduced compounds, mostly $H_2S$ and $CH_4$, mixed in vent fluids. Symbioses between these bacteria and their hosts, vent invertebrates, are foundation of the vent ecosystem. Gene flow and population genetic studies in parallel with larval biology began to unveil hidden dispersal barrier under deep sea as well as various dispersal characteristics cross taxa. Comparative molecular phylogenetics of vent animals revealed that vent faunas are closely related to those of cold-water seeps in general. In perspective additional interesting discoveries are anticipated particularly with further refined and expanded studies aided by new instrumental technologies.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.948-951
• /
• 2014

Road traffic noise is closely related with urban forms and urban components, such as population, building, traffic and land-use, etc. Hence, it is possible to minimize the noise exposure problem depending on how to plan new town or urban planning alteration. This paper provides ways to apply for urban planning in consideration of noise through exposed noise estimation for urban planning alteration. Spatial autoregressive model which explains about 81.4% of road traffic noise from the former paper is used. The simulation results by the spatial statistical model are compared with those by the engineering program-based modeling for 5 small-scaled scenarios of urban planning alteration. The error from the limitation of containing informations inside the grid cell and the difficulties of reflecting acoustic phenomena is existed. Nevertheless, in the stage of preliminary design, the use of the statistical models that have been estimated well is useful in time and economically.