• Journal for History of Mathematics
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• v.22 no.2
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• pp.27-52
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• 2009

This article discusses the contributions of the leader Oswald Veblen, who was the president of AMS during 1923-1924. In 2006, Korea ranked 12th in SCIE publications in mathematics, more than doubling its publications in less than 10 years, a successful model for a country with relatively short history of modern mathematical research. Now there are 192 four-year universities in Korea. Some 42 of these universities have Ph.D. granting graduate programs in mathematics and/or mathematical education in Korea. Rapid growth is observed over a broad spectrum including a phenomenal performance surge in International Mathematical Olympiad. Western mathematics was first introduced in Korea in the 17th century, but real significant mathematical contributions by Korean mathematicians in modern mathematics were not much known yet to the world. Surprisingly there is no Korean mathematician who could be found in MaC Tutor History Birthplace Map. We are at the time, to have a clear vision and leadership for the 21st century. Even with the above achievement, Korean mathematical community has had obstacles in funding. Many people thinks that mathematical research can be done without funding rather unlike other science subjects, even though they agree fundamental mathematical research is very important. We found that the experience of early American mathematical community can help us to give a vision and role model for Korean mathematical community. When we read the AMS Notice article 'The Vision, Insight, and Influence of Oswald Veblen' by Steve Batterson, it answers many of our questions on the development of American mathematics in early 20th century. We would like to share the story and analyze its meaning for the development of Korean Mathematics of 21st century.

• Journal of the Korean Applied Science and Technology
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• v.36 no.2
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• pp.394-406
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• 2019

The cellular senescence may be due to damage by the reactive oxygen species (ROS). This study has compared the antioxidant activity in the human cell lines of various origins, including 10S and 50S-derived normal skin fibroblasts, and 10S bone marrow, dental tissue and adipose-derived adult stem cells. After being exposed to $H_2O_2$, half inhibitory concentration ($IC_{50}$) values by cytotoxicity assay was significantly (P<0.05) lower in 50S-derived skin fibroblasts, than in 10S-derived skin fibroblasts and various adult stem cell lines. The cell population doubling time (PDT) and the cell frequency with high senescence associated-${\beta}$-galactose activity were remarkably increased in 50S-derived fibroblasts exposed to 50 ppm $H_2O_2$ for 7 days, than those of 10S-derived fibroblasts and various adult stem cell lines. Further, the expression level of antioxidant-related genes, glutathione peroxidase (GPX) and catalase (CAT), was investigated in 10S and 50S-derived skin fibroblasts, and 10S-derived various adult stem cells by reverse transcription polymerase chain reaction (RT-PCR). The expression level of GPX was higher in most of cell lines, compared to CAT, and a significantly (P<0.05) higher expression level of GPX was observed in 10S-derived skin fibroblasts and adult stem cell lines, compared to 50S-derived skin fibroblasts. We concluded that old-aged skin fibroblasts seemed to be less resistant against ROS than young-aged skin fibroblasts and adult stem cells.

• Journal of Life Science
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• v.29 no.6
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• pp.724-734
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• 2019

The present study investigated the cytotoxicity of particulate matter (PM) derived from car air filter (outdoor PM) and home cleaner filter (indoor PM) in the various human cell lines. Each outdoor and indoor PM were harvested by ethanol extraction method, subsequently sieved with 10 um filter paper, sterilized with autoclave and added to culture media. The half maximal inhibitory concentration ($IC_{50}$) values was significantly (p<0.05) lower in the outdoor PM, compared with indoor PM, and the significantly (p<0.05) higher $IC_{50}$ values were observed in the cancer cell lines (A-549 lung adenocarcinoma and AGS stomach adenocarcinoma), than those of normal MRC-5 fibroblasts and dental papilla tissue derived-mesenchymal stem cells (DSC). After being exposed to $100{\mu}g/ml$ outdoor PM for 7 days, the population doubling time (PDT) was significantly (p<0.05) increased in especially MRC-5 and DSC cell lines, compared with untreated cell lines. Further, the expression of senescence-associated ${\beta}$-galactosidase activity was up-regulated in all the cells exposed to outdoor PM than those of untreated control. Besides, the expression level of inflammation-associated genes, such as cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) was found to be significantly (p<0.05) increased in the outdoor PM-treated cell lines than those of untreated cell lines. Our results showed that PM induces the cytotoxicity via arrest of cell growth, cell damage and inflammation response.

• Korean Journal of Social Welfare Studies
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• v.41 no.4
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• pp.225-246
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• 2010

The family environment children are exposed to growing up greatly influences their future potential and achievements. Previous findings show that changes in family structure during childhood, particularly those resulting from divorce or death, cause lasting negative consequence that affect the child physically, psychologically, economically, and socially. Unfortunately, single-parent households are becoming increasingly common in Korea, nearly doubling to more than a million cases in the last two decades. Existing domestic and international studies of this area tend to focus on the short-term effects of growing up in a single-parent household. In addition, these studies group their samples in ways that result in findings that may be too broad or are not necessarily an accurate representation of the subjects. This study attempts to address some of these shortcomings by focusing on the long-term effects of how changes in family structure early in children's lives affect achievement during their transition to adulthood. In addition, it takes into account the development cycle the child is in at the time of family restructuring, and what kind of long-term effects result from that. In this analysis, we find that there are several cases of statistically significantly differences in domain achievement depending on the developmental stage the child was in when the parental divorce or death occurred. The findings indicate that changes in family structure during the infant/toddler period influence health condition and depression, while changes in family structure during middle-childhood and adolescence do not. Meanwhile, changes in family structure during any point in the developmental stages have negative effects on educational attainment, with the severity of these negative effects depending on when the family changes occur. The negative effect on educational attainment is most prominent when a change in family structure occurs during the infant/toddler period, followed by adolescence, then middle-childhood.