• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.220-227
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• 2009

This study was conducted to select superior families based on the open-pollinated (OP) progeny tests of P. densiflora. A total of 232 OP families were analyzed for relative height growth. The OP progeny test trials were established at 1 to 4 sites from 1975 to 1987. To minimize temporal and spatial variation, we applied the standardization method for family selection. In each progeny test, superior and inferior families were selected at ages of 10, 20 and 30. Relative height growth rate (RHGR), growth speed at a given time unit, was comparatively high at age of 10 with range from 0.1 to 0.6 and showed a large variation among families. However, after age 15, the RHGR was low (average 0.04) and also the variation was not significantly different among families. To reduce selection errors due to age differences (from age 23 to 35) of tests, we made the family selection after age 15 when the values of RHGR were stable. Height growth at each age was transformed to be height growth at age 35 based on the RHGR. As the results, family CB2, CB3, KW99 and KW2 were selected as superior families and KW158, KW22, KB40 and GG1 were considered as inferior ones, respectively. Rank correlations (r) between test ages and selection age 35 were high and statistically significant; r = 0.881 between age 30 and 35, 0.653 between age 20 and 35, and -0.222 between age 10 and 35.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.323-327
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• 2006

This study was conducted to understand response of damage and tolerance to ozone between ozone tolerant and sensitive families of P. densiflora which had been selected by the based on visual injury and growth. Five individuals were selected in each group, and were exposed to 100ppb ozone for 90 days. Every 30 days after ozone fumigation, diamter at root collar (ORC), superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content were measured. In early state of ozone fumigation tolerant families showed three times higher relative DRC growth rate than sensitive families. And during whole fumigation period growth rate of tolerant families was superior to growth rate of sensitive families. SOD activity in sensitive families was increased 30 days after fumigation, and in accordance with fumigation period extended it was decreased continuously. MDA content in ozone treatment showed higher than in control, and MDA content of tolerant families was higher than that sensitive families. In our results tolerant families has higher antioxidative activity than sensitive families. Therefore tolerant families can restrain lipid peroxidation and damage on physiological activity.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.124-132
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• 2001

This study was conducted to reveal the relationship between physiological characteristics and growth by family for open-pollinated progeny stand of Korean white pine in Gapyung site. Average growth performance of total 25 families for 18 years old progeny stand in this study site showed 5.9m in mean height, 8.9cm in mean DBH, $12.0m^2$ in basal area per hectare and $46.5m^3$ in volume per hectare, respectively. By the analysis result of growth performance for all 25 families, family No. 20 showed the most excellent growth and middle in family No. 10. On the other hand, family No. 3 represented the worst growth among the 25 families. The change of seasonal photosynthesis rate by increasing luminous intensity was the same tendency as the growth pattern of all 25 families and showed the same results in all four seasons. In the seasonal analysis, the photosynthesis rate was increased as the season has changed from winter to summer. Chlorophyll contents was also increased from winter to summer. Especially, family No. 20 which is the best in growth performance has more chlorophyll contents than the others. In addition, family No. 20 was also better than other families in the weight of assimilation tissue(g), length of needle(cm), width of needle(cm), and number of Stoma. However, in water utilization rate, family No. 3 which is the worst in the growth performance showed the best result that is reverse tendency compared with the photosynthesis rate. The changes of water utilization rate represented to be increased as the season has changed from winter to summer.

• Journal of Families and Better Life
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• v.13 no.1
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• pp.207-219
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• 1995

본 연구는 우리나라 도시가계의 부채보유여부 및 부채부담의 관련요인을 규명하고자 하였다. 분석을 위하여 국민은행이 실시한 1990년도 가계금융이용실태조사 자료를 이용하였다. 부채보유여부의 관련요인분석을 위하여 로짓분석을 사용하였으며, 월평균가계소득에 대한 월평균부채상환액의 비율로 측정된 부채부담에 대한 관련요인의 분석을 위하여는 회귀분석을 사용하였다. 주요 연구결과는 다음과 같다. (1) 도시가계의 부채보유비율은 38.2%였고, 부채를 보유할 확률은 가계속득, 금융자산, 주택소유여부, 가구주 연령과 유의한 상관관계가 있었다. (2) 부채보유가구의 평균부채부담율은 33.99%였고, 부채부담은 가계소득, 금융자산, 부채원 수, 가구주 직업 및 거주지역과 유의한 상관관계가 있는 것으로 나타났다.

• Proceedings of the KHMA Conference
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• 2002.11a
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• pp.54-69
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• 2002

• Proceedings of the KHMA Conference
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• 2002.11a
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• pp.70-71
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• 2002

• KDI Journal of Economic Policy
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• v.26 no.1
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• pp.35-69
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• 2004

Using household survey data set during 1993~1998 period, this paper analyzes patterns and determinants of household stock market participation. The results shows that the age profile of stock market participation in Korean household is humped-shaped as in other developed countries. Also, households with a higher level and lower variability of income, bigger financial asset, and higher education level are more likely to be stockholders. The stock market participation rate of the self-employed is substantially lower than that of the employed. In Korea, the high proportion of self-employed among total labor force seems to lower the stock market participation rate.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.136-142
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• 2008

We conducted this study to compare physiological response according to growing conditions between superior and inferior family of Pinus densiflora. In 1981, open-pollinated (OP) progenies of P. densiflora were planted in Chuncheon (CC) and Naju (NJ). We selected KW2 as a superior family and KW23 as a inferior family based on volume index among 30 OP progenies. We calculated general combining ability of each 30 OP progenies in each sites, and compared family growth rank. We collected needles of selected families in CC and NJ, and analyzed chlorophyll content, nitrated reductase (NR) activity, nitrogen content, and superoxide dismutase (SOD) acitivity. In CC, chlorophyll content and nitrogen content were more in needles of KW2 than those of KW23. In NJ, KW2 showed higher NR activity than KW23, and according to site, families in CC showed higher NR activity than those in NJ. SOD activities of both families were higher in NJ, and KW23 showed higher activity than KW2 in both sites. Consequently, inconsistency of the growth performance of two families was caused by different genetic and physiological responses.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.297-307
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• 2009

Korean household debt is one of the main sources of the current financial crisis. This paper studies the impact of household members' attributes such as a type of housing(self-own or rent), education, age, average monthly income of the head of household, and the area of residence, on the stress level of the household members due to household debt. We analyze a real data set collected by KB Kookmin Bank in 2004. We consider low and high stress level as a binary response variable and use a logistic regression model with the attributes of household members as explanatory variables. A simple but well-fitting model is selected by backward elimination method based on the likelihood statistic for goodness-of-fit test, and the impact of the attributes on the stress level is studied from parameter estimates of the selected model. We also perform the similar analysis on a binary response variable which distinguishes households with no debt from the rest. From the analysis, the stress level tends to be low for households with self-own houses, high average monthly income, low education level, and young members.

• Journal of Digital Convergence
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• v.14 no.5
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• pp.177-183
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• 2016

The purpose of this study is to analyze the affecting factors and debt characteristics with household debt. The method of analysis was used SPSS 22.0. The main results were as follows. First, psychological debt burden group were found to be lower academic background, more household members, job in agriculture, forestry and fisheries and women among demographic characteristics. This suggests the need for the governments who are interested in the risk from household debt. Second, psychological debt burden group showed higher level of debt and average monthly debt repayments. This study implies that it is necessary to do financial education and consulting. Third, psychological debt burden group seemed that the households with more the average monthly interest payments and repayments on income, the more total liabilities compared to total assets. As the ages get higher, it was gradually increased. It suggests that the development of psychological counseling program for debtor with household debt. Other factors(property prices or the financial environments) will be dealt with in the subsequent studies.