• Korean Journal of Ecology and Environment
• /
• v.46 no.3
• /
• pp.429-439
• /
• 2013

This study was conducted to determine the changes of the ecological niche breadth and niche overlap of Quercus acutissima and Quercus variabilis under elevated $CO_2$ concentrations and under elevated temperature conditions. We investigated the growth responses by environmental factor, $CO_2$ concentration, air temperature, light, soil moisture and nutrients. Rising $CO_2$ concentration was treated with 1.6 times than control (ambient) and increased temperature with $2.2^{\circ}C$ above the control (ambient) in the glass greenhouse. Ecological niche breadth and niche overlap was calculated the two oak species (Q. acutissima and Q. variabilis), which were cultivated with light, soil moisture and nutrient gradients at four levels. As a result, the ecological niche breadth of Quercus acutissima was determined to be increased under the warming treatment, but decreased under soil moisture and nutrient environments. The ecological niche breadth of Quercus variabilis was increased under light, soil moisture and nutrients of the warming treatment than control. Ecological niche overlap between Quercus acutissima-Quercus variabilis was increased under light of the warming treatment than control, but decreased under soil moisture and nutrient environments. These results means that two oak species are more severe competition in light environments than soil moisture and nutrient environments. According to analyses of the Cluster and PCA, the two oak species were more sensitive react under light environment than to elevated $CO_2$ concentration or elevated temperature.

• Korea journal of population studies
• /
• v.26 no.2
• /
• pp.197-219
• /
• 2003

Using the panel data from the National Longitudinal Survey of Youth 79, we test the effects of relative status inconsistency within American young couples on the direction of migration as well as on migration propensities. Key findings in this study indicate that only couples in which the wife's education is greater than the husband's education are less likely to migrate than couples for which the wife's status is as lower than the husband's. There are no differences in the propensity for rural couples to migrate to urban counties or for urban couples to migrate to rural counties based on status inconsistency between spouses. However, we find that there is the gendered difference in the effect of status inconsistency on the probability of family migration. A spouse's higher status has an impact on a wife's probability of migration but does not affect a husband's migration propensity in a comparable situation. These findings are most consistent with a gender role perspective on migration since increases in the wife's status have little effect on family migration, once the presence and age of children is controlled.

• Journal of the Korean Society of Child Welfare
• /
• no.57
• /
• pp.43-82
• /
• 2017

As material perspective that stresses absolute income has limitations in explaining socioeconomic gradients in health, research on the relationship between an individual's subjective socioeconomic status(SSS) and health has emerged in recent years. Although previous research has been conducted mostly on adults, late school-aged children, who frequently evaluate themselves using social comparisons, are likely to subjectively perceive their socioeconomic status and be affected by their perception. Accordingly, this study examined the relationship between late school-aged children's SSS and their physical health, and its underlying path based on a psychosocial perspective. For this purpose, data from the first year survey of the Seoul Education and Health Welfare Panel (2014), which consisted of responses from 394 children ($4^{th}$ graders in elementary school) and their parents, were analyzed utilizing structural equation modeling. The results showed an indirect but significant relationship between late school-aged children's SSS and their physical health, via stress, self-efficacy, and health behaviors, which are mediating variables grounded on a psychosocial perspective. No direct relationship was found between late school-aged children's SSS and physical health. Based on these findings, we suggested several implications to improving children's health, including efforts to prevent adverse effects of low SSS on physical health through psychosocial factors.

• Korean Journal of Culture and Social Issue
• /
• v.11 no.1
• /
• pp.43-57
• /
• 2005

Data were collected from 310 6th, 7th, and 8th grade students and parents by questionnaires and analyzed by t-test and multiple regression analysis. The higher parents attachment and parents monitoring, the higher prosocial behavior towards parents and siblings, the higher perspective-taking, the higher prosocial behavior towards parents, and the higher socioeconomic status, the higher prosocial behavior towards siblings. More prosocial behavior toward parents was reported by girls than by boys. Prosocial behavior toward siblings did not show a gender difference. In the total group, high parent attachment and perspective-taking predicted prosocial behavior towards parents; high parent attachment and socioeconomic status predicted prosocial behavior towards siblings. In the boy group, high parent attachment and perspective-taking predicted prosocial behavior towards parents; high socioeconomic status predicted prosocial behavior towards siblings. In the girl group, high parent attachment predicted prosocial behavior towards parents and high parent attachment and socioeconomic status predicted prosocial behavior towards siblings. Discussion focused on the relative importance of parents attachment, perspective-taking, and socioeconomic status in predicting early adolescents' prosocial behavior.

• Journal of the Korean Applied Science and Technology
• /
• v.39 no.6
• /
• pp.892-905
• /
• 2022

This study attempted to derive high-risk groups of adolescent status delinquency(ASD) and to identify related factors. This study was conducted with 1,979 adolescents enrolled in the first year of high school, data from the 7th year of the 4th grade panel of the Korean Children and Youth Panel Survey. Classification and regression tree analysis method was used. The ASD group was 264, which was 13.3% of the total. The high-risk group for ASD is that is male who has a low perception of positive parenting style. Positive parenting style was found to be the most important influencing factor in ASD, followed by gender, emotional problems, relationship with teacher, and achievement value. In order to prevent ASD, it is necessary to develop a parenting education program and an intervention program specialized for male adolescents. In addition, interventions that comprehensively deal with emotional problems such as depression and social withdrawal are required, going beyond the previous interventions that focused on aggression. In particular, it has been found that relationship with teachers is the most important influencing factor in the school environment. Through education on the causes and consequences of ASD and training on counseling techniques, the promotion of relationships with teachers will act as a protective factor to prevent ASD.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.7 no.3
• /
• pp.181-190
• /
• 2012

After industrialization, the labor force participation rates of women, especially married women is drastically increasing. So, this study was designed to analyze the determinants of married women's employment status considered. For this, the determinants of married women's employment status were divided into individual-related, children-related, household-related and job-related variables to establish the research models. Based on this, the following results were drawn from a multinominal logistic regression analysis of the determinants of married women's employment status. First, an analysis of individual-related variable showed that married women had the employment status of labor wages with residence in the center of the city and high academic background. Second, an analysis of children-related variable showed that they had the employment status of labor wages with many their children and no their children under the age of six. Third, an analysis of household-related variable showed that they had the self-employment status of labor wages with nuclear family and few income earners of family members. Finally, an analysis of job-related variable showed that they had the employment status of labor wages when they got a job before they got married, their husband didn't get a job, and their husband worked in a professional field. As for findings stated above, as there was a difference in the determinants of married women's employment status, the ways for improvement in the married women's employment status would be suggested as follows. First, married women with young children have the low employment status, basically, requiring problem-solving ways for this because the housekeeping and child-rearing burden caused by marriage and childbirth are factors that continue to obstruct a job. For this, the flexible working hours system, which housekeeping and child-rearing can harmonize with economic activities like developed countries, needs to be activated. But the activation of such flexible working system will produce actual results under institutional protection, such as a related-protection law. Second, the Leave of Child Care System is debated as one of the most representatively systems that housekeeping can harmonize with economic activities. Now, although the System is legislated, the use is very poor.

• Journal of Korean Society of Forest Science
• /
• v.90 no.3
• /
• pp.380-387
• /
• 2001

The characteristics of ecological niche, breadth and overlap, for seventeen major tree species were evaluated in the natural deciduous forest in Mt. Chumbong area. Employed by the plot sampling method, the environmental gradient for vertical niche was based on the intensity of light within the forest, and that for horizontal niche was based on multi-dimensional resources in distribution pattern. The result showed that Fraxinus rhynchophylla had the highest value of vertical niche breadth and Maackia amurensis had the lowest, and Acer pseudo-sieboldianum had the highest value of horizontal niche breadth and Betula costata had the lowest. There was no significant correlation between both measures of niche breadth. However, the tolerance index for each species was positively correlated to the values of niche breadth. Spearman's rank correlation coefficients were applied to test the correlationship between the species ranks of tolerance index and those of two ecological niche breadths. The coefficient of $r_s=0.432$ ($P{\leq}0.1$) was not enough to support significant correlationship between the tolerance index and vertical niche breadth at the 95% probability. If Carpinus cordata, rarely reach canopy of the forest due to its own growth form, are excluded from the analysis, coefficient was calculated as $r_s=0.650$ ($P{\leq}0.01$), resulting in highly significant correlationship. The Spearman's rank correlation coefficient was $r_s=0.797$ ($P{\leq}0.01$) for tolerance indices and the values of horizontal niche breadth, indicating highly significant. Four distinctive species groups, produced by cluster analysis on the basis of ecological niche overlap for each pair of species, were in considerable accord with the positively associated species constellation pattern created by the inter-species association analysis.

• Journal of Korean Society of Forest Science
• /
• v.82 no.4
• /
• pp.420-430
• /
• 1993

This study was conducted to investigate the effect of the forest environmental factors(5 items) and physico-chemical properties of soil(13 items) on the growth of Pinus thunbergii stands. The 218 plots were sampled over the coastal district of the whole country. In statistical analysis, the explanatory variables were soil and environmental factors(18 items), and the response variable was the site index of Pinus thunbergii stands. Data computation was processed in order of preparation of original data, computation of inner correlation matrix table by correlation analysis, calculation of partial correlation coefficients and coefficients of determination, estimation of regression equation by stepwise begression analysis, and stepwise regression analysis by factor score of factor analysis. The main results obtained were summarized as follows ; 1. The site index in Pinus thunbergii stands way highly correlated with effective soil depth(r=0.8668), slope percentage, organic matter, and total nitrogen. 2. According to the coefficients by partial correlation analysis, effective soil depth(r=0.6270), slope percentage (r=-0.5423) and base saturation(r=0.3278) among environmental factors had a great effect on tree growth. 3. With stepwise regression analysis, the factors effecting on the Pinus thunbergii stands growth were effective soil depth, slope percentage, organic matter, base saturation, soil pH, content of silt, exchangeable Ca, and etc. 4. Estimation equation for the site index of Pinus thunbergii stands was given by $Y=13.2691+0.0242\;X_2-1.2244\;X_4+0.6142\;X_5-0.3472\;X_{11}+0.0355\;X_{13}+0.1552\;X_{15}-0.1002\;X_{17}$. The coefficient of determination for the estimation model was 0.77, which was significant at the 1 percent level. 5. In result of factor analysis by the environmental factors, principal components were 6 factors, and communality contribution percentage was 71.1 percent. 6. By stepwise regression analysis between factor score and site index of Pinus thunbergii stands, the factor group effecting on site index was 5 principal components. The coefficients of determination was 85 percent, which was significant at the 1 percent level. In conclusion, on the occasion of analizing which factors to effect on the tree height growth in Pinus thunbergii stands the stepwise regression analysis proved to be greatly significant. Also the management of Pinus thunbergii stands should be working by the above selected growth factors.

• Journal of Korean Society of Forest Science
• /
• v.111 no.2
• /
• pp.311-318
• /
• 2022

We conducted this study to derive the site index, which is a criterion for the planting of Robinia pseudoacacia, a honey plant, and to investigate the diameter distribution change by derived site index. We applied the Chapman-Richards equation model to estimate the site index of the Robinia pseudoacacia stand. The site index was distributed within the range of 16-22 when the base age was 30 years. The fitness index of the site index estimation model was low, but we judged that there was no problem in the application because the residual distribution of the equation had not shifted to one side. We used the Weibull diameter distribution function to determine the diameter distribution of the Robinia pseudoacacia stand by site index. We used the mean diameter and the dominant tree height as independent variables to present the diameter distribution, and our analysis procedure was to estimate and recover the parameters of the Weibull diameter distribution function. We used the mean diameter and the dominant tree height of the Robinia pseudoacacia stand to show distribution by diameter class, and the fitness index for dbh distribution estimation was about 80.5%. As a result of schematizing the diameter distribution by site indices as a 30-year-old, we found that the higher the site index, the more the curve of the diameter distribution moved to the right. This suggests that if the plantation were to be established in a high site index stand, considering the suitable trees on the site, the growth of Robinia pseudoacacia woul d become active, and not onl y the production of wood but al so the production of honey would increase. We therefore anticipate that the site index classification table and curve of this Robinia pseudoacacia stand will become the standard for decision making in the plantation and management of this tree.

• Proceedings of KOSOMES biannual meeting
• /
• 2018.06a
• /
• pp.19-19
• /
• 2018