• The Bulletin of The Korean Astronomical Society
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• v.38 no.1
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• pp.39-39
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• 2013

We present a study of correlations between the elemental abundances and galaxy morphologies of 91 blue compact galaxies (BCGs) at z=0.20-0.35 with Sloan Digital Sky Survey (SDSS) DR7 data. We classify the morphologies of the galaxies as either 'disturbed' or 'undisturbed', by visual inspection of the SDSS images, and using the Gini coefficient and M20. We derive oxygen and nitrogen abundances using the Te method. We find that a substantial fraction of BCGs with disturbed morphologies, indicative of merger remnants, show relatively high N/O and low O/H abundance ratios. The majority of the disturbed BCGs exhibit higher N/O values at a given O/H value compared to the morphologically undisturbed galaxies, implying more efficient nitrogen enrichment in disturbed BCGs. We detect Wolf-Rayet (WR) features in only a handful of the disturbed BCGs, which appears to contradict the idea that WR stars are responsible for high nitrogen abundance. Combining these results with Galaxy Evolution Explorer (GALEX) GR6 ultraviolet (UV) data, we find that the majority of the disturbed BCGs show systematically lower values of the $H{\alpha}$ to near-UV star formation rate ratio. The equivalent width of the $H{\beta}$ emission line is also systematically lower in the disturbed BCGs. Based on these results, we infer that disturbed BCGs have undergone star formation over relatively longer time scales, resulting in a more continuous enrichment of nitrogen. We suggest that this correlation between morphology and chemical abundances in BCGs is due to a difference in their recent star formation histories.

• Korean Journal of Social Welfare
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• v.61 no.2
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• pp.391-415
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• 2009

The purpose of this study is to examine the trends of income inequality by gender since 1997 economic crisis and to investigate what is the most influential factor on these changes for males and females. Data used for this study are nine waves of Korean Labor and Income Panel Study(KLIPS). Income inequality is measured by the Gini coefficient and the mean logarithmic deviation(MLD) and the MLDs are decomposed into three components to quantify within- and between-group inequalities. The results show that the extent of income inequality is greater for women during the whole period and is fluctuated more widely. Women's income inequality is mainly affected by the family-related variables, such as age and marital status, while men's inequality is primarily determined by the labor market factors, such as employment status, industrial types and occupation status. These results imply that gender-sensetive welfare policies need to be implemented and that it is necessary to assist the poor women and men through the benefits from the income assistance programs and labor market programs.

• Journal of Digital Convergence
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• v.18 no.7
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• pp.37-46
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• 2020

The aim of this research is to analyze the concentration and deconcentration development of cruise ports in the Mediterranean area by utilizing the concentration ratio (CR), the Herfindahl-Hirschman Index (HHI), the Gini coefficient, and shift share analysis (SSA). The results of analysis indicated a concentration trend in the West Mediterranean. The cruise ports located in Venice, Piraeus, Naples and Livrno in Adriatic and East Med region lost cruise passengers, while the those in West Mediterranean gained the passengers and showed the trend of concentration. This paper providing the shifting passengers among cruise ports that indicates the competitiveness of cruise ports for industrial stake holders to better understand the cruise ports such as tourist boards, ship agents, and port agents.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.2
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• pp.361-367
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• 2019

Ramp metering is a traffic management technique that reduces the congestion of Expressway by controlling vehicles entering the highway. It is widely used outside the country, and Korea is also operating in seven sites (Seoul Ring Expressway). Ramp metering has the advantage of reducing congestion of Expressway, but there are disadvantages, as queuing occurs because vehicles are waiting for ramp, and the ramp queue affects adjacent roads at rush hour. To solve this problem, we improved the ramp metering algorithm to reduce the metering rate more spaces on ramp and to increase the metering rate less spaces. In order to evaluate this, the combined evaluation index was used and it was found that the result satisfied the equity and efficiency at the same time.

• Journal of Digital Convergence
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• v.17 no.1
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• pp.55-62
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• 2019

This study analyzed the relationship between housing price, purchase price, Gini coefficient, interest rate, and the employment, considering that the change in housing price was an important factor influencing macroeconomic variables and income inequality. The panel VAR model was constructed considering the panel data, and the Granger causality, Impulse response and Variance dispersion analysis were performed. As a result, when compared to before and after the global financial crisis, it was shown that the rent price had an effect on income inequality, but in the following period, both the rent price and the selling price affected the income inequality. And that it has a large impact on inequality. In addition, the causality between income inequality and employment rate, interest rate, and tax rate was confirmed. Therefore, it is expected that it will be a desirable policy to mitigate income inequality considering the influence of policy variables for economic activation including government real estate policy.

• The Journal of Korean Society for School & Community Health Education
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• v.20 no.1
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• pp.69-84
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• 2019

Objectives: The purpose of this study is to examine change in adolescent depression across time and to determine the relation between individual and neighborhood socioeconomic status (SES) and depression. Methods: This study employed multilevel latent growth analysis using longitudinal data from Korea Children and Youth Panel Survey. A sample of this study consists of 2,351 adolescents who were in first grade of middle school in 2010. Results: Results showed that both initial level and downward trajectory of depression varied significantly across individuals as well as across neighborhoods. On the individual level, self-rated economic condition(b=-0.203, p<.001) was related to the initial level of depression. Adolescents whose father had a high educational level(b=0.028, p<.001) or whose mother had a low educational level(b=-0.022, p=.011) had lower rates of decline in adolescent depression. On the neighborhood level, neighborhood deprivation index (b=0.003, p=.019) and gini coefficient(b=0.124, p=.040) were associated with lower rates of decline in depression. Conclusions: Low SES in adolescence is correlated with worse mental health, especially depression. Social disparities in depression likely originate before adulthood. The findings argue for the importance of understanding depression in adolescence from a multilevel or ecological framework.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.64-77
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• 2021

The purpose of this study is to examine the spatial distribution of highly educated human capital and to identify key factors affecting their spatial distribution. We analyzed the spatial concentration and inequality using Gini's coefficient and exploratory spatial data analysis and identified the economic and amenity factors to affect the spatial concentration of highly educated human capital using spatial regression model. The findings show that the spatial pattern of highly educated human capital is concentrated, imbalanced, and clustered in Capital region and part of Chungcheong and Gangwon region. The spatial concentration were more affected by economic factor than by amenity factors. This study provides some implication on the regional economic strategies to attract the human capital.

• Korean Journal of Social Welfare Studies
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• v.40 no.1
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• pp.261-296
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• 2009

I constructed the 2003 Korean 'social accounting matrix'(SAM) to analyze the multipliers of total demand for each economic activity. I find that the relative magnitude of the influence of the welfare policy to the national economy measured by input-output production multipliers tends to be underestimated compared to SAM multipliers. This is because the total demand multipliers of SAM include the private sector effects, which is not considered in the input-output model. The result also support that income inflows in public service areas including education, health and social work, generate gains in the relative income of households.

• Journal of the Economic Geographical Society of Korea
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• v.26 no.3
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• pp.310-323
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• 2023

Urbanization and income distribution issues are global interest, and the results of studies on the impact of urbanization on income inequality are different for each country and period. This study analyzes the impact of urbanization on income inequality using regional data from 2000-2021. In particular, serial correlation, spatial dependence, and common factor effects of the Gini coefficient are confirmed and analyzed through a dynamic spatial panel regression model. As a result, urbanization has a positive effect on reducing income inequality. Therefore, it is necessary to continuously promote regional urbanization to improve the income distribution problem. Areas with already high urbanization rates should reduce income inequality by narrowing the wage gap by expanding training opportunities for low-skilled workers, and need to come up with measures to prevent counter-urbanization.

• Korean Journal of Agricultural and Forest Meteorology
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• v.17 no.1
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• pp.58-68
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• 2015

This study compares the wind stability of Larix kaempferi (Lamb.) Carr., Pinus koraiensis Sie. & Zucc. and Abies holophylla Maxim. to understand and inform wind risk management of these plantation trees at Daegwallyeong, Korea. Temporary square plots of $20m{\times}20m$ ($400m^2$) were laid out, and DBH (Diameter at Breast Height) and height for trees greater than 10 cm in DBH were measured by species. A total of 15 plots with 5 plots each in L. kaempferi, P. koraiensis and A. holophylla stands were sampled at random. Among the species, A. holophylla and P. koraiensis have comparatively lower h/d (Height/DBH) ratios than L. kaempferi. These results indicate that the former two species are more wind firm than the latter species. About 9% of the L. kaempferi trees have higher h/d ratios than the critical threshold limit 80. These trees are vulnerable to wind damage and should be removed in the next thinning regime. The analysis of variance detected a significant difference (p < 0.05) in the h/d ratios and Gini coefficient indicating species differences and DBH size variation, respectively. Gini coefficient was 16.4% in A. holophylla, 15.9% in P. koraiensis and 14% in L. kaempferi stands indicating limited DBH size variation. Lower h/d ratios are attributed to thinning in these stands and tree morphological differences. To increase wind firmness, low thinning should concentrate to remove trees with the h/d ratio above 80 coinciding at the time of stand distinction phase. Forest managers and practitioners should measure and maintain h/d ratios of trees below the critical threshold limit of 80 through stand density management. Variable density thinning approach should be tested to increase tree DBH sizes of the even-aged stands.