• Journal of the Korean Data and Information Science Society
• /
• v.26 no.2
• /
• pp.323-334
• /
• 2015

he current VaR model based on the J.P. Morgan's RiskMetrics structurally can not reflect the future economic situation. In this study, we propose a One-factor model resulting from the Wiener stochastic process decomposed into a systematic risk factor and an idiosyncratic risk factor. Therefore, we are able to perform a preemptive risk management by means of reflecting the predicted common risk factors in the model. Stocks in the portfolio are satisfied with the independence to each other because the common factors are fixed by the predicted value. Therefore, we can easily determine the investment in each stock to minimize the variance of the portfolio. In addition, the portfolio VaR is decomposed into the sum of the individual VaR. So we can effectively implement the constitution of the portfolio to meet the target maximum losses.

• Korean Journal of Social Welfare Studies
• /
• v.47 no.3
• /
• pp.139-159
• /
• 2016

This study aims to investigate the wage gap between male and female workers at social welfare institutions and to determine its factors. For this purpose, a Blinder-Oaxaca decomposition and regression models are applied to analyze wage survey data. The results are as follows. Firstly, the gender wage gap of social workers is a bit smaller, compared to the average of wage earners. Secondly, about two-thirds of wage gap is due to differences in productivity(endowment) factors; the other part is due to discrimination. Thirdly, the most important cause of gender wage gap is career disruptions of female workers largely due to marriage and birth. Fourthly, other causes of gender wage gap include differences in education, in job grade, in employment status, and in the characteristics of institutions. Finally, among the discriminating factors worsening gender wage gap, a key factor is a gender discrimination in the compensation for age.

• Korea journal of population studies
• /
• v.21 no.1
• /
• pp.5-41
• /
• 1998

Over the past 30 years, Korea experienced demographic transition which typically substitutes quality(education) for quantity(number) of population. This paper decomposed labor supply into quantity and quality aspects and estimated the respective employment elasticities of economic growth in the past. Then, based on the assumptions about the future population (by age, sex and education) and labor force participation rates, the future labor supply(both quantity and quality) is projected and growth potential of the Korean economy is evaluated. The result shows that labor supply in Korea is relying gradually more on the qualitative rather than the quantitative aspect but since the increase in the former will not fully compensate the decrease in the latter, the potential growth rate of the Korean economy will be substantially reduced in the futrue.

• Korean Journal of Environmental Agriculture
• /
• v.28 no.3
• /
• pp.238-242
• /
• 2009

The effect of earthworm and dung beetle on cattle dung pat decomposition was assessed by combining quantification of earthworm density and with or without dung beetle in pats and measurements of the decomposition rate of these pats. Cattle dung decomposition rate was higher in the pots treated with both earthworm and dung beetle than in the pots with either earthworm or beetle alone. After dung beetle and earthworm activity, the growth of oat in earthworm with dung beetle treatment was similar effect with fertilizer treatment. Dung beetle was responsible for dung decomposition until 78% moisture content in the dung, earthworm was responsible for up to 30% moisture of dung, and two group were not shown any activity for decomposition less 30% moisture content of dung. Therefore dung in the different periods could be broken down by each group. The disappearance and conveyance of dung by earthworm and dung beetle was 72% of the initial dung amount. 10.2% of 72% dung was used making brood balls by dung beetle. Earthworm activity was not an impediment on making brood balls by dung beetles. The interaction of earthworm and dung beetle may have a complementary cooperation rather than competition in the same dung pat. Indeed, development of earthworm accelerate to coexist with dung beetles instead without dung beetles. From this result, maximum benefits of the effective earthworm and dung beetle can be achieved, it is needed to preserve population of earthworm and dung beetles in pasture to sustainable agricultural environment.

• Journal of Soil and Groundwater Environment
• /
• v.9 no.3
• /
• pp.38-48
• /
• 2004

Natural attenuation of petroleum hydrocarbon was investigated at an industrial complex about 45 Km away from Seoul. The three-years monitoring results indicated that the concentrations of DO, nitrate, and sulfate in the contaminated area were significantly lower than the background monitoring groundwater under the non-contaminated area. The results also showed a higher ferrous iron concentration, a lower redox potential, and a higher (neutral) pH in the contaminated groundwater, suggesting that biodegradation of TEX(Toluene, Ethylbenzene, Xylene) is the major on-going process in the contaminated area. Groundwater in the contaminated area is anaerobic, and sulfate reduction is the dominant terminal electron accepting process in the area. The total attenuation rate was about 0.0017∼0.0224day$^{-1}$ and the estimated first-order degradation rate constant(λ) was 0.0008∼0.0106day$^{-1}$ . However, the reduction of TEX concentration in the groundwater was resulted from not only biodegradation but also dilution and reaeration through recharge of uncotaminated surface and groundwater. The natural attenuation was, therefore, found to be an effective, on-going remedial process at the site.

• Journal of Information Technology and Architecture
• /
• v.10 no.2
• /
• pp.181-195
• /
• 2013

This study is to investigate into the factors that influence the use of a military logistics information system in Korean army. We developed the research model based on DTPB (Decomposed Theory of Planned Behavior) because the DTBP is an appropriate model in a mandatary using environment through the study of previous technology-acceptance models. A questionnaire survey was conducted with Korean army solders and civilian components who use the army logistics information system and 266 valid questionnaires are recovered. The collected data were analyzed by SPSS and AMOS. The results show that perceived usefulness and ease of use did not affect the attitude of the use intention. The influence of colleagues and upper class officers was all satisfactory and computer self-efficiency affected perceived control of behavior. The results of this study will contribute to the further use of the military logistics information system and future development strategy.

• Korean Journal of Social Welfare
• /
• v.64 no.4
• /
• pp.163-188
• /
• 2012

This study examines recent trends in income inequality among the elderly in Korea. Aggregate income inequality trends are explained by examining evidence from inequality index decomposition by population subgroup and by income source. Data come from Korean Labor and Income Panel Study(KLIPS). The results are as follows. First, elderly income inequality increased from 1999 to 2002, and then decreased until 2008. Second, household composition changes appear to have disequalizing influence. The proportion of elderly people who are economically dependent on non-elderly family member or living with adult children has declined. Equalizing influence of private transfers also decreased between 2002 and 2008. These results indicate that the redistributive role of family has weakened over time. Third, the improvement of education level and changing occupational structure among the elderly household head contributed to increase in elderly income inequality. Fourth, earning's factor share has declined steadily, and the diminishing role of earnings provides equalizing influence on elderly income inequality from 2002 to 2008. Fifth, the impact of recent expansion of social insurance has changed over time. Inequality contribution of social insurance income increased from 1999 to 2002, and then decreased from 2002 to 2008.

• International Area Studies Review
• /
• v.13 no.3
• /
• pp.145-161
• /
• 2009

Applying the shift-share analysis, this paper decomposes FDI inflow into Korea for the period of 2003-2006. The paper finds that Korea has been lagging behind the world average in absorbing inward FDI, thereby recording negative aggregate industry-mix effects and negative aggregate competitive effects as well. However, the following industries have recorded positive competitive effect: electrical and electronic equipment, motor vehicles and other transport equipment, hotels and restaurants, transport, storage and communications, finance, and business services. In a nutshell, Korea is revealed to have competitive advantage in absorbing inward FDI in a few manufacturing industries and most of service industries. Government policies should accordingly be focused on these industries to encourage more inward FDIs.

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

• Applied Biological Chemistry
• /
• v.18 no.1
• /
• pp.30-41
• /
• 1975

A substituted diphenyl ether herbicide(MC-4379) was studied on the decomposition by some environmental factors; sunlight, microorganisms, and the crude enzyme in rice plant extract. All the decomposition products were confirmed by means of TLC, GLC, and IR. The parent compound and the decomposition products were put to the test for the effect on the growth of some plants. The results obtained are summarized as follows: 1. Photolysis Amino-MC-4379, 2,4-dichloro-3'-carboxyl-4'-nitrodiphenyl ether, Nitrofen, 2,4-dichloro-3'-carboxyl-4'-amino-diphenyl ether, amino-Nitrofen, 3-carboxymethyl-4-nitrophenol, p-nitrophenol, p-aminophenol, etc. were confirmed as photoproducts, in addition to a relatively small amount of an unknown compound. It was confirmed that the solution-phase photolysis of MC-4379 was accelerated much more by the aid of a photosensitizer benzophenone. 2. Degradation by the crude extract of germinating rice seeds Nitrofen was confirmed as a major degradation product, in addition to a relatively small amount of and unknown compound. Most of the parent compound remained unchanged. 3. Degradation by microorganisms Nitrofen and amino-MC-4379 were confirmed as the major products. in addition to a small amount of an unknown compound. 4. The germinating rice seeds and soybean were grown in the 1,000 ppm emulsions of some chemicals, respectively. The effect on rice plant growth was in the inhibitory order of p-nitrophenol > C-6989> Nitrofen > amino-Nitrofen > MC-4379. The effect on soybean was in the order of Nitrofen > amino-Nitrofen > MC-4379. Two weeds, Amantus blitum and Setaria viridis were grown in the 500 ppm emulsions containing the compounds, respectively. After incubation for 3 days, it was observed that all the shoots had been dead.