• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.4
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• pp.37-44
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• 2003

In order to evaluate the contribution of MMSTP operation to the improvement of marine water quality of Mokpo harbour and to estimate the change of pollution loads flowing into Mokpo harbour after the operation of Mokpo Municipal Sewage Treatment Plant (MMSTP), the pollution loads flowing into Mokpo harbour from land in dry weather were surveyed and estimated on the bases of the seasonal flow rates and the seasonal water qualities of streams and effluents located around Mokpo harbour from summer, 1997 to spring, 1998 before the operation of MMSTP, and the pollution loads of the inflow and the effluent of MMSTP were also surveyed and estimated from winter, 1998 to spring, 1999 after the operation of MMSTP. The treatment rates of MMSTP were shown to be about 49% in COD, 76% in TSS, 79% in VSS, 3% in T-N, 7% in DIP, 29% In T-P and -32% in DIN. The change rates of pollution loads flowing into the inner harbour of Mokpo due to the operation of MMSTP were shown to be about 56% in COD, 78% in TSS, 84% in VSS, 45% in DIN, 22% in T-N, 34% in T-P and -14% in DIP The contribution rates of MMSTP operation to the reduction of total pollution loads flowing into the entire Mokpo harbour were found to be about 3% in COD, 3% in TSS, 5% in VSS, 1% in DIP, 3% in T-P and -1% in DIN.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2572-2578
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• 2022

An approximate method for calculating the cadmium ratio of a cyclotron-based thermal neutron radiography system was developed. In this method, the Monte-Carlo code, MCNP6.2, was employed to calculate the neutron capture rates of Au-197, and the cadmium ratio was obtained by computing the ratio of neutron capture rates. From the simulation results, the computed cadmium ratio is reasonably acceptable, and the assumption of ignoring the fast neutron contribution to the cadmium ratio is valid.

• Korean Journal of Human Ecology
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• v.4 no.1
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• pp.39-50
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• 1995

To determine contribution rate to matrimonial wealth accumulation of urban housewives, a survey was made toward them by using questionaires from September 1994 to October 1994. Three hundred-eighteen housewives were randomly selected from Pusan area. The results obtained were as follows. Average contributing rate to household income was 65.7 percent for husbands and 34.3 percent for wives. The contribution rates evaluated by themselves of wives were 38.1 percent for the house property; 36.5 percent for the savings; 9.6 percent for the real estate; 5.2 percent for the land; 9.3 percent for the stocks & bonds; and 9.2 percent for others. It is suggested that 50 percent and over 50 percent of matrimonial properties have to be recognized to the wives who changed their occupations to house work and employed wives, respectively.

• Bulletin of the Korean Chemical Society
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• v.7 no.2
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• pp.124-129
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• 1986

The effects of molecular attraction and orientations for the energy mismatch variance, vibrational energy level and double-quantum transition, in the vibration-vibration energy exchange, have been considered. The contribution of molecular attraction increases the exchange rate of the purely repulsive interaction, in general, significantly, but which becomes smaller as the temperature is increased. As the energy mismatch is increased, its contribution is also increased, but which is small. However, its contribution for the double-quantum transition is very paramount. At each orientation, the exchange rate constants have been calculated and compared with the results for rotational average, and it is found that the exchange rate is a strong function of the orientation angles of colliding molecules. We have also discussed about the system having the strong interaction such as the hydrogen bond, and it is found that for this system the preferred orientation should be considered in order to calculate the exchange rates.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.1
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• pp.23-45
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• 2015

We consider counterparty risk in CDS rates. To do so, we use a multivariate jump diffusion process for obligors' default intensity, where jumps (i.e. magnitude of contribution of primary events to default intensities) occur simultaneously and their sizes are dependent. For these simultaneous jumps and their sizes, a homogeneous Poisson process. We apply copula-dependent default intensities of multivariate Cox process to derive the joint Laplace transform that provides us with joint survival/default probability and other relevant joint probabilities. For that purpose, the piecewise deterministic Markov process (PDMP) theory developed in [7] and the martingale methodology in [6] are used. We compute survival/default probability using three copulas, which are Farlie-Gumbel-Morgenstern (FGM), Gaussian and Student-t copulas, with exponential marginal distributions. We then apply the results to calculate CDS rates assuming deterministic rate of interest and recovery rate. We also conduct sensitivity analysis for the CDS rates by changing the relevant parameters and provide their figures.

• The Korean Journal of Ecology
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• v.19 no.6
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• pp.563-573
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• 1996

Macroinvertebrate contribution to the leaf litter breakdown of Carpinus cordata was estimated at headwater streams at Mt. Jumbong (38°03'N, 128°25'E) during spring and winter spring by using two types of litter bag. Coarse-mesh bags with 10 g of leaf letter were placed in a 1st-order stream in April (the spring experiment) and December 1995 (the winter-spring experiment). Fine-mesh bags with 5 g of leaf letter were placed in a nearby 3ed-order steam. The breakdown of Carpinus in coarse-mesh bags was rapid, and, in terms of season, leaf litter processed rapidly during spring. daily mass loss rates of leaf litter (-k±1 SE) were highest for coarse-mesh bags in the spring experiment (-0.0429±0.0048), followed by coarse-mesh bags in the winter-spring (-0.0146±0.0014), fine-mesh bags in the spring (-0.0078±0.0004), fine-mesh bags in the winter-spring experiment (-0.0054±0.0005). Macroinvertebrate contribution to the litter breakdown was estimated by the difference of % leaf letter remaining between coarse -mesh bage and fine-mesh bags. Although shredders were more abundant during the winter-spring, their contribution was greater during the spring (50%) than the winter-spring (22∼33%). This result appeared to be due to the change in the chemical composition of leaf letter during processing, and to the seasonal growth patterns of major shredder taxa.

• Journal of the Korean Home Economics Association
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• v.31 no.1
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• pp.13-24
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• 1993

The reformed family law was enforced from Jan.1,1991 and the claim to division of matrimonial property in case of divorce, a newly enacted right in the law, is expected to increase the economic position of married women. By this system, married woman can claim her share in the matrimonial property in case of divorce if she verifies her contribution to it. But actually, household work of housewives has not been evaluated properly as compared with their husbands' work in deciding of property division rate, because there is no economic base about the value of household work. So, this study verified wives' role of contribution to matrimonial property and compared their work hours with their husbands. As the result, following suggestions can be presented. 1. The contribution rates of husband and wife to the matrimonial property have to be acknowledged equally and, in case of employed wife, her rate has to be evaluated higher than her husband. 2. Because the property division is not a solatium but a transfer of wife's share, responsibility which marriage has dissolved should not be taken more to women than men. 3. Decision of division rate has to be made regardless the amount fo property unless there are special reasons. 4. The donation tax and inheritance tax should not be imposed on matrimonoal property which was returned to wife from her husband.

• Journal of Preventive Medicine and Public Health
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• v.44 no.6
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• pp.249-259
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• 2011

Objectives: This study aimed to analyze long-term trends in the contribution of each cause of death to socioeconomic inequalities in all-cause mortality among Korean adults. Methods: Data were collected from death certificates between 1990 and 2004 and from censuses in 1990, 1995, and 2000. Age-standardized death rates by gender were produced according to education as the socioeconomic position indicator, and the slope index of inequality was calculated to evaluate the contribution of each cause of death to socioeconomic inequalities in all-cause mortality. Results: Among adults aged 25-44, accidental injuries with transport accidents, suicide, liver disease and cerebrovascular disease made relatively large contributions to socioeconomic inequalities in all-cause mortality, while, among adults aged 45-64, liver disease, cerebrovascular disease, transport accidents, liver cancer, and lung cancer did so. Ischemic heart disease, a very important contributor to socioeconomic mortality inequality in North America and Western Europe, showed a very low contribution (less than 3%) in both genders of Koreans. Conclusions: Considering the contributions of different causes of death to absolute mortality inequalities, establishing effective strategies to reduce socioeconomic inequalities in mortality is warranted.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.4
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• pp.52-62
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• 2015

This study estimated the contribution rates of inlet air flow, moisture content, air-filled porosity and particle size on the total pressure drop for the sawdust used as the bulking agent in the composting. The statistical model for pressure drop including the affecting factors was proposed.($R^2=0.998{\sim}0.950$) While the laminar air flow(v) and particle size(SIZE*v) had the positive relations to the total pressure drop, the turbulent air flow($v^2$), moisture content(MC*v) and air-filled porosity(AFP*v) had the negative relations. Total pressure drop sharply increased with increasing of the inlet air flow. And the most significant factors affecting to total pressure drop were the particle size(SIZE*v) as positive factor and air-filled porosity(AFP*v) as negative factor. The contribution rate to total pressure drop by the particle size(SIZE*v) was continuously increased with increasing of the inlet air flow, but the contribution rate by air-filled porosity(AFP*v) was decreased. And total pressure drop was little changed even though the increasing of moisture content above the range of dry moisture content 0.25. The contribution rates of affecting factors had the different tendencies with increasing of the moisture content, especially in the negative factors as air-filled porosity(AFP*v) and moisture content(MC*v). For effective composting process, it is preferable to select the sawdust with higher air-filled porosity as bulking agent to enhance the air permeability.

• Journal of Environmental Health Sciences
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• v.49 no.5
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• pp.262-274
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• 2023

Background: Exposure levels for heavy metals such as lead (Pb), mercury (Hg), and cadmium (Cd) have increased due to human activities. They are known to be a public health concern. Objectives: This study aimed to determine the exposure levels to heavy metals in the blood and urine of South Korean adults and to present the contribution rate of exposure pathways using an exposure algorithm for men aged 19~64, women aged 19~64, and all seniors aged 65 or older. Methods: We analyzed data from the Korean National Environmental Health Survey (KoNEHS) Cycle 4 (2018~2020). A total of 2,646 participants aged ≥19 years were included. Multiple regression analysis was performed to determine the factors affecting heavy metal concentrations. The contribution rate was calculated by applying three exposure algorithms for ingestion, inhalation, and dermal exposure. Results: Factors that commonly affect heavy metal concentrations in blood and urine were gender and age. The main influencing factors for Pb and Cd were education level and smoking status, while frequency of fish consumption and of alcohol consumption were indicated to be the main influencing factors for mercury. The contribution rates of lead and cadmium from food ingestion were 78.03~79.62% and 88.39~92.89%, respectively. Additionally, the highest contribution for mercury was accounted for by food at 81.69~85.77%. As a result of the risk assessment, cadmium was found to pose a potential health risk a with total cancer risk (TCR) of more than 1×10^-6. Conclusions: The KoNEHS could be an important study for determining the level of exposure to heavy metals and their influencing factors. Integrated exposure to heavy metals could assess the main exposure pathways, and this methodology could be applied to exposure management of heavy metals.