• Journal of Preventive Medicine and Public Health
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• v.25 no.1 s.37
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• pp.44-52
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• 1992

This study was conducted to evaluate the relations between alcohol intake and blood lipid level in a group of 1,138 Korean adult men, ages 20 to 69 years. Total number of each of a variety of drinks in the previous two weeks was obtained by questionnaire and converted into grams of alcohol consumed in a week. The levels of blood lipid such as Cholesterol, HDL-Cholesterol, Triglyceride and LDL-Cholesterol were examined by enzyme method. We also observed the effects of various variables such as age, body mass index, smoking, exercise and blood pressure on blood lipid level. The results obtained were as follows : 1. Average weekly alcohol intake was $129.0{\pm}167.4gm$ and that of 30-39 age group was the highest as $149.3{\pm}170.4gm$. 2. Levels of Cholesterol Triglyceride and LDL-Cholesterol tended to increase with increasing age, but level of HDL-Cholesterol showed no significant relationship with age. 3. The positive linear regressions of alcohol intake on HDL-Cholesterol and Triglyceride were noted statistically significant. 4. Multiple regression analysis demonstrated that the effect of alcohol on HDL-Cholesterol and Triglyceride was statistically significant and the contribution rates were 5.0% and 0.8%, respectively. And, in the case of HDL-Cholesterol, the alcohol intake was the most significant independent variable.

• Journal of Korean Society on Water Environment
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• v.36 no.1
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• pp.14-28
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• 2020

Future climate change may affect the hydro-thermal and biogeochemical characteristics of dam reservoirs, the most important water resources in Korea. Thus, scientific projection of the impact of climate change on the reservoir environment, factoring uncertainties, is crucial for sustainable water use. The purpose of this study was to predict the future water temperature and stratification structure of the Soyanggang Reservoir in response to a total of 42 scenarios, combining two climate scenarios, seven GCM models, one surface runoff model, and three wind scenarios of hydrodynamic model, and to quantify the uncertainty of each modeling step and scenario. Although there are differences depending on the scenarios, the annual reservoir water temperature tended to rise steadily. In the RCP 4.5 and 8.5 scenarios, the upper water temperature is expected to rise by 0.029 ℃ (±0.012)/year and 0.048 ℃ (±0.014)/year, respectively. These rise rates are correspond to 88.1 % and 85.7 % of the air temperature rise rate. Meanwhile, the lower water temperature is expected to rise by 0.016 ℃ (±0.009)/year and 0.027 ℃ (±0.010)/year, respectively, which is approximately 48.6 % and 46.3 % of the air temperature rise rate. Additionally, as the water temperatures rises, the stratification strength of the reservoir is expected to be stronger, and the number of days when the temperature difference between the upper and lower layers exceeds 5 ℃ increases in the future. As a result of uncertainty quantification, the uncertainty of the GCM models showed the highest contribution with 55.8 %, followed by 30.8 % RCP scenario, and 12.8 % W2 model.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.99-104
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• 2011

BACKGROUND: Application of urea may increase $CO_2$ emission from soils due both to $CO_2$ generation from urea hydrolysis and fertilizer-induced decomposition of soil organic carbon (SOC). The objective of this study was to investigate the effects of increasing urea application on $CO_2$ emission from soil and mineralization kinetics of indigenous SOC. METHODS AND RESULTS: Emission of $CO_2$ from a soil amended with four different rates (0, 175, 350, and 700 mg N/kg soil) of urea was investigated in a laboratory incubation experiment for 110 days. Cumulative $CO_2$ emission ($C_{cum}$) was linearly increased with urea application rate due primarily to the contribution of urea-C through hydrolysis to total $CO_2$ emission. First-order kinetics parameters ($C_0$, mineralizable SOC pool size; k, mineralization rate) became greater with increasing urea application rate; $C_0$ increased from 665.1 to 780.3 mg C/kg and k from 0.024 to 0.069 $day^{-1}$, determinately showing fertilizer-induced SOC mineralization. The relationship of $C_0$ (non-linear) and k (linear) with urea-N application rate revealed different responses of $C_0$ and k to increasing rate of fertilizer N. CONCLUSION(s): The relationship of mineralizable SOC pool size and mineralization rate with urea-N application rate suggested that increasing N fertilization may accelerate decomposition of readily decomposable SOC; however, it may not always stimulate decomposition of non-readily decomposable SOC that is protected from microbial decomposition.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1790-1800
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• 2002

The DNA nucleosides(dA, dC, dG, dT)bound to gold nanoparticles (~13 nm) in aqueous solution has been studied as a probe by the SERS and their coordination structures have been proposed on the basis of them. According to UV-Visible absorption of gold nanoparticles after modifying with DNA nucleosides, the rates of absorption of dA, dC, and dG were much faster than that of dT as monitored by the aggregation kinetics at 700 nm. These data indicated that the nucleosides dA, dC, and dG had a higher affinity for the gold nanoparticles surface than nucleoside dT. As the result of SERS spectra, the binding modes of each of the nucleosides on gold nanoparticles have been assigned. A dA binds to gold nanoparticles via a N(7) nitrogen atom of the imidazole ring, which the C(6)-$NH_2$ group also participates in the coordination process. In the case of dC, it binds to the gold surface via a N(3) nitrogen atom of the pyrimidine ring with a partial contribution from the oxygen of C(2)=O group. A coordination of dG to the gold surfaces is also proposed. Although the dG has the two different nitrogens of a pyrimidine ring and the amino group, the N(1) nitrogen atom of a pyrimidine ring has a higher affinity after the hydrogen migrates to the amino group. Conversely, dT binds via the oxygen of the C(4)=O group of the pyrimidine ring. Accordingly, these data suggest that the nitrogen atom of the imidazole or the pyrimidine ring in the DNA nucleosides will bind more fast to the gold nanoparticles surfaces than the oxygen atom of the carbonyl group.

• Journal of the Korean Home Economics Association
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• v.30 no.1
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• pp.283-309
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• 1992

This study examines work and family life of married women employed in a manufacturing industry. Data were gathered from the use of fact-to-face interview method from a sample of 230 married working women. The major findings of this study can be summarized as follows : (1) With high rates of change of job, most of the respondents remain unstable in their working situation. It was shown that the important factors influencing job satisfaction of married women are women's life cycle, degree of contribution of wife's income toward total family income, and husband's attitude toward wife's empolyment. The degree of job satisfaction is also strongly influenced by labor structural factors such as pay, work environment and fringe benefits. (2) The amount of household labor time was limited by job-related factors rather than by family-related factors, because among these working women employment itself is necessarily for their subsistance. (3) It was shown that wives participated more actively in their marital communications than their husbands. Most of the respondents showed the syncratic type of the decision making patterns, but this results does not necessarily mean wives exercised an equal power with their husbands. The economic factors and the emotional instability of the husband are the ones mostly influencing marital conflicts of the employed women. It was found that the respondents easily revealed marital conflicts related to personal problems of their husbands(such as extramarital affairs, gambling and alchoholism). However, they tried to overcome the structural conflicts related to authoritarian attitudes of their husbands or economic problems without any complaints. (4) Mothers have difficulty in controlling their adolescent children, due to the weakening of parental authority. Although most of the respondents perceived their employment as having negative impacts on their children, they still have high expectations toward their children. Inspite of low degree of father role expectations and facther role performance of their husbands, most of the respondents anticipated expressive roles as well as traditionally instrumental role from their husbands. Finally, these findings would help us determine family welfare policies in Korea. Improvements in paid and household labor structure of married women should be accomplished at the national level. Also, the acting programs for parent education, marital councelling services, and law enforcement for equal employment between men and women should be provided in our society.

• Journal of Environmental Health Sciences
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• v.35 no.1
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• pp.1-10
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• 2009

This study assessed the relationships between levels of $PM_{10}$ and hospitalization rates for asthma among children from 2003 to 2005 at four major cities in Korea. In addition, we estimated the reduced number of asthma hospitalization associated with an ambient $PM_{10}$ improvement to the acceptable levels as recommended by the World Health Organization (WHO). The Generalized Additive Model (GAM) was used to estimate the relative risks (RR) of asthma hospitalization associated with changes in $PM_{10}$ The RRs of children's asthma hospitalization for every $10{\mu}g/m^3$ increment in $PM_{10}$ were 1.009(95% CI = 1.004-1.014) in Seoul, 1.013(95% CI = 1.006-1.021) in Incheon, 1.009(95% CI = 1.002-1.016) in Busan, and 1.021(95% CI = 1.005-1.037) in Ulsan. We assessed $PM_{10}$ related health benefits from implementing the WHO's guidelines (24-hour average $50{\mu}g/m^3$) using the U.S. Environmental Protection Agency's Environmental Benefits Mapping and Analysis Program. The estimated benefits were 439(95% CI = 216-666) reduced asthma hospitalization in Seoul, 720(95% CI = 304-1,151) in Incheon, 260(95% CI = 66-459) in Busan, and 126(95% CI = 30-228) in Ulsan. It was concluded that improving $PM_{10}$ condition to the WHO guideline would make a significant contribution to the reduction in asthma hospitalization among children. Therefore, public health measures are still needed to improve air quality in Korea.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.4
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• pp.172-178
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• 2006

In this paper, an advanced demand clustering algorithm which can explore the planned maintenance outage of generators in changed electricity industry is proposed. The major contribution of this paper can be captured in the development of the long-term estimates for the generation availability considering planned maintenance outage. Two conflicting viewpoints, one of which is reliability-focused and the other is economy-focused, are incorporated in the development of estimates of maintenance outage based on the advanced demand clustering algorithm. Based on the advanced clustering algorithm, in each demand cluster, conventional effective outage of generators which conceptually capture maintenance and forced outage of generators, are newly defined in order to properly address the characteristic of the planned maintenance outage in changed electricity markets. First, initial market demand is classified into multiple demand clusters, which are defined by the effective outage rates of generators and by the inherent characteristic of the initial demand. Then, based on the advanced demand clustering algorithm, the planned maintenance outages and corresponding effective outages of generators are reevaluated. Finally, the conventional demand clusters are newly classified in order to reflect the improved effective outages of generation markets. We have found that the revision of the demand clusters can change the number of the initial demand clusters, which cannot be captured in the conventional demand clustering process. Therefore, it can be seen that electricity market situations, which can also be classified into several groups which show similar patterns, can be more accurately clustered. From this the fundamental characteristics of power systems can be more efficiently analyzed, for this advanced classification can be widely applicable to other technical problems in power systems such as generation scheduling, power flow analysis, price forecasts, and so on.

• Journal of Biosystems Engineering
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• v.34 no.2
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• pp.114-119
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• 2009

Field test was conducted to investigate primary factors reducing rapeseed harvesting using a reciprocating cutter-bar of combine. The results showed that the correlation between crop moisture content and yield loss had a U-type, which indicated that the yield reduction increased at too high and too low crop moisture contents. The proper ranges of crop moisture contents were 27${\sim}$35%, 21${\sim}$56%, and 62${\sim}$73% in case of grain, pod and stem, respectively. Crop moisture content was negatively correlated with header loss, but positively correlated with threshing loss. In contrary, stem moisture content showed positive correlations with total loss, threshing loss and separation loss. Working speed was positively correlated with header loss. Total flow rate, pod flow rate and stem flow rate were highly correlated with threshing loss and separation loss. However, grain flow rate did not show any correlation with total loss. According to the principal component analysis, two principal components were derived as components with eigenvalues greater than 1.0. The contribution rates of the first and the second components were 52.7% and 38.9%, which accounted for 91.6% of total variance. As a contributive factor influencing total loss of rapeseed mechanical harvesting, a crop moisture content factor was greater than a crop flow rate factor. The stepwise multiple regression analysis for total loss was conducted using crop moisture content factor, crop flow rate factor and coefficient. However, the model did not show any correlation among independent and dependent factors ($R^2$=0.060).

• Journal of the Korean Society of School Health
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• v.8 no.1
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• pp.155-166
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• 1995

The aim of this study was to determine the extent to which sociodemographic and health related life-style variables explain body weight distribution and to understand weight contol behavior. To study this study 298 students were selected, it was consisted of obesity group(101) and control group(197). The average age of subjects was 14.2 and the prevalence of obesity was 2-3 per class as 5.6% among 1,793. 71% among same subject was showed higher weight pattern than last one year, ovesity group which was obesity both in 93 and 94 was 34%. Correlation between body weight(under weight/obesity) and independent variables including sociodemographic factor and health- related life style tested through Multiple Classification Analysis was very significant, explained 36% of the total variance. Sociodemografic and hereditary factors such as education level, age of father and physical features of parents, life style factors as exercise preference and perceived health status showed highly contribution to body weight. Concretely, there were showed a higher obesity prevalence tendency when education level and age of father was high, physical features of parents was obesity. In otherwise, there were showed a higher underweight prevalence tendency when education level and age of father was low. Experience rates of weight control was 53% generally, 84% in obesity group, and 11% in underweight group. There were utilized weight control behaviors through diet method mainly in obesity group, diet and exercise methods in underweight group. There were showed that underweight group are prefer exercise to obesity group. Conclusionally, These findings suggest that education, age, physical features of parents, exercise preference and perceived health status is important factors related to body weight among middle school girls. Therefore, there will be considered as valuable factors when we practice health education and consultation related to body weight. Furthermore it is necessary to provide of various informations about weight control and to develop systematic weight control program.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.123-133
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• 2008

Information collection systems and applications in a ubiquitous environment has emerged as a leading issue in transportation and logistics. A productive application example is a traffic information collection system based on probe vehicles and wireless communication technology. Estimation of hourly OD pairs using probe OD data is a possible target. Since probe OD data consists of sample OD pairs, which vary over time and space, computation of sample rates of OD pairs and expansion of sample OD pairs into static OD pairs is required. In this paper, the authors proposed a method to estimate sample OD data with probe data in Jeju City and expand those into static OD data. Mean absolute percentage difference (MAPD) error between observed traffic volume and assigned traffic volume was about 22.9%. After removing abnormal data, MAPD error improved to 17.6%. Development of static OD estimation methods using probe vehicle data in a real environment is considered the main contribution of this paper.