• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.1
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• pp.1-15
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• 2012

Marine scientific monitoring, including monitoring of oil pollution, marine ecosystems, and the marine environment in general, has been being carried out continuously in order to assess the impact of oil pollution since the Hebei Spirit oil spill in December 2007. GIS thematic maps containing visual and summarized information are very useful for conducting exploratory analyses on the spatio-temporal variability of the marine environment and marine ecosystems due to oil pollution. Defining map types and building a legend in accordance with data characteristics are essential elements for mapping. In the present study, map types were defined according to the data attributes and GIS data types for each data item and classification of data intervals for the legend was defined by using two data distribution types through a histogram analysis. The data interval method was defined as follows: If the histogram of data has a uniform distribution, an equal interval method is applied; in the case of a normal distribution, a standard deviation method is applied. In addition, thematic map templates were made for each map type through the definition of marginal elements. Through the establishment of systematic mapping methods and procedures in this study, it was possible to effectively make standardized thematic maps for various kinds of marine scientific data.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.995-1006
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• 2013

The purposes of this study were to develop an instrument to measure high school students' systems thinking and to validate the scale. The scale of systems thinking was made up for 5 factors - systems thinking, mental model, shared vision, personal mastery, and team learning through analyses of related literature. Six items per factor were constructed and the scale consisted of a total of 30 items for the pretest. After exploratory factor analysis, the number of total items was reduced to 20 items. For the main test, 280 students were sampled from high school and analyzed valid cases were 260 students. The finding of the exploratory factor analysis indicated 5 factors in the model, and 4 items per single factor. The result of confirmatory factor analysis was generally appropriate and acceptable (5 factor model: $x^2/df$=1.275, TLI=.946, CFI=.959, RMSEA=.033). The reliability for 20 items turned out to be reliable because the Cronbach's alphas were .840 and .604~.723 per each factor. This study should be expanded to various school levels and should be standardized for further research. The subsequent studies regarding diverse learning program development and implementation and the verification on the students' impact within the developed program can be recommended.

• Korean Journal of Construction Engineering and Management
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• v.11 no.1
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• pp.101-112
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• 2010

The Korean real estate market currently is experiencing a slowdown due to the global economic crisis which has resulted from subprime mortgage lending practices. In response, the Korean government has enforced various policies, based on intend to deregulate real estate speculation, such as increasing the Loan to value ratio (LTV) in order to stimulate housing supply, demand and accompanying housing transactions. However, these policies have appeared to result in deep confusion in the Korean housing market. Furthermore, analyses for housing market forecasting particularly those which examine the impact of the international financial crisis on the Korean real estate market have been partial and fragmentary. Therefore, a comprehensive and systematical approach is required to analyze the real estate financial market and the causal nexus between market determining factors. Thus, with an integrated perspective and applying a system dynamics methodology, this paper proposes Korean Real Estate and Mortgage Market dynamics models based on the fundamental principles of housing markets, which are determined by supply and demand. As well, the potential effects of the Korean government's deregulation policies are considered by focusing on the main factor of these policies: the mortgage loan.

• Korean Journal of Social Welfare
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• v.69 no.2
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• pp.171-190
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• 2017

This study examined the impact of indebtedness on depressive symptoms and suicidal ideation. The data came from the 4th to 10th waves of the Korea Welfare Panel Study, collected from 2009 to 2015. Analyses were conducted using logistic regression for longitudinal data that combines the fixed effects and random effects approaches. The results show that a high level of indebtedness substantially increased the risk of depressive symptoms. The household leverage ratio-the ratio of total household debt to disposable personal income-of 400% or higher increased the odds of probable depression by 50% compared with the ratio under 100%. When the percentage of personal income that goes toward paying debt is 30% or higher, the odds of probable depression went up by 66% than when the percentage of debt payment of disposal income is under 10%. The findings suggest that debt relief agencies and their programs need to incorporate means to identify and address emotional stress related to the excessive debt. This study also contributed to enriching the literature on social determinants of health by demonstrating that indebtedness is an important socioeconomic characteristic affecting individuals' mental health.

• Journal of Preventive Medicine and Public Health
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• v.37 no.3
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• pp.260-266
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• 2004

Objectives : To assess the impacts of implementing case payment system (CPS) to Medical Aid (MA) hemodialysis patients on the frequencies and expenditure of dialysis. Methods : Fifty-eight clinics and 35 tertiary care hospitals were identified as having a minimum of 10 hemodialysis patients for each of the MA and Medical Insurance (MI) programs, who received hemodialysis from the same dialysis facilities for both periods of July 2001 and July 2002. From these facilities, a total of 2,167 MA and 2,928 MI patients were identified as the study subjects. Using electronic claims data, the changes in the total number of monthly treatments and charges for outpatient hemodialysis treatments for each patient after the introduction of the CPS were compared between the MA and MI patients. Multiple regression analyses were performed to examine the independent impact of the CPS on the utilization and expenditure of dialysis treatments among the MA patients. Results : There was a significant decrease in the total charges for the hemodialysis treatments of the MA patients, 3.4% (p<0.05), whereas a significant increase was observed for the MI patients, 2.5% (p<0.05). For both the MA and MI patients, the frequency of the monthly hemodialysis treatments were significantly increased, 5.5 (from 12.1 to 12.7) and 7.8% (from 11.6 to 12.5), for the MA and MI patients, respectively. However, a multivariate regression analysis showed no significant difference in the changes in the total number of monthly hemodialysis treatments between the MA and MI patients after implementation of the CPS. Another regression model, regressing on the changes in the monthly claims of dialysis treatments, showed a significant negative coefficient for the MA ((=-70725, p<0.05). Conclusion : The significant decrease in the total charges for hemodialysis treatments among MA as compared to MI patients suggests that there was a cost reduction in the MA program following the introduction of the CPS.

• Korean Journal of Construction Engineering and Management
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• v.18 no.5
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• pp.11-19
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• 2017

The purpose of this study is to analyze the efficiency of PV according to installation condition in the complex type buildings. For this purpose, annual performance of solar power generation in a certain area was investigated and various methods were conducted including post operation evaluation. In addition, we tried to find out influencing factors that affect the efficiency and sought to identify their relative impact of degree through the data analysis and site visits together. In the middle of this process we can draw up major considerations for the efficient photovoltaic power generation installation. In the mean while, previous studies are making something new related with method for efficiency enhancement and individual influential factors based on experimental environment rather than the empirical data site based. As a result of the study, it was confirmed that even if installed in the same area, the power generation efficiency is 1.5 times as high as the installation condition. Furthermore, statistical analyses were performed on azimuth, tilted angle and shade, which are variables affecting conversion efficiency, and it was statistically confirmed that all variables are meaningful factors that affect the conversion efficiency which is a dependent variable. The most influential factor is the azimuth, followed by the tilted angle and the shade factor. From this result, we expect to be able to provide installation guidelines for the solar power generation equipments on the rooftop zone.

• Environmental and Resource Economics Review
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• v.27 no.3
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• pp.495-520
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• 2018

Because of structural changes in the international oil market and the economy, it is widely recognized that the impact of oil shocks on the economy has weaken since the mid-1980s. This study tries to examine the validity of the recent perception about the relationship between oils shocks and the economy, estimating the time-varying effects of oil shocks on the Korean economy. The results show that the dynamic effects of oil shocks normalized to a one standard deviation has been relatively constant, in contrast to the recent perception and a number of existing studies. In addition, because the shape of impulse response functions at each point in time spanning from 1984:II to 2017:IV has not been changed significantly, it seems that the propagation mechanism of oil shocks also has not been substantially altered. These findings indicate that even though structural changes of the economy, such as the reduction in the share of oil consumption and the spread of high-efficiency energy technologies, have been rapidly progressed, it is not still enough to offset the negative effects of oil shocks. Rather, it seems that the recent perception about the shrinking effects of oil shocks is mainly due to the assumptions that do not reflect changes in the size of oil shocks. In particular, this problem appears more pronounced in the case of the typical a one standard deviation increase oil shock under homoskedasticity assumption, which is widely adopted in the most VAR analyses. Therefore, in estimating the effects of oil shocks on the economy, it is important to specify the correct model and normalization method, to reflect changes in the size of oil shocks.

• Journal of the Korean association of regional geographers
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• v.12 no.4
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• pp.508-521
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• 2006

The results of environmental equity analysis vary dramatically depending on different methods used. The information and data available to the researcher are also often uncertain and imprecise in empirical studies. A sensitivity analysis approach was used too handle uncertainties and methodological inconsistencies in environmental equity analysis. This paper explores the sensitivity of environmental equity analysis to two spatial measures such as proximity and scale. Two experiments were implemented to evaluate the effects of two spatial measures on the environmental equity analysis using a combination of control and experimental factors. Fulton County, Georgia was selected as a case study area for these experiments. Two major data sets including demographic characteristics and toxic release inventory (TRI) database for the study area in 1990 were integrated into a GIS environment. Two statistical analyses such as independent samples t-test and coefficient of variation were performed to determine the environmental equity in the study area and to compare the relative variability in the socioeconomic characteristics of populations over different spatial measures. The findings from two experiments indicate that the outcomes of environmental equity analysis are slightly sensitive to the buffer distance used to determine the impact zones of TRI facilities, but not to the geographic scale used in the analysis. The findings also suggest that the consequences of these choices can alter spatially and statistically the results in environmental equity analysis.

• Environmental Analysis Health and Toxicology
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• v.27
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• pp.3.1-3.4
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• 2012

Objectives: The current use of humidifier detergent and its harmful impact on humans has arisen as a societal environmental health issue. Therefore, in this study we aimed to explore the relationship between demo-socio characteristics and humidifier use, as well as the monthly usage changes in pregnant women; thus, we report the actual status of humidifier usage of Korea's pregnant population. Methods: From a birth cohort of a Mothers and Children's Environmental Health (MOCEH) study, 1,144 pregnant women who responded through questionnaires including demo-socio characteristics, obstetric status and household environment including whether they use humidifier and frequency of use were included in this study. Statistical analyses were performed to explore the relationship between maternal characteristics and the relevance of the use of humidifiers was performed using a chi-square test, a t-test and univariate logistic regression analysis. The monthly usage rate was demonstrated in the graph. Results: The humidifier usage rate in pregnant women was 28.2%. The average frequency of humidifier usage was 4.6 days per week, 7.3 hours per day. The usage rate was higher in the multipara group and the above the age of 34 age group than in the primipara and below the age of 34 groups. Seoul showed a higher usage rate than Cheonan and Ulsan and as the education level and income increased, the usage rate of humidifiers among pregnant women also increased. In the monthly trend of usage rate, the winter season showed the highest usage rate of over 45% and the lowest in late summer and beginning of fall with a value of 12% or less. Conclusions: During pregnancy, the mother's body is especially vulnerable to hazardous environmental exposure that not only affects the pregnant woman but also the fetus. Further research is still needed to elucidate the route and effect of environmental risk factors. Therefore, based on precautionary and preventive principles, special interest and caution in harmful environments are strongly needed not only at an individual level but also at a national level.

• Korea journal of population studies
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• v.31 no.1
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• pp.1-26
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• 2008

This research examines the effect of area level characteristics on individual health, particularly focusing on the vulnerable populations in Seoul. We consider adult individuals whose family income is under 1.5 million won, who are aged 65 and over, or who have neither spouse nor job but aged 40 and over as vulnerable populations. Using the 2005 Seoul Citizens' Health Interview Survey, we conducted multilevel analyses to simultaneously investigate the effect of area and individual level characteristics on health. Between-area variance of self-rated health status was greater for the elderly population than for all populations. Area material deprivation index and happiness index were associated with the self-rated health of economically disadvantaged populations. Vulnerable populations showed greater between-area variances in emotional health than the same for all populations. Area happiness index, material deprivation index, the proportion of households below poverty line and street safety showed statistically significant association with emotional health. The effect of area characteristics were particularly salient for the emotional health of elderly population and its between area variance was also notable.