• Journal of Environmental Health Sciences
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• v.10 no.2
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• pp.9-40
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• 1984

This thesis purports to overview the diverse administrative and organizational factors and plannings developed by the government organizations, municipal or otherwise, to tackle the Han River water pollution issues in the past years. This thesis also looks into the ever-worsening Han River water pollution problems, in particular, in terms of the various government plans ostensibly designed to reduce the pollution level but with little success. Also dealt with are the efficiencies with which the laws and decrees on water pollution the administrative organizations put to use in the prosecution of the diverse antiwater pollution projects involving the Han River basin. From the early 1960's up to the 1970's the government had concentrated on the growth-oriented economic policy with the result that little attention had been paid to the water pollution and other environmental issues that are bound to arise from the massive economic growth. Belatedly, the five-year Hah River Development Project was initiated in 1982 with emphasis on reducing the water pollution level at Hah River to the minimum. The following are the gists of the thesis and recommendations for the future antiwater pollution plans by the administrative organizations: 1. Documents to date indicate that the irrigation projects along the Han River area had been the main focus of attention during the Yi Dynasty and under the Japanese rule of the country. 2. Despite that the water pollution issue became the subject of many debates among the academic and research institutions in the 1960's and in the 1970's, the administrative organizations in charge of the Han River water quality control failed to come up with a concrete plan for the river's water quality control. 3. Nevertheless, the water pollution of the Han River area in fact began in the 1950's, with the unprecedented concentration into Seoul of population and the industrial facilities on a larger scale, in particular, enforced by the government's strong growthoriented policy in its Economic Development plans in the 1960's. 4. Starting in the 1960's, the Han River water pollution level dramatically increased, but the government was reluctant to promulgate or put into effect strong measures to curb the many factors contributing to the river water pollution, thus worsening the environmental issues along the Han River basin. 5. The environmental protection law and other laws and decrees relating to the antiwater and air pollution issues that were subsequently put into effect underwent so many changes that efficient anti-water pollution policies could not be effected for the Han River basin. The frequent organizational reshuffle within the administrative units concerned with environmental problems has resulted in the undue waste in personnel management and finance. 6. The administration on the environmental protection could not be efficiently carried out due to the organizational overlapping. Under the existing law, frequent organizational frictions and inefficiency are bound to occur among the central government offices themselves, as well as between the central government and the Seoul city administration, and among the city's administrative offices over the conservation of the Han River basin and over the river's anti-water pollution issue. 7. In the planning and prosecution of the Han River project, political influences from the president down to the lower-level politicious appear to have been involved. These political influences in the past had certainly had negative influence on the project, nevertheless, it appears that in the recent years, these political influences are not all that negative in view of the fact that they serve as a positive contributing factor in developing a better water quality control project along the Han River basin. The following are a few recommendations based on the data from the thesis: First, officials in charge of the Han River water quality control should pay attention to a careful screening of the opinions and recommendations from the academic circles and from the public should be made so that the government could better grasp the core issues in the environmental problems that require preventive and other necessary measures. Second, vigorous redistribution policies of population and industrial facilities away from the Seoul area should be pursued. Third, the government should refrain from revising or revamping too frequently the laws and decrees on the anti-water pollution, which is feared to cause undue inconveniences in the environmental administration. Fourth, a large-scale streamlining should be made to the existing administrative organization in an effort to do away with the inter- and intra-organizational friction. It is recommended that a secretariat for the Hah River basis conservation be established. Fifth, High-level administrative officials, with a thorough knowledge and vision on the Han River water quality control, should be prepared to better deal with the budgeting and personnel management for the Han River water pollution control not only at the control government, but also at the Seoul city municipal government levels. Environmental issues should be kept distinct from political issues. Environmental issues should not serve as a window-dressing for sheer political purposes. Sixth, the Hah River proiect should also include, along with the main Han River basin, those areas covering North Han River, South Han River, and the tributaries to the main river basin. The 'Han River Basin Water Quality Control Board' should be established immediately as a means of strengthening the current Han River basin water quality control policy. Seventh, in drawing up the Han River proiect, the administrative officials should be aware that Han River basin is a life line for those people in the region, providing them with not only a sheer physical space, but with a psychological living space for their everyday life.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.3
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• pp.1-11
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• 2012

This study focused on establishing a natural rainwater circulation system using rainwater meant for relatively large urban development projects such as a new town development. In particular, when the location selection techniques for individual elements of a natural rainwater circulation system are developed for the integrated rainwater management, changes in hydrological environment will be minimized and the natural water circulation would be restored to realize the low impact development (LID). In that case, not only the excess will be reduced but water space and green areas in a city would also increase to improve the urban sustainability. First of all, there were five elements selected for the location selection of a rainwater circulation system intended for the integrated rainwater management: rainwater collection, infiltration, filtration, retention and movement spaces. After generating these items, the location selection items and criteria were defined for each of the five elements. For a technique to apply the generated evaluation items and criteria, a grid cell analysis was conducted based m the suitability index theory, and thematic maps were overlapped through suitability assessment of each element and graded based on the suitability index. The priority areas were identified for each element. The developed technique was applied to a site where Gim-cheon Innovation City development is planned to review its feasibility and limitations. The combined score of the overlapped map for each element was separated into five levels: very low, low, moderate, high and very high. Finally, it was concluded that creating a rainwater circulation system conceptual map m the current land use plan based on the outcome of the application would be useful in building a water circulation system at the de1ailed space planning stage after environmental and ecological planning. Furthermore, we use the results of this study as a means for environment-friendly urban planning for sustainable urban development.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.11
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• pp.509-520
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• 2015

College Scholastic Ability Test(CSAT) is a primary test to evaluate the study achievement of high-school students and used by most universities for admission decision in South Korea. Because its level of difficulty is a significant issue to both students and universities, the government makes a huge effort to have a consistent difficulty level every year. However, the actual levels of difficulty have significantly fluctuated, which causes many problems with university admission. In this paper, we build two types of data-driven prediction models to predict correct answer rate and to identify significant factors for CSAT English test through accumulated test data of CSAT, unlike traditional methods depending on experts' judgments. Initially, we derive candidate question-specific factors that can influence the correct answer rate, such as the position, EBS-relation, readability, from the annual CSAT practices and CSAT for 10 years. In addition, we drive context-specific factors by employing topic modeling which identify the underlying topics over the text. Then, the correct answer rate is predicted by multiple linear regression and level of difficulty is predicted by classification tree. The experimental results show that 90% of accuracy can be achieved by the level of difficulty (difficult/easy) classification model, whereas the error rate for correct answer rate is below 16%. Points and problem category are found to be critical to predict the correct answer rate. In addition, the correct answer rate is also influenced by some of the topics discovered by topic modeling. Based on our study, it will be possible to predict the range of expected correct answer rate for both question-level and entire test-level, which will help CSAT examiners to control the level of difficulties.

• The Korean Journal of Physiology
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• v.7 no.2
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• pp.9-16
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• 1973

In view of the recent knowledge on the radioprotective action of reduced glutathione (GSH), the present study was designed the elucidate the effect of some concentrations of GSH on the levels of intrinsic non-protein sulfhydryl (NP-SH) and non-protein disulfide (NP-SS) of the mouse liver incubated at 4, 25 and 37C in vitro, respectively. The liver slice of the mouse was incubated at 4, 25 and 37C in the medium composed of 100 ml of Krebs-Ringer phosphate buffer (KRP) with the addition of 10, 20 and 30 mg of GSH, respectively. Measurement of NP-SH and NP-SS was made at 5, 30 and 60 min during the course of the incubation, and the results were compared with the controls which were incubated only in KRP medium, and the normal. The results thus obtained are summarized as follows: 1. When the mouse liver slice was incubated at 4C, the values of both NP-SH and NP-SS of the control and the group where 10 mg of GSH was added to the incubation medium were similar to those of the normal group, and the increase of NP-SH and NP-SS with the increased concentrations of GSH was not prominent. 2. When the liver slice was incubated in the concentrations of GSH 20 mg/100 ml KRP and GSH 30 mg/100 ml KRP at 25 C, the rate of increase of both NP-SH and NP-SS was proportional to the increase of GSH concentration. In the group where 10 mg of GSH was added to the incubation medium, the value of NP-SH and NP-SS reached the highest value at 30 min, but a tendency of decrease was observed at 60 min. 3. The rate of increase of NP-SH and NP-SS of the liver was most marked of all the group. studied when the incubation temperatuse was elevated to 37C, and the increase was proportional to the concentration of GSH and the incubation time.

• Korean Journal of Community Nutrition
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• v.9 no.2
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• pp.173-182
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• 2004

We carried out a validation-calibration study of the food frequency questionnaire (FFQ) that we had previously developed for a community-based cohort of the Korean Genome and Health Study of the Korea National Genome Research Institute. We have collected a total of 254 3-day diet records (DRs) from 400 subjects, 200 each randomly selected from the two study cohorts of Ansung and Ansan. FFQ was administered at the time of cohort recruitment in 2001, and DRs were collected during a two month period from January through February of 2002. The mean age was 52.2 years. Farming for men and housewife for women were the most common occupations. The majority of the subjects had undergone 6∼12 years of education. The general characteristics including demographic and other data were not different from the total cohort subjects. Absolute levels of consumed nutrients including total energy (energy), protein, fat, carbohydrate, calcium, phosphorus, sodium, potassium, iron, retinol, carotene, vitamin A, thiamin, riboflavin, niacin and vitamin C were compared. The average of energy intake was not significantly different between the data collected by the 2 methods. However, consumptions of protein and fat were higher in data of DRs, whereas that of carbohydrate was higher in FFQ data. Significant correlation of each nutrient consumption between the data sets was observed (p ＜ 0.05) except in the case of iron, while the average correlation coefficient between them was 0.22 ranging from 0.33 for energy to 0.11 for iron. The results of cross classification by quantile for exact classification ranged from 25.2% (carotene) to 35.0% (phosphorus), and from 64.6% (vitamin A) to 76.4% (retinol) for adjacent classification. The proportion of completely opposite classification was 8.1% in average. Calibration slope was estimated by regression and calibration parameters ranged from 0.025 for carotene to 0.423 for niacin. We conclude that the FFQ we have developed is an appropriate tool for assessing the nutrient intakes as ranking exposures in epidemiology studies in view that amounts of consumed nutrients obtained by FFQ were similar to those collected by DRs, that correlations between consumed nutrients collected by these methods were significant, and that classification results were relatively fair. The correlation coefficients, however, were lower than expected, which may be mainly due to the survey season. In fact, any short-term dietary survey cannot accurately reflect the overall dietary intakes that change heavily depending on seasons. Further studies including the analysis of chemical indices would be helpful for the studies of causal relationship between the diet and disease.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.4
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• pp.61-75
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• 2018

This study aims to verify the effect of green buffers, built as urban planning facilities on the reduction of ultra-fine particulate($PM_{2.5}$) and analyze changes in ultra-fine particles by structure, green volume and planting types of wayside green buffers, thus drawing the factors that can be used when green buffers are built to reduce ultra-fine particulate based on the results. This study selected Songpa-gu, and investigated 16 sites on 5 green buffers adjacent to two of Songpa-gu's main roads, 'Yangjaedaero' and 'Songpadaero'. This study divided all the green spaces into three different types-slope type, plain type and mounding type, and analyzed the mean green volume. As a result of measuring the concentration of $PM_{2.5}$, this study found that it was $55.5{\mu}g/m^3$ on average in winter, which was a harmful level according to the integrated environmental index provided by Seoul City, saying that levels above $50{\mu}g/m^3$ may have a harmful effect on sensitive groups of people. Particularly, the concentration of $PM_{2.5}$ was $38.6{\mu}g/m^3$ on average in spring, which exceeded the mean concentration of $PM_{2.5}$ in Seoul City in 2015. The mean concentrations of $PM_{2.5}$ in every investigation spot were $46.6{\mu}g/m^3$ for sidewalks, $45.5{\mu}g/m^3$ for green spaces and $42.9{\mu}g/m^3$ for residential areas, all of which were lower than $53.2{\mu}g/m^3$ for roads, regardless of the season. The concentration of $PM_{2.5}$ for residential areas was the lowest. In the stage of confirming the effect of green buffers, this study analyzed the correlation between the green volume of vegetation and the fluctuated rate of ultra-fine particles. As a result, it was found that the green coverage rate of trees and shrubs was related to the crown volume in every investigation spot but were mutually and complexly affected by each other. Therefore, this study judged that the greater the number of layers of shrubs that are made, the more effective it is in reducing the concentration of $PM_{2.5}$. As for seasonal characteristics, this study analyzed the correlation between the concentration of $PM_{2.5}$ for residential areas in winter and the green coverage rate of each green space type. As a result, this study found that there was a negative correlation showing that the higher the shrub green coverage rate is, the lower the concentration value becomes in all the slope-type, plain-type and mounding-type green spaces. This study confirmed that the number of tree rows and the number of shrub layers have negative correlations with the fluctuated concentration rate of $PM_{2.5}$. Especially, it was judged that the shrub green volume has greater effect than any other factor, and each green space type shows a negative correlation with the shrub coverage rate in winter.

• Restorative Dentistry and Endodontics
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• v.29 no.2
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• pp.170-176
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• 2004

Objectives : In the unique metal iris method. the developing interfacial gap at the cavity floor resulting from the cavity wall property during polymerizing composite resin might affect the nominal shear bond strength values. The aim of this study is to evaluate that the iris method reduces the cohesive failure in the substrates and the cavity wall property effects on the shear bond strength tests using iris method. Materials and Methods : The occlusal dentin of 64 extracted human molars were randomly divided into 4 groups to simulate two different levels of cavity wall property (metal and dentin iris) and two different materials ($ONE-STEP^{\circledR}$ and $ALL-BOND^{\circledR}$ 2) for each wall property. After positioning the iris on the dentin surface. composite resin was packed and light-cured. After 24 hours the shear bond strength was measured at a crosshead speed of 0.5 mm/min. Fracture analysis was performed using a microscope and SEM. The data was analyzed statistically by a two-way ANOV A and t-test. Results : The shear bond strength with metal iris was significant higher than those with dentin iris (p＝0.034). Using $ONE-STEP^{\circledR}$, the shear bond strength with metal iris was significant higher than those with dentin iris (p＝0.005), but not in $ALL-BOND^{\circledR}$ 2 (p＝0.774). The incidence of cohesive failure was very lower than other shear bond strength tests that did not use iris method. Conclusions：The iris method may significantly reduce the cohesive failures in the substrates. According to the bonding agent systems. the shear bond strength was affected by the cavity wall property.

• Journal of Animal Environmental Science
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• v.12 no.3
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• pp.123-132
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• 2006

This study was conducted to determine the volume of Holstein heifers manure excreted and its characteristics. The average dry matter intake of heifers was 6.7 kg/head/day. The intake rate was lowest in spring among four seasons. The average dry matter intake rate during spring, summer, fall, and winter was 4.6, 8.3, 7.1, and 6.8 kg/head/day, respectively. The average water intake of heifers was $19.3{\ell}/head/day$. The wale. consumption was highest value ($21.8{\ell}/head/day$) in summer and lowest values ($18.3{\ell}/head/day$) in spring and winter. Values were found not to be statiscally different for the four seasons. The average manure production of heifers (average live weight was 363.1 kg) was 20.3 kg/head/day and it was 5.6% of live animal weight. The manure production during spring, summer, fall, and winter was 13.7, 23.5, 25.0, and 20.2 kg/head/day, respectively. Production during spring was lower than the other seasons (p<0.05). A higher correlation between live weight and manure production ($R^2=0.7816$) and between live weight and feed intake ($R^2=0.7296$) was observed for heifers. Correlations between manure production and water intake and between manure production and feed intake were found to be relatively low for heifers. The moisture content of feces was 83.5% and that of urine 94.6%. The pH of feces and urine were in the ranges of 7.4 and 7.5, respectively. The $BOD_5$, COD, SS, T-N, T-P concentrations of the heifer feces were 18,048, 50,114, 119,833, 2,519, and $427mg/{\ell}$, respectively. Heifer urine showed lower levels of $BOD_5(5,434mg/{\ell})$, COD$(6,550mg/{\ell})$, SS$(825mg/{\ell})$, T-N$(3,616mg/{\ell})$, and $T-P(28mg/{\ell})$ than feces. The fertilizer nutrient concentrations of heifer feces was 0.25% N, 0.1% $P_2O_5$ and 0.14% $K_2O$. Urine was found to contain 0.36% N, 0.006% of $P_2O_5$ and 0.31% $K_2O$.

• Journal of Hospice and Palliative Care
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• v.7 no.1
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• pp.37-48
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• 2004

Purpose: Population using complementary and alternative medicine (CAM) and the cost or it are increasing all over the world. In this study, we investigated the utilization state of CAM in the elderly people during the last 6 months of life. Methods: We found 4,210 persons in Seoul, older than 65 years who received a funeral subsidy from health insurance after death during the latter half of the year, 2001. We stratified them by age and gender and selected 301 persons and surveyed them by questionnaire. Results: 247 persons (83.1%) used at least one of CAM during their last 6 months of life. Diet and Nutrition remedy showed the highest utilatization rate (65.5%), and drug therapies also were much used (29.9%). Utilization rate was higher in female (60%) and according to the cause of death, the highest in a geriatric disease groups, and the lowest in the cancer group. Whole satisfaction to CAM was high with average 4.25 points out of total 6, and adverse effects were almost free with average 5.55 points out of total 6. Satisfaction was the highest in Diet and Nutrition remedy but the lowest in Manipulative and Body-Based methods. Adverse-effect score was best in Manipulative and Body-Based methods. According to age and the causative disease of death, there were significant differences in satisfaction and adverse effect levels. Conclusion: Majority of old people used at least one of CAM during their last 6months of life. Whole satisfaction and adverse-effect level were very excellent.

• Journal of Food Hygiene and Safety
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• v.21 no.4
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• pp.250-257
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• 2006

The purpose of this study is to evaluate microbiological contamination of leafy vegetables. Total aerobic bacteria and coliforms were monitored to get the contamination levels and Staphylococcus aureus, Bacillus cereus, Clostridium perfringens, Escherichia coli, Escherichia coli O157:H7, Salmonella spp., Vibrio parahaemolyticus, Listeria monocytogenes, Yersinia enterocolitica, Campylobacter jejuni to detect pathogens with risk of foodpoisoning from fresh vegetables. The colony count of total aerobes and coliforms was also performed to determine the efficacy of washing with tab water by common consumers. 124 samples which are divided into 8 kinds of vegetables - Sesame leaf, Dropwort, Chinese cabbage, Korean leek, Lettuce, Crown daisy, Pimpinella brachycarpa, Chicory were sampled in 2 wholesale markets in Incheon. Mean counts of total aerobic bacteria for individual vegetables ranged from $2.2\times10^6\;CFU/g\;to\;6.0\times10^7\;CFU/g$ and total coliforms were from $4.1\times10^5\;CFU/g\;to\;9.8\times10^6\;CFU/g$. Both show the peaks in summer on this study from March to September. Decrease rates after washing with tab water averaged 81.0% and 82.5% in total aerobic bacteria and coliform counts respectively. Staphylococcus aureus was isolated 8.1%, Bacillus cereus 14.5%, Clostridium perfringens 5.6%, Escherichia coli 18.5%. 11 samples showed overlapped bacterial contamination. For respective vegetables Staphylococcus aureus isolated from 0.0% to 22.2%, Bacillus cereus from 0.0% to 29.4%, Clostridium perfringens from 0.0% to 23.1 %, Escherichia. coli from 0.0% to 35.0%. Escherichia coli O157:H7, Salmonella spp., Vibrio parahaemolyticus, Listeria monocytogenes, Yersinia enterocolitica, Campylobacter jejuni were not isolated. This study is expected to be available as the reference for the basal data of pathogens in fresh vegetables.