• Journal of Radiation Protection and Research
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• v.41 no.1
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• pp.31-39
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• 2016

Background: It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. Materials and methods: A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. Results and discussion: A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. Conclusion: The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.295-303
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• 1999

An experiment was conducted to evaluate the possibility of using basic oxygen furnace (BOF) slag as a soil conditioner in rice paddy field. In 1997, rice (Oryza sativa B. cv. Dongjinbyeo) crop was cultivated under different application rates of BOF slag at three different places, Inandong Sunchon city, Youjunglee Bosung province, and Nampyung Najoo city. In each paddy field, five treatments, four application rate of BOF slag (0, 4, 8, $12Mg\;ha^{-1}$) and one application rate of lime ($2Mg\;ha^{-1}$) were tried with three replications. Plant height, number of tillers per hill, leaf area per hill, leaf dry weight, calm dry weight or shoot dry weight per hill were measured five times at the interval of seven days. Chemical contents of rice plants and soil were also measured at the same sampling date Yield were estimated by harvesting $6.6m^2$ per experimental unit and yield components were measured by sampling 10 plants per experimental unit at the harvest date. Application of BOF slag hardly affected contents of soil organic matter, available phosphate and potassium in soil. Soil pH and contents of Ca, Mg, Fe and $SiO_2$ enhanced as BOF slag rate increased. Enhancement of soil pH by ROF slag treatment appeared to be closely related with increase in soil Ca content. Application tate of $2Mg\;ha^{-1}$ of lime showed almost the same effect, in increase of soil Ca content as application rate of $4{\sim}8Mg\;ha^{-1}$ of BOF slag, Fe content in soil decreased sharply as time passed after slag treatment and stabilized more or less at the later sampling date. Contents of inorganic matter in plant such as total nitrogen, phosphate, potassium and Mg were not affected by BOF slag treatment. However, contents of Ca, Fe, and $SiO_2$ in plants increased as slag rate became higher. The growth of rice plants with BOF slag treatment was more or less slower but continued persistently up to the later growth stage, so that growth of plants with BOF slag treatment was almost the same nr even greater than that of control or lime treatment. However, BOF slag rate of $12Mg\;ha^{-1}$ seemed to be too high because all the measurements of plant, growth at this rate showed lower values than those of other treatments at all the sampling dates. Treatments of BOF slag $4Mg\;ha^{-1}$ or $8Mg\;ha^{-1}$ showed higher rough rice yield than other treatments, so that the optimum BOF slag ratein rice paddy field seemed to be in the rage of $4{\sim}8Mg\;ha^{-1}$.

• Korean Journal of Environment and Ecology
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• v.23 no.6
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• pp.528-534
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• 2009

Styan's Grasshopper Warblers (Locustella pleskei) are vulnerable species distributed in East-Asia only. Its known breeding sites in Korea are remote islets including Hongdo Islet, Chilbal Islet, Mara Islet, and Chuja Islets, and, therefore, the breeding biology of this species is still poorly known. This study was conducted on Mara Islet (N $33^{\circ}$ 06', E $126^{\circ}$ 16') from May to September 2008 to investigate the breeding status and breeding site characteristics of the grasshopper warblers. A total of 11 breeding pairs and their nests were found on trees and shrubs at artificially planted forests and hedges of Pinus thunbergii. The grasshopper warblers preferentially utilized the shrub trees for nesting places, and major nesting trees were Camellia japonica, Pittosporum tobira and Pinus thunbergii as nesting trees. Average heights of nesting trees and nests were $2.77{\pm}1.10m$ and $1.75{\pm}0.56m$, respectively. The grasshopper warblers selected lower shrubs and trees for nesting than randomly selected ones around them, probably to avoid strong and prevailed winds in flat and un vegetated environments on Mara Islet. The shape of nests was a round bowl-type, and measurements of nests were $11.9{\pm}0.5cm$ in exterior nest diameter, $11.1{\pm}1.1cm$ in height of exterior nest, $5.8{\pm}0.4cm$ in interior nest depth, and 6.0cm in interior nest diameter. It incubated eggs until the early August on Mara islet, and incubation periods of Mara Islet was possibly later than that of other areas. Furthermore, the clutch size in the study area was three, and they laid smaller number of eggs than normal clutch size (4~5 eggs) reported in other areas. Although we could not observe any nest predator on this species in the study area, selective cutting and pruning of trees will diminish dense shrub layer of forests. Therefore, it may affect the breeding of this threatened species which prefers dense shrubs of artificially planted forest of Pinus thunbergii. This study suggests that detailed and consistent further research on breeding biology and habitats of the grasshopper warblers are needed to conserve and manage of Pinus thunbergii forests on Mara Islet as an important breeding site of Styan's Grasshopper Warblers.

• Journal of Preventive Medicine and Public Health
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• v.29 no.3 s.54
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• pp.439-449
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• 1996

This study was conducted to evaluate the relationship between change in obesity indices and change in serum lipids in adult male workers. Two-hundred-eight adult male workers of an industry in Taegu city were followed-up from 1991 to 1995. Height, weight, circumferences of hip and waist, blood pressure were measured and serum lipids were analysed. Data on life style were obtained using self-administered questionnaires. Mean differences of anthropometric measurements between 1991 and 1995 were as follows: 1.63kg in weight, 3.61cm in waist circumferences, 4.23cm in hip circumferences, $0.52kg/m^2$ in BMI and -0.021 in WHR. Those of lipids were as follows; 15.09mg/dl in total cholesterol, 20.43mg/dl in triglyceride, 9.40mg/dl in HDL-cholesterol, 2.87 in MI - index (p<0.01) and 350mg/dl in LDL-cholesterol. The changed value of BMI and Katsura index were strongly correlated with that of total cholesterol(r=0.174, p<0.05), the changed value of BMI correlated with that of triglyceride(r=0.374, p<0.01) and the changed value of weight correlated with that of MI index(r=-0.173, p<0.05). The changed value of WHR was signifiantly correlated with that of total cholesterol(r=0.162, p<0.05), however, was not significantly correlated with HDL-cholesterol, LDL-cholesterol, triglyceride and MI index. The changed value of weight, BMI and Katsura index were correlated with that of triglyceride (r=0.262, p<0.01; r=0.267, p<0.01; r=0.258, p<0.01) and the changed value of MI index(r=0.143, p<0.05; r=-0.158; r=-0.144, p<0.01), adjusting the pattern of change in life style. The changed values of HDL - cholesterol and MI index between 1991 and 1995 in low WHR group were significantly higher than those in high WHR group(p<0.05, p<0.01), adjusting the baseline value of them. Similar pattern was observed when considering Katsura index. When stratifying by BMI value of 1991, in low BMI group, the changed value of HDL - cholesterol and MI index showed the same pattern as above, however that of triglyceride was statistically higher in obese group than in non obese group(p<0.05). In conclusion BMI might be a better indicator to predict serum lipids change than other obesity indices.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.2
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• pp.196-205
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• 2008

Variability in vertical ozone and meteorological profiles was measured by 2Z electrochemical concentration cells (ECC) ozonesonde at Bangyi in Seoul ($37.52^{\circ}N$, $127.13^{\circ}E$) during June $6{\sim}9$, 2003 in odor to identify the vertical distribution of ozone and its relationship with the lower-atmospheric structure resulted in the high ozone concentrations near the surface. The eight profiles obtained in the early morning and the late afternoon during the study period clearly showed that the substantial change of ozone concentrations in lower atmosphere(${\sim}5\;km$), indicating that it is tightly coupled to the variation of the planetary boundary layer (PBL) structure as well as the background synoptic flow. All profiles observed early in the morning showed very low ozone concentrations near the surface with strong vertical gradients in the nocturnal stable boundary layer due to the photochemical ozone loss caused by surface NO titration under very weak vertical mixing. On the other hand, relatively uniform ozone profiles in the developed mixing layer and the ozone peaks in the upper PBL, were observed in the late afternoon. It was noted that a significant increase in ozone concentrations in the lower atmosphere occurred with the corresponding decrease of the mixing height in the late afternoon on June 8. Ozone in upper layer did not vertically vary much compared to that in PBL but changed significantly on June 6 that was closely associated with the variation of synoptic flows. Interestingly, heavily polluted ozone layers aloft (a maximum value of 115 ppb around 2 km) were formed early in the morning on 6 through 7 June under dominant westerly synoptic flows. This indicates the effects of the transport of pollutants on regional scale and consequently can give a rise to increase the surface ozone concentration by downward mixing processes enhanced in the afternoon.

• Journal of Nutrition and Health
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• v.40 no.6
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• pp.517-525
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• 2007

This study was performed to assess the effects of physiological factors and lifestyles on bone mineral density (BMD) in 64 postmenopausal women. Sixty four subjects were selected out of 223 postmenopausal women in Seoul and Kyunggido. The BMD of the lumbar spine (L2 ${\rightarrow}$ L4) and femoral neck were measured dual energy X-ray absorptiometry (DEXA). Subjects were assigned to one of three groups such as normal (T-score > -1, n = 20), osteopenia (-2.5 < Tscore ${\leq}$ -1, n = 24), and osteoporosis (T-score ${\leq}$ -2.5, n = 20). Anthropometric measurements and questionares were administered to these women. The mean age, height, weight and BMI were 62.09 yrs, 153.78 cm, 56.09 kg and 23.70 $kg/m^2$ respectively. The BMDs of lumbar spines (L2 ${\rightarrow}$ L4), femoral neck were 0.84 $g/cm^2$, 0.71 $g/cm^2$ respectively. Years after menopause and age of last delivery of the osteoporosis and osteopenia group were significantly longer than the normal group (p < 0.05). The hours of exercise and outdoor activity of the normal group were longer than the osteoporosis and osteopenia group, but there were no significant differences among the three groups. The BMDs of these two sites were positively correlated with weight, BMI, hip and body fat and negatively correlated with LBM, TBW. These results show there are no consistent effects on bone mineral density, adjusting for age and BMI, of physiological factors and lifestyles in postmenopausal women. Therefore. this study confirmed that one of the most effective ways to minimize bone loss in postmenopausal women would be to maintain an adequate body weight.

• Korean Journal of Agricultural Science
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• v.16 no.1
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• pp.62-70
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• 1989

This study was conducted to determine the main effects of the sire, farrowing year, month and parity on the average daily gain, feed efficiency, body weight and body type on the basis of data obtained from 64 Korean native bulls from 8 sires raised at Chungnam Animal Breeding Station from 1985 to 1987. The results obtained are summarized as follows; 1. Average daily gain, DCP and TDN requirement were 1.049, 0.977 and 4.584kg, and the effect of sire was highly significant(p<0.01) for average daily gain and TDN requirement, respectively. 2. Body weight at 6 and 12 months of age were 182.023 and 371.750kg, and the effects of sire, farrowing year and month were highly significant(p<0.01) for body weights, respectively. 3. Wither height and body length were 106.672 and 108.986cm for 6 months of age, 119.984 and 132.312cm for 12 month of age, and the effect of sire was significant(p<0.05) for these all traits, respectively. 4. Chest girth and chest width were 129.578 and 27.937cm for 6 months of age, 166.281 and 38.357cm for 12 months of age, and the effect of sire was significant(p<0.05) for chest girth at 6 and 12 months of age, respectively.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.950-955
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• 2008

Purpose : The objective of this study was to provide current estimates of the prevalence and examine trends of overweight and obesity in children and adolescents. Methods : Height and weight measurements from 183,159 (112,974 in 1997, 70,185 in 2005) children and adolescents aged 2 to 18 years were obtained via the 1997 and 2005 National Growth Survey. Obesity among children and adolescents was defined as being at or above the 95th percentile of the gender-specific body mass index (BMI) for age in the 2007 Korean National Growth Charts or a BMI of 25 or higher; overweight was defined as being at or above the 85th percentile to less than the 95th percentile BMI. Results : In 2005, 9.7% (11.3% for boys, 8.0% for girls) of South Korean children and adolescents were obese; 19.0% (19.7% for boys, 18.2% for girls) were overweight or obese. The overall prevalence of obesity increased from 5.8% in 1997 to 9.7% in 2005 (from 6.1% in 1997 to 11.3% in 2005 for boys and from 5.5% in 1997 to 8.0% in 2005 for girls); the increasing trend was most evident in boys, especially those aged 13-18 years. Conclusion : The prevalence of obesity among children and adolescents increased significantly during the eight-year period from 1997 to 2005. This study suggests that we need to make a priority of developing strategies to control obesity in children and adolescents; the potential health effects of increases in obesity are of considerable public health importance.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.3 no.2
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• pp.175-180
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• 2000

Purpose: Leptin is an adipocyte-derived blood-borne satiety factor that acts on its cognate leptin receptor in the hypothalamus, thereby regulating food intake and energy expenditure. We measured the leptin concentrations in serum of normal and obese children with human leptin ELISA kit, unlike previous study with leptin RIA kit and investigated the relationship between leptin concentrations and body mass index, gender, and age. Methods: We measured serum concentrations of leptin in 67 children who were visited to the Department of Pediatrics, Chungnam National University Hospital during the period of 5 months from February, 1999 to June, 1999. Height, weight, obesity index, and body mass index were measured in 67 subjects. Leptin values in serum were measured by sandwich ELISA method. Data analysis was done according to the obesity, body mass index, gender and age. Results: The mean concentration of leptin was $7.69{\pm}8.83\;ng/ml$ in normal children group and $36.34{\pm}18.57\;ng/ml$ in obese group. Serum leptin concentrations were significant correlation with the body mass index (p<0.01). Serum leptin concentration was significant higher in the group of over 10 years of age (p<0.01). Leptin levels showed no significant difference by gender. Conclusion: Serum leptin levels were significantly higher in obesity group than in control one, and they were correlated with body mass index and age. Measurements of leptin value by sandwich ELISA method are very useful and easily applicable to determine obesity.

• Clinical and Experimental Pediatrics
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• v.49 no.7
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• pp.769-776
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• 2006

Purpose : Pulse wave velocity(PWV) and ankle brachial index(ABI) are not only noninvasive methods used to assess arterial stiffness in adults, but also useful, simple ways to estimate the severity of hypertension, end stage renal disease and atherosclerosis in adults. But there are few studies on PWV and ABI in adolescents and children. In this study, hypertensive adolescents were compared to normal individuals to find out the usefulness of PWV as the index of progress in the disease. Methods : 413 teenagers were divided into three groups. The first group consisted of adolescents that only had hypertension(Group 1 : 23 teenagers). The second group consisted of the adolescents who had hypertension with obesity(Group 2 : 17 teenagers), and the last group was the normal subjects(Group 3 : 328 teenagers). Weight, height and body mass index were measured. Simultaneous measurements of systolic, diastolic and average blood pressure were obtained from the four extremities. PWV, ABI, ejection time and preejection period were also measured. Results : Right brachial-ankle PWV was significantly higher in both group 1 and group 2 compared with group 3, and significantly higher in group 2 compared with group 1. Likewise, left brachial-ankle PWV also showed significantly higher values in both group 1 and group 2 compared with group 3, and also higher values in group 2 compared with group 1. Positive correlations were found between the systolic, diastolic, average blood pressure and PWV. There were also positive correlations between the blood pressure and weight, body mass index. Conclusion : Higher PWV was demonstrated in adolescents with essential hypertension compared to normal subjects. Follow-up study is needed to evaluate the progress.