• Economic and Environmental Geology
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• v.37 no.1
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• pp.61-72
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• 2004

The soil samples were collected from the paddy field near the mine tailing dumps in the abandoned Duckum mine in Korea. In the laboratory, the soil solution was extracted from the soil using centrifuge, and analysed for the chemical composition. Physical and chemical soil properties were also analysed. Kaolinite is the main clay minerals in the paddy soil and the CEC value is therefore relatively low. Nearly all soil samples show enrichment in their trace elemental concentrations(Cd, Cu, Pb and Zn) compared with natural background level. Some soil samples exceed the soil remediation intervention values for Cd, Pb and Zn and target value for Cu, when compared with Dutch standard, whereas As, Ni and Cr are in normal range. Lead concentrations in some samples near the mine tailing dumps also exceed the standard for remediation act for agricultural area set by Korean soil conservation law. The trace elemental concentrations are higher in the paddy soil nearer the mine tailing dumps and lower for the samples from distance. Similar trend with distance is found for the soil solution chemistry but the decrease with distance from the mine tailing dumps are sharper than the changes in soil chemistry. Cadmium, Cu and Pb concentrations in the soil solution are very low, ranging from a tenth and hundredths to a maximum of several mg/l, whereas their concentrations in soils are highly enriched for natural background. Most of the trace elements are thought to be either removed by reduced iron sulphides or iron oxides, depending on the redox changes. Geochemical equilibrium modelling indicate the presence of solubility controlling solid phases for Cd and Pb, whereas Zn and Cu might have been controlled by adsorption/desorption processes. Although pollutants migration through solution phase are thought to be limited by adsorption onto various Fe, Mn solid phases, the pollutants exist as easily releasable fractions such as exchangeable site. In this case, the paddy soil would act as pollutant pool, which will supply to plants in situ. whenever the geochemical conditions favour.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.2
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• pp.146-152
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• 2007

The present study was carried out to investigate the potential acute toxicity of ethanol extracts of the aleurone layer of Oryza sativa cvs. Obongbyeo, Ilpumbyeo, and Aranghyangchalbyeo by a single oral dose in ICR mice. The test article was orally administered once by gavage to male and female mice at dose levels of 0, 2.5, 5.0, and 10.0 g/kg body weight (n=10 for male and female mice for each dose). We examined numbers of deaths, general signs, weight measurement and biochemical analysis for sexes and doses of mice control and experimental groups. All mice were alive during the experimental period so can not yield death rate and $LD_{50}$. Any significant clinical symptom was not observed in all treated groups. No significant body weight changes in treatment groups in comparison with those of control groups was observed at any dose levels in experimental groups. Plasma glucose levels were valued both control and treated groups and there were no significant differences between groups. The activities of ALT and AST were not increase in all sample treated groups when compared with the control groups. The results suggest that the toxicity of Oryza sativa cvs. Obongbyeo, Ilpumbyeo, and Aranghyangchalbyeo are low and its $LD_{50}$ is over 10.0 g/kg body weight in both male and female mice.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.64-70
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• 2006

Purpose : The natural courses of prenatally diagnosed hydronephrosis(HN) are diverse. Our purpose was to determine if the findings of renal ultrasonography(USG) in patients with prenatal HN at 1 month of age can predict the 1 year follow-up results and determine the guideline of follow-up study. Methods : Among 462 hydronephrotic patients registered between 1996 and 2004, 153 unilateral hydronephrotic renal units were enrolled in this study, bilateral HN, vesicoureteral reflux and other associated anomaly were excluded. These were classified into four groups respectively, according to anterior posterior pelvic diameter(APPD) or Society for Fetal Urology(SFU) grading by USG findings at 1 month after birth. Renal USG and $Tc^{99m}$-mercaptoacetyl triglycerine(MAG3) scan were done according to a set protocol. Results : Most cases improved or remained stationary. No one underwent an operation SFU grade 1,2 groups and only one case of SFU grade 3 group was operated. Thirty two cases(64 percent) were operated on among the 50 cases of SFU grade 4 group. 0/2(0 percent), 5/11(45.5 percent), 11/17(64.7 percent) and 16/20(80 percent) were operated on in each group with APPD <10, 10-19, 20-29, >30 mm, and the operation risk is higher as the APPD is increased. Conclusion : In group with SFU grade below 3 and APPD below 10 mm, we can delay the follow-up study beyond existing set protocol. Operations are recommended immediately if diuretic renogram show the obstructive pattern or decreased renal function in SFU grade 4 group with APPD over 10 mm.

• Clinical and Experimental Pediatrics
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• v.50 no.8
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• pp.767-773
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• 2007

Purpose : Obesity has become a pandemic and especially the prevalence of childhood obesity has increased remarkably over the past years. Childhood obesity is often accompanied by the expected morbidities such as hyperlipidemia, fatty liver and glucose intolerance. We evaluated the pattern of alteration in the body mass index (BMI), serum adiponectin concentration, insulin resistance (HOMA-IR), and complication rates after one year follow-up. Methods : Forty two obese children (age: 8-15 years, 95th percentile of BMI for age and sex) were examined twice annually on June, 2004 and July, 2005. The body mass index (BMI) and sexual maturityrating (SMR) were determined annually by the same examiner and serum fasting glucose, liver enzyme, lipid profiles, adiponectin, insulin and HOMA-IR were measured and annual results were compared. Upper abdominal sonography was performed to detect fatty liver. Results : BMI ($25.3{\pm}2.9kg/m^2$ vs. $26.0{\pm}2.9kg/m^2$) and HOMA-IR ($3.6{\pm}1.8$ vs. $4.7{\pm}1.9$) have increased significantly after one-year follow-up. The serum adiponectin concentration ($17.2{\pm}5.2g/mL$ vs. $12.6{\pm}5.2g/mL$) has decreased after one year. The prevalence of hyperlipidemia and fatty liver were not changed significantly but that of hyperinsulinemia increased after one-year. HOMA-IR showed a positive correlation with BMI and SMR, but was negatively correlated with serum adiponectin concentration. Conclusion : Obese children in our study showed significant increment of insulin resistance during one year. These results suggest that well-organized and continuous obesity control is required especially for obese adolescent to prevent complication of obesity.

• Childhood Kidney Diseases
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• v.4 no.1
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• pp.33-39
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• 2000

Purpose: Our study was designed to investigate the association of MHC Class II (DR, DQ) allele with IgA nephropathy and its significance as a prognostic factor for progression to ESRD Material and Methods: 69 children with IgA nephropathy with normal renal function(serum creatinine $\leq$ 1.5mg/dL) was classified as group A and 70 patients who received renal transplantation due to IgA nephropathy were selected as group B. The HLA-DQB1 and HLA-DRB1 alleles were studied by polymerase chain reaction using sequence specific primers. We have compared the difference in alleles between these two groups and with normal control and also examined any possible effect of the MHC class II genes on the histopathological severity and prognosis of IgAN. Results: Mean age was $8.8{\pm}2.9$ years in group A and $35.0{\pm}15.5$ years in group B. Male to female ratio was 2.8:1 in group A and 2.5:1 in group B. There was a significantly higher frequency of HLA-$DQB1^*03\;and\;DQB1^*05$ in Group B. The frequency of HLA-$DQB1^*0302\;and\;^*05031$ allele had increasing tendency in Group B(P<0.05). HLA-$DRB1^*03\;and\;^*05$ were more common in Group B(P<0.05). HLA-$DRB1^*04$ allele was the most common DR alleles in both group, but there was no statistical significance. There were no significant correlation with MHC class 13 genes on the hjstopathological severity in Group A. Conclusion: In conclusion, $HLA-DQB1^*0302\;and\;HLA-DQB1^*05031 $ allele seemed to be more common in transplanted patients compared to group with normal renal function suggesting that this allele is associated with poor prognosis in IgAN. However larger studies and follow up are required to confirm this due to uncharacterized heterogeneity in etiopathogenesis of IgA nephropathy and possibly one or more than one gene may exert influence in determining susceptibility to the diseases.

• Geotechnical Engineering
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• v.12 no.4
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• pp.157-178
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• 1996

Current design methods for reinforced earth structures take no account of the magnitude of the strains induced in the tensile members as these are invariably manufactured from high modulus materials, such as steel, where straits are unlikely to be significant. With fabrics, however, large strains may frequently be induced and it is important to determine these to enable the stability of the structure to be assessed. In the present paper internal design method of analysis relating to the use of fabric reinforcements in reinforced earth structures for both stress and strain considerations is presented. For the internal stability analysis against rupture and pullout of the fabric reinforcements, a strain compatibility analysis procedure that considers the effects of reinforcement stiffness, relative movement between the soil and reinforcements, and compaction-induced stresses as studied by Ehrlich 8l Mitchell is used. I Bowever, the soil-reinforcement interaction is modeled by relating nonlinear elastic soil behavior to nonlinear response of the reinforcement. The soil constitutive model used is a modified vertsion of the hyperbolic soil model and compaction stress model proposed by Duncan et at., and iterative step-loading approach is used to take nonlinear soil behavior into consideration. The effects of seepage pressures are also dealt with in the proposed method of analy For purposes of assessing the strain behavior oi the fabric reinforcements, nonlinear model of hyperbolic form describing the load-extension relation of fabrics is employed. A procedure for specifying the strength characteristics of paraweb polyester fibre multicord, needle punched non-woven geotHxtile and knitted polyester geogrid is also described which may provide a more convenient procedure for incorporating the fablic properties into the prediction of fabric deformations. An attempt to define improvement in bond-linkage at the interconnecting nodes of the fabric reinforced earth stracture due to the confining stress is further made. The proposed method of analysis has been applied to estimate the maximum tensions, deformations and strains of the fabric reinforcements. The results are then compared with those of finite element analysis and experimental tests, and show in general good agreements indicating the effectiveness of the proposed method of analysis. Analytical parametric studies are also carried out to investigate the effects of relative soil-fabric reinforcement stiffness, locked-in stresses, compaction load and seepage pressures on the magnitude and variation of the fabric deformations.

• Journal of Environmental Science International
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• v.16 no.5
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• pp.571-581
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• 2007

The mechanism of water pollution in Lake Shihwa, one of highly eutrophicated artificial lakes in Korea, has been studied using a numerical 3D physical-biochemical coupled model. In this study, the model was applied to estimate the contribution of land-based pollutant load to water quality of heavily polluted Lake Shihwa. The chemical oxygen demand(COD) was adopted as an index of the lake water quality, and the spatial distribution of an average COD concentration during the summer from 1999 to 2000 was simulated by the model. The simulated COD showed a good agreement with the observed data. According to reproducibility of COD, the high-est levels between 8 and 9 mg/L were shown at the inner site of the lake with inflow of many rivers and ditches, while the lowest was found to be about 5 mg/L at the southwestern site near to dike gate. In the pre-diction of water quality of Lake Shihwa, COD showed still higher levels than 3 mg/L in case of reduction of 95% for land-based pollutant load. This suggests that the curtailment of land-based pollutant load is not only sufficient but the improvement of sediment quality or the increase of seawater exchange should be considered together to improve a water quality in Lake Shihwa.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.479-495
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• 2018

This study was carried out to research the multimedia fate modeling, concentration distribution and impact assessment of polycyclic aromatic hydrocarbons (PAHs) emitted from automobiles, which are known as carcinogenic and mutation chemicals. The amount of emissions of PAHs was determined based on the census data of automobiles at a target S-city and emission factors of PAHs, where multimedia fugacity modeling was conducted by the restriction of PAHs transfer between air-soil at the impervious area. PAHs' Concentrations and their distributions at several environmental media were predicted by multimedia fugacity model (level III). The residual amounts and the distributions of PAHs through mass transfer of PAHs between environment media were used to assess the health risk of PAHs at unsteady state (level IV), where the sensitivity analyses of the model parameter of each variable were conducted based on Monte Carlo simulation. The experimental result at S-city showed that Fluoranthene among PAHs substances are the highest residual concentrations (60%, 53%, 32% and 34%) at all mediums (atmospheric, water, soil, sediment), respectively, where most of the PAHs were highly accumulated in the sediment media (more than 80%). A result of PAHs concentration changes in S-city over the past 34 years identified that PAHs emissions from all environmental media increased from 1983 to 2005 and decreased until 2016, where the emission of heavy-duty vehicle including truck revealed the largest contribution to the automotive emissions of PAHs at all environment media. The PAHs concentrations in soil and water for the last 34 years showed the less value than the legal standards of PAHs, but the PAHs in air exceeded the air quality standards from 1996 to 2016. The result of this study is expected to contribute the effective management and monitoring of toxic chemicals of PAHs at various environment media of Metropolitan city.

• Archives of design research
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• v.17 no.2
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• pp.95-104
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• 2004

Creativity is a important keyword for users as well as for main design organization who needs it. But little attention has been given to the aspect of user's creativity, also there has been a few attempt to apply it into design development until now. Nowadays in design areas, user's experiences and actions are changing the passive states receiving meanings into the active states creating meanings voluntarily. It is resonable to suppose that creative stage is important for users and they have the possibility of new ideas of uses and creating new productions. User's experiences of objects includes that of being formed or supported previously and that of voluntary interpretations acquired for himself, which it may be the possibilities predicted in design process or unknown user's action areas. It is likely that creative use process by themselves are the actions applied and deviated from usability and function by main design organization, also creative productions are arranged and made by users. These have a scope of examination and research in probability that is occurs frequently in user. In this research, approaching with a term, 'User gestures', User gestures are the characteristic action areas based on user's voluntary behaviors, where are revealed a unessential and non-operational function as a action itself and various transformation and creation of products as a outcome of action. This fact proves clearly that user gestures have a worth of alive spectrum to observe aspects of user culture and could be a attractive approach to seek easily new design concept for designer and developer. A further direction of this study will be following areas, Ethnography methods research of user gestures, Cultural research to phenomenon of user design and UGSBD(User gesture scenario based design) research. And it seems probable that they are applied in design development as follows, User initiative customization products, User participatory recycling products and creativity-experience design.

• 한국지구물리탐사학회:학술대회논문집
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• 2004.08a
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• pp.104-117
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• 2004

Dmitri Donskoi, which went down during the Russo-Japanese War occurred 100 years ago, was found by using geophysical exploration techniques at the 400 m water depth of submarine valley off Jeodong of Ulleung Island. In the submarine area with the rugged seabed topography and volcanic seamounts, in particular, the reliable seabed images were acquired by using the mid-to-shallow Multibeam exploration technique The strength of corrosion (causticity) of the sunken Donskoi, measured by the electrochemical method, decreased to 2/5 compared with the original strength.