• Journal of the Korean association of regional geographers
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• v.3 no.1
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• pp.63-80
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• 1997

This study attempts to establish the criteria of site selection for establishing solid waste disposal facility, to determine optimal solid waste disposal sites with the criteria, and to examine the suitability of the selected sites. The Multi-Criteria Evaluation(MCE) module in Idrisi is used to determine optimal sites for solid waste disposal. The MCE combines the information from several criteria in interval and/or ratio scale to form a single index of evaluation without leveling down the data scale into ordinal scale. The summary of this study is as follows: First, the considerable criteria are selected through reviewing the literature and the availability of data: namely, percent of slope, fault lines, bedrock characteristics, major residential areas, reservoirs of water supply, rivers, inundated area, roads, and tourist resorts. Second, the criteria maps of nine factors have been developed. Each factor map is standardized and multiplies by its weight, and then the results are summed. After all of the factors have been incorporated, the resulting suitability map is multiplied by each of the constraint in turn to "zero out" unsuitable area. The unsuitable areas are discovered in urban district and its adjacencies, and mountain region as well as river, roads, resort area and their adjacency districts. Third, the potential sites for establishing waste disposal facilities are twenty five districts in Youngyang-gun. Five districts are located in Subi-myun Sinam-ri, nine districts in Chunggi-myun Haehwa-ri and Moojin-ri, and eleven districts in Sukbo-myun Posan-ri. The first highest score of suitability for waste disposal sites is shown at number eleven district in Chunggi-myun Moojin-ri and the second highest one is discovered at number twenty one district in Sukbo-myun Posan-ri that is followed by number nine district in Chunggi-myun Haehwa-ri, number seventeen and twenty three in Sukbo-myun Posan-ri, and number two in Subi-myun Sinam-ri. The first lowest score is found in number six district in Chunggi-myun Haehwa-ri, and the second lowest one is number five district in Subi-myun Sinam-ri. Finally, the Geographic Information System (GIS) helps to select optimal sites with more objectively and to minimize conflict in the determination of waste disposal sites. It is important to present several potential sites with objective criteria for establishing waste disposal facilities and to discover characteristics of each potential site as a result of that final sites of waste disposal are determined through considering thought of residents. This study has a limitation of criteria as a result of the restriction of availability of data such as underground water, soil texture and mineralogy, and thought of residents. To improve selection of optimal sites for a waste disposal facility, more wide rage of spatial and non-spatial data base should be constructed.

• The Journal of Engineering Geology
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• v.18 no.4
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• pp.447-457
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• 2008

Laboratory tests for single plane sliding were conducted using the model rock slope to investigate the cut slope deformability and failure mechanism due to combined effect of engineering characteristics such as angle of sliding plane, water force, joint roughness and infillings. Also the possibility of prediction of slope failure through displacement monitoring was explored. The joint roughness was prepared in forms of saw-tooth type having different roughness specifications. The infillings was maintained between upper and lower roughness plane from zero to 1.2 times of the amplitude of the surface projections. Water force was expressed as the percent filling of tension crack from dry (0%) to full (100%), and constantly increased from 0% at the rate of 0.5%/min and 1%/min upto failure. Total of 50 tests were performed at sliding angles of $30^{\circ}$ and $35^{\circ}$ based on different combinations of joint roughness, infilling thickness and water force increment conditions. For smooth sliding plane, it was found that the linear type of deformability exhibited irrespective of the infilling thickness and water force conditions. For sliding planes having roughness, stepping or exponential types of deformability were predominant under condition that the infilling thickness is lower or higher than asperity height, respectively. These arise from the fact that, once the infilling thickness exceeds asperities, strength and deformability of the sliding plane is controlled by the engineering characteristics of the infilling materials. The results obtained in this study clearly show that the water force at failure was found to increase with increasing joint roughness, and to decrease with increasing filling thickness. It seems possible to estimate failure time using the inverse velocity method for sliding plane having exponential type of deformability. However, it is necessary to estimate failure time by trial and error basis to predict failure of the slope accurately.

• Korean Journal of Environmental Agriculture
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• v.27 no.1
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• pp.60-65
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• 2008

Current soil remediation principles for toxic metals have some limitations even though they vary with different technologies. An alternative technology that transforms hazardous substances into nonhazardous ones would be environmentally beneficial. Objective of this research was to assess optimum conditions for Cr(VI) reduction in soils as influenced by ZVI(Zero-Valent Iron), organic matter and moisture content. The reduction ratio of Cr(VI) was increased from 37 to 40% as organic matter content increased from 1.07 to 1.75%. In addition, Cr(VI) concentration was reduced as soil moisture content increased, but the direct effect of soil moisture content on Cr(VI) reduction was less than 5% of the Cr(VI) reduction ratio. However, combined treatment of ZVI(5%), organic matter(1.75%) and soil moisture(30%) effectively reduced the initial Cr(VI) to over 95% within 5 days and nearly 100% after 30 days by increasing oxidation of ZVI and concurrent reduction of Cr(VI) to Cr(III). The overall results demonstrated that ZVI was effective in remediating Cr(VI) contaminated soils, and the efficiency was synergistic with the combined treatments of soil moisture and organic matter.

• Journal of Soil and Groundwater Environment
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• v.11 no.3
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• pp.31-42
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• 2006

Drought indices, such as PDSI (palmer Drought Severity Index), SWSI (Surface Water Supply Index) and SPI (Standardized Precipitation Index), have been developed to assess and forecast an intensity of drought. To find the applicability of groundwater level data to a drought assessment, a correlation analysis between SPI and groundwater levels was conducted for each time series at a drought season in 2001. The comparative results between SPI and groundwater levels of shallow wells of three national groundwater monitoring stations, Chungju Gageum, Yangpyung Gaegun, and Yeongju Munjeong, show that these two factors are highly correlated. In case of SPI with a duration of 1 month, cross-correlation coefficients between two factors are 0.843 at Chungju Gageum, 0.825 at Yangpyung Gaegun, and 0.737 at Yeongju Munjeong. The time lag between peak values of two factors is nearly zero in case of SPI with a duration of 1 month, which means that groundwater level fluctuation is similar to SPI values. Moreover, in case of SPI with a duration of 3 month, it is found that groundwater level can be a leading indicator to predict the SPI values I week later. Some of the national groundwater monitoring stations can be designated as DIW (Drought Index Well) based on the detailed survey of site characteristics and also new DIWs need to be drilled to assess and forecast the drought in this country.

• Journal of Soil and Groundwater Environment
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• v.10 no.4
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• pp.45-53
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• 2005

The objective of this study is to evaluate the effects of changes in soil temperature on biodegradation rate of diesel compounds from a field pilot test using hot air injection process. Total remediation time was estimated from in-situ biodegradation rate and temperature for optimum biodegradation. All tests were conducted by measuring in-situ respiration rates every about 10 days on highly contaminated area where an accidental diesel release occurred. The applied remediation methods were hot air injection/extraction process to volatilize and extract diesel compounds followed by a bioremediation process to degrade residual diesels in soils. Oxygen consumption rate varied from 2.2 to 46.3%/day in the range of 26 to $60^{\circ}C$, and maximum $O_2$ consumption rate was observed at $32.0^{\circ}C$. Zero-order biodegradation rate estimated on the basis of oxygen consumption rates varied from 6.5 to 21.3 mg/kg-day, and the maximum biodegradation rate was observed at $32^{\circ}C$ as well. In other temperature range, the values were in the decreasing trend. The first-order kinetic constants (k) estimated from in-situ respiration rates measured periodically were 0.0027, 0.0013, and $0.0006d^{-1}$ at 32.8, 41.1, and $52.7^{\circ}C$, respectively. The estimated remediation time was from 2 to 9 years, provided that final TPH concentration in soils was set to 870 mg/kg.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.350-358
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• 1998

To determine the optimum application of fertilizers for the cultivation of tomato in plastic film house, eighteen soils which contained different salt contents were taken from four different areas under plastic film house cultivation, Youngdong, Boeun, Cheongweon county, and Cheongju city. The dry weight and the amount of N, P, and K uptakes of tomato in the plot with no fertilization were considered as the factors representing the fertility of the soil. The differences in the dry weight and in the amounts of N, P, and K uptakes of plants between the plots with fertilization and with no fertilization were considered as the factors representing the total effect of fertilizer and the effects of fertilizer N, P, and K, respectively. These factors of soil fertility and fertilizer effects were estimated by correlation and regression with the chemical properties of the soil in order to find the critical levels and recommended method for optimum fertilization of tomato. The standardized partial regression coefficients of inorganic nitrogen ($NO_3-N+NH_4-N$) contents in soil for the factors of fertility ranged from 247 to 1,159, showing the best, while those of the others ranged from 0.02 to 4.02. Those of inorganic nitrogen ($NO_3-N+NH_4-N$) contents in soil for the electrical conductivity were also the best and were ranged from 35.2 to 36.0 compared with the values of less than 1.0 of the others. These results demonstrate that the content of inorganic nitrogen in the soil is the best index for both soil fertility and electrical conductivity of the soil. The critical level of inorganic nitrogen ($NO_3-N+NH_4-N$) in the soil for maximum productivity with zero value of fertilizer effects for tomato, estimated through Cate-Nelson split method was $220mg\;kg^{-1}$. This was the same value as evaluation for the cultivation of chinese cabbage. In conclusion, for optimal application of fertilizer in plastic film house, 1) no fertilization is recommended when the contents of inorganic nitrogen in the soil is more than $220mg\;kg^{-1}$; however, 2) in the case of less than $220mg\;kg^{-1}$ of inorganic nitrogen content in the soil, the optimal level of fertilization could be estimated through the regression equation between fertilizer effects and content of inorganic nitrogen in the soil.

• Journal of Korean Ophthalmic Optics Society
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• v.16 no.3
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• pp.265-272
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• 2011

Purpose: The clinical usefulness of rotation evaluation using objective refraction in toric soft lenses fitting was investigated. Methods: Toric soft lenses were fitted for 32 subjects (64 eyes; mean age of 24.69 ${\pm}$ 1.65 years) with astigmatism and both eyes of each subject were fitted with toric soft lenses. Objective refraction-based lenses rotation was evaluated from refraction and over-refraction data by indirect calculating technique. These calculated data were compared with the measured data from slit lamp with direct measuring technique. Results: Orientation of toric soft lenses around zero position (within ${\pm}$ 5$^{\circ}$ vertical line) was investigated. The orientations to the direction of nose of measured and calculated values were 69.78% and 63.64%, respectively, which showed similar values between two techniques. Agreement frequency between measured and calculated values in the magnitude of lenses rotation 54.69% and 82.82% for 10$^{\circ}$ and 20$^{\circ}$ of vertical line, respectively. The 95% limits of agreement between calculation and measurement were from -10.08$^{\circ}$ to 12.65$^{\circ}$, and mean difference was 1.29$^{\circ}$ within ${\pm}$ 10$^{\circ}$. The result showed there was no significant difference (p = 0.1984) and high correlation (r = 0.56, p = 0.0004) between two techniques. But the 95% limits of agreement was widen in ${\pm}$ 20$^{\circ}$ of vertical line. The magnitude of lens rotation between two methods was 9.66 ${\pm}$ 6.16$^{\circ}$, 16.17 ${\pm}$ 12.38$^{\circ}$ and 10.58 ${\pm}$ 12.02$^{\circ}$ for normal, loose and tight fitted conditions. Conclusions: From the results with smaller difference between two techniques, it was found that higher availability of subjective over-refraction data can be used as a supplementary tool for subjective refraction. An application using objective refraction with direct measuring could be provide high success in prescription on toric soft lenses.

• The Korean Journal of Nuclear Medicine
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• v.36 no.6
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• pp.317-324
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• 2002

Purpose: The use of statistical parametric mapping (SPM) program has increased for the analysis of brain PET and SPECT images. Montreal Neurological Institute (MNI) coordinate is used in SPM program as a standard anatomical framework. While the most researchers look up Talairach atlas to report the localization of the activations detected in SPM program, there is significant disparity between MNI templates and Talairach atlas. That disparity between Talairach and MNI coordinates makes the interpretation of SPM result time consuming, subjective and inaccurate. The purpose of this study was to develop a program to provide objective anatomical information of each x-y-z position in ICBM coordinate. Materials and Methods: Program was designed to provide the anatomical information for the given x-y-z position in MNI coordinate based on the Statistical Probabilistic Anatomical Map (SPAM) images of ICBM. When x-y-z position was given to the program, names of the anatomical structures with non-zero probability and the probabilities that the given position belongs to the structures were tabulated. The program was coded using IDL and JAVA language for 4he easy transplantation to any operating system or platform. Utility of this program was shown by comparing the results of this program to those of SPM program. Preliminary validation study was peformed by applying this program to the analysis of PET brain activation study of human memory in which the anatomical information on the activated areas are previously known. Results: Real time retrieval of probabilistic information with 1 mm spatial resolution was archived using the programs. Validation study showed the relevance of this program: probability that the activated area for memory belonged to hippocampal formation was more than 80%. Conclusion: These programs will be useful for the result interpretation of the image analysis peformed on MNI coordinate, as done in SPM program.

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.145-151
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• 2002

The effect of low pH on physiological changes was studied with the acidophilic green alga, Clamydomonas acidophila, UTCC 122. The growthrates (${\mu}$) were identical, $0.5{\sim}0.7\;day^{-1}$, at pH 3.7${\sim}$6.7 and no significantly different (ANOVA, p =0.134), showing cell volume reduced gradually as they were growing, whereas that at pH 2.7 was falling to zero and cell volume increased dramatically. Chlorophyll a concentration of the cultures incubated for one day was $191{\sim}255\;pg\;cell^{-1}$, after then it declined from $60{\sim}103\;pg\;cell^{-1}$ at pH 3.7${\sim}$6.7 except $210\;pg\;cell^{-1}$ at pH 2.7, which was directly related with cell volume. External carbonic anhydrase (CA) activity was varied from1.1 to$3.7{\times}10^{-4}\;E.U.\;mm^{-2}$, showing the gradualincrease during culture, except at 2.7 and pH 5.7. However there was not found any relationship among the pH gradient cultures. CA molecular mass of C. acidophila was 29 kBa, and concentration of that was identical in all cultures. The proteins of 41 kDa and 63 were not or very　faintly expressed in low pH cultures, in contrast that of 17 kDa more expressed. In this work, we found that C. acidophila could live optimally within a wide range of acidic pH, and 17 kDa of unidentified protein might be concerned with tolerating in low acid environment.

• Korean Journal of Ecology and Environment
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• v.42 no.1
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• pp.9-18
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• 2009

The objectives of this study were to evaluate seasonal and interannual variations of water quality and nutrient input (N, P) in Junam Reservoir, a nesting waterbody of migratory birds, over 10 years during 1998$\sim$2007 along with dynamic relations of trophic parameters using empirical models. Concentrations of COD averaged 7.8 mg $L^{-1}$ during the study, while TN and TP were $1.4\;mg\;L^{-1}$ and $83{\mu}g\;L^{-1}$, respectively, indicating an eutrophic-hypereutrophic state. Values of monthly COD had strong positive relations (r=0.669, p<0.001) with conductivity, indicating that summer rainfall resulted in an ionic dilution of the reservoir water by rainwater and contributed better water quality. One-way ANOVA tests showed significant differences (F=$5.2{\sim}12.9$, p<0.05) in TN and TP between the before and after the bird migration. In other words, nutrient levels were greater in the absence of migratory birds than in the presence of the migratory birds, suggesting a no-effect on nutrient inputs by the birds. Also, one-way ANOVA indicated no significant differences (F=$0.37{\sim}0.48$, p>0.05) in $NO_{3^-}N$ and $NH_{3^-}N$ between the before and after the birds migration. Linear empirical models using trophic parameters showed that algal biomass as CHL, had significant low correlations with TN ($R^2$=0.143, p<0.001, n=119) and TP ($R^2$=0.192, p<0.001, n=119). These results suggest that influences of nutrients on the CHL were evident, but the effect was weak. This fact was supported by analysis of Trophic State Index Deviation (TSID). Over 70% in the observed values of "TSI (CHL)-TSI (SD)" and "TSI (CHL)-TSI (TP)" were less than zero, suggesting a light limitation on the CHL by inorganic suspended solids.