• Journal of Environmental Science International
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• v.26 no.7
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• pp.847-858
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• 2017

For 26 soil series distributed more than 1% among 63 soil series in Jeju Island, natural uncultivated soil samples were collected. For these soils, the chemical speciation of eight heavy metals (Cd, Cr, Cu, Mn, Ni, Pb, V, and Zn) was examined. Further, the Plant Bioavailability (PB) and Mobility Factor (MF) of these heavy metals were evaluated using Tessier's 5-step sequential extraction method (exchangeable, carbonate, reducible (bound to Fe/Mn oxides), oxidizable (bound to organic matter), and residual fraction). The main form present was residual fraction for Cd and Zn; residual and oxidizable fractions for Cr, Cu, Ni, and Pb; reducible fraction for Mn; and carbonate fraction for V. The average plant availability and average mobility factor were found to be V (57.37%) > Zn (12.49%) > Cd (11.76%) > Cu (11.19%) > Pb (9.37%) > Cr (9.09%) > Mn (3.13%) > Ni (2.63%), and Mn (61.04%) > V (59.94%) > Zn (31.54%) > Cd (17.65%) > Cr (15.66%) > Ni (13.89%) > Pb (13.80%) > Cu (13.53%), respectively.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.427-433
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• 2005

The use of the microwave-assisted process for the extraction of effective constituents from ginseng was investigated at various operating conditions. The influence of solvent (ethanol-water, 50% v/v) to ginseng ratio, particle size and applied microwave power on the efficiency of extraction was examined. The microwave extraction system used was custom manufactured so that the intensity of microwave may be varied by using anode-voltage controller. It was found that the ratio of 6 : 1 (vol/mass) gave a good extraction efficiency. Small particle size gave high yield but it caused difficulties in the separation of solvent from the sludge. The higher power was no guarantee of the efficient extraction yield. The more important factor than the employed power was the adequate temperature under sufficient contact time. Using deionized-water as swelling agent, the degree of swelling of ginseng by microwave heating and conventional heating in water-bath was also studied. It was observed that the microwave heating enhanced the swelling much more than the conventional heating. It is believed that this enhanced swelling was responsible for the rapid microwave-assisted extraction rate.

• Journal of the Korean Institute of Rural Architecture
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• v.14 no.3
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• pp.85-92
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• 2012

This study aims to evaluate the residential exterior environment and ascertain the factors having an effect on the visual environment viewed through the living room window. This study is based on a questionnaire on the exterior environment targeting residents living in the area of Nohyunng in Jeju city, Jeju-do. The results are as follows. First, residents are satisfied with the exterior environment as a whole; however, the longer-term residents' level of satisfaction is found to be relatively low while dissatisfaction is high. Additionally, there is a difference in satisfaction and dissatisfaction levels between the residents in their own housing and those in rental housing. The residents living in rental housing were found to have a relatively low level of satisfaction and high dissatisfaction. Second, in the case where the living room window faces roads, low satisfaction and high dissatisfaction levels with the visual environment were found, where the living room is on the first or second floor. Third, satisfaction and dissatisfaction with the exterior environment have a close correlation to the impression or nature elements of 26 questions but they show low correlation in size, height, color, design, traffic, artifact elements. Finally, as a result of extracting the factors influencing satisfaction and dissatisfaction with the visual environment, four factors were extracted including "Impression & Nature factor", "Building factor", "Design factor", and "Traffic volume & Artifacts factor". "Impression & Nature factors" is the most influencing factor with satisfaction and dissatisfaction and "Traffic volume & Artifacts factor" was found to have an effect on satisfaction, but not as clearly on dissatisfaction.

• KIPS Transactions on Software and Data Engineering
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• v.2 no.5
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• pp.341-346
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• 2013

In this paper, we propose a rule extraction method using a modified Fuzzy Min-Max (FMM) neural network. The suggested method supplements the hyperbox definition with a frequency factor of feature values in the learning data set. We have defined a relevance factor between features and pattern classes. The proposed model can solve the ambiguity problem without using the overlapping test process and the contraction process. The hyperbox membership function based on the fuzzy partitions is defined for each dimension of a pattern class. The weight values are trained by the feature range and the frequency of feature values. The excitatory features and the inhibitory features can be classified by the proposed method and they can be used for the rule generation process. From the experiments of sign language recognition, the proposed method is evaluated empirically.

• Journal of the Korean Home Economics Association
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• v.20 no.4
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• pp.83-89
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• 1982

The purpose of this study was to analyze the 45 measuring items for the clothing construction in order to observe the factorial structure of items and to extract the common factor and the special unique factor from data. The sample for the study was drawn randomly out of senior high schoolgirls in Seoul urban area. The size of sample was 301 girls between age 16 and 18. The method of analysis was applied by the principal component analysis with orthogonal rotation after extraction of 9 major factors. All of the above data was analyzed by the computer installed at Seoul National University. From these analyses, the major findings can be summerized as follows: 1. The results of factor analysis generally indicated that the first factor was clustered with 15 items, length measures and height measures. The eigenvalue of the first factor was 16.5 and the cumulative percentage of variables 36.6%. 2. The second factor was clustered with width measures, girth measures and weight of 19 items. The eigenvalue of the second factor was 6.5 and the cumulative percentage of variables 51.0%.

• Resources Recycling
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• v.23 no.2
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• pp.37-45
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• 2014

Solvent extraction experiments have been performed to separate Nd and Pr from chloride leaching solution of monazite sand using single Cyanex272 and mixed extractants as PC88A+Cyanex272 and PC88A+TBP. For this purpose, the effect of the concentration of extractants on the extraction and separation of the two metals were studied by varying the pH of aqueous solution. In the experimental ranges conducted in this study, the distribution coefficients of Nd were higher than those of Pr. In Cyanex272 system, our results indicated that concentration of extractant and initial pH did not affect distribution coefficients, but separation factor was increased with increasing initial pH. In binary extractant system, distribution coefficients were lower than those of single PC88A system, whereas separation factor was similar in both mixed and single extractant system.

• Advances in nano research
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• v.10 no.3
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• pp.295-312
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• 2021

A new ionic liquid functionalized magnetic silica nanoparticle was synthesized and characterized and tested as an adsorbent. The adsorbent was used for magnetic solid phase extraction on ICP-MS method. Simultaneous determination of precious metal Au has been addressed. The method is simple and fast and has been applied to standard water and surface water analysis. A new method for separation/analysis of trace precious metal Au by Magnetron Solid Phase Extraction (MSPE) combined with ICP-MS. The element to be tested is rapidly adsorbed on CoFe2O4@SiO2@[BMIM]PF6 composite nano-adsorbent and eluted with thiourea. The method has a preconcentration factor of 9.5-fold. This method has been successfully applied to the determination of gold in actual water samples. Hydrophobic Ionic Liquids (ILs) 1-butyl-3-methylimidazole hexafluorophosphate ([BMIM]PF6) coated CoFe2O4@SiO2 nanoparticles with core-shell structure to prepare magnetic solid phase extraction agent (CoFe2O4@SiO2@ILs) and establish a new method of MSPE coupled with inductively coupled plasma mass spectrometry for separation/analysis of trace gold. The results showed that trace gold was adsorbed rapidly by CoFe2O4@SiO2@[BMIM]PF6 and eluanted by thiourea. Under the optimal conditions, preconcentration factor of the proposed method was 9.5-fold. The linear range, detection limit, correlation coefficient (R) and relative standard deviation (RSD) were found to be 0.01~1000.00 ng·mL-1, 0.001 ng·mL-1, 0.9990 and 3.4% (n = 11, c = 4.5 ng·mL-1). The CoFe2O4@SiO2 nanoparticles could be used repeatedly for 8 times. This proposed method has been successfully applied to the determination of trace gold in water samples.

• Honam Mathematical Journal
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• v.38 no.3
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• pp.661-674
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• 2016

In [15] they introduced a new finite element method for accurate numerical solutions of Poisson equations with corner singularities, which is useful for the problem with known stress intensity factor. They consider the Poisson equations with homogeneous Dirichlet boundary condition, compute the finite element solution using standard FEM and use the extraction formula to compute the stress intensity factor, then they pose a PDE with a regular solution by imposing the nonhomogeneous boundary condition using the computed stress intensity factor, which converges with optimal speed. From the solution we could get accurate solution just by adding the singular part. This approach works for the case when we have the accurate stress intensity factor. In this paper we consider Poisson equations with mixed boundary conditions and show the method depends the accrucy of the stress intensity factor by considering two algorithms.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.316-321
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• 1995

Some properties of $\beta$-1, 3-glucan synthase system in Saccharamyces cerevisiae were investigated. By extraction with detergent and salt, the membrane preparations could be dissociated into two components, one soluble, the other still membrane bound. Both components, in addition to GTP, were necessary for the activity of $\beta$-1, 3-glucan synthase like other fungi. The protective effect of guanosine nucleotides on the soluble factor pointed to the possibility that this fraction contained a GTP-binding protein. Addition of increasing amounts of soluble factor to a constant amount of insoluble catalytic factor, vice versa, gave rise to a saturation curve. These results, including different types of evidence, indicate that the soluble factor and the catalytic factor form a complex.

• The korean journal of orthodontics
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• v.17 no.2
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• pp.321-333
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• 1987

The purpose of this study was to observe the changes of the lower 3rd molars following the extraction of the lower 2nd molars by Lateral Cephalograms and Orthopantomograms. The subjects consisted of twenty malocclusion, 7 males 13 females, were 19 year 5 month old at the removal of the lower 2nd molars, 19 year 1 month old at the end of the orthodontic supervision after the removal of the lower 2nd molars (mean age) The obtained results were as follows, 1 It is recommended to extract the lower 2nd molars when the lower 3rd molars are Nolla's Stage 4 or 5 2 With the pre-extraction variables obtained by factor analysis, it was possible to predict the long axis of the lower 3rd molars after 2nd molar extraction. 3 There were no impacted 3rd molars.