• Applied Chemistry for Engineering
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• v.7 no.3
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• pp.464-472
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• 1996

The mechanism of thin-film formation by Ionized Cluster Beam Deposition(ICBD) was investigated. A simulation program based on the Monte-Carlo method was developed in order to investigate the effects of the acceleration voltage, substrate temperature, activation energy for the surface migration, and critical nuclei size on grain size and surface roughness. Studies of the effect of kinetic energy of clusters on the film formation processes revealed that high acceleration voltage enhanced the surface-migration of adatoms and made it easier for an epitaxial film to be formed. The relaxation time of kinetic energy of adatoms increased with the substrate temperature, which in turn increased the grain size of the crystalline film. This effect was more clearly distinguished when the critical nuclei size was large. The surface-migration activation energy was found to affect the interaction between the adatoms and the substrate and thus the relaxation time of kinetic energy. Investigations of the surface roughness revealed that the acceleration voltage, the substrate temperature, and the surface-migration activation energy exerted a collective effect on the morphology of the film surface.

• The Journal of the Korea Contents Association
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• v.15 no.3
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• pp.114-122
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• 2015

This study aims to analyze the satisfaction of seniors living in Cheonan City downtown as to their residential environment. Also, this study intends to identify which factors should be improved first to make downtown a favorable residential area. To that end, 'social indicators of Chungnam' was used. The collected data was analyzed through a statistical analysis method using ANOVA (analysis of variance) and a cluster analysis. It led to the following findings. First, 6.9% of the elderly residents expressed their wish to move from their downtown residence. Thus, the majority of the residents do not want to move. Second, the satisfaction of the elderly residents in their downtown residence scored 6.09. The score is higher than those of other regions. Thus, it is highly possible to develop downtown into a senior-friendly area. Third, as for satisfaction in downtown residence, it was higher among the following groups: men; those with high school or higher level of education; those earning at least a million won a month; family of one generation. Fourth, satisfaction in the following factors was relatively low: culture and education; interaction with neighbors and trust in them; car accidents. Thus, those factors should be improved for downtown residents. Above all, community-faced facilities should be expanded to increase exchanges with neighbors and trust in them. To attract women dissatisfied with downtown residence. it is imperative to increase daily safety by reducing car accidents and crime.

• Journal of the Korean Home Economics Association
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• v.28 no.4
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• pp.177-189
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• 1990

The purpose of this study were to measure the body cathexis and the characteristics of middle-aged women groups segmented by their fashion orientation. Self-administered questionaire method was used. Seven demographic variables, 9 self-images, body cathexis were included as independent variables. Fashion orientation developed by Gutman and Mills was used. Data was collected from 369 Middle-aged women in Chonbuk Province. Frequencies, Percentages, means, standard deviation were caculated. ANOVA, cluster analysis, and discriminant analysis were used for data analysis. The results were as follows: 1. The body cathexis of the subjects were lower than capital city and increased according to age. 2. The self-image of the subjects were down-to-earth, modern, conventional, playing it safe, confident, stable, reserved and blending out into a crowd. The subjects with the self-image of being more sophisticated, confident, creative, stood out in a crowd, or complicated life style had higher body cathexis. 3. When the subjects were divided into segmentations according to their fashion orientation by cluster analysis, the best suitable number of groups was seven. The characteristics of seven groups were: *Fashion negatives showed low levels of fashion leadership and fashion interest, and medium level of importance of being well-dressed, and high level of antifashion attitudes. *Fashion neutrals showed medium levels of fashion leadership, fashion interest, and importnace of being-well dressed, and low level of antifashion attitudes. *Fashion uninvolveds showed low levels of fashion leadership, fashion interest, and antifashion attitudes. *Fashion followers showed high levels of fashion interest and importance of being well dressed, but low levels of fashion leadership and antifashion attitudes. *Fashion independents showed a littel bit high levels of fashion leadership, fashion interest, and importance fo being well-dressed, but low level of antifashion attitudes. *Fashion rejectors showed low levels of fashion leadership, fashion interest, and importance of being well-dressed, but high level of antifashion attitudes. 4. The seven groups segemented by their fashion orientation showed significant differences according to the educational levels, employment status, and total monthly income. Fashion leaders and fashion independents had higher educational level and monthly income, and involved more women with jobs. 5. Fashion leaders had self-image of being most sophisticated modern, diffenrent, creative, sociable, stood out in a crowd, and complicated life style. Fashion rejectors had self-image of being most down-to-earth, traditional, conventional, stable, reserved, blend into a crowd, and simplified life style. 6. The most effective variables among body cathexis, demographic variabls and self-images in discirminating fashion oreintation group differences were different-conventional, creativestable, and employment status. The discriminating power of above variables were high in very low in discriminating fashion negatives, fashion neutrals, and fashion independents, and the total discriminating power of these variables was 32.25%.

• Journal of the Korean Magnetics Society
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• v.16 no.3
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• pp.168-172
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• 2006

We studied the magnetic and the related electronic properties of Ni-doped rutile $TiO_{2-{\delta}}$ films (including oxygen deficiency $\delta$) prepared using a sol-gel method. A room-temperature ferromagnetism was observed in the $TiO_{2-{\delta}}$ : Ni films with the saturation magnetization ($M_S$) decreasing with increasing Ni doping and remaining constant above 6 at% Ni doping. The observed ferromagnetism below 6 at% Ni doping is interpreted as due to magnetic polaron formed by a trapped electron in oxygen vacancy and magnetic impurity ions around it. For small Ni doping, $M_S$ up to $3.7{\mu}B/Ni$ was obtained. The ferromagnetism for Ni doping above 6 at% is interpreted as due to the existence of Ni clusters that can explain the p-n conductivity transition observed by Hall effect measurements.

• Korean Journal of Microbiology
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• v.33 no.3
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• pp.175-180
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• 1997

In an artificial pH-gradient hatch culture system, the author analyzed the effects of acidification on the species composition of heterotrophic bacteria. As the result of this study, it was found that the numbers of total bacteria were not affected by acidification and that the population size of heterotrophic bacteria decreased as pH became lower. The heterotrophic bacteria isolated from all of the pH gradient were 12 genera and 22 species. and among them, gram negative and gram positive bacteria were 64% and 36%, respectivcly. As pH decreased, the distribution rate of gram negative bacteria increased while that of gram positive bacteria decreased. Regarding to distrihution rate of genuses in each pH gradient, 13 genuses appeared at pH 7 while only 5 genuses appeared at pH 3. which means that the diversity of genera decrease as pH decreased. As a result of cluster analysis, diversity indices 01 species had ranges from 1.13 to 2.37, and decreased as pH decreased. In order to evaluate the diversity of different size samples, we analyzed the expected number of species appearance according to pH by rarefaction method. The statistical significance of species diversity was verified by the fact that the number decreased at lower pH.

• Journal of Korean Society of Forest Science
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• v.104 no.1
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• pp.14-25
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• 2015

This study was carried out to classify forest communities and to aggregate forest cover types for the complex and diversified natural forest areas of Guryongsan, Sobaeksan, Baekhwasan, Sokrisan, and Baekhaksan in the middle part of Baekdudaegan. The vegetation data were collected by point-centered quarter sampling method. One thousand one hundred fourteen sample points were subjected to cluster analysis to classify 27 forest communities, which were aggregated into 7 representative forest cover types on the basis of community similarity from composition of canopy species. They were Quercus mongolica forest cover type, mixed mesophytic forest cover type, Q. variabilis forest cover type, Pinus densiflora forest cover type, the others deciduous forest cover type, Q. serrata forest cover type, and subalpine forest cover type. The Q. mongolica forest cover type was most widely distributed in the study areas. It was assumed that abundance of Q. mongolica might be negatively associated with species diversity. Mixed mesophytic forest cover type and the others deciduous forest cover type were commonly distributed in the areas of valley, on the other hand, Q. mongolica cover type and P. densiflora cover type tended to be distributed in the areas of ridge.

• Korean Journal of Environment and Ecology
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• v.28 no.6
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• pp.741-750
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• 2014

To investigate the vegetation structure of mountain ridge from Guryongryeong to Mt. Yaksu, 22 plots ($100m^2$) installed with random sampling method were surveyed. Three groups of Quercus mongolica-Acer pseudosieboldianum community, Q. mongolica community, Cornus controversa-Q. mongolica community were classified by cluster analysis. Q. mongolica was a major woody plant species in the ridge area from Guryongryeong to Yaksusan and Carpinus cordata and C. controversa was partly occupied in some area. High positive correlations showed between Q. mongolica and Symplocos chinensis for. pilosa, Rhododendron schlippenbachii; Tilia amurensis and Tilia mandshurica, Symplocos chinensis for. pilosa; Tilia mandshurica and S. chinensis for. pilosa, R. schlippenbachii; Betula costata and Acer mono; Symplocos chinensis for. pilosa and Rhododendron schlippenbachii, and relatively high negative correlations showed between A. pseudosieboldianum and S. chinensis for. pilosa, R. schlippenbachii. Species diversity(H') of investigated groups were ranged 0.8170~1.1446 and it was lower compared to those of the ridge area of the national parks in Baekdudaegan.

• Korean Journal of Materials Research
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• v.8 no.8
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• pp.757-765
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• 1998

This study was performed to investigate the influence of fuel/oxygen ratio (F/O= 3.2, 3.0, 2.8) on the oxidation behavior of two kinds of (20wt%NiCr claded $\textrm{Cr}_{3}\textrm{C}_{2}$, and 7wt%NiCr mixed $\textrm{Cr}_{3}\textrm{C}_{2}$) composite powder with different manufacturing method. The results show that the oxidation behavior between the 20wt% NiCr claded $\textrm{Cr}_{3}\textrm{C}_{2}$ and 7wt% NiCr mixed $\textrm{Cr}_{3}\textrm{C}_{2}$ coating was widely different. The surface morphology of the coating composed of 7wt% NiCr mixed $\textrm{Cr}_{3}\textrm{C}_{2}$ was changed to porous with F/O ratio by the aggressive evolution of gas phases($\textrm{CO}_2$, CO and $\textrm{CrO}_3$) and the oxide cluster composed of Ni and Cr were grown after oxidation at $1000^{\circ}C$ for 50 hours. But the surface morphology of the coating composed of 20wt% NiCr claded $\textrm{Cr}_{3}\textrm{C}_{2}$ was not changed to porous after oxidation at $1000^{\circ}C$ for 50 hours. Therefore, the reason for high oxidation rate is due to activation of $\textrm{Cr}_{3}\textrm{C}_{2}$ to oxidation by entrapped oxygen gases within coating layer, and to closely relate with the decomposition of $\textrm{Cr}_{3}\textrm{C}_{2}$ to $\textrm{Cr}_{7}\textrm{C}_{3}$ phase. Accordingly, On the evidence of these results, the study about the oxidation behavoir of the HVOF sprayed $\textrm{Cr}_{3}\textrm{C}_{2}$ coating depending on hydrogen flow rate must be done.

• The Korean Journal of Mycology
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• v.38 no.1
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• pp.34-39
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• 2010

We have attempted to verify 30 strains of Hypsizigus marmoreus from various mushroom stocks in Korea using random amplified polymorphic DNA (RAPD) methodology. Chromosomal DNAs of them were extracted and subjected to PCR analyses with 3 random primers. Each PCR produced approximately 30 distinct PCR bands with the size from 200 bp to 3000 bp. A dendrogram was acquired using the unweighted pair-group method with arithmetic average (UPGMA) clustering methodology on the basis of the DNA band pattern. The analysis revealed that 30 strains of H. marmoreus were clustered into two distinct clusters. Cluster 1 contained 3 subgroups while the cluster 2 consisted of rather diverse strains. Interestingly, Hm3-10, a wild strain collected from Deog-Yu mountain, was not included in either clusters, indicative of uniqueness of this strain. We nextly attempted to develop strain-specific DNA markers to verify a specific strain. A unique band in the RAPD gel lane of Hm0-4 was extracted and its sequence was determined. PCR with a primer set from the determined sequence revealed that the primer set gave a 250 bp DNA band only for Hm0-4, indicating that this approach works well for the strain-specific identification of H. marmoreus.

• Journal of Biomedical Engineering Research
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• v.21 no.4
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• pp.333-338
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• 2000

In this paper, an automated segmentation algorithm is proposed for MR brain images using T1-weighted, T2-weighted, and PD images complementarily. The proposed segmentation algorithm is composed of 3 step. In the first step, cerebrum images are extracted by putting a cerebrum mask upon the three input images. In the second step, outstanding clusters that represent inner tissues of the cerebrum are chosen among 3-dimensional(3D) clusters. 3D clusters are determined by intersecting densely distributed parts of 2D histogram in the 3D space formed with three optimal scale images. Optimal scale image is made up of applying scale space filtering to each 2D histogram and searching graph structure. Optimal scale image best describes the shape of densely distributed parts of pixels in 2D histogram and searching graph structure. Optimal scale image best describes the shape of densely distributed parts of pixels in 2D histogram. In the final step, cerebrum images are segmented using FCM algorithm with its initial centroid value as the outstanding clusters centroid value. The proposed cluster's centroid accurately. And also can get better segmentation results from the proposed segmentation algorithm with multi spectral analysis than the method of single spectral analysis.