• Journal of Korea Multimedia Society
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• v.5 no.1
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• pp.18-27
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• 2002

A hierarchical representation scheme for planar curves, MBO-tree, is proposed in this paper, which provides natural approximation and efficient localization. MBO-tree is based on the Douglas-Peucker algorithm (iterative end-point fit algorithm), but approximation errors that are stored with corresponding points in MBO-tree nodes and are used for abstraction measures are adjusted by force to eliminate unnatural approximation. The error adjusting is just making the approximation error of a node in a MBO-tree to be less than or equal to that of its parent. In point of localization, the bounding area of a curve is represented with a minimum bounding octangle (MBO), which can enclose the curve more compactly compared with those of other hierarchical schemes, such as the strip tree, the arc tree and the HAL tree. The MBO satisfies the hierarchical inclusion property that is useful for hierarchical geometrical operations, such as the point-inclusion test and the polygon intersection test. Through several experiments, we found that the proposed scheme was able to approximate more naturally and to localize more effectively.

• Korean Journal of Social Welfare Studies
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• no.37
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• pp.295-318
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• 2008

The purpose of this study is to examine the validity of adolescent's status offenses model based on general strain theory. To perform this research, a survey was conducted to adolescents of mixed gender from middle and high schools in Seoul and Gyeonggi Province, who were 9th to 11th grade students. A total of 1167 cases were collected, and without 27 inappropriate cases, 1140 cases were used for the analysis. A structural equation model was applied to the child abuse experience with depression mediator and the adolescents status offense, and the calculation of model fit index reached to .986(TLI), .994(CFI), and .032(RMSEA). The result of Aroian test on the effectiveness of depression as a mediator demonstrates that depression has a prominent effect as a mediator to the model. However, the self control of an adolescent, which were presented in this research as a primary moderating variable, did not display any salient effect on the course of a depression developing to the level of status offense.

• Journal of Convergence for Information Technology
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• v.9 no.10
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• pp.122-132
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• 2019

This study aims to explain the effect of mother's child rearing behavior on aggression of young children and to verify the mediating effect of self-control between two variables. For the purpose, 1,524 children who fit this study among children aged 5 through 7th year of the Korean Children's Panel were selected. The data were analyzed by using the hierarchical regression method and the Sobel test. The main findings are as follows. First, the mother's warmth of rearing behavior was shown to decrease aggression of children, while mother's control of rearing behavior had no influence their aggression. Second, It was shown that the self-control of young children had a negative effect on their aggression. Third, self-control was shown to have a partial mediating effect in the relationship between the mother's warmth of rearing behavior and aggression of children. Accordingly, various programs to reduce the aggression of young children were suggested and an alternative plan was proposed to be applied to child care sites.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.5
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• pp.429-434
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• 2007

This study was conducted to estimate site productivity of Quercus acutissima and Quercus mongolica by four forest climatic zones. We used site environmental variables (28 geographical and pedological factors) and site index as a site productivity indicator from nation-wide 23,315 stands. Based on multiple regression analysis between site index and major environmental variables, the best-fit multivaliate models were made by each species and forest climatic zone. Most of site index prediction models by species were regressed with seven to eight factors, including altitude, relief, soil depth, and soil moisture etc. For those models, three evaluation statistics such as mean difference, standard deviation of difference, and standard error of difference were applied to the test data set for the validation of the results. According to the evaluation statistics, it was found that the models by climatic zones and species fitted well to the test data set with relatively low bias and variation. Also having above middle of site index range, total area of productive sites for the two Quercus spp. estimated by those models would be about 6% of total forest area. Northern temperate forest zone and central temperate forest zone had more productive area than southern temperate forest zone and warm temperate forest zone. As a result, it was concluded that the regressive prediction with site environmental variables by climatic zones and species had enough estimation capability of forest site productivity.

• Fashion & Textile Research Journal
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• v.23 no.5
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• pp.624-633
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• 2021

This study was intended to compare the comfort of wearing each type of commercially available bralette. The trial wearing experiment was conducted on five women in their 20s who wear an average Korean bra size of 70A. The experimental bralettes were of four types: a bralette with both hooks and pads and a bralette without both, a bralette with hooks but no pads, and a bralette with pads but no hooks. The wearing test results are as follows. First, in terms of functional satisfaction, the padded bralette provided the greatest satisfaction in supporting the chest from the bottom up and bringing it to the center, and the bralette without the pad provided the least satisfaction. In addition, the level of convenience of attaching/detaching was about twice as high in the bralette with hooks than those without hooks. Chest compression was found to be greater in bralettes without hooks than in those with hooks. In terms of the pressure on the shoulder strap and on the lower chest band, it was found that bralettes with hooks had a greater sense of pressure than those without. In the appearance characteristics test, the unpadded bralettes scored higher than the padded one in the matter of feeling embarrassed, because in unpadded bralettes, the nipples were exposed underneath the clothes . This study is meaningful in classifying the design of the bralette and evaluating the fit for each design in the absence of prior research on the bralette.

• The Journal of Advanced Prosthodontics
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• v.13 no.2
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• pp.89-99
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• 2021

PURPOSE. This study aimed to compare the accuracy (trueness and precision) of interim crowns fabricated using DLP (digital light processing) according to post-curing time. MATERIALS AND METHODS. A virtual stone study die of the upper right first molar was created using a dental laboratory scanner. After designing interim crowns on the virtual study die and saving them as Standard Triangulated Language files, 30 interim crowns were fabricated using a DLP-type 3D printer. Additively manufactured interim crowns were post-cured using three different time conditions-10-minute post-curing interim crown (10-MPCI), 20-minute post-curing interim crown (20-MPCI), and 30-minute post-curing interim crown (30-MPCI) (n = 10 per group). The scan data of the external and intaglio surfaces were overlapped with reference crown data, and trueness was measured using the best-fit alignment method. In the external and intaglio surface groups (n = 45 per group), precision was measured using a combination formula exclusive to scan data (10C2). Significant differences in accuracy (trueness and precision) data were analyzed using the Kruskal-Wallis H test, and post hoc analysis was performed using the Mann-Whitney U test with Bonferroni correction (α=.05). RESULTS. In the 10-MPCI, 20-MPCI, and 30-MPCI groups, there was a statistically significant difference in the accuracy of the external and intaglio surfaces (P<.05). On the external and intaglio surfaces, the root mean square (RMS) values of trueness and precision were the lowest in the 10-MPCI group. CONCLUSION. Interim crowns with 10-minute post-curing showed high accuracy.

• Journal of Fashion Business
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• v.25 no.3
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• pp.144-158
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• 2021

The purpose of this study is to develop a bodice block suitable for women in their 20s with turtle neck syndrome. The problem of turtle neck syndrome body type was derived through the evaluation of bodice blocks. First, the length of the front bodice was longer and the length of the back bodice was shorter. Second, the front neck point, back neck point, and the shoulder line were not in place. Third, the side neck was pushed up. Fourth, the length of armhole was long and it floated. Fifth, the front hem was attached to the body and the back hem was away from the body. A finally developed pattern was designed by developing four test patterns to solve the problem that appeared in a selected bodice pattern, and a t-test was conducted to determine the difference in the appearance evaluation by virtual clothing between the two patterns, bodice block and the development pattern. According to the result, the fit was not good from the side body because the position of the side neck point was not in a place due to the characteristics of the body shape of turtle neck syndrome, but the problems of the anterior neck position, the position of the back neck point, the shoulder line position, and the armhole shape were improved in the developed pattern.

• Journal of the Korea Society for Simulation
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• v.30 no.3
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• pp.19-29
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• 2021

To explain the interregional infections in COVID-19, we designed a multi-group compartmental model by applying the SEIQRD model, a compartmental model of a single group. The model is segmented by compartments to account for hidden infections, such as latent periods and asymptomatic cases, and is capable of comparing infection indices and test rates between regions. Through this, it estimated which region was centered during the second wave in August 2020 and the third wave in November 2020. Subgroups were set up in Seoul, Gyeonggi (including Incheon), and a non-metropolitan area. We fit the model to the Ministry of Health and Welfare's data to estimate the average infection index between regions, average rate of rT-PCR test by region, and the expected number of hidden infections by region.

• Journal of Korean Clinical Nursing Research
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• v.27 no.3
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• pp.279-293
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• 2021

Purpose: The purpose of this study was to develop a Korean nursing work environment scale for critical care nurses (KNWES-CCN) and verify its validity and reliability. Methods: A total of 46 preliminary items were selected using content validity analysis of experts on 64 candidate items derived through literature reviews and in-depth interviews with critical care nurses. 535 critical care nurses from 21 hospitals responded to the preliminary questionnaire from February to March 2021. The collected data were analysed using construct, convergent and discriminant validities, and internal consistency and test-retest reliability. Results: The 23 items in 4 factors accounted for 55.6% of the total variance were identified through item analysis and exploratory factor analysis (EFA). EFA was performed with maximum likelihood method including direct oblimin method. In the confirmatory factor analysis, KNWES-CCN consisted of 21 items in 4 factors by deleting the items that were not meet the condition that the factor loading over .50 or the squared multiple correlation over .30. This model was considered to be suitable because it satisfied the fit index and acceptable criteria of the model [𝒳²=440.47 (p<.001), CMIN/DF=2.41, GFI=.86, SRMR=.06, RMSEA=.07, TLI=.90, CFI=.91]. The item total correlation values ranged form .32 to .73 and its internal consistency was Cronbach's α=.92. The reliability of the test-retest correlation coefficient was .72 and the intra-class correlation coefficient was .83. Conclusion: The KNWES-CCN showed good validity and reliability. Therefore, it is expected that the use of this scale would measure and improve nursing work environment for critical care nurses in Korea.

• Journal of Astronomy and Space Sciences
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• v.39 no.2
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• pp.43-50
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• 2022

The unified scheme of Seyfert galaxies hypothesizes that the observed differences between the two categories of Seyfert galaxies, type 1 (Sy1) and type 2 (Sy2) are merely due to the difference in the orientation of the toroidal shape of the obscuring material in the active galactic nuclei. We used in this paper, a sample consisting of 120 Seyfert galaxies at 1.40 × 10⁹ Hz in radio, 2.52 × 10¹⁷ Hz in X-ray and 2.52 × 10²³ Hz in γ-ray luminosities observed by the Fermi Large Area Telescope (Fermi-LAT) in order to test the unified scheme of radio-quiet Seyfert galaxies. Our main results are as follows: (i) We found that the distributions of multiwave luminosities (L_radio, L_X-ray, and L_γ-ray) of Sy1 and Sy2 are completely overlapped with up to a factor of 4. The principal component analysis result reveals that Sy1 and Sy2 also occupy the same parameter spaces, which agrees with the notion that Sy1 and Sy2 are the same class objects. A Kolmogorov-Smirnov test performed on the sub-samples indicates that the null hypothesis (both are from the same population) cannot be rejected with chance probability p ~ 0 and separation distance K = 0.013. This result supports the fact that there is no statistical difference between the properties of Sy1 and Sy2 (ii) We found that the coefficient of the best-fit linear regression equation between the common properties of Sy1 and Sy2 is significant (r > 0.50) which plausibly implies that Sy1 and Sy2 are the same type of objects observed at different viewing angle.