• Journal of Korean Dental Science
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• v.8 no.2
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• pp.49-56
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• 2015

Purpose: The effect of accelerated aging on color stability of various dual-cured self-adhesive resin cements were evaluated in this study. Materials and Methods: Color stability was examined using three different brands of dual-cured self-adhesive resin cements: G-CEM LinkAce (GC America), MaxCem Elite (Kerr), and PermaCem 2.0 (DMG) with the equivalent color shade. Each resin cement was filled with Teflon mold which has 6 mm diameter and 2 mm thickness. Each specimen was light cured for 20 seconds using light emitting diode (LED) light curing unit. In order to evaluate the effect of accelerated aging on color stability, color parameters (Commission Internationale de l'Eclairage, CIE $L^*$, $a^*$, $b^*$) and color differences (${\Delta}E^*$) were measured at three times: immediately, after 24 hours, and after thermocycling. The $L^*$, $a^*$, $b^*$ values were analyzed using Friedman test and ${\Delta}E^*$ values on the effect of 24 hours and accelerated aging were analyzed using t-test. These values were compared with the limit value of color difference (${\Delta}E^*=3.7$) for dental restoration. One-way ANOVA and Scheff's test (P<0.05) were performed to analyze each ${\Delta}E^*$ values between cements at each test period. Result: There was statistically significant difference in comparison of color specification ($L^*$, $a^*$, $b^*$) values after accelerated aging except $L^*$ value of G-CEM LinkAce (P<0.05). After 24 hours, color difference (${\Delta}E^*$) values were ranged from 2.47 to 3.48 and $L^*$ values decreased and $b^*$ values increased in all types of cement and MaxCem Elite had high color stability (P<0.05). After thermocycling, color change's tendency of cement was varied and color difference (${\Delta}E^*$) values were ranged from 0.82 to 2.87 and G-CEM LinkAce had high color stability (P<0.05). Conclusion: Color stability of dual-cured self-adhesive resin cements after accelerated aging was evaluated and statistically significant color changes occurred within clinically acceptable range.

• Phonetics and Speech Sciences
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• v.2 no.3
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• pp.75-80
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• 2010

The present research investigated the characteristics of voice between genders and nationalities by measuring the acoustic parameter values of Korean and Chinese students. Sound Forge was used to collect voice samples and Praat was used to measure and analyze jitter, shimmer, NHR, $sF_0$, and pitch range. The results of this research are a follows. First, during prolongation of the vowels, there was no significant difference in $F_0$ between Korean and Chinese males and Korean and Chinese females. Korean males and females had higher $F_0$ values than Chinese males and females. Secondly, during sentence reading, there was no significant difference between Korean and Chinese males in $sF_0$. But between female groups, there was a significant difference in $sF_0$. Thirdly, during sentence reading, the pitch range in Korean males was found to be narrower compared to Korean and Chinese females who had wider pitch range, showing a significant difference. Fourthly, jitter in the five vowels /a, i, u, e, o/ was found to be higher in Chinese than Korean subjects. In the vowels /a, e, u/ females were higher than males showing a significant difference. Fifthly, shimmer in the vowels /a, e, u/ was found to be higher in Chinese than Korean subjects showing a significant difference. Finally, NHR in the vowels /a, u, o/ was found to be higher in Chinese than Korean subjects showing a significant difference.

• Culinary science and hospitality research
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• v.14 no.1
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• pp.21-38
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• 2008

This research aimed to analyze the differences in financial variables classifying chain restaurants. A total of 126 samples were drawn from financial statements for $2001{\sim}2006$. As a result of analysis, there was a significant difference in Pillai's Trace, Wilks' Lambda, Hotelling's Trace, and Roy's Largest Root values at the significant probability value(p<0.05) based on F value in terms of stability among chain restaurants. Difference was found only in current rate and liabilities in ANOVA. There was a great difference in current rate among institutional restaurants, fast food restaurants, and cafeterias. There was a significant difference in Pillai's Trace, Wilks' Lambda, Hotelling's Trace, and Roy's Largest Root values at the significant probability value(p<0.05) based on F value in terms of restaurants' profitability. In ANOVA, difference was found only in net profits to net sales. It was revealed that all factors showed no significant differences in multiple comparison. All multi-variant test statistics showed a significant difference in growth and turnover. ANOVA showed a significant difference in net sales growth rate, net profit growth rate, and total assets growth rate.

• Journal of Technologic Dentistry
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• v.29 no.2
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• pp.9-15
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• 2007

As the development of nanotechnology, the use of composite resins which containing nanofillers becomes popular. The purpose of this study was to test the degree of polymerization of nanofillercontaining composite resins. For the study, three different nanofiller-containing composite resins and two different light-curing units were used. To evaluate the degree of polymerization, the maximum polymerization shrinkage taking place during the light curing, and the microhardness, after the light curing, were measured. As results, two light-curing units exhibited a similar emission spectrum to that of the included photoinitiator, camphorquinone. The only difference between the light-curing units were the width of the emission spectrum. Three different composite resins showed different microhardness values. Among them, Grandio showed the greatest microhardness value. However, there was less microhardness difference on the top and bottom surfaces due to the difference of the light-curing units. The maximum polymerization shrinkage values were also similar in the tested specimens regardless of the difference of the light-curing units. However, Grandio showed the least polymerization shrinkage. According to the manufacturers' data, Grandio showed the highest filler content(vol%).

• Journal of Families and Better Life
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• v.15 no.4
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• pp.355-368
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• 1997

This study explored the instrumental values of homemakers by object family living and other social living. Homemakers' instrumental values on family living were compared with those on other social living. Through this it make to explain differences in instrumental values on 2 objects. 650 homemakers were adapted as data. The data were analyzed by frequency percentage means one-way ANOVA duncan-test and paired T-test The results showed significant differences in instrumental values by objects.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.242-245
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• 2000

In this paper we present new idea to highly compress the images. The previous image is transformed with wavelet and the transformed data are transmitted. The previous image is subtracted from the next image. Then difference values per pixel are scanned to search motion areas and boundaries. In the motion boundaries, motion vectors and error values are transformed with wavelet and transmitted. We also include camera motion estimation and compensation. In this method this system has advantages of more compressive data, better quality of picture and shorter processing time compared to MPEG2, MPEG4.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.399-406
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• 2009

This research target students who are majoring in sports at junior colleges and it purpose lies in analyzing the differences in the perspectives towards sports related occupations following the individual characteristics of the students. First, when it comes to the difference of the interest in an organization, sophomore shows more difference than freshman and students who are more than 23 years old shows more difference than students who are 21 or 22 years old. Second, when it comes to the difference in economic incomes, sophomore shows more difference than freshman and students who are more than 23 years old shows more difference than students who are 19 or 20 years old. Third, when it comes to the difference in societal status, sophomore shows more difference than freshman. Fourth, when it comes to the difference in the sense of pride towards one's occupation, male students shows more difference than female students, freshman shows more difference than sophomore and students who are more than 23 years old shows more difference than students who are 21 or 22 years old and 19 or 20 years old. Fifth, when it comes to the difference in preference, male students shows more difference than female students. Sixth, when it comes to the rise of social position, there is no difference in sex, school year or age.

• Journal of the Korean Mathematical Society
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• v.55 no.4
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• pp.785-795
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• 2018

In this paper, we give a uniqueness theorem on meromorphic solutions f of finite order of a class of differential-difference equations such that solutions f are uniquely determined by their poles and two distinct values.

• Communications of the Korean Mathematical Society
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• v.38 no.3
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• pp.925-935
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• 2023

In this paper, we consider a boundary value problem for a sixth order difference equation. We prove the monotone behavior of the eigenvalue of the problem as the coefficients in the difference equation change values and the existence of a positive solution for a class of problems.

• Journal of the Korean Society of Clothing and Textiles
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• v.11 no.1
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• pp.29-42
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• 1987

This study was an attempt to survey, the relationships between women's values and preference in clothing design. For the measurement of values scale was to relect the theoretical, economic aesthetic, social. political and religious values explained by Allport-vernon- Lindzey. The preference rate in clothing design consisted of 50 items and 3 factors including color, form and texture. The questionnaire were administered to a sample of women (between college students and adult) who lined in Seoul, Korea. The date for 910 respondents were analyzed by person's carrelation coefficient, to-test and $x^2$ test. Through this study, the followings were founds; 1. Aesthetic value was the mast important of female college students values and economic value was the most important of adult's values. 2. There were significant relation between values and the preference for clothing form in line and style; 1) In line preference, adult women indicated negative correlation with religious values but positive correlation with aesthetic and political values. 2) In style preference, adult women indicated negative correlation with economic values positive correlation with social values, for female college students indicated positive correlation with aesthetic social and political values. 3. There were significant relation between values and preference for texture in touch, thickness, weight, light and luster; 1) In relationship between texture and values, adult women indicated touchness preference negative correlation with theoretical and religious values, for female college students indicated positive correlation with aesthetic and social values. 2) In thickness preference adult women indicated negative correlation with theoretical values but female college students indicated positive correlation with political values. 3) In weight preference, adult women indicated negative correlation with theoretical values. But female college students indicated positive correlation with religious values. 4) In brightness preference, only adult women indicated positive correlation with social values, negative correlation with economic values. In transparency preference, adult women indicated positive correlation with aesthetic values, negative correlation with religious values. 4. There were significant correlation among color and economic, aesthetic; political and religious values, that is, evacuation and economic political values in adult women there were positive correlation with religious values in female students. 1) In chroma only adult women indicated negative correlation with religious values. In warm and cold, positive correlation with economic values in both of them. 2) In coloration, adult women like a complement color indicated negative correlation with aesthetic values, but positive correlation with political values. 5. There were significant differences in the preference of clothing design between female college students and adult women; correlationship with color variables. Evacuation, both of them indicated negative correlation with chroma positive correlation with warm and cold and coloration. In chroma, adult women indicated negative correlation with coloration and warm and cold, for female students indicated negative correlation with coloration. 6. Comparison with clothing preference: 1) In color preference, adult women liked the most white, brown, blue and black in sequence. Female college students liked the most white, also the next is blue and pink. 2) Clothing design preference, there was significant difference in warm and cold and coloration, adult women more liked than female students. In shape of clothing, both of them indicated significant difference in line and style, female students more liked sporty style. In texture, adult women more liked soft thin light weight and bright. 3) In silhouette preference, the most is H-line, female college students more liked.