• The Journal of Korean Academy of Prosthodontics
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• v.45 no.2
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• pp.191-202
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• 2007

Statement of problems: Long-term success of esthetic restorations, depends on various factors, especially on color stability of the restorations. The color stability is affected by resin cements beneath the porcelain laminate veneers. Purpose: The purpose of this study was to comprehend the color stability of resin cements by comparing with 4 different kinds of resin cements (Choice, Variolink II, Nexus 2, Rely-X). Material and methods: Porcelain laminate disk samples were luted with resin cements. After thermocycling of each 1000, 2000 and 3000 cycle, specimens were measured by spectrophotometers and the color differences were. Results: 1. After thermocycling of 1000, 2000 and 3000cycle, color difference, $({\Delta}E^*)$ of all specimens were incresed, but were not statiscally significant differences. 2. In the Choice of A1 shade and the Nexus 2 of A3 shade, color difference$({\Delta}E^*)$ after thermocycling of 3000cycle was $incre^*ased$ significantly than after thermocycling of 1000cycle. However, other groups did not show any statistically significant differences (P<0.05). 3. After thermocycling of 3000cycle, color difference$({\Delta}E^*)$ between A1 shade and A3 shade of Nexus 2 showed statistically significant difference. However no statistically significant differences were observed in other groups (P<0.05). 4. The mean of color difference$({\Delta}E^*)$ is 1.0-2.06 after 3000 thermocycling and the data were ranked in the ascending order of Variolink II, Nexus 2, Choice and Rely-X in A1 shade group and Choice, Rely-X, Variolink II and Nexus 2 in A3 shade group. Conclusion: Above results revealed that, after 3000 thermocycing, the color difference $({\Delta}E^*)$ of experimental resin cements was within clinically acceptable ranges. Color stability of 4 different resin cements was comparatively excellent.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.9
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• pp.679-684
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• 2012

This paper aims to evaluate performances of ventilation and insulation of 6types PVS(Passive ventilation skin) by numerical simulation. The results are as follows. 1) The result of Performance of ventilation by pressure difference, it was shown that the amount of ventilation changed bigger under 1Pa and amount of ventilation increased according to increase opening area (${\alpha}A$). Although same opening area of PVS, it can predict that pressure differences cause ventilation differences. 2) In case of same opening area of PVS, however, it was changed the amount of ventilation each types of PVS that is distinguished opening area by flow coefficient. 3) Dynamic U-value that represents performance of insulation PVS was similar change upper ${\alpha}A40\;cm^2/m^2$, great change in casse of 0.1 Pa pressure difference. In case of ${\alpha}A10\;cm^2/m^2$, it was changed bigger under 0.3 Pa pressure difference, ${\alpha}A20\;cm^2/m^2$ of PVS was changed under 0.2 Pa pressure difference.

• Journal of Families and Better Life
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• v.22 no.6 s.72
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• pp.219-232
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• 2004

The purpose of this study was to investigate the gender differences in conversational styles of students. This research based on Quantitative survey and qualitative observation. The quantitative data were collected by questionnaire from 708 respondents who were college students and resided in Sunchon. Statistical methods for the data analysis were frequencies, t-test. The cases of observation were 21. As a result, gender differences were founded in lots of conversational styles. Women showed more tendencies than men In communi-cations to listen, to make relationships, to take care of others, to express intimacy and to make private conversation. Men tended to dominate others, to show off capacities and to make public conversation. This gender differences in conversational styles were related to sex role and major studies. From this results it was proposed that education on gender differences in conversational styles should be developed for students to improve their communication skills and to adapt their changing sex role.

• Communications of the Korean Mathematical Society
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• v.14 no.3
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• pp.581-595
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• 1999

In the present paper we provide a short of the uni-form CLT for the function-indexed martingale difference process under the uniformly integrable entropy by establishing a maximal inequality.

• Journal of the Korea Fashion and Costume Design Association
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• v.9 no.2
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• pp.93-101
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• 2007

The purpose of the study was to offer basic documents to the textile fashion industry by investigating changes of figures followed by various factors as each other social and cultural environment regardless of the same race. The study conducted a questionnaire survey of Korean women and Korean women in Japan to twenties, forties and sixties. The study enforced measurement from February, 2006 to March, 2006 and from July, 2006 to August, 2006 with R. Martin's Measurement Method of Anthropometry in total 49 measurement items. Also, the study treated statistics of the documents with SPSS WIN 10.0 program. As the result which studied comparison of figures with basic statistics, t-test and more, the study got the following conclusion. Most of Korean women and Korean women residing in Japan have big individual differences in obesity, especially width, thickness, and girth of waist showed the largest variation proving considerable individual difference in waist. In a body measurement comparison, twenties, forties, and sixties of Korean women residing in Japan are higher in heights compare to Korean women, while Korean women have wider and thicker waists than Korean women residing in Japan. In a body difference comparison, categories that showed significant differences are 40's>20's>60's in order and twenties and sixties showed only small difference. In conclusion, Korean women have longer, wider, thicker and smaller waist than Korean woman residing in Japan. When divided by age groups, forties and sixties Korean women are longer in waist, shorter in heights, fatter in weights. Twenties have long waist similar to forties and sixties, but had no significant difference in heights and weights.

• PNF and Movement
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• v.7 no.2
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• pp.1-10
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• 2009

This research measures the conditions of spinal scoliosis of college students and analyses the factors that affect spinal scoliosis. From September 15, 2008 to October 30, 2008, the study was conducted with 142 C College students and measured the degrees of spinal scoliosis. The analysis was evaluated according to the Pneumex Analysis program. The collected data was compiled into statistics using the SPSS PC+ 12.0 program. The results were as follows: 1. It appeared that in the cases of C curve, reverse C curve, S curve, and the normal, there was a statistical significance(p=.010) between the conditions of spinal scoliosis of the two genders. 2. It appeared that the comparison among the three groups according to the characteristics of the subjects showed a statistical significance in spinal length(p=.000) in the C curve group, age(p=.019) and spinal length(p=.004) in the reverse C curve group, and spinal length (p=.035), difference in apparent leg length(p=.019), and difference in true leg length(p=.012) in the S curve group. 3. It appeared that in the normal group without spinal scoliosis, the results of comparing the differences in apparent true leg length and spinal length according to the characteristics of the subjects showed a statistical significance in spinal length and gender(p=.000), age (p=.008), height(p=.000), and whether or not there was a regular exercise over once per week(p=.001). 4. On the correlations between C curve, reverse C curve, and S curve and differences in apparent true leg length and spinal length, it appeared that: (a) As the difference in apparent leg length gets bigger the difference in true leg length gets big in C curve(r=.551, p=.000). (b) As the difference in apparent leg length gets bigger the difference in true leg length gets big in reverse C curve(r=.511, p=.006). (c) There is no correlation in S curve.

• Proceedings of the Korean Association for Survey Research Conference
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• 2001.04a
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• pp.109.2-130
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• 2001

The purpose of this study is (1) to demonstrate that ignoring group differences may mislead to incorrect conclusion when analyzing correlation data (e.g., factor analysis), (2) to highlight the importance of the data analytic method considering group differences, and (3) to provide ways of incorporating group differences in data analysis. In study, 1, ignoring group difference in factor analysis may mislead to incorrect factor structure. To remedy this, z-transform method and group analysis tool in covariance structure models were suggested. In study 2, the group differences effect was illustrated by using real data (IQ test data).

• Survey Research
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• v.2 no.2
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• pp.109-130
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• 2001

The purpose of this study is (1) to demonstrate that ignoring group differences may mislead to incorrect conclusion when analyzing correlation data (e.g.. factor analysis). (2) to highlight the importance of the data analytic method considering group differences. and (3) to provide ways of incorporating group differences in data analysis. In study 1. ignoring group difference in factor analysis may mislead to incorrect factor structure. To remedy this. z-transform method and group analysis tool in covariance structure models were suggested. In study 2. the group differences effect was illustrated by using real data (IQ test data).

• Korea Trade Review
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• v.46 no.2
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• pp.229-243
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• 2021

This study aims to establish a research model to see how cultural differences affect negotiation outcomes. People from different countries tend to communicate in slightly different ways. So Recognizing the cultural differences in global businesses is an important preparation process and strategy. If such preparations are not made before doing business with companies in other cultures, many conflicts could arise in the negotiation process and even the negotiations could break down. Therefore, it is important to recognize cultural differences and establish appropriate strategies in international negotiations, and it is necessary to take a look at the factors that affect them one by one. For the purpose of this study, Cultural differences based on Edward Hall's context theory and Personal characteristics were set as moderator variables. and The EU countries(low context cultures) and the Korea(high context cultures) were sampled to study the effects of Negotiation strategy(Problem-Solving Approach).

• Journal of The Korea Institute of Healthcare Architecture
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• v.29 no.4
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• pp.69-77
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• 2023

Purpose: During the COVID-19 pandemic, there have been many cases of converting regular hospital wards into temporary negative pressure isolation wards. The purpose of this study is to evaluate the minimum airflow differences that satisfies the pressure difference criteria(-2.5 Pa) according to airtightness of switching type wards, in preparation for utilization of aging regular wards as negative pressure isolation wards. Methods: Visual inspection and field measurements were conducted using blower door to evaluate airtightness of 5 hospital wards. CONTAM simulation was used to assess the airflow differences when pressure difference between the corridor and wards met the criteria at various levels of airtightness. Results: The ACH₅₀ of evaluated wards ranged from 19.3 to 50.1 h^-1 with an average of 37.0 h^-1, indicating more than four times leakier than other building types. The minimum airflow differences increased as the airtightness of the wards decreased and the size of the wards increased. Implications: When operating rapidly converted negative pressure isolation wards, understanding airtightness is crucial for determining the minimum airflow differences to maintain the pressure differences. The analysis of this study suggests that improving the airtightness of aging rooms is essential and the minimum airflow differences should be suggested considering both the airtightness and size of rooms.