• The Journal of Advanced Prosthodontics
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• v.16 no.2
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• pp.115-125
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• 2024

PURPOSE. The purpose of this in vitro study was to investigate the fracture resistance, surface hardness, and color stain of 3D printed, CAD-CAM milled, and conventional interim materials. MATERIALS AND METHODS. A total of 80 specimens were fabricated from auto polymerizing polymethyl methacrylate (PMMA), bis-acryl composite resin, CAD-CAM polymethyl methacrylate resin (milled), and 3D printed composite resin (printed) (n = 20). Forty of them were crown-shaped, on which fracture strength test was performed (n = 10). The others were disc-shaped specimens (10 mm × 2 mm) and divided into two groups for surface hardness and color stainability tests before and after thermal cycling in coffee solution (n = 10). Color parameters were measured with a spectrophotometer before and after each storage period, and color differences (CIEDE2000 [DE00]) were calculated. The distribution of variables was measured with the Kolmogorov Smirnov test, and one-way analysis of variance (ANOVA), Tukey HSD, Kruskal-Wallis, Mann-Whitney U tests were used in the analysis of quantitative independent data. Paired sample t-test was used in the analysis of dependent quantitative data (P < .05). RESULTS. The highest crown fracture resistance values were determined for the 3D printed composite resin (P < .05), and the lowest were observed in the bis-acryl composite resin (P < .05). Before and after thermal cycling, increase in mean hardness values were observed only in 3D printed composite resin (P < .05) and the highest ΔE₀₀ value were observed in PMMA resin for all materials (P < .05). CONCLUSION. 3D printing and CAD-CAM milled interim materials showed better fracture strength. After the coffee thermal cycle, the highest surface hardness value was again found in 3D printing and CAD-CAM milled interim samples and the color change of the bis-acryl resin-based samples and the additive production technique was higher than the PMMA resin and CAD-CAM milled resin samples.

• Restorative Dentistry and Endodontics
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• v.36 no.2
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• pp.125-131
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• 2011

Objectives: The purpose of this study was to evaluate the effect of surface treatment of FRC-Post on bonding strength to resin cements. Materials and Methods: Pre-surface treated LuxaPost (DMG), Rely-X Fiber Post (3M ESPE) and self adhesive resin cement Rely-X Unicem (3M ESPE), conventional resin cement Rely-X ARC (3M ESPE), and Rely-X Ceramic Primer (3M ESPE) were used. After completing the surface treatments of the posts, posts and resin cement were placed in clear molds and photo-activation was performed. The specimens were sectioned perpendicular to the FRC-Post into 2 mm-thick segments, and push-out strength were measured. The results of bond strength value were statistically analyzed using independent samples t-test and oneway ANOVA with multiple comparisons using Scheffe's test. Results: Silanization of posts affect to the bond strength in LuxaPost, and did not affect in Rely-X Fiber Post. Rely-X ARC showed higher value than Rely-X Unicem. Conclusions: Silanization is needed to enhance the bond strength between LuxaPost and resin cements.

• Restorative Dentistry and Endodontics
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• v.36 no.2
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• pp.132-138
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• 2011

Objectives: The purpose of this study was to evaluate curing degree of three dual-cure resin cements with the elapsed time in self-cure and dual-cure mode by means of the repeated measure of micro-hardness. Materials and Methods: Two dual-cure self-adhesive resin cements studied were Maxcem Elite (Kerr), Rely-X Unicem (3M ESPE) and one conventional dual-cure resin cement was Rely-X ARC resin cement (3M ESPE). Twenty specimens for each cements were made in Teflon mould and divided equally by self-cure and dual-cure mode and left in dark, $36^{\circ}C$, 100% relative humidity conditional-micro-hardness was measured at 10 min, 30 min, 1 hr, 3 hr, 6 hr, 12 hr and 24 hr after baseline. The results of micro-hardness value were statistically analyzed using independent samples t-test and one-way ANOVA with multiple comparisons using Scheffe's test. Results: The micro-hardness values were increased with time in every test groups. Dual-cure mode obtained higher micro-hardness value than self-cure mode except after one hour of Maxcem. Self-cured Rely-X Unicem showed lowest value and dual-cured Rely-X Unicem showed highest value in every measuring time. Conclusions: Sufficient light curing to dual-cure resin cements should provided for achieve maximum curing.

• The Journal of the Convergence on Culture Technology
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• v.8 no.4
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• pp.53-60
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• 2022

This study attempted to find out the differences in care efficacy according to MBTIs in nursing students. The study subjects are 109 students in grades 3 and 4 of nursing departments at 1 university in Gyeongnam Region. Data analysis was performed with independent t-test and one-way ANOVA. The general characteristics that showed significant differences in care efficacy as a result of the study were major satisfaction (3.63, p<.001), practice satisfaction (4.49, p=0.013), and health status (2.91, p=0.004). The MBTI, which showed a significant difference in care efficacy, was an EP type (3.74, p=0.013) among the attitude indicators. We believe that the results of this study will serve as a basis for educational programs to improve the efficacy of care. Suggest repeated studies that apply large samples to generalize research for follow-up research, educational programs that apply MBTIs to improve care efficacy, program effectiveness analysis studies, and research on the development of tools to measure care efficacy.

• Korean Journal of Adult Nursing
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• v.27 no.5
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• pp.572-582
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• 2015

Purpose: This study was conducted to provide an effective nursing intervention using an individualized educational program composed with knowledge, compliance, and physiologic parameters for long-term hemodialysis patients. Methods: A quasi-experimental study using a non-equivalent control group and pre- and post-test design was conducted with 40 hemodialysis patients at G university hospital in the J city from June to August, 2015. A data was analyzed using frequency, percentage, ${\chi}^2$ test, Shapiro-Wilk test, independent-samples t-test and repeated measures ANOVA using SPSS 21.0 program. Results: knowledge about hemodialysis and patient role behaviors were not significantly different between the two measures. In the biological index, there was significant difference between the groups by points in time and group in blood potassium, albumin, and Kt/v. However, there was no difference in gaining weight between hemodialysis, hemoglobin, and blood phosphorus. Conclusion: The individual training program in this study had an effect on changing some physiological indicators of long-term hemodialysis patients. Future research is warranted for developing various kinds of education program incorporating the findings of the study for the given population.

• Journal of Fashion Business
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• v.27 no.2
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• pp.52-69
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• 2023

Based on five types of health KF masks currently being commercialized, this study analyzed results of a survey of 316 male and female college students with experience in wearing health masks in Seoul metropolitan area. By identifying problems and improvement requirements according to current status of wearing health masks, results of this study could be used as basic data for designing ergonomic health mask with improved ease of wearing and satisfaction for human safety protection in the future. SPSS 26.0 statistical program was used for all data analyses, including post-hoc test, χ² test for cross-analysis, frequency analysis, independent samples t-test, ANOVA, and Duncan test. Considering that masks are worn for more than 8 hours a day on average, it is necessary to design masks considering materials, sizes of mask ear straps, elasticity and thickness of straps. The design should minimize contact with lips and cheeks with improved fit and comfort, blocking performance, and aesthetics. According to this survey, nearly 50% of respondents said they were willing to wear masks even after the end of COVID-19. Thus, it is necessary to perform research and improve masks to have excellent colors, designs, shapes, fit, and functions suitable for both pandemic and post-pandemic era when wearing masks is common.

• Fashion & Textile Research Journal
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• v.6 no.1
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• pp.71-77
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• 2004

Various types of industry, from manufacturing industry to service industry, can be a subject of exhibition. So, subdivided studies about exhibition for each type of industry or field are necessary. However, there are still insufficient studies about them. Also, fashion industry related exhibitions should be classified differently from other industries' exhibitions because of their special features. Therefore, this study examines that how an exhibition is utilized as a promotion means of a company and the present condition of a fashion exhibition. It also compares a fashion exhibition with other industrial exhibitions to suggest the effective operations and the progressive promotion of the fashion exhibition. This study uses questionnaire from 140 companies for 5 exhibitions, which participated fashion related exhibitions. Data of this study is statistically analyzed using SPSS for window ver. 10.0 program. It also uses frequency, cross tabs, paired t-test, Independent Samples t-test. As a result of this study, fashion related companies' recognition of exhibitions has been increased. However; in terms of exhibition participation, attitudes such as pre-promotion or pre-education for the staff, who are in charge of the exhibition booths, and the outcome of the exhibition aren't maximized because the right understanding concerning exhibitions is lacking and long-term preparation is insufficient. Also, advertisement for the exhibitions isn't enough because of insufficient preparation and absence of pre-promotion, so consultation with promising buyers can't be activated. Even though there are consultations, the consultations don't have much effect.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.117-131
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• 2016

The purpose of this study is to develop the prevention program of child abuse and to verify the effects of the program for marriage immigrant women in Korea. The prevention program was consist of 5 sessions and it was provided to participants once a week for five weeks. Participants were recruited thru the community centers for multi-cultural families in Korea. This study verified the effects of the prevention program with the comparison groups(pre-post). With the independent-samples t-test and paired-samples t-test, the program verified significant effects on the variables of acculturation stress, social support, and recognition of social policy. This study suggests the parenting education of child abuse for multi-cultural families in Korea.

• The Journal of Internal Korean Medicine
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• v.28 no.2
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• pp.346-353
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• 2007

Background : Over a thousand years of clinical preparation of Ephedrain traditional Korean medicine has confirmed effectiveness and security. Recently. Ephedra-containing herbal preparations to treat obesity are common. The aim of this study is to identify effects of Ephedra on psychological anxiety. Objectives : To determine effects of Ephedraon psychoactivity and autonomic nervous system. Methods : The study design was a double-blind randomized controlled trial. The subjects of this study were healthy adults. They were allocated to either the Ephedragroup (N =66) or the placebo group (N =32), Ephedra(8 g) or a placebo in similar opaque capsules was given twice a day for 2 weeks. Anxiety score was estimated with State-Trait Anxiety Inventory before first and after last medication. 36 of the Ephedragroup and 24 of the placebo group finished the trial and were analyzed. Paired samples T-test and independent samples T-test were applied to statistical analysis. Results : The following result was obtained: After taking Ephedra. state anxiety increased significantly. In the placebo group. both state and trait anxiety increased although significance was not reached. Conclusions : It is concluded that the intake of Ephedraplays a significant role in the increase of anxiety in healthy adults. It is suggested that anxiety level change should be considered when using Ephedra in clinics.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.8
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• pp.723-733
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• 2020

The study investigates the effects of online instructional facilitator's qualities on student performance of online class activities. The study explores the roles of instructional facilitators who may influence student performance of online class activities and their academic achievement. The study employs a set of aggregated data from 1,362 subjects and 10 facilitators who participated in multiple online classes. The results of independent samples t-test reveal that the student performance in online classes has no association with facilitators' educational background or academic degree, as well as demographic characteristics, student evaluation records and instructional achievement. The results of multiple regression analysis show that the facilitator engagement has a positive relation to the enhancement of student interaction, reading discussion messages, and the quality of discussion messages in online discussions. The results of correlation analysis show that the facilitator engagement has a positive impact on both increasing the number of reading discussion messages and enhancing the quality of discussion messages. The facilitator engagement increases the quantity of reading discussion postings and enhances the quality of discussion messages, which would be a substantial contribution to student performance by facilitators. The findings suggest that student performance and academic achievement in online classes are not independent of facilitator engagement.