• The Journal of Advanced Prosthodontics
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• v.4 no.3
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• pp.162-169
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• 2012

PURPOSE. Fracture of the veneering material of zirconia restorations frequently occurs in clinical situations. The purpose of this in vitro study was to compare the fracture strengths of zirconia crowns veneered with various ceramic materials by various techniques. MATERIALS AND METHODS. A 1.2 mm, $360^{\circ}$ chamfer preparation and occlusal reduction of 2 mm were performed on a first mandibular molar, and 45 model dies were fabricated in a titanium alloy by CAD/CAM system. Forty-five zirconia copings were fabricated and divided into three groups. In the first group (LT) zirconia copings were veneered with feldspathic porcelain by the layering technique. In the second group (HT) the glass ceramic was heat-pressed on the zirconia coping, and for the third group (ST) a CAD/CAM-fabricated high-strength anatomically shaped veneering cap was sintered onto the zirconia coping. All crowns were cemented onto their titanium dies with Rely $X^{TM}$ Unicem (3M ESPE) and loaded with a universal testing machine (Instron 5583) until failure. The mean fracture values were compared by an one-way ANOVA and a multiple comparison post-hoc test (${\alpha}$= 0.05). Scanning electron microscope was used to investigate the fractured interface. RESULTS. Mean fracture load and standard deviation was $4263.8{\pm}1110.8$ N for Group LT, $5070.8{\pm}1016.4$ for Group HT and $6242.0{\pm}1759.5$ N for Group ST. The values of Group ST were significantly higher than those of the other groups. CONCLUSION. Zirconia crowns veneered with CAD/CAM generated glass ceramics by the sintering technique are superior to those veneered with feldspathic porcelain by the layering technique or veneered with glass ceramics by the heat-pressing technique in terms of fracture strength.

• Journal of Dental Rehabilitation and Applied Science
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• v.30 no.1
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• pp.81-92
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• 2014

It is so hard to obtain optimal anterior esthetics in the implant prosthesis. This is not only because of hard and soft tissue problem such as alveolar bone resorption and interdental papilla loss but also because of prosthetic limitation related to marginal exposure of metal abutment and metal ceramics and low transillumination. In this case, guided soft tissue healing is obtained using a long term provisional restoration with soft and hard tissue augmentation or immediate implantation. Then, this healed tissue is transferred to final master model using a customized impression coping and the implant is restored with a customized zirconia abutment and a all ceramics. This case presents satisfying result esthetically and functionally.

• The Journal of Korean Academy of Prosthodontics
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• v.61 no.1
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• pp.1-17
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• 2023

Purpose. The purpose of this study was to examine the correlation between the finish line designs and the marginal adaptation of nonprecious metal alloy coping produced by different digital manufacturing methods. Materials and methods. Nonprecious metal alloy copings were made respectively from each master model with three different methods; SLS, milling and casting by computer aided design and computer aided manufacturing (CAD-CAM). Twelve copings were made by each method resulting in 72 copings in total. The measurement was conducted at 40 determined reference points along the circumferential margin with the confocal laser scanning microscope at magnification ×150. Results. Mean values of marginal gap of laser sintered copings were 11.8 ± 7.4 ㎛ for deep chamfer margin and 6.3 ± 3.5 ㎛ for rounded shoulder margin and the difference between them was statistically significant (P < .0001). Mean values of marginal gap of casted copings were 18.8 ± 20.2 ㎛ for deep chamfer margin and 33 ± 20.5 ㎛ for rounded shoulder margin and the difference between them was significant (P = .0004). Conclusion. Within the limitation of this study, the following conclusions were drawn. 1. The variation of finish line design influences the marginal adaptation of laser sintered metal coping and casted metal coping. 2. Laser sintered copings with rounded shoulder margin had better marginal fit than deep chamfer margin. 3. Casted copings with deep chamfer margin had better marginal fit than rounded shoulder margin. 4. According to the manufacturing method, SLS system showed the best marginal fit among three different methods. Casting and milling method followed that in order.

• Journal of Venture Innovation
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• v.5 no.2
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• pp.49-66
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• 2022

This study intends to examine how the perception of covid-19 risk affects consumers' consumption behavior based on previous studies in a situation where the spread of covid-19 is prolonged. This study demonstrates how consumers' perception of covid-19 risk affects online and offline consumption behavior through the perceived severity, perceived vulnerability, coping effectiveness, and self-efficacy of the revised protective motivation theory (Rogers, 1983). We want to test it through analysis. In order to achieve the purpose of this study, consumers living in Seoul and Gyeonggi Province who have purchased within the past 3 months were selected as a sample. In addition, variable data such as risk perception of covid-19, perceived severity, perceived vulnerability, coping effectiveness, self-efficacy, online purchase attitude and purchase intention, offline purchase attitude and purchase intention were collected through the questionnaire.A total of 363 copies of valid responses were tested to test the hypothesis of the relationship between variables through the covariance structure model. The analysis results of this study were first, that covid-19 risk perception had a significant positive (+) effect on perceived severity, perceived vulnerability, and coping effectiveness. Second, perceived severity and perceived vulnerability were found to have a significant positive (+) effect on offline purchasing attitude. Third, perceived severity, perceived vulnerability, coping plan effectiveness, and self-efficacy were all found to have significant positive (+) effects on online purchase attitude. Finally, it was found that offline purchase attitude and online purchase attitude had a significant positive (+) effect on offline purchase intention and online purchase intention, respectively. Also, it was found that online purchase attitude had a negative (-) effect on offline purchase intention. The results of this analysis will provide meaningful implications for the establishment of strategies for distribution channels according to the social risk of infectious diseases.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.56-66
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• 2016

This study is a descriptive research study which attempts to determine the effects of self-efficacy, self-esteem, loneliness, stress, stress coping, and use expectancy on the smartphone addiction of university students based on the GIA model. Data was accumulated by means of questionnaire surveys from December 2015 to January 2016, which targeted 224 college students attending universities within Seoul and analyzed by descriptive statistical analysis, correlation analysis, and multiple regression analysis using SPSS 21.0. The average smartphone addiction score was $2.5{\pm}0.8$ (1.2-4.9) and 125 students were in the normal category (55 %), 90 in the danger category (40.2%), and 9 in the addiction category (4%). The correlation analysis showed that loneliness and stress had positive correlations with use expectancy, while self-esteem had a negative correlation. Loneliness, stress, use expectancy, and self-esteem proved to be the major factors affecting smartphone addiction and it was concluded that the development and application of programs which strengthen self-esteem are necessary. This study contributed to the research application and availability of the GIA model by analyzing the factors affecting smartphone addiction based on the GIA model.

• Korean Journal of Culture and Social Issue
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• v.30 no.3
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• pp.349-378
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• 2024

This study aimed to identify latent profiles of anxiety and anger symptoms experienced by Korean adults during the COVID-19 pandemic and factors that influence group classification. To this end, a latent profile analysis(LPA) was conducted on 1,434 Korean adults from February to March 2021 after the pandemic was announced. First, as a result of confirming the suitability of the latent model, a 5-class-model was found to have the best model fit with 'low anxiety/high anger group(Group 1)', 'low anxiety/low anger group(Group 2)', 'middle anxiety/middle anger group(Group 3)', 'middle anxiety/high anger group(Group 4)', 'high anxiety/high anger group(Group 5)'. Second, gender, economic status, emotion-focused coping, and dysfunctional coping were significant predictors of group classification. Third, there were differences between latent groups in PTSD symptom and suicidal ideation. Finally, discussions and implications of the study were discussed.

• Journal of Korean Academy of Nursing
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• v.45 no.1
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• pp.97-106
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• 2015

Purpose: This study was done to develop and test a structural model for caregiving experience including caregiving satisfaction and caregiving strain in families providing care for family members with a mental disorder. Methods: The Stress-appraisal-coping model was used as the conceptual framework and the structural equation model to confirm the path that explains what and how variables affect caregiving experience in these families. In this hypothesis model, exogenous variables were optimism, severity of illness and uncertainty. The endogenous variables were self efficacy, social support, caregiving satisfaction and caregiving strain. Data were collected using structured questionnaires. Results: Optimism and caregiving self-efficacy had significant direct and indirect effects on caregiving satisfaction. Optimism, severity of illness and uncertainty had significant direct and indirect effects on caregiving strain. The modified path model explained effects of optimism on caregiving self-efficacy with social support in the path structure as a mediator. Also, there were direct and indirect effects of optimism and uncertainty on caregiving satisfaction with social support and caregiving self-efficacy in the path structure as a mediators. Conclusion: Results suggest the need to improve caregiving self-efficacy of these families, establish support systems such as a mental health professional support programs for caregiving self-efficacy. Optimism, severity of illness and uncertainty perceived by families need to be considered in the development of support programs in order to increase their effectiveness.

• Journal of Korean Academy of Nursing
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• v.24 no.4
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• pp.666-677
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• 1994

In comparison with the long and continuous his-tory of research in the general area of stress and coping, theoretical and clinical interest in family stress and adaptation is a recent phenomenon. To understand the phenomena of family behavior, a comprehensive theoretical framework is needed to us provide an adequate background to for research. This study was designed to develop and test a hypothetical model for family stress and adaptation in families with handicapped children. A hypothetical model was constructed on the basis of the family stress theory developed by McCubbin etc. The model included six paths. For the purpose of model testing, empirical data was collected from May to August, 1992. The subjects of the study were 190 parents of chidren in five special schools and one private institute in Seoul and Choong Nam. An SPSS P $C^{+}$ and PC-LISREL 7.13 computer programs were used for descriptive and covariance structure analysis. The results of the study are as follows. (1) Family Stress(${\gamma}$$_{3l}$=-.288, T=-4.942) had a direct effect on Family Adaptation. (2) Family Functioning ($\beta$$_{21}$=-.373, T=5.595) had a direct effect on Situational Definition. (3) Family Functioning ($\beta$$_{31}$ =.334, T=5.375) had a direct effect on Family Adaptation. (4) Situational Definition( a2=.270, T=4.285) had a direct effect on Family Adaptation The model was supported by the empirical data. Thus it is suggested that the model could be adequately applied to family nursing care of families with a mentally handicapped child. In particular, the nursing interventions that enhance family functioning and the situational definition would improve family adaptation in families with mentally handicapped children.n.n.

• Research in Community and Public Health Nursing
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• v.29 no.3
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• pp.359-370
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• 2018

Purpose: The purpose of this study is to identify effects of the variables of Health Action Process Approach (HAPA) Model on physical activity. Methods: This study has conducted a systematic literature review and meta-analysis. Sixteen articles were searched through electronic databases (PsycINFO, PubMed, CINAHL, Web of science, Science Direct, RISS, KMBASE, KoreaMed, KISS, DBpia) and additional journals from 2000 to July, 2017. To estimate the effect size (ES), the meta-analysis of the studies was performed by using Comprehensive Meta-Analysis programs. Results: The overall effect size of the variables of HAPA on physical activity was median (ES=.28). Of the core variables of HAPA model, action control (ES=.43) showed the largest effect size, followed by coping self-efficacy (ES=.31) and planning (ES=.31).Additional variables were identified as preparatory behavior (ES=.39) and past physical activity (ES=.24). Through the moderator effect analysis, the effect size was higher in the volitional phase than in the motivational phase, and higher in the healthy group than in the patient group. The higher the proportion of males and the lower the age, the larger the effect size. Conclusion: This finding shows empirical evidence that all core variables of the HAPA model are useful for predicting physical activity. We propose the use of the HAPA model to develop physical activity promotion intervention.

• The Journal of Korean Academic Society of Nursing Education
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• v.8 no.1
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• pp.61-71
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• 2002

purpose : The purpose of this study was to find out the influencing factors of smoking-cessation behavior of patients with coronary heart disease and to suggest the model of smoking-cessation behavior which was based on the relationship between influencing factors and then to test its fitness empirically. method : This study was based on the Theory of Reasoned Action and a hypothetical model was constructed with fifteen paths in consideration of main predictive factors of smoking-cessation behavior such as biological factor, disease-related characteristics, self-efficacy, supportive factor, environmental factor, disease-related perception factor, intention-to-quit, and psychological factor. The validity of a smoking- cessation model was tested to 264 patients with coronary heart disease by using SPSS 8.0 and Window LISREL 8.12a. results : 1. Seven of the 15 paths of smoking-cessation behavior proved to be significant. 2. The final model excluded three paths in the hypothetical model was demonstrated to be improved by $x^2$=44.31 (df=38, p=.22), Goodness of Fit Index (GFI)=.98, Adjusted Goodness of Fit Index (AGFI)=.96, Non-Normed Fit Index(NNFI)=1.00, Normed Fit Index(NFI)=1.00, and Root Mean Square Residual(RMR)=.24. 3.The smoking-cessation behavior was influenced directly by biological factor, self-efficacy, supportive factor, environmental factor, intention-to-quit, and psychological factor. The smoking-cessation behavior was accounted for 82% of variance by these factors. conclusion : although the adolescents' smoking behavior can be predicted by only smoking intention, it is hard to predict the adults' smoking-cessation behavior by only this factor. Therefore, intention-to-quit, self-efficacy, supportive factor should be improved because these are promotive factors for smoking-cessation behavior. Biological factor, environmental factor, and psychological factor are inhibitive factors, so nicotine replacement therapy is helpful to the high nicotine-dependents, and ex-smokers avoid other smokers in their environment and also patients should learn and practice the stress coping-skills.