• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.61-69
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• 2009

Statement of problem: Porcelain veneers have become a popular treatment modality for aesthetic anterior prosthesis. Fitting porcelain veneers in the mouth usually involve a try-in appointment, which frequently results in salivary contamination of fitting surfaces. Purpose: An in vitro study was carried out to investigate the effect of silane treatment timing and saliva contamination on the resin bond strength to porcelain veneer surface. Material and methods: Cylindrical test specimens (n=360) and rectangular test specimens (n=5) were prepared for shear bond test and contact angle analysis. Whole cylindrical specimens divided into 20 groups, each of which received a different surface treatment and/or storage condition. The composite resin cement stubs were light-polymerized onto porcelain adherends. The shear bond strengths of cemented stubs were measured after dry storage and thermocycling (3,000 cycles) between 5 and $55^{\circ}C$. The silane and their reactions were chemically monitored by using Fourier Transform Infrared Spectroscopy analysis (FTIR) and contact angle analysis. One-way analysis of variance (ANOVA) and Dunnett's multiple comparison were used to analyze the data. Results: FT-IR analysis showed that salivary contamination and silane treatment timing did not affect the surface interactions of silane. Observed water contact angles were lower on the saliva contaminated porcelain surface and the addition of 37% phosphoric acid for 20 seconds on saliva contaminated porcelain increased the degree of contact angle. Silane applied to the porcelain, a few days before cementation, resulted in increasing the bond strength after thermocycling. Conclusion: Within the limitation of this study, it can be concluded that it would be better to protect porcelain prosthesis before saliva contamination with silane treatment and to clean the contaminated surface by use of phosphoric acid.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.16-19
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• 2019

A thinner film has superior electrical properties and a better amorphous structure. Amorphous structures can be effective in improving conductivity through a depletion effect. Research is needed on the Schottky contact, where potential barriers are formed, as a way to identify these characteristics. $SiO_2/SnO_2$ thin films were prepared to examine the amorphous structure and Schottky contact, $SiO_2$ thin films were prepared using Ar = 20 sccm. $SnO_2$ thin films were deposited using mixed gas with a flow rate of argon and oxygen at 20 sccm, and $SnO_2$ thin films were added by magnetron sputtering and treated at $100^{\circ}C$ and $150^{\circ}C$. To identify the conditions under which the amorphous structure was constructed, the XRD patterns were investigated and C-V and I-V measurements were taken to make Al electrodes and perform electrical analysis. The depletion layer was formed by the recombination of electrons and holes through the heat treatment process. $SiO_2/SnO_2$ thin films confirmed that the pores were well formed when heat treated at $100^{\circ}C$ and an electric current was applied over the micro area. An amorphous $SiO_2/SnO_2$ thin film with heat treatment at $100^{\circ}C$ showed no reflection at $33^{\circ}\;2{\theta}$ in the XRD pattern, and a reflection at $44^{\circ}2\;{\theta}$. The macroscopic view (-30 V

• Korean Chemical Engineering Research
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• v.45 no.2
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• pp.117-123
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• 2007

The effect of aluminium addition to MCM-41 on product yield and carbon number distribution was investigated in the catalytic cracking of a polymer mixture, LDPE, LLDPE, and EVA copolymer, with a composition similar to that found in real agricultural film wastes. Al-MCM-41 catalyst synthesized by post-synthetic grafting method (Al-MCM-41-P) as well as Al-MCM-41 catalyst synthesized by direct sol-gel (Al-MCM-41-D). The catalytic cracking of polymer mixture was carried out in vapor phase contact as well as in liquid phase contact. The amount of acid sites increased with aluminium addition by post method as well as direct method, which was seemed to be due to Lewis acid sites. In liquid phase catalytic cracking, the yield of light hydrocarbon fraction increased with aluminium addition. The effect of aluminium addition on production of $C_5-C_{12}$ hydrocarbons over Al-MCM-41-P catalysts was greater than that over Al-MCM-41-D catalysts. In the case of vapor phase catalytic cracking, the effect of aluminium addition was smaller than that of liquid phase catalytic cracking. The selectivity to $C_{13}-C_{32}$ hydrocarbons was smaller in vapor phase catalytic cracking.

• Journal of Distribution Science
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• v.12 no.11
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• pp.67-76
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• 2014

Purpose - PB (Private Brand) refers to the product for which the distribution company plans the production independently, consigns the production to the manufacturer, or attaches the self-developed trademark and sells it. To reinforce competitiveness in such a market environment, diverse products development, systematic management activities, and marketing efforts to analyze and understand the consumers' behavior regarding PB products are emphasized. Therefore, this study aims to investigate the relationships among PB product attributes, consumption emotion, brand attitude, and brand loyalty in general supermarkets. First, PB product attributes were defined using the five categories of perceived price, store image, familiarity, perceived service, and perceived quality, based on preceding studies. This study examined the influence of PB product attributes on consumption. Further, this study examined the relation among consumption emotion, brand attitude, and brand loyalty. This study provides more detailed and concentrated strategic implications. Research design, data, and methodology - In this study, the research model was designed to examine the relation among PB product attributes, consumption emotion, brand attitude, and brand loyalty. For the data collection method, the questionnaire survey comprised multiple items for each component and the direct interview method was employed. To collect data, the questionnaire survey was conducted for customers who personally visited the general supermarket after verifying the PB product purchase experience. The questionnaire survey was performed for one month, May 2014. A total of 300 questionnaires were distributed and 240 questionnaires were used for the analysis, excluding the unanswered and insincere questionnaires. The data were analyzed using SPSS ver. 20.0. Results - First, PB product attributes had a significantly positive effect on consumption emotion. The PB product attributes perceived by the customer at the point of service contact are important to form the positive consumption emotion. Second, consumption emotion had a significantly positive effect on brand attitude. Third, the consumption emotion had a significantly positive effect on brand loyalty. Such consumption emotion is an important factor in causing the positive evaluation on the brand attitude perceived by the customer. Fourth, brand attitude had a significantly positive effect on brand loyalty. The consumption emotion was positively represented to invoke the relational continuance behavior. The relational continuance behavior accompanies the repetition of purchase, word of mouth, and recommendation activities, and influences trust regarding the brand, for which the customer maintains the transaction continuously. Conclusions - The PB product attributes perceived by the customer at the point of service contact are important factors to form the positive consumption emotion. Based on this result, the discount store service provider would prepare the measures that can make the customer recognize the positive value, and make more detailed efforts. Consumption emotion is an important factor to cause the positive evaluation on the brand attitude perceived by the customer. Based on this result, the general supermarket must make efforts to provide fun or convenience in the purchase process for consumers.

• Journal of the Korea Convergence Society
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• v.12 no.5
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• pp.39-50
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• 2021

In this study, a meta-analysis was conducted to find out the effects of convergent "untact" exercise programs on the balance, gait, and falls efficacy of Parkinson's patients. In this study, the PICO were Parkinson's disease, virtual reality program and an e-exercise program intervention, a comparative intervention with the contact interventions applied, and without any interventions applied, outcomes were balance, gait, and fall efficacy. The survey period was between January and February 2021, and five papers were selected and subjected to meta-analysis. Risk of bias, a tool commonly used for randomized control trial studies, was used. Furthermore, RevMan program was used to investigate effect size of untact exercise programs. The result of the meta-analysis showed that the effect size of balance of the untact exercise program group was 1.27 (SMD=1.27; 95% CI 0.72 to 1.83) (Z=4.51, p<0.001), the effect size of fall efficacy was 0.52 (SMD=0.52; 95% CI -0.000 to 1.03) (Z=1.96, p=0.05), and the effect size of gait was -0.40 (SMD=-0.40; 95% CI -1.00 to 0.10)(Z=1.32, p>0.05). A total of 5 literature analysis showed that untact exercise program is more effective in improving balance and falls efficacy than contact exercise program, but no difference in effectiveness was shown on gait.

• Journal of radiological science and technology
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• v.44 no.2
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• pp.133-140
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• 2021

This study aims to analyze the quality and satisfaction of healthcare perceived by patients using hospitals and to provide basic data necessary for expanding and settling Vietnamese healthcare services by analyzing the impact on recommendation intentions. The research method selected one hospital in Vietnam and collected data from patients using the hospital and used a total of 286 effective samples as data for hypothesis verification. The research model and hypothesis verification were analyzed with the statistical data from SPSS and AMOS. The findings show that, first, tangibility, accessibility, and reliability all have a positive effect on the quality of healthcare. Second, it has been shown that only accessibility among the quality of healthcare has a positive effect on recommendation intentions. Third, customer satisfaction has been shown to have a positive effect on recommendation intentions. Fourth, when looking at the mediating effect, reliability among the quality of healthcare was shown as a full-mediated effect, but accessibility was shown to have a partial mediating effect and tangibility to have no mediating effect. Contact management is important because customer satisfaction is highly regarded when customers feel positive emotions at the interface from the provision of convenience facilities that support medical services to the reduction of waiting time for patients, employees kindness, treatment, medication, and inspection. It is also confirmed that the demand for convenient and rapid use of hospitals is increasing in Vietnam. In addition, if customer satisfaction is increased through friendly medical staff's response, the intention of recommendation will be even greater.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.4
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• pp.508-518
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• 2013

In this study, the influence of sub-factors of Big Five personality (extraversion, agreeableness, conscientiousness, neuroticism, openness to experience) to job satisfaction and turnover intention, and mediating effect of job satisfaction between Big Five personality and turnover intention were empirically analysed. Also the relationship between job satisfaction and turnover intention was investigated. The sample of this study were customer-contact employees of restaurant among Youngnam province. 243 questionnaires were used for the empirical analyses. According to the empirical analysis results, openness to experience and conscientiousness respectively had positive influences to job satisfaction and turnover intention. Also neuroticism gave negative influence to turnover intention. Another research finding of this study was that mediating effect of job satisfaction existed in the causal relationship of 'openness to experience' and conscientiousness to turnover intention. Managerial implications of the research findings are that restaurant managers are recommended to select employees of having much of conscientiousness and 'openness to experience', and to employ those of having much of agreeableness. In the field of restaurant industry, training is very important for employees to foster these personalities, because this industry does not have environment of hiring employees of having much of these personalities. Also training can be applied to employees of having high neuroticism for minimizing their turnover intention.

• Steel and Composite Structures
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• v.36 no.6
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• pp.703-710
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• 2020

This paper presents numerical and theoretical investigations on the strain rate in steel-concrete composite (SC) panels under low-velocity impact of a hemispherical rigid body. Finite element analyses were performed on five specimens with different loading rates. The impact energy was kept constant to eliminate its influence by simultaneously altering the velocity and mass of the projectile. Results show that the strain rate in most parts of the specimens was low and its influence on bearing capacity and energy dissipation was limited in an average sense of space and time. Therefore, the strain rate effect can be ignored for the analyses of global deformation. However, the strain rate effect should be considered in local contact problems. Equations of the local strain and strain rate were theoretically derived.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.1-15
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• 1998

In this paper, thermo-viscoplastic finite element analysis of the effect of tool edge radius on cutting process are performed. The thermo-viscoplastic cutting model is capable of dealing with free chip geometry and chip-tool contact length. The coupling with thermal effects is also considered. Orthogonal cutting experiments are performed for 0.2% carbon steel with tools having 3 different edge radii and the tool forces are measured. The experimental results are discussed in comparison with the results of the FEM analysis. From the study, we confirm that this cutting model can well be applied to the cutting process considered the tool edge radius and that a major causes of the "size effect" is the tool edge radius. With numerical analysis, the effects of the tool edge radius on the stress distributions in workpiece, the temperature distributions in workpiece and tool, and the chip shape are investigated.estigated.

• Journal of Food Hygiene and Safety
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• v.5 no.3
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• pp.111-120
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• 1990

Effects of royal jelly(RJ) on the immune system in normal and cyclophosphamide(CY)-treated mice were investigated. The results were as following: 1. Body weight, spleen weight, thymus weight, WBC, cell-mediated immunity (CMI, contact hypersensitivity to DNFB), humoral immunity (HI, Hemagglutinin-, Hemolysin-titer) were increased or decreased dependent on the day of administration of RJ in normal mice. But it showed no effect on liver weight and RBC. 2. Combined treatment with RJ in CY-treated mice on the day which RJ showed the increasing activities in normal mice inhibited the decrease of survival rate, body weight, spleen weight, WBC and CMI caused by CY, but no effect on the decrease of thymus weight and HI induced by CY.