• Journal of the KSME
• /
• v.18 no.4
• /
• pp.5-10
• /
• 1978

1. 공작기계의 Slide way 방식은 공작기계의 내마모성의 아내면으로서 앞으로 더욱 증가될 것이 예상된다. 2. 우리나라의 경우 공작기계안내면으로서 적합한 meehanite cask iron을 개발하여 사용할 수 있 으나 조,용해시설불비와 기술자부족, 시설투자비 생산원가상승조래 등의조건을 감안할 때, Silde way를 Bearing과 같은 부품과 같이 외주에 의존하여 조립하는 것은 바람직하다.

• 대한치과보철학회:학술대회논문집
• /
• 2001.11a
• /
• pp.42-42
• /
• 2001

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.10
• /
• pp.6611-6617
• /
• 2015

The purpose of this study is to compare the marginal and internal fit of metal and zirconia coping which is fabricated by manual and CAD/CAM(Computer Aided Design/Computer Aided Manufacturing). The model is prepared with Urethane material and two abutment teeth are fabricated with a knife and chamfer margin. Silicon replica technique is used to measure the marginal fit of manually fabricated and the CAD/CAM coping. Internal fitting level is measured with a microscope and the image is captured with a CCD camera. The distance between abutment teeth and coping is measured with a callibrated image analyzer software; marginal opening (MO), marginal gap (MG), internal gap (IG) at maximum curvature area, axial gap (AG), and occlusal gap (OG). Two-way ANOVA test is applied to compare fabrication technique and to analysis of abutment pattern. In addition, one-way ANOVA and Scheffe's test is used to analyze each parameter of the test. The result shows that the fit is < $120{\mu}m$ except OG of CAD/CAM and MO of knife margin. The CAD/CAM fabricated coping showed higher fit level at chamfer margin. However, knife margin showed better fitness compared to chamfer margin at MG. AG showed the minimum dimension with a constant result (< $38{\mu}m$).

• Journal of dental hygiene science
• /
• v.14 no.3
• /
• pp.405-410
• /
• 2014

The purpose of this study in vitro investigation was to compare the marginal and internal fit of Ni-Cr alloy metal ceramic crown before and after porcelain veneering. Furthermore, this study evaluated whether the influence of the porcelain firing on the precision of fit of dental prostheses. The maxillary right incisor was selected as an abutment for experiments. Ten working models were prepared. Ni-Cr alloy cores appropriate for each abutment were prepared by lost wax technique. The marginal area and four internal areas of the crowns were measured at two stages: before veneering process and after upper porcelain firing. Silicone replica techniques were used. The data were statistically analyzed with the paired t-test (${\alpha}=0.05$). $Mean{\pm}SD$ marginal and internal gap were $67.1{\pm}23.3{\mu}m$ for the nickle chrome alloy core group and $74.4{\pm}21.9{\mu}m$ for the metal ceramic crown group. There were statistically significant differences in all investigated areas (p<0.05). Within the limitations of this study, none of the Ni-Cr alloy metal crown values measured after porcelain firing process exceeded $120{\mu}m$, which is the clinically acceptable threshold.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.21 no.5
• /
• pp.501-509
• /
• 2001

For the enhancement of ECT reliability on the primary water stress corrosion cracks of nuclear steam generator tubes, of which the occurrence is on the increase, it is important to comprehend the signal characteristics on crack morphology and to select an appropriate probe type. In this paper, the sizing accuracy and the detectability for the inner wall axial cracks of tubes were quantitatively evaluated using the following specimens: the electric discharge machined notches and the corrosion cracks which were developed on the operating steam generator tubes. The difference of eddy current signal characteristics between pancake and axial coil were also Investigated. The results obtained from this study provide a useful information for more precise evaluation on the inner wall axial tracks oi stram generator tubes.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.10
• /
• pp.336-343
• /
• 2017

In this study, we analyze the relationship between long-term care workers' emotional labor, professional quality of life, and service quality. The subjects of this study were 211 long-term care workers working in long-term care facilities. Self-administered questionnaires were used. In the research model, emotional labor(surface behavior, internal behavior) was verified using independent variables, with professional quality of life (compassion satisfaction, compassion fatigue) as the parameters and service quality as the dependent variables. The results of this study are as follows. First, the fit of the model was good. Second, the direct effects of emotional labor on service quality were not significant. However, there was a positive correlation between internal behavior and service quality, and a negative correlation between surface behavior and service quality. Third, professional quality of life(empathy satisfaction) was the most influential variable in terms of service quality. The results of this study demonstrate the necessity to payclinical and academic attention to long-term care workers' emotional labor and quality of life.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.3
• /
• pp.476-484
• /
• 2021

In this study, we analyze the relationships between long-term care workers' person-centeredness and job satisfaction, emotional labor, and service quality. Self-administered questionnaires were used to collect data from 460 long-term care workers in long-term care facilities. In the research model, person-centered care was verified using independent variables, with emotional labor (surface behavior, internal behavior) and job satisfaction applied as parameters, and service quality applied as a dependent variable. The results of this study are as follows. First, the fit of the model is good. Second, the implicit behavior of emotional labor is found to be an important factor affecting service quality. Also, emotional labor is an important mediator, improving the value of person-centered care and service quality. There is a positive correlation between internal behavior and service quality, and a negative correlation between surface behavior and service quality. Third, emotional labor (surface behavior, internal behavior) is the most influential variable in terms of service quality. The results of this study demonstrate the necessity to pay clinical and academic attention to person-centered care in terms of long-term care workers' emotional labor and service quality.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.33 no.3
• /
• pp.491-497
• /
• 2006

Orthodontic seamless bands are frequently used in pediatric dentistry. In the process of seating bands with luting cement coated inside, not uniformed coating might bring about various problems such as enamel decalcification and/or gingivitis, and this clinical trial was made to review several band-seating methods to exclude these risks. One kind of band luting cement and one size of seamless bands were used on the resin replicas of an extracted maxillary and mandibular 1st molar with three different seating methods 1. seating the band with the luting cement coated only inside the band, 2. seating the band with the luting cement coated inside the band and on axial surfaces of the teeth, 3. seating the band with the adhesive tape on the occlusal opening of the band and the luting cement coated only inside the band. After cement was completely set, bands were peeled off from the teeth and the status of cement coating was evaluated. With this experiment more uniformed coating of the luting cement was found in latter two groups. These methods are thought more appropriate to almost completely rule out the risk of unevenly coated cement beneath the bands by conventional method.

• The Journal of Korean Academy of Prosthodontics
• /
• v.59 no.4
• /
• pp.395-404
• /
• 2021

Purpose. The purpose of present study was to evaluate the effect of changing structural stability of wax disc on the fit of prosthesis when the milling proceeded in order. Materials and methods. Prepared maxillary left first molar was used to fabricate a Ni-Cr alloy reference model. This was scanned to design crown and then wax pattern was milled, invested and cast to fabricate prosthesis. The wax patterns located in a row centrally within a single wax disc were set into a total of five groups ranging from WM1 group that was first milled to WM5 group that was last milled and the number of each group was set as 10. Silicone replica technique was used to measure the marginal gap, axial internal gap, line angle internal gap, occlusal internal gap. Data was evaluated with one-way ANOVA with significance level set at α = .05 and then Tukey HSD test was conducted for post analysis. Results. Marginal gap measured in each group, it was 40.41 ± 2.15 ㎛ in WM1 group, 40.44 ± 2.23 ㎛ in WM2 group, 39.96 ± 2.25 ㎛ in WM3 group, 39.96 ± 2.48 ㎛ in WM4 group, and 40.57 ± 2.53 ㎛ in WM5 group. No significant difference was found between groups. The significant difference between the groups was also not found in the axial internal gap, line angle internal gap, and occlusal internal gap. Conclusion. Internal and marginal fit of single crown to the sequential order of milling processing in the single machinable wax disc did not seem to be affected by the sequence.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.36 no.4
• /
• pp.254-261
• /
• 2020

Purpose: The purpose of this study was to assess the marginal and internal fit of interim crowns fabricated by two different manufacturing method (subtractive manufacturing technology and additive manufacturing technology). Materials and Methods: Forty study models were fabricated with plasters by making an impression of a master model of the maxillary right first molar for ceramic crown. On each study model, interim crowns (n = 40) were fabricated using three types of 3D printers (Meg-printer 2; Megagen, Zenith U; Dentis, and Zenith D; Dentis) and one type milling machine (imes-icore 450i; imes-icore GmbH). The internal of the interim crowns were filled with silicon and fitted to the study model. Internal scan data was obtained using an intraoral scanner. The fit of interim crowns were evaluated in the margin, absolute margin, axial, cusp, and occlusal area by using the superimposition of 3D scan data (Geomagic control X; 3D Systems). The Kruskal-wallis test, Mann-Whitney U test and Bonferroni correction method were used to compare the results among groups (α = 0.05). Results: There was no significant difference in the absolute marginal discrepancy of the temporary crown manufactured by three 3D printers and one milling machine (P = 0.812). There was a significant difference between the milling machine and the 3D printer in the axial and occlusal area (P < 0.001). The temporary crown with the milling machine showed smaller axial gap and higher occlusal gap than 3D printer. Conclusion: Since the marginal fit of the temporary crown produced by three types of 3D printers were all with in clinically acceptable range (< 120 ㎛), it can be sufficiently used for the fabrication of the temporary crown.