• Restorative Dentistry and Endodontics
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• 제35권3호
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• pp.173-179
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• 2010

본 연구의 목적은 실란, 과산화수소, 불산, 샌드블라스팅을 이용한 섬유포스트의 표면 처리가 복합레진 코어와의 결합강도에 미치는 영향을 평가하기 위한 것이다. 32개의 FRC Postec Plus를 표면 처리를 하지 않은 대조군과 표면 처리 방법에 따라 7개의 실험군(S군, HP군, HP-S군, HF군, HF-S군, SB군, SB-S군)으로 분류하였다. S군은 실란을 적용하였고, HP군은 28%의 과산화수소로 부식하였으며, HP-S군은 과산화수소 처리 후 실란을 적용하였다. HF군은 4% 불화수소산 젤로 부식하였고, HF-S군은 불화수소산 젤 처리 후 실란으로 처리하였다. SB군은 산화 알루미늄으로 샌드블라스팅 하였고, SB-S군은 샌드블라스팅 후 실란을 적용하였다. 표면 처리한 포스트는 Tetric Flow를 사용하여 광중합 시키면서 주위에 원통형의 코어를 축조하였다. 형성된 포스트-코어 복합체를 막대 형태로 절단하여 미세인장결합강도를 측정하였다. One-way ANOVA와 LSD test로 결합강도 값을 분석한 결과, 샌드블라스팅은 섬유포스트와 복합레진 코어와의 결합력을 증가시켰으며 샌드블라스팅 후 실란으로 처리한 경우 다른 처리 방법들보다 유의하게 증가된 결합력을 나타냈다(p < 0.05).

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.104-109
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• 2013

PURPOSE. Among the surface treatment methods suggested to enhance the adhesion of resin cement to fiberreinforced composite posts, conflicting results have been obtained with silanization. In this study, the effects of silanization, heat activation after silanization, on the bond strength between fiber-reinforced composite post and resin cement were determined. MATERIALS AND METHODS. Six groups (n=7) were established to evaluate two types of fiber post (FRC Postec Plus, D.T. Light Post) and three surface treatments (no treatment; air drying; drying at $38^{\circ}C$). Every specimen were bonded with dual-curing resin cement (Variolink N) and stored in distilled water for 24 hours at $37^{\circ}C$. Shear-bond strength (MPa) between the fiber post and the resin cement were measured using universal testing device. The data were analyzed with 1-way ANOVA and by multiple comparisons according to Tukey's HSD (${\alpha}$=0.05). The effect of surface treatment, fiber post type, and the interactions between these two factors were analyzed using 2-way ANOVA and independent sample T-tests. RESULTS. Silanization of the FRC Postec Plus significantly increased bond strength compared with the respective non-treated control, whereas no effect was determined for the D.T. Light Post. Heat drying the silane coupling agent on to the fiberreinforced post did not significantly improve bond strength compared to air-syringe drying. CONCLUSION. The bond strength between the fiber-reinforced post and the resin cement was significantly increased with silanization in regards to the FRC Postec Plus post. Bond strength was not significantly improved by heat activation of the silane coupling agent.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.967-976
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• 2021

This study aimed to investigate the mechanism by which service companies transfer their services overseas and create new value while interacting with local characteristics. A narrative analysis method was used in a case study of Ajisen Ramen, a Japanese service company that created a Japanese-style ramen restaurant, which experienced rapid growth in China. This study analyzed the restaurant as global service innovation and constructed a causal mechanism to explain the resulting rapid growth. In the pre-entry stage, the tangible value source core service facilitated its successful overseas transfer. In the post-entry stage, value source core service standardization and value sharing were interrelated and locally accepted factors. Knowledge of the local characteristics influenced the local storefront format that allowed contact with local customers. This local front format made it possible to offer local customers new value. The global service innovation mechanism developed through this study reflects a causal diagram that correlated the theoretical concepts of these events.

• 구강회복응용과학지
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• 제27권3호
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• pp.253-265
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• 2011

근관치료된 치아의 수복에서 fiber post 크기와 포스트 공간의 직경이 일치하지 않은 경우, 포스트 공간은 두꺼운 레진 시멘트로 채워지게 된다. 레진 시멘트가 두꺼워지면 시멘트 내에 기포가 형성되어 포스트 분리가 발생되기 쉽다. 이런 문제점을 해결하기 위한 방법은 composite resin을 이용하여 fiber post를 relining하는 것이다. 이렇게 형성된 해부학적 포스트는 포스트 공간에 잘 적합하고 시멘트의 두께를 감소시킨다. 이 연구의 목적은 relining 과정과 임상 과정의 간소화를 위해 사용되고 있는 luting agents 종류에 따른 fiber post의 push-out 결합 강도를 평가하는 것이다. 42개의 발치된 치아는 6개의 그룹(n=7)으로 나누어졌다. (A1: relined fiber post를 Luxacore/all-bond 2로 합착, A2: non-relined fiber post를 Luxacore/all-bond 2로 합착. B1: relined fiber post를 Calibra/XP-bond로 합착. B2: non-relined fiber post를 Calibra/XP-bond로 합착. C1: relined fiber post를 RelyX Unicem으로 합착. C2: non-relined fiber post를 RelyX Unicem으로 합착.) Push-out 결합 강도는 relining procedure와 cement type의 상호작용에 의해 영향을 받는 것으로 나타났다. relined fiber post 그룹이 non-relined fiber post 그룹보다 더 높은 결합 강도를 가지며 fiber post relining 과정은 결합강도에 유의한 영향을 가진다.(p<0.05) Luting agent에 따라 모든 그룹에서 RelyX Unicem의 결합강도가 Luxacore/All-bond 2와 Calibra/XP bond에 의한 것보다 유의하게 더 높았다(p<0.05).

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 1996년도 춘계학술발표회논문집(2)
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• pp.405-410
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• 1996

New methodology for mass and energy release assessment in LBLOCA post blowdown is needed and, first of all, the phenomenologically improved and quantitative assessments through experiment are essential. For tile experiment of a hot leg break LBLOCA in post blowdown, the test facility was set and its feature is that tile broken hot leg has two broken sections in the tore side and in the SG side respectively and a separation valve between the two in order to measure the release rate dividedly. Specially it was focused on whether the mass release through the SG side broken section happened or not. The mass release through the core side broken section is dependent on tile safety injection flow and that through the SG side broken section varies depending on several factors. The principal factor is the primary system pressure and the subfactors such as SI flow rate, SI temperature and initial primary pressure, may contribute, too.

• 한국임상보건과학회지
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• 제5권2호
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• pp.850-863
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• 2017

Purpose. The purpose of this study was to investigate effects of preclinical OSCE(Objective Structured Clinical Evaluation) on knowledge, confidence in their Core fundamental nursing skills and self-efficacy in nursing students. Method. The research design was a one group pretest-posttest design and it was done to assess changes in knowledge, confidence in core fundamental nursing skills and self-efficacy from pre to the post-test which was given after the OSCE. Data were collected from March 5 to April 7, 2016 from 37 nursing students who were taking the 15-hours using OSCE learning module at one Gyeongbuk-do, P-city. This practicum was composed of 4 core fundamental nursing skills and 5 other fundamental nursing skills. The knowledge consisted of a 10-item by researchers and the confidence of core fundamental nursing skills consisted of an 9-item NRS and the self-efficacy consisted of a 17-item 5-point scale and measured in both the pretest and posttest. The collected data were analyzed with SPSS IBM 20.0 program for the frequency, percentage, x2-test, and paired t-test. Rusult. The results showed that although scores of knowledge of OSCE learning module were significanlty increased from 5.22 to 7.03(t=5.30, p<.001). There were significantly increased in scores of confidence in core fundamental nursing skills from 5.13 to 7.27(t=10.01, p<.001), In the sub-scales of each core fundamental nursing skills was scored the highest. otherwise, there was no significant difference in self-efficacy(t=1.42, p=.161). Conclusions. Based on the results, this study suggests that OSCE module development activities for nursing students in nursing education-learning in order to improve nursing skills.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.560-563
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• 2008

A condensed model is proposed for the simulation of forming of sandwich sheet with pyramid core. A corresponding finite element analysis for L-type bending is carried out to prove the accuracy and the effectiveness. Simulation results are compared with those of experiment. Deformation shape and post-buckling behavior by simulation are in good agreement with those of experiment for the considerable range of deformation. From the comparison of force-displacement curve, it is shown that the proposed model shows good prediction of the forming force compared to the experiment. Thus, the effectiveness of the proposed method is sufficiently demonstrated.

• The Journal of Advanced Prosthodontics
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• 제5권2호
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• pp.126-132
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• 2013

PURPOSE. Post surface conditioning is necessary to expose the glass fibers to enable bonding between fiber post and resin cement. The purpose of the present study was to evaluate the effect of different surface conditioning on tensile bond strength (TBS) of a glass fiber reinforced post to resin cement. MATERIALS AND METHODS. In this in vitro study, 40 extracted single canal central incisors were endodontically treated and post spaces were prepared. The teeth were divided into four groups according to the methods of post surface treatment (n=10): 1) Silanization after etching with 20% $H_2O_2$, 2) Silanization after airborne-particle abrasion, 3) Silanization, and 4) No conditioning (Control). Adhesive resin cement (Panavia F 2.0) was used for cementation of the fiber posts to the root canal dentin. Three slices of 3 mm thick were obtained from each root. A universal testing machine was used with a cross-head speed of 1 mm/minute for performing the push-out tests. Two-way ANOVA and Tukey post hoc tests were used for analyzing data (${\alpha}$=0.05). RESULTS. It is revealed that different surface treatments and root dentin regions had significant effects on TBS, but the interaction between surface treatments and root canal regions had no significant effect on TBS. There was significant difference among $H_2O_2$ + Silane Group and other three groups. CONCLUSION. There were significant differences among the mean TBS values of different surface treatments. Application of hydrogen peroxide before silanization increased the bond strength between resin cements and fiber posts. The mean TBS mean values was significantly greater in the coronal region of root canal than the middle and apical thirds.

• 한국안전학회지
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• 제29권6호
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• pp.166-171
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• 2014

Nuclear power plants are equipped with the reactor trip system (RTS) and the engineered safety features actuation system (ESFAS) to improve safety on the normal operation. In the event of the design basis accident (DBA), a various of post accident monitor(PAM)systems support to provide important details (e.g. Containment pressure, temperature and pressure of reactor cooling system and core exit temperature) to determine action of main control room (MCR). Operator should be immediately activated for the accident mitigation with the information. Especially, core exit temperature is a critical parameter because the operating mode converts from normal mode to emergency mode when the temperature of core exit reaches $649^{\circ}C$. In this study, uncertainty which was caused by exterior environment, characteristic of thermocouple/connector and accuracy of calibrator/indicator was evaluated in accordance with ANSI-ISA 67.04. The square root of the sum of square (SRSS) methodology for combining uncertainty terms that are random and independent was used in the synthesis. Every uncertainty that may exist in the hardware which is used to measure the core exit temperature was conservatively applied and the associative relation between the elements of uncertainty was considered simultaneously. As a result of uncertainty evaluation, the channel statistical allowance (CSA) of single channel of core exit temperature was +1.042%Span. The range of uncertainty, -0.35%Span ($-4.05^{\circ}C$) ~ +2.08%Span($24.25^{\circ}C$), was obtained as the operating criteria of core exit temperature.

• Journal of Periodontal and Implant Science
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• 제25권1호
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• pp.111-120
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• 1995

This case report presents two maxillary anterior cases for clinical crown lengthening by forced eruption. In the first case, clinical crown of maxillary right lateral incisor was almost lost by fracture. Forced eruption using intracoronal splint and elastic thread accomplished vertical root movement successfully. Then, post & core was inserted and final restoration was harmonious with adjacent teeth. In the second case, the crown portion of maxillary right central incisor was almost mutilated by secondary caries. Forced eruption using removable Hawley appliance and elastic accomplished vertical root movement successfully. Then, post & core was inserted and final restoration was placed. In conclusion, clinical crown lengthening by vertical root movement can be accomplished by a simple appliance without any sacrifice of periodontal support in selected patients. A clinical crown so created can be restored to adequate function and arch integrity without compromising adjacent teeth. Therefore, forced eruption is preferred in the anterior region of the dentition where esthetics is of major concern.