• The Journal of Advanced Prosthodontics
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• 제13권5호
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• pp.292-303
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• 2021

PURPOSE. The aim of this in vitro study was to evaluate the effect of silane and universal adhesive applications on the micro-shear bond strength (µSBS) of different resin-matrix ceramics (RMCs). MATERIALS AND METHODS. A total of 120 slides (14 × 12 × 1 mm) were produced from 5 different RMC materials (GC Cerasmart [GC]; Brilliant Crios [BC]; Grandio blocs [GB]; Katana Avencia [KA]; and KZR-CAD HR 2 [KZR]) and sandblasted using 50 ㎛ Al₂O₃ particles. Each RMC material was divided into six groups according to the surface conditioning (SC) method as follows: control (G1), silane primer (G2), silane-free universal adhesive (G3), silane-containing universal adhesive (G4), silane primer and silane-free universal adhesive (G5), and silane primer and silane-containing universal adhesive (G6). Three cylindric specimens made from resin cement (Bifix QM) were polymerized over the treated surface of each slide (n = 12). After thermal cycling (10000 cycles, 5 - 55℃), µSBS test was performed and failure types were evaluated using a stereomicroscope. Data were analyzed using 2-way ANOVA and Tukey tests (α = .05). RESULTS. µSBS values of specimens were significantly affected by the RMC type and SC protocols (P < .001) except the interaction (P = .119). Except for G2, all SC protocols showed a significant increase in µSBS values (P < .05). For all RMCs, the highest µSBS values were obtained in G4 and G6 groups. CONCLUSION. Only silane application did not affect the µSBS values regardless of the RMC type. Moreover, the application of a separate silane in addition to the universal adhesives did not improve the µSBS values. Silane-containing universal adhesive was found to be the best conditioning method for RMCs.

• 디지털융복합연구
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• 제17권1호
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• pp.73-84
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• 2019

보편적 서비스에 정당성을 부여하는 철학적 근거에 대해 한.미간 비교연구를 진행한 결과 그동안 우리나라에서는 보편적 서비스를 인간의 기본권 보장이라는 관점에서 이해하고 이를 바탕으로 보편적 서비스를 구현하고자 하는 노력이 부족했으며 보편적 서비스를 추진했던 동기 및 배경에는 주로 경제적 요인이 있었음을 확인할 수 있었다. 하지만, 오늘날에도 보편적 서비스에 대해 기존의 접근방식을 그대로 유지하는 것은 긍정적인 효과보다는 오히려 부작용이 더 클 수 있다는 우려의 목소리가 높다. 이 같은 부작용을 막고 미래지향적인 보편적 서비스 제도 및 정책방향을 정립하기 위해서는 보편적 서비스를 경제적 관점에서 이해하던 과거의 방식에서 벗어나 '인간의 기본권 보장'이라는 관점에서 이해하기 위한 노력을 기울여야 할 것이다. 또 새로운 커뮤니케이션 기술의 등장이 보편적 서비스에 미치는 영향에 대해 꾸준한 관심을 기울이고 후속 연구를 진행하는 것이 필요할 것이다.

• The Journal of Advanced Prosthodontics
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• 제16권2호
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• pp.105-114
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• 2024

PURPOSE. This study aimed to evaluate the effect of pretreatment of three different universal adhesives (Single Bond Universal [SBU], All-Bond Universal [ABU], and Prime&Bond universal [PBU]) on the bonding durability of an adhesive (Panavia F 2.0, PF) and a conventional (Duo-Link, DL) resin cements to air-abraded zirconia. MATERIALS AND METHODS. Rectangular-shaped zirconia specimens were prepared. The chemical composition and surface energy parameters of the materials were studied by Fourier transform infrared spectroscopy and contact angle measurement, respectively. To evaluate resin bonding to the zirconia, all the bonding specimens were immersed in water for 24 h and the specimens to be aged were additionally thermocycled 10000 times before the shear bond strength (SBS) test. RESULTS. The materials showed different surface energy parameters, including the degree of hydrophilicity/hydrophobicity. While the DL/CON (no pretreatment) showed the lowest SBS and a significant decrease in the value after thermocycling (P < .001), the PF/CON obtained a higher SBS value than the DL/CON (P < .001) and no decrease even after thermocycling (P = .839). When the universal adhesives were used with DL, their SBS values were higher than the CON (P < .05), but the trend was adhesive-specific. In conjunction with PF, the PF/SBU produced the highest SBS followed by the PF/ABU (P = .002), showing no significant decrease after thermocycling (P > .05). The initial SBS of the PF/PBU was similar to the PF/CON (P = .999), but the value decreased after thermocycling (P < .001). CONCLUSION. The universal adhesive pretreatment did not necessarily show a synergistic effect on the bonding performance of an adhesive resin cement, whereas the pretreatment was beneficial to bond strength and durability of a conventional resin cement.

• 대한치과보철학회지
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• 제53권4호
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• pp.295-300
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• 2015

목적: 레진과 니켈-크롬 합금의 결합력에 미치는 금속 프라이머 및 다용도 접착제의 영향에 대하여 비교 평가하고자 한다. 재료 및 방법: 실험을 위해 120개의 니켈-크롬 합금(Vera Bond 2V) 디스크를 제작하여 아크릴 레진 실린더에 포매하였다. 시편의 표면은 220 grit, 600 grit의 실리콘 카바이드지로 연마한 뒤 $50{\mu}m$의 알루미늄옥사이드 입자를 분사하여 처리하였다. 실험군은 메탈 프라이머의 적용(Metal primer II, Alloy primer, Metal & Zirconia primer, MKZ primer)과 다용도 접착 시스템(Single Bond Universal, All Bond Universal)에 따라 6개 군으로 나뉘었다. 각 시편의 중앙에 높이 2 mm, 직경 3 mm로 복합레진을 충전하였으며, 제작된 모든 시편은 $37^{\circ}C$ 증류수에서 24시간 보관하였다. 만능시험기에 시편을 위치시킨 후 1 mm/min cross head speed로 전단결합강도를 측정하였다. 통계분석은0.05의 유의수준으로 일원분산분석을 시행하였고 Tukey's multiple coMParison test로 사후검정을 하였다. 결과: Single Bond Universal, All Bond Universal, Metal Primer II 3개 군과 Alloy Primer, MKZ Primer, Metal & Zirconia Primer 3개 군 사이에 통계학적으로 유의한 차이를 보였다(P<.001). 결론: 니켈-크롬 합금에 대한 다용도 접착 시스템의 전단결합강도는 Metal Primer II를 제외한 기존의 금속 프라이머를 적용했을 때 보다 높게 나타났다. 본 실험에서 더 나아가 다용도 접착 시스템 내 실란(Silane) 포함 여부에 따른 효과를 평가할 수 있는 연구가 필요할 것이다.

• 충청수학회지
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• 제16권1호
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• pp.73-79
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• 2003

A subgroup S(X, ${\gamma}$) of the group of automorphisms of a universal minimal transformation group is introduced and a necessary and sufficient condition for two subgroups to be identical is obtained.

• East Asian mathematical journal
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• 제28권5호
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• pp.605-615
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• 2012

In this paper, we show that any definite lattice over $\mathbb{F}_q[x]$ is universal if and only if it is quaternary and its discriminant is of degree 2, where $ch(\mathbb{F}_q){\neq}2$. The Four Conjecture follows as an immediate consequence.

• 대한수학회보
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• 제47권3호
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• pp.513-526
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• 2010

In this paper, the theory of n-ary hypergroups and some applications of hyperalgebras (Fredholm-Voltra integral, copula) are studied. We define some new concepts of topological hyperdynamical systems, universal hyperdynamical systems and immersed universal hyperalgebra. Also, we present some results in this respect.

• 한국수학사학회지
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• 제12권1호
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• pp.21-31
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• 1999

This paper deals with the development of universal algebras. We first investigate how the abstract algebra has emerged as a common generalization of arithmetic and algebra of logic, which was finalized by A. N. Whitehead in his "A treatise on universal algebra with applications." And we investigate also the process of formalizing universal algebras by G. Birkhoff. Birkhoff.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2005년도 추계 학술발표대회 논문집
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• pp.180-181
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• 2005

• East Asian mathematical journal
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• 제26권5호
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• pp.649-654
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• 2010

A positive definite Hermitian lattice is said to be 2-universal if it represents all positive definite binary Hermitian lattices. We find some finiteness theorems which ensure 2-universality of Hermitian lattices over several imaginary quadratic number fields.