• 한국결정성장학회지
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• 제25권1호
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• pp.1-5
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• 2015

AlN 단결정의 특별한 용도로 이를 개발하기 위한 노력이 전 세계적으로 매우 활발하게 이루어지고 있다. 이러한 AlN을 기반으로 하는 자외선 LED는 생활, 의학, 자동자 등에 유용한 용도로서 살균, 정화, 경화 및 분석 등 분야에 이용된다. 이에 실험을 통해 PVT법으로 카본 도가니를 사용하여 AlN 단결정을 성장시켰으며 실험 중 3가지 형태의 도가니를 이용하여 성장에 미치는 영향을 분석하였으며, 그 온도 조건은 $1900{\sim}2100^{\circ}C$이고 실험 압력으로는 1~200 Torr였다. 그 결과, 높이가 높은 형태의 도가니를 사용할 경우 증발량은 기준 형태보다 증가 하는데 그쳤다. 반면, 넓은 형태의 도가니는 더욱 많은 증발양의 증가를 보였으며, 기준 형태에 비하여 훨씬 안정하다는 것을 알았다. 또한, 제한된 크기의 도가니를 이용한 PVT법에서의 도가니 형태의 변화에 따른 결과는 성장률에 따른 최적 조건, 성장 결정의 품질변화 및 성장 조건 안정성에 영향을 주는 것을 알았다.

• 대한심미치과학회지
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• 제32권1호
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• pp.23-32
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• 2023

비기능적 습관을 가진 환자는 턱관절 장애, 저작 근육의 근막통증증후군 등과 함께 치아의 광범위한 마모를 유발한다. 지속되는 교모는 수직교합고경의 감소를 동반하게 되며 이는 안모의 변화, 저작 효율 저하, 측두하악 관절 장애 등의 문제가 발생할 수 있다. 이런 수직교합고경 감소 환자의 3차원적인 교합 회복과 재구성을 위해서는 정확한 진단 및 분석과 예지성 있는 치료계획 수립이 필요하며, 생리적인 수직교합고경의 회복 및 정상적인 교합평면 재설정을 동반한 보철치료가 필요하다. 본 증례는 구강 악습관에 의한 전반적인 치아의 마모와 저작근의 불편감, 그리고 수직교합고경 감소로 인한 심미적 불만족을 호소하는 환자의 수직교합고경 증가를 동반한 완전 구강 회복 증례이다. 교합안정장치를 통한 측두하악관절의 안정과 고딕아치 기록장치를 이용한 악간관계 재설정 및 임시 수복물을 통한 경과 관찰을 통해 기능적, 심미적으로 좋은 결과를 보였기에 이를 보고하고자 한다.

• 진공이야기
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• 제4권4호
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• pp.14-17
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• 2017

Recently, quantum-dots light emitting diodes (QLEDs) are considered as a next-generation display due to the superior luminescence behaviors, photo stability and narrow spectral emission bandwidth. Moreover, the emission color of QLEDs can be easily controlled by changing the dimension of quantum dots (QDs). A flexible display based on QLEDs can be achieved using low-cost solution process, such as a printing technology. Therefore, QLEDs are expected as a next generation display. In this document, recent progresses in QDs technology will be introduced.

• 대한수학회지
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• 제58권4호
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• pp.977-1000
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• 2021

Consider the high dimensional torus 𝕋ⁿ and the set 𝜺 of its endomorphisms. We construct a map in 𝜺 that is robustly transitive if 𝜺 is endowed with the C² topology but is not robustly transitive if 𝜺 is endowed with the C¹ topology.

• 대한치과의사협회지
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• 제50권1호
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• pp.13-21
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• 2012

In an edentulous situation, the dentist must make several determinations when constructing artificial teeth. These include vertical and horizontal relationships of mandible with respect to the maxilla, occlusal form and position, vertical dimension, occlusal relationships during both centric closure and eccentric excursive movements. Artificial teeth are attached to a movable base resting on movable and displaceable living tissue subject to damage. They act as a unit; therefore, they must be arranged to function as a unit. Bilateral balanced occlusion is that stability of the denture is attained when bilateral contacts ex ist throughout all dynamic and static states of the denture during function. Lateral excursion in a balanced scheme implies simultaneous working side and nonworking side contact, while occlusal contacts are maintained on both anterior and posterior teeth as the mandible moves anteriorly into protrusion.

• 산업기술연구
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• 제21권B호
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• pp.51-58
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• 2001

The Distinct Element Method (DEM) was used to analyze the stability of jointed rock slope, of which dimension are about 200m(length), 60m(height), $55^{\circ}$ dip. The Barton-Bandis joint model was used, as a constitutive model. The parameters such as JRC and spatial distribution characteristics of discontinuities were acquired through field investigation. Three different cases such as $51^{\circ}$, $45^{\circ}$ and $38^{\circ}$ in angle of rock slope were analyzed to decide a stable slope. To keep the jointed rock slope safely, it is proposed to reduce the height of slope from 60m to 48m and to reduce the angle of the from $55^{\circ}$ to $38^{\circ}$ too.

• Structural Monitoring and Maintenance
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• 제7권1호
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• pp.27-42
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• 2020

Dynamic stability of graded nonlocal nano-dimension plates on elastic substrate due to in-plane periodic loads has been researched via a novel 3- unknown plate theory based on exact position of neutral surface. Proposed theory confirms the shear deformation effects and contains lower field components in comparison to first order and refined 4- unknown plate theories. A modified power-law function has been utilized in order to express the porosity-dependent material coefficients. The equations of nanoplate have been represented in the context of Mathieu-Hill equations and Chebyshev-Ritz-Bolotin's approach has been performed to derive the stability boundaries. Detailed impacts of static/dynamic loading parameters, nonlocal constant, foundation parameters, material index and porosities on instability boundaries of graded nanoscale plates are researched.

• 한국염색가공학회지
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• 제7권2호
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• pp.55-62
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• 1995

Plasma polymerization of Perfiuoropropene(PFP) and n-Hexane was carried out in a tubular type reactor by means of 13.56MHz radio frequency generator at the fixed RF discharge power of 25W and at the pressures of 100mTorr, 140mTorr and 200mTorr. The thin films were deposited on PAN fabrics in order to improve the dimemsional stability of woven states in hot water laundry. IR spectroscopy was used for the analysis of the structures of the thin films deposited and SEM for examination of surfaces of the fabrics. the PAN fabrics, which were coated by thin films at several experimental conditions, were immersed in boiling water for 2 hours and then the dimension stability of woven states were evaluated. In spite of very thin films, the results of surface modification were satisfactory. In general the performace of thin films by PFP was superior to that of n-Hexane.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2003년도 춘계학술발표회 논문집
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• pp.219-222
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• 2003

Even through hundreds of meters high steep slope is stable, only several ten meters high dull slope could be collapsed. This means that stability of slope is depend on the slope of a surface of discontinuity like faults existing in rock floor. The existence and nonexistence of a discontinuity surface have a very important effect to the stability of a rock floor slope, and examination for geologic peculiarity is one of the most important pant for investigation of stabilities. Accordingly, in the study, we extracted three dimension coordinates of slope with close photogrammetry, and through interpretations of three dimensions' position of fault within rock floor slope, we expect this will be use as a important sauces when evaluate stabilities of rock floor slope.

• Macromolecular Research
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• 제16권5호
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• pp.467-472
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• 2008

Rigid polyurethane foams (RPUFs) were fabricated from crude MDI (CMDI) and polypropylene glycols (PPGs) of various isocyanate indices with a physical blowing agent (HFC 365mfc). There was a tendency for the gel time to decrease and the tack-free time to increase with increasing index value. With increasing index value the foam density and compression strength decreased and the glass transition temperature, dimension stability and thermal insulation increased, while the cell size and closed cell content were virtually unchanged. Allophanate crosslinks and condensation reactions between the isocyanate groups, which are favored with a high index value, exerted significant effects on the properties of RPUFs.