• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.232-235
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• 2007

A comprehensive numerical study was carried out to identify the on-set condition of the cell structures of oblique detonation waves (ODWs). Mach 7 incoming flow was considered with all other flow variables were fixed except the flow turning angles varying from 35 to 38. For a given flow conditions theoretical maximum turning angle is $38.2^{\circ}$ where the oblique detonation wave may be stabilized. The effects of grid resolution were tested using grids from $255{\times}100$ to $4,005{\times}1,600$. The numerical smoked foil records exhibits the detonation cell structures with dual triple points running opposite directions for the 36 to 38 turning angles. As the turning angle get closer to the maximum angle the cell structures gets finer and the oscillatory behavior of the primary triple point was observed. The thermal occlusion behind the oblique detonation wave was observed for the $38^{\circ}$ turning angle.

• PNF and Movement
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• 제18권1호
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• pp.65-75
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• 2020

Purpose: The purpose of this study was to investigate the differences in muscle thickness and ground reaction force of the vastus medialis oblique and vastus lateral oblique muscles during squats at ankle angles of toe 0°, toe in 10°, and toe out 10°. Methods: In this study, 9 male and 17 female students in their 20s participated in a randomized controlled trial and were compared according to the ankle angles of toe 0°, toe in 10°, and toe out 10°. To determine the reliability and measurement of muscle thickness according to ankle angle using ultrasound equipment and muscle thickness, the participants' ankle angles-toe 0°, toe in 10°, and toe out 10°-were measured three times at the vastus medialis oblique and vastus lateralis oblique muscles during squats. At the same time, the maximum vertical ground reaction force was measured with a force plate. A total of three measurements were taken and averaged, and two minutes of squat movements were assessed between ankle angles to prevent target action. Results: The results of this study illustrated that the reliability of the vastus medialis oblique muscles and vastus lateralis oblique muscles in ankle angle was high. The difference in muscle thickness was significantly greater in comparing the toe out 10° angle with the toe 0° angle than between toe in 10° and toe out 10° in vastus medialis oblique and vastus lateralis oblique (p < 0.05). There was no statistically significant difference between the ankle angle of toe 0° and toe in 10° (p > 0.05). The maximum vertical ground reaction force was significantly greater at toe out 10° than at the ankle angle of toe 0° and toe out 10° and between toe in 10° and toe out 10° (p < 0.05). There was no statistically significant difference in the comparison between toe 0° and toe in 10° (p > 0.05). Conclusion: Squatting at an ankle angle of toe out 10° increases the dorsi flexion; thus, the stability of the ankle and the thickness of both oblique muscles increased to perform more effective squats. In addition, as the base of support widens, it is thought that the stability of the posture increases so that squat training can be performed safely.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.297.1-297.1
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• 2016

높은 굴절률(n_H) 의 ITO films 위에 homoepitaxial 성장 기술로 낮은 굴절률(n_L) 의 ITO를 이중으로 증착한 반사방지막을 연구하였다. 우리는 기판 상에 vapor flux 입사 각도 및 columnar 성장막과 경사각 사이의 상관 관계에 기초하여 낮은 굴절률의 ITO 박막을 Oblique-angle sputtering을 사용하여 증착하였다. Oblique-angle 증착동안 columns 경사각이 incident flux angle 의 증가에 따라 linear 하게 증가했다. 반대로 incident flux angle 이 증가할때 ITO 박막의 굴절률은 현저하게 감소하였는데, 이는 원자의 shadowing effect와 표면 diffusion으로 인하여 필름내의 porosity를 증가시킨 것으로 보여진다. 이러한 결과로 homoepitaxial으로 성장시킨 ITO 이중층 구조 반사방지막 특성이 향상되었으며, 유리 기판 위에서 weight average reflectance가 n_L=1.72, n_H=1.90 에서 6.57%를 달성하였다.

• 한국전기전자재료학회논문지
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• 제12권1호
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• pp.75-80
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• 1999

In this study, we have investigated the relationship between the generation of pretilt angle and the polarization component in cells with UV light irradiation on polyimide (PI) surface. It was found that the generated pretilt angle is about $1.4^{\circ}$ with S-polarized UV light irradiation of $75^{\circ}$ on PI surface; it may be attributed to the asymmetry triangular of polymer surface with oblique S-polarized UV light irradiation on PI surface. Also, we measured that the generated pretilt angle is about $2.0^{\circ}$ with oblique P polarized UV light irradiation of $75^{\circ}$ on PI surface. Consequently, we suggest that the generated pretilt angle of the NLC is attributed to the interaction between the LC molecules and the polymer surface with oblique polarized UV light irradiation on PI surface.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• 제3권1호
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• pp.23-28
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• 2000

A numerical investigation was made to examine characteristics of rectangular pontoon type floating breakwaters in oblique waves. Sway and heave wave exciting forces, roll moment acting on the floating breakwater and three motion reponses decrease as the incident wave angle increases for the most of the wave ranges. There exists a minimum wave transmission coefficient which is a function of wave frequency. In short wave range wave transmission coefficient increases as the incident wave angle increases. In long wave range, however, wave transmission coefficient decreases as the wave incident angle increases.

• International Journal of Naval Architecture and Ocean Engineering
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• 제11권1호
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• pp.119-130
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• 2019

This paper establishes an iterative calculation model for the hydrodynamic performance of propeller in oblique flow based on low order potential based surface panel method. The hydrodynamic performance of propeller is calculated through panel method which is also used to calculate the induced velocity. The slipstream of propeller is adjusted according to the inflow velocity and the induced velocity. The oblique flow is defined by the axial inflow velocity and the incident angle. The calculation results of an instance show that the thrust and torque of propeller decrease with the increase of axial inflow velocity but increase with the incident angle. The unsteadiness of loads on the propeller blade surface gets more intensified with the increases of axial inflow velocity and incident angle. However, comparing with the effect of axial inflow velocity on the unsteadiness of the hydrodynamic performance of propeller, the effect of the incident angle is more remarkable.

• International Journal of Internet, Broadcasting and Communication
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• 제16권1호
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• pp.156-162
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• 2024

The purpose of this study was to investigate the muscle activity of internal oblique, rectus femoris, and multifidus according to knee posture and foot bar angle during pilates reformer high flank exercise. Twelve women in their 20s were recruited within six months of their experience as pilates instructors. The subjects performed six types of high flanks according to knee posture and foot bar angle. EMG signals of internal oblique, rectus femoris, and multifidus during exercise were measured and analyzed by integral EMG. The collected data were processed by repeated measures two-way ANOVA. In this paper it shows the following results. First, internal oblique iEMG was not significantly different according to knee posture and foot bar angle. Second, the rectus femoris had an interaction effect according to knee posture and foot bar angle. Third, there was no significant difference in multifidus according to knee posture and foot bar angle. In conclusion, according to the exercise method, the activity of the rectus femoris was the highest in the knee bending and high foot-bar angle high plank exercise, and there was no difference between the internal oblique and multifidus.

• 한국방사선학회논문지
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• 제5권4호
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• pp.161-169
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• 2011

본 연구는 입체적 분포를 형성한 시각신경계에 대하여 MRI 시스템의 경사자기장으로써 하나의 스캔 대상단면을 3차원 형태의 여러 방향으로 향하게 하는 다중사위 스캔각도의 변화에 관하여 실험하였고 기존의 단순각도 사방향 검사방법과 비교 고찰 하였다. 입체적 분포를 이루는 뇌의 시각신경계에 대하여 MR 시스템의 경사자기장으로써 국내 정상 성인을 대상으로 시각신경의 사위영상화를 위한 기존의 사위(시상-관상단면) 스캔방법과 다중사위(시상-관상-횡단면) 스캔각도의 변화를 실험하였다. 그 결과 다중각도를 이용한 사위스캔 방법이 기존의 스캔방법에 비해 더 넓은 영역의 해부학적 정보를 나타내는 것을 영상으로 확인하였다. 또한 시각신경을 명료하게 나타내기 위해서는 영상단면두께와 펄스시퀀스의 선택도 고려되어야할 것으로 확인 되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 D
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• pp.1261-1263
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• 1998

In this paper, we obtained that the monodomain alignment of nematic liquid crystal (NLC) increases with increasing irradiation time with linearly polarized ultraviolet (LPUV) light irradiation on polyimide (PI) surfaces. It was found that the monodomain alignment of NLC is obtained in a cell with normally LPUV light irradiated on PI surface at 30 min. and then oblique LPUV is secondly irradiated on PI surfaces rotated by $90^{\circ}$. The pretilt angle of NLC is generated about $2.5^{\circ}$ with oblique angle of $60^{\circ}$ and then decreased with increasing the oblique angle of IN light irradiation. It is considered that the pretilt angle of NLC is attributed to the photo-depolymerization of polymer with the oblique angle of UV light. The voltage-transmittance and response time characteristics of photo-aligned twisted nematic (TN)-LCD with UV light irradiation time of 60 min. were almost same in comparison with rubbing treated TN-LCD.

• 한국표면공학회지
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• 제45권3호
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• pp.111-116
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• 2012

Oblique angle deposition (OAD) is a physical vapor deposition method which utilizes non-normal angles between the substrate and the vaporizing source. It has been known that tilting the substrate changes the properties of the film deposited on it, which was thought to be a result of morphological change of the film. In this study, OAD has been applied to prepare single and multilayer Al films by magnetron sputtering. The magnetron sputtering source of 4 inch diameter was used to deposit the films. Al films have been deposited on Si wafers and cold-rolled steel sheets. The multilayer films were prepared by changing the tilting angle upside down at each layer interval, which means that when the first layer was deposited at an angle of $+45^{\circ}$, the second layer was deposited at an angle of $-45^{\circ}$, and vice versa. The microstructure, surface roughness and reflectance of the films were investigated using a scanning electron microscope, a surface profiler and a spectrophotometer, respectively. The corrosion resistance was measured and compared using the salt spray test. The single layer film prepared at an oblique angle of $60^{\circ}$ prepared at other angles. However, for the multilayer films, the film prepared at an oblique angle of $45^{\circ}$ showed the most compact and featureless structure. The multilayer films were found to exhibit higher corrosion resistance than the single layer films.