• 동력기계공학회지
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• 제4권4호
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• pp.32-40
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• 2000

A study on the fluid flow with ultrasonic forcing was carried out to get the enhancement of turbulence by laying emphasis on the ultrasonic incidence angles and reflectors. A large water tank was made of the transparent acrylic plates and city water of $25^{\circ}C$ was used as working fluid. 7 angles ($30^{\circ},\;45^{\circ},\;60^{\circ},\;90^{\circ},\;120^{\circ},\;135^{\circ},\;150^{\circ}$) as the ultrasonic incidence angle and 4 materials (wood, acryl, glass, iron) as the reflector were selected arid experiments for the above were made. The velocity vector distribution, kinetic energy and turbulence intensity of the turbulence flow fields enhanced by ultrasonic forcing were measured, compared and discussed by using the PIV measurement which was possible to measure the velocities of simultaneous multipoints. In results, it was cleared that the incidence angle of ultrasonic and material of reflector influenced the enhancement of turbulence.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.232-232
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• 2003

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.625-630
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• 2006

A new method to get reliable viewing angle measurements on LCD reflective display is presented. This method is based on the use of commercial Fourier optics viewing angle instruments already proposed by ELDIM for more than 15 years. This apparatus is capable to measure simultaneously quasi all the incidence and azimuth angles and to control very precisely the illumination of the sample. We show that, in contrast to other instruments, a clever illumination procedure with two different conditions allows separation of the intrinsic reflective contribution of the display and of the parasitic front end reflection. In this way, intrinsic performances of the display can be obtained at any incidence and azimuth angles and realistic observer conditions can be simulated.

• International Journal of Aeronautical and Space Sciences
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• 제14권1호
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• pp.67-74
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• 2013

Nonlinear guidance law combined with a pseudo pursuit guidance is proposed, to perform stationary target observation mission. Multiple UAVs are considered, with waypoint constraint. The whole guidance is divided into two steps: firstly, waypoint approach, with specified incidence angle; and secondly, loitering around the stationary target. Geometric approach is used to consider the constraint on the waypoint, and a specified phase angle between the loitering UAV and the approaching UAV. In the waypoint approach step, UAVs fly to the waypoint using the pseudo pursuit guidance law. After passing the waypoint, UAVs turn around the target, using a distance error dynamics-based guidance law. Numerical simulations are performed, to verify the performance of the proposed guidance law.

• 한국결정성장학회지
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• 제25권1호
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• pp.27-31
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• 2015

내화물은 슬래그 등과의 화학반응뿐만 아니라 입자 충돌이나 마찰에 의한 물리적인 마모도 일어난다. 그러나 내화물의 에로젼에 의한 마모에 대해서는 거의 알려져 있지 않다. 본 실험에서는 내화도가 1300과 $1500^{\circ}C$인 캐스터블에 대해서 SiC 마모입자의 입사 각도에 따른 마모량의 변화를 분석하였다. 그 결과 최대 마모량을 나타내는 각도는 입자가 내화물에 수직으로 부딪힐 때가 아니라 $60{\sim}75^{\circ}$로 입사될 때인 것을 알았다. 또한 내화물의 기공률이 에로젼 마모에 가장 큰 영향을 미치는 것으로 생각되었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1615-1618
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• 2007

Performances of LCDs are generally evaluated in terms of luminance and color versus viewing angle. In the present paper we show that this type of display can be favorably characterized in terms of polarization. We show that ELDIM EZContrast instrument can be used to measure the degree of polarization the light and the ellipticity and polarization direction of the polarized component. This measurement is made versus incidence angle between 0 and $88{\circ}$ and for all the azimuth angles. Important differences between the displays can be detected and related to their internal structures when luminance and color profiles are quite similar.

• Steel and Composite Structures
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• 제22권4호
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• pp.855-874
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• 2016

In this paper, it is aimed to evaluate the earthquake angle influence on the seismic performance of steel highway bridges. Upper-deck steel highway bridge, which has arch type load bearing system with a total length of 216 m, has been selected as an application and analyzed using finite element methods. The bridge is subjected to 1992 Erzincan earthquake ground motion components in nineteen directions whose values range between 0 to 90 degrees, with an increment of 5 degrees. The seismic weight is calculated using full dead load plus 30% of live load. The variation of maximum displacements in each directions and internal forces such as axial forces, shear forces and bending moments for bridge arch and deck are attained to determine the earthquake angle influence on the seismic performance. The results show that angle of seismic input motion considerably influences the response of the bridge. It is seen that maximum arch displacements are obtained at X, Y and Z direction for $0^{\circ}$, $65^{\circ}$ and $5^{\circ}$, respectively. The results are changed considerably with the different earthquake angle. The maximum differences are calculated as 57.06%, 114.4% and 55.71% for X, Y and Z directions, respectively. The maximum axial forces, shear forces and bending moments are obtained for bridge arch at $90^{\circ}$, $5^{\circ}$ and $0^{\circ}$, respectively. The maximum differences are calculated as 49.12%, 37.37% and 51.50%, respectively. The maximum shear forces and bending moments are obtained for bridge deck at $0^{\circ}$. The maximum differences are calculated as 49.67%, and 49.15%, respectively. It is seen from the study that the variation of earthquake angle effect the structural performance of highway bridges considerably. But, there is not any specific earthquake angle of incidence for each structures or members which increases the value of internal forces of all structural members together. Each member gets its maximum value of in a specific angle of incidence.

• 반도체디스플레이기술학회지
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• 제19권3호
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• pp.100-105
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• 2020

Recently, as display and semiconductor devices have been miniaturized and highly integrated, there is a demand for optimization of the structural characteristics of the thin film accordingly. The sputtering device has the advantage of stably obtaining a desired thin film depending on the material selected for the target. However, due to the structural characteristics of the sputtering equipment, the structural characteristics of the film may be different depending on the incidence angle of the sputtering target material to the substrate. In this study, the characteristics of the thin film material according to the scattering angle of the target material and the incidence position of the substrate were studied to find the optimization design rule of the sputtering equipment. To this end, a Si thin film of 1 ㎛ or less was deposited on the Si(100) substrate, and then the microstructure, reflectance, surface roughness, and thin film crystallinity of the thin film formed for each substrate location were investigated. As a result of the study, it was found that as the sputter scattering angle increased and the substrate incident angle decreased, the gap energy along with the surface structure of the thin film increased from 1.47 eV to 1.63 eV, gradually changing to a non-conductive tendency.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제35권6호
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• pp.420-425
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• 2009

Purpose: The aim of this study is to analyze the correlation between incidence of mandibular angle fracture and eruption state of mandibular third molar using clinical and radiographic findings. Materials and Methods: The data were obtained from the clinical and radiographic records of 205 patients who visited the Department of Oral and Maxillofacial Surgery, Chonbuk National University Hospital for treatment of the mandibular fracture. Panoramic radiographies were taken for radiographic examination and the mandibular third molars were classified according to age, gender, position and eruption state. Data were analyzed by a chi-square statistics. Results: In this study, the incidence of mandibular angle fracture had a tendency to be greater when a mandibular third molar was present(p>0.05), but there was not a statistically significant difference. Of the 255 cases with a mandibular third molar, 67 had an angle fractures. Of the 155 cases without a mandibular third molar, 138 had not angle fracture. And the incidence of mandibular angle fracture was high at class BII(by Pell & Gregory system)(p<0.05). Conclusion: Although there was not a statistically significant difference, mandibular third molar was more susceptible to mandibular angle fracture. When the reduction of mandibular angle fracture, it was recommended that mandibular third molar should be extracted especially in case of pericoronitis, periodontitis and other infections.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 1997년도 특별강연 및 추계학술발표 개요집
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• pp.265-268
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• 1997