• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.1341-1344
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• 2009

A novel method to control the viewing direction by moving aperture location in 4-f illumination optics to control light direction is proposed. Based on integral imaging principle, the relayed point light sources by 4-f optics are modulated by a spatial light modulator, displaying three-dimensional images. In the proposed method, we locate the aperture, which acts as a band pass filter, around an optic axis to control the light direction. Resultantly, assuming that we know the viewer position by a tracking system, we can display appropriate three-dimensional images over large viewing angle.

• 대한치과교정학회지
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• 제34권5호
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• pp.429-438
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• 2004

본 연구는 Plasma arc light를 이용하여 금속 브라켓의 부착시 광조사 방향, 중합시간 그리고 경화시간이 전단결합강도에 미치는 영향을 평가하기 위해서 시행되었다. 240개의 발거된 소구츠를 16군으로 나눈 후. 광중합기(Plasma arc light와 Halogen light), 중합시간(Plasma arc light 2. 4. 6초와 Halogen light 20초). 그리고 광조사 방향(Vertical 방향과 Oblique 방향)을 다르게 하여 브라켓을 부착하였다. 광증합 접착제는 Transbond XT를 이용하였으며 브라켓 부착 후 5분과 24시간 후에 만능물성시험기를 이용하여 전단결합강도를 측정하였다. 결과는 다음과 같다. 광중합기의 종류와 중합시간에 관계없이 Vertical군과 Oblique군간의 전단결합강도는 유의한 차이가 없었다.(p>0.05) Plasma arc light를 이용하여 2초 동안 광중합한 군들의 전단결합강도는 다른 중합시간의 군들보다 현저히 낮았다(P<0.05). 부착 5분 후의 전단결합강도는 24시간 후보다 현저히 낮았다(P<005), ARI 점수는 군들 간에 통계적으로 유의한 차이가 없었다. 이상의 결과는 plasma arc light를 사용한 금속 브라켓의 부착시 광조사 방향은 전단결합강도에 영향을 끼치지 않으며. Halogen light와 유사한 결합강도를 얻기 위해서는 4초 이상의 중합시간이 필요함을 시사한다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.17-18
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• 2018

With the technological advancement of the construction industry, construction materials with future direction appeared. In Korea, LEFC(Light Emotion Friendly Concrete) has been developed and studied, which has improved labor productivity and economic efficiency over semi-transparent concrete by introducing transparent plastic rods into concrete matrix. However, there is a problem in that the bending performance is lowered according to the insertion of the rod and the bending performance is different according to the light transmission direction. In this study, the incorporation of PVA fibers in the direction of light transmission was increased and the change of flexural performance according to the interval of light transmission was examined.

• 한국화재소방학회논문지
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• 제33권6호
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• pp.28-34
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• 2019

본 연구는 공간의 형태와 출입문의 개폐방향, 유도등 픽토그램의 형상에 따라 재실자(피실험자)들의 경로선택에 어떤 영향을 미치는지를 살펴보기 위한 것으로 컴퓨터 가상현실을 활용한 시뮬레이션 실험을 통해 수행하였다. T형 복도와 +형 복도를 대상으로 하여 시나리오별로 피난구유도등, 복도통로유도등을 배치하고 이를 컴퓨터 그래픽화하여 시뮬레이션을 수행하였다. 피난구유도등 픽토그램의 2가지 방향(좌, 우)에 대한 인간 행동의 반응(응답)과 출입구의 열리는 방향에 따른 영향 등을 분석하였다. 또한 통로유도등의 존재 유무에 따른 의사결정의 변화 등을 확인하였다. 실험결과, 방향선택 응답률을 살펴보면 첫째, T자형 복도에서 출입문에 유도등이 없을 경우, 출입문이 열리는 방향에 의해 영향을 받음을 알 수 있었다. 둘째, 출입문 상단에 유도등이 있을 경우에는 유도등 픽토그램의 방향과 일치하는 방향의 응답률이 높게 나타나 유도등의 픽토그램의 방향이 재실자의 피난경로선택에 영향을 미침을 확인하였다.

• Design & Manufacturing
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• 제17권2호
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• pp.22-26
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• 2023

As Light-Emitting Diodes(LEDs) continue to advance in performance, their application in automotive lamps is increasing. Automotive LEDs utilize light guides not only for aesthetics but also to control light quantity and direction. Light guides employ patterns of a few hundred micrometers(㎛) to regulate the light, and the surface roughness(Ra) of these patterns can reach tens of nanometers(nm). Given that these light guides are produced through injection molding, mold processing technology with high surface quality micro-patterns is required. This study serves as a preliminary investigation into the development of high surface quality micro-pattern processing technology. It examines the surface roughness of the workpiece based on the cutting direction of the pattern and the cutting fluid type when cutting micro-patterns on STAVAX steel using cubic Boron Nitride(cBN) tools. The experiments involved machining a step-shaped micro-pattern with a height of 60 ㎛ and a pitch of 400 ㎛ in a 22×22 mm area under identical cutting conditions, with only the cutting direction and cutting fluid type being varied. The machining results of four cases were compared, encompassing two cases of cutting direction(parallel to the pattern, orthogonal to the pattern) and two cases of cutting fluid type (flood, mist). Consequently, the Ra value was found to be the highest(Ra 128.33 nm) when machining with the flood type in parallel to the pattern, while it was the lowest(Ra 95.22 nm) when machining with the mist type orthogonal to the pattern. These findings confirm that there is a difference of up to 25.8 % in the Ra value depending on the cutting direction and cutting fluid type.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.429-429
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• 2007

In this study, it was investigated about the variation of luminance properties in LED backlight with geometrical shape such as prism or lens shape on the light-entering face. Generally, LED light source has the loss in backlight system because it has horizontal direction light. PMMA(Poly-Methyl-Meta-Acrylate) is used LGP(Light-Guide-Plate) in conventional backlight system. PMMA has low refraction angle. so that. horizontal direction light was not used in backlight system. The addition of geometrical shape in light-entering face in LGP improves the luminance characteristics because it prevents horizontal direction light generation in light-entering-face. Prism or lens shape in same pitch disposition was almost same without these treatment such as the value of 1% rising. Besides. It is particular that the gap of these shape such as the value of 0.407~0.22mm prevents horizontal direction light, so then it contributes luminance rising at 5.6%.

• 한국지진공학회논문집
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• 제26권6호
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• pp.219-226
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• 2022

The seismic responses of traffic light poles are investigated using a finite element analysis. Among the traffic light poles, single- and bi-directional traffic light poles are considered since such poles are frequently installed on vehicle roads. For a more detailed investigation, three different lengths of the mast arm are considered for each directional pole. For a time-history analysis, six actual and two artificial earthquakes are considered and applied to each direction of the poles (x and y) to investigate which direction input provides more significant responses due to the unsymmetrical structural shape. Herein, the x and y directions are respectively parallel and perpendicular based on the single mast pole case. From the analysis results, the average maximum displacement response is developed with the x-direction input case for both types of light poles. Also, the bi-directional traffic light poles show a 13% larger response than the single-directional traffic light poles. Even though the y-direction input case produces a smaller response, the response difference between the single- and bi-directional light poles considerably increases by about 60%. The average maximum acceleration responses are almost similar for both types of light poles.

• International Journal of Internet, Broadcasting and Communication
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• 제10권4호
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• pp.70-74
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• 2018

In order to ensure the flow of goods available and more flexible, reduce labor costs, many factories and industrial zones around the world are gradually moving to use automated solutions. One of them is to use Automated guided vehicles (AGV). Currently, there are a line tracing method as an AGV operating method, and a method of estimating the current position of the AGV and matching with a factory map and knowing the moving direction of the AGV. In this paper, we propose ceiling Light and guided line based moving direction estimation algorithm using multi-camera on the AGV in smart factory that can operate stable AGV by compensating the disadvantages of existing AGV operation method. The proposed algorithm is able to estimate its position and direction using a general - purpose camera instead of a sensor. Based on this, it can correct its movement error and estimate its own movement path.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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• pp.59-62
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• 1994

Tact Electrical conductivity. optical absorption spectra of poly(p-phenylene vinylene) and their dependence on stretching are discussed in detail. The conductivity in the parallel direction to the stretching is higher over one order in magnitude than that in the perpendicular direction to the stretching is higher over one order in magnitude than that in the perpendicular direction to the stretching. The photocurrent spectrum for the ligh polarized parallel to the chain direction is much enhanced in lower photon energy compared with that for the light polarized perpendicular to that direction. The result may be originated in the difference of energies which is needed to photogenerate carriers wi th the light polarized parallel and perpendicular to the chain stretched direction.

• Fibers and Polymers
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• 제1권1호
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• pp.25-31
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• 2000

Poly(3-hexyl thiophene)(P3HT) and poly(3-dodecyl thiophene)(P3DT) were polymerized by oxidative coupling with ferric chloride. The P3HT light-emitting device emitted red light and it could be observable in the ordinary indoor light. The device had the turn-on electric field of about 3$\times$$10^7$ V/m. The maximum electroluminescene (EL) intensity was obtained when the thickness of polymer layer was about 130 nm in IT0/P3HT/Al device. The maximum external quantum yield was 0.002%. The maximum luminance was 21 cd/$m^2$. The EL intensity decreases with increasing the crystallinity of the polymer layer. By using the oriented poly(3-alkyl thiophene)(PAT) layer as an electroluminescent layer in the ITO/polymer/Al light-emitting devices, the polarized EL light emission was observed. The EL intensity ratio of parallel to perpendicular direction to the stretch direction for P3HT was about 1.40.