• 분석과학
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• 제30권4호
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• pp.159-166
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• 2017

Exposure to UV light, i.e., UV-A (320-400 nm) or UV-B (290-320 nm) radiation, can cause skin cancer. Titanium dioxide ($TiO_2$) effectively disperses UV light. Therefore, it is used as a physical UV filter in many UV light blockers. Usually, the $TiO_2$ content in commercialized UV blockers is 25 % at most. To block UV-B, a chemical UV blocker, octyl-methoxy cinnamate (OMC) is used. OMC is commonly used in combination with $TiO_2$. In this study, $TiO_2$ and OMC were mixed in different proportions to produce UV blockers with different compositions. Also the changes in the sun protection factor (SPF) based on the composition and $TiO_2$ particle sizes were investigated. In order to analyze the $TiO_2$ particle size, dynamic light scattering (DLS) and asymmetrical flow field-flow fractionation (AsFlFFF) were used. The results showed that the SPF was influenced by the proportion of $TiO_2$ and OMC, where the proportion of $TiO_2$ induced a more significant influence. In addition, changes in the $TiO_2$ particle size based on the proportion of OMC were observed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.319-320
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• 2006

In this paper, automatic sunvisor system is introduced for driver's safety and convenience. This system has the mechanism which keeps the sun off without obstruction of driver's sight. The mechanism can make the sunvisor move forward or rotate left while remaining inside inner roof. The control system consists of a CPU, a motor driver, light sensors, and the algorithm that can control the movement of sunvisor efficiently. When the light sensors take the sun light, they give the signal to the CPU and the CPU calculates the best position of the sunvisor with the information of driver's eyes height. Then, the CPU gives the signal to motors that can move the sunvisor.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2005년도 추계학술발표대회 논문집
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• pp.151-154
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• 2005

These days we are more interested in the space of architecture that how the change is likely to affect and how to be realized human. Human beings are recognizable the space and the creation of the space is eventually effected through human beings being perceptible the space of architecture and the equivalence of the space. That is the light, one of phenomenological elements, has been the first visual experience at birth. This study will concentrate on the importance of the phenomenological light especially indoors and study how architectural elements influence human beings with the light as one of the basic design factors for human life. That is exactly purpose of this research paper and this paper can make our lives worth living significant with the actively various uses inside spaces through the phenomenological light as a natural light in our human beings.

• 대한가정학회지
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• 제20권1호
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• pp.1-10
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• 1982

This experiment was made on the basis of the general observation that silk fabrics is flaccid in sun light. The purpose of this test is to examine efficiency between the processed thread and the unprocessed one after putting the later under the xenon-lit system, which produces continuous spectrum of bright white beam similar to sun light. (i) Color division of silk thread : white, yellow blue (ii) light division and irradiation time : sun lightlongrightarrow210 hrs, Xenonlongrightarrow50,100, 150 hrs. Under the above conditions each object was be tested with and extensometer, TENSILON Type III for the results of (a) the weight-expansibility curve of the silk thread (b) the relationship between cutting in tensity and maximum, weight (c) maximum expansion rate (d) the expansion energy of the tested silk thread (e) the beginning pull-stretch resistance rate of the tested silk thread (f) color difference after processing The results are illustrated in the appropriate tables and figures. Consequently the generalobservation that silk fabrics is flaccid is relevant only in terms of color. So for as Cutting-intensaty is concerned, it turned out to be less flaccid than in color. On the contrary when the untested silk thread was conpared with the xenon-irradiated ones, the latter proved itself to be more flaccid in cutting expansibility than the former. We have learned through this experiment that, after the all rounds of this test, the color tone and chroma of the colored materials remained without significant change, where as their color value changed to a large extent.

• 한국실내디자인학회논문집
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• 제22권6호
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• pp.251-258
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• 2013

Space and figure are formed not by themselves but by the existence of light. It is important that plays a role as an intermediary of cognition which enables the formation of space and figure through Human's recognition in the process of design. Human perceive space and identity every basic form by the contrast of light and dark. The existence of light is very inclusive concept in the space, so space and form are completed by light. The change of based on time, place, and its amount acts as an important element Which can change the form of Space. In Space light doesn't work simply as light itself, but have a very close relation with Space, Form, Structure, Material, Color elements, Space is limited by physical form but human perceive space relatively by many other conditions, So same space can be experienced differently by the characters of light. Human can recognized and observe an object in the space as he processes information collected through light. In this process light make it possible for human to see the shape in space. therefore, the shape of space can get meanings when light exists. the space recognized by light is the mean that activates human activates in space.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.49.4-50
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• 2009

We report stray light modeling and analysis results for the current and proposed next generation ocean color imagers with Sun and the target area around Korean penninsular as viewed from geostationary orbit. The imagers used in this study are GOCI of 140mm in diameter and a proposed next generation GOCI (GOCI-II) of about 300mm in diameter. First, we built complete GOCI and GOCI-II 3D optical system models with the realistic surface characteristics. These optical models were incorporated into the in-house built Intergrated Ray Tracing (IRT) algorithm, connecting the Sun, the measurement target area and the instruments via single ray tracing computation for radiative transfer and scattering. The stray light level was then estimated for possible orbital configurations for science measurement and in-orbit calibration operation. The simulation details, results and their implications are presented.

• 한국항공우주학회지
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• 제49권3호
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• pp.243-249
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• 2021

별추적기는 우주공간에서 미세한 별 빛을 감지한 후 저장된 별 목록과 비교하여 관성좌표계상에서 위성의 자세 정보를 제공한다. 별 이외에 태양이나 지구와 같은 다른 빛이 광학계(OH : Optical Head)로 들어가게 될 경우 별을 인식할 수 없음으로 별추적기를 운영할 수 없다. 특히, 태양과 같은 강한 빛이 들어올 경우 별추적기 운영뿐 아니라 성능에도 영향을 미친다. 별추적기의 태양 차폐각(SEA : Sun Exclusion Angle)은 별추적기의 성능을 결정하는 중요한 요소 중 하나이다. 본 논문에서는 별추적기의 태양 차폐각에 대한 검증을 수행하였다. 태양 차폐각 검증을 위해서 별추적기의 태양 차폐 시간을 예측하였으며 실제 천리안 2A호 별 추적기에서 발생한 태양 차폐 시간과 비교하였다. 또한, 광학계에 태양에 의한 차폐가 발생할 경우 별추적기가 정상적으로 동작하는지에 대한 분석을 수행하였다. 분석 결과 별추적기는 성능 요구사항인 26° 이내에서 태양 차폐가 발생하였으며 태양 차폐가 발생할 경우에도 정상 동작함을 확인하였다.

• 임산에너지
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• 제22권3호
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• pp.20-28
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• 2003

참나무류 주요 수종을 대상으로 다양한 광선 조건에 식재된 실생묘의 활착 및 상대생장량과 광선에 대하여 민감하게 작용하는 엽록소 함량의 계절적인 변화를 조사하기 위하여 상수리나무 1-1묘, 1-0묘, 신갈나무 1-0묘, 졸참나무 1-0묘, 굴찬나무 1-0묘를 상수리나무 임분내에 상층임분 밀도를 자연광의 81%, 34%, 21% 등 3가지로 조절하였다. 조사대상 수종의 묘목을 20m x l0m 크기의 시험구에 100본씩 식재하여 활착율, 상대생장량, 엽록소 함량을 비교하였다. 상수리나무 1-1묘가 평균 73%로 다른 수i종에 비해 높은 활착율을 보였고, 상수리나무 1-0묘가 66%, 신갈나무와 졸참나무가 각각 56%, 45%였으며, 굴참나무는 41%로 이식후 활착율이 가장 낮게 나타났다. 또한 자연광의 81% 실험구에서 대부분의 주요 참나무류 수고, 근원경 생장이 가장 좋은 경향을 보여 주고 있었으며 자연광의 21% 실험구에서는 오히려 광도가 낮아지면서 생장이 상대적으로 저해되는 경향을 보여 주고 있다. 엽록소 함령(a, b, 총엽록소 함향)은 광도가 낮아지면서 엽록소 함량도 낮아지는 것을 알 수 있었다. 그러나 주요 참나무류 수종의 피음 효과에 대한 생장반응은 지속적으로 관찰해야 하며, 엽록소 함량과 생장에 밀접한 관련이 있는 생리적 특성에 대한 연구도 필요할 것으로 생각된다.

• Journal of the Optical Society of Korea
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• 제19권4호
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• pp.421-426
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• 2015

This paper presents a hybrid single optical system for an LED surgical light that combines the advantages of both lens- and reflector-type single optical systems. The proposed hybrid single optical system includes a lens in the center and the LED light originating from the lens is redirected using a reflector to achieve a high beam spread. Iterative optical software simulations are used to provide data for the design of the lens and reflector for a single optical system, and for a complex optical system for the LED light assembly. The resulting data is also used to fabricate a prototype system. Experiments using the prototype of the hybrid single optical system and a mock-up LED surgical light confirm the system's shadow dilution performance and its applicability to surgical operations.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2013년도 추계학술발표대회
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• pp.290-293
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• 2013

본 연구에서는 최근 각광받고 있는 융합기술 중의 하나인 가시광 통신 기술을 개발하고 실제 시제품을 구현하기 위한 시스템 기술에 대해서 기술한다. 전 세계적으로 LED조명 시장이 급성장하고 있고 또한 이를 활용한 가시광통신(visible light communication:VLC) 기술이 화두가 되고 있다. 이에 따라서 본 논문에서는 현재 개발중인 LED기반 VLC 시스템 기술을 송신 및 수신 모듈로 분류하고 개별 모둘에 대한 구체적인 개발 시스템에 대해서 소자 및 주요 부품의 특성을 기반으로 제시한다. 또한 실제 개발된 시스템을 통해 약 0.5m 거리에서 약 12Mbps의 데이터 전송이 가능함을 보인다. 개발된 기술은 가정 내 또는 실내 주차장 등과 같이 실내 측위 또는 데이터 서비스 등에서 중요한 역할을 할 것으로 기대된다.