• 비파괴검사학회지
• /
• 제33권2호
• /
• pp.154-159
• /
• 2013

본 논문은 마운트의 형상 정밀도와 볼트의 체결력에 따라 마운트에 고정되는 반사경에 발생되는 응력과 변형량에 대해 연구하였다. 일반적인 반사광학계에 사용되는 고정밀 반사경은 볼트나 접착제로 마운트에 조립되는데 이러한 경우 볼트의 체결력과 접착제의 접착력으로 인해 발생하는 장력이 반사경면을 뒤틀리게 한다. 또한 반사경과 마운트를 조립한 후 반사경에 접촉되는 마운트의 표면 형상 정밀도에 따라 반사경면이 뒤틀려서 형상 정밀도가 변한다. 본 논문에서는 유한요소법을 이용한 구조 해석을 통해 반사경과 접촉되는 마운트의 형상 정밀도와 볼트의 체결력에 의해 고정밀 반사경의 반사경면에 발생되는 응력분포와 뒤틀림 변형량에 대해 연구하였다.

• Journal of Information Display
• /
• 제9권1호
• /
• pp.26-32
• /
• 2008

The dependence of optical performances of collimating films such as prism films and pyramid films on the reflecting properties of reflection films were investigated by using a ray tracing technique. The angular distribution of the luminance and the on-axis luminance gain were obtained by using a simple backlight model composed of a reflection film, a virtual flat light source, and a collimating film. Three kinds of reflecting properties were used, which were a perfect Lambertian reflector, a perfect mirror reflector, and a reflector having both diffuse and specular properties. It was found that the on-axis luminance gain was the highest in the simulation where a mirror reflector was used, while the viewing angle was the widest where the Lambertian reflector was used. This result indicates that it is necessary to optimize the simulation condition such as the reflecting properties in order to predict the optical performances of collimating films accurately. Quantitative correlation between the optical characteristics of collimating films and the reflecting properties of reflection films can be used to improve simulation technique for the development and the optimization of collimating films for LCD backlight applications.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.662-667
• /
• 2007

The thermal performance comparisons of the dish solar collector system are numerically investigated with mirror arrays and receiver shapes. In order to compare the performances of the dish solar collector systems, six different mirror arrays and four different receiver shapes are considered and the radiative heat flux distribution on the inside of the receiver is analyzed. A parabolic-shaped perfect mirror of which diameter is 1.5 m is considered as a reference of the mirror arrays. Five different mirror arrays of twelve identical parabolic -shaped mirror facets of which diameter are 0.4 m are proposed in this study. Their reflecting areas, which are 1.5 $m^2$, are the same. Four different receiver shapes are a dome, a conical, a cylindrical and a unicorn type. The solar irradiation reflected by mirrors is traced using the Monte-Carlo method. In addition, the radiative properties of the mirror surface can vary the thermal performance of the dish solar collector system so that the effects of the surface reflectivity and the surface absorptivity are considered. Based on the calculation, the design information of dish solar collector system for producing the electric power can be obtained. The results show that the dome type has the best performance in receiver shapes and the 2AND4INLINE has the best performance in mirror arrays except the perfect mirror.

• 설비공학논문집
• /
• 제20권1호
• /
• pp.35-41
• /
• 2008

The radiative heat loss from a receiver of a dish solar collector is numerically investigated. The dish solar collector considered in this paper consists of a receiver and multi-faceted mirrors. In order to investigate the performance comparison of dish solar collectors, six different mirror arrays and four different receivers are considered. A parabolic- shaped perfect mirror of which diameter is 1.40 m is considered as the reference for the mirror arrays. The other mirror arrays which consist of twelve identical parabolic-shaped mirror facets of which diameter are 0.405 m are suggested for comparison. Their reflecting areas, which are 1.545 $m^{2}$, are the same. Four different receiver shapes are a conical, a dome, a cylindrical, and a unicorn type. The radiative properties of the mirror surfaces and the receiver surfaces may vary the thermal performance of the dish solar collector so that various surface properties are considered. In order to calculate the radiative heat loss in the receiver, two kinds of methods are used. The Net Radiation Method that is based on the radiation heat balance on the surface is used to calculate the radiation heat transfer rate from the inside surface of the receiver to the environment. The Monte-Carlo Method that is the statistical approach is adopted to predict the radiation heat transfer rate from the reflector to the receiver. The collector efficiency is defined as the results of the optical efficiency and the receiver efficiency. Based on the calculation, the unicorn type has the best performance in receiver shapes and the STAR has the best performance in mirror arrays except the perfect mirror.

• 한국전자통신학회논문지
• /
• 제15권1호
• /
• pp.93-100
• /
• 2020

본 논문에서는 다양한 헤어스타일을 머리에 비춰봄으로써 사용자가 시술 전 결과물을 미리 가늠하는 것을 돕는 스마트 미러를 구현하였다. 카메라를 사용해 실시간으로 얼굴을 촬영하고 얼굴임을 인식하면 저장된 헤어 이미지를 올려 가상 이미지를 제공한다. 또한 기존 스마트 미러가 갖는 문제점인 높은 제작비용을 라즈베리 파이, Open CV, 하프미러 필름을 사용해 절감했고 터치 제어로 다양한 기능수행 능력을 구현했다. 또한 날씨, 달력 및 시간 등의 정보도 제공하도록 설계하였다.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2005년도 춘계학술대회 논문집
• /
• pp.448-451
• /
• 2005

An aspheric mirror, which requires less than $\lambda/2\;(\lambda=632.8nm)$ of form error for the $\phi$ 200mm reference curved surface, has been manufactured with an ultra-precision turning machine. We have known through several tests that the deformation patterns of the reflecting surface is related with bolting positions. In this paper the effect of main factors on deformation of a reflector is studied with a FE code. The considered factors are angular velocity, natural frequencies for a mirror, temperature increment during machining. The obtained test results are similar to the deformation shape due to the assumed temperature increment.

• 한국태양에너지학회 논문집
• /
• 제22권2호
• /
• pp.49-59
• /
• 2002

Recently, due to high rise building by rapid urbanization, the spaces incapable of being penetrated by sunlight into interior is increasing. So, sunlighting systems are important means to be able to get sunlight into indoors and to make sure of sunshine awareness. This study aims to evaluate lighting performance of sunlighting mirror systems. As results. these are very useful for the increase of an average illuminance of indoors and the penetration of sunlight. Especially, the second reflecting mirrors can be applied to spaces lack of sunlight. And these sunlighting systems developed in the present study is validated physical and psychological performance to both building and people.

• 한국재료학회지
• /
• 제28권4호
• /
• pp.201-207
• /
• 2018

Infrared(IR) heating has many advantages, such as energy efficiency, reduced heating time, cleanliness, equipment compactness, high drying rate and easy automation. These features of IR heating provide widely industrial applications, such as surface heat treatment in semiconductor fabrication, thermoforming of polymers, drying and disinfection of food products, heating to metal forging, and drying of wet materials. In this study, the characteristics of a protected gold mirror were examined by spectrophotometer and the lifetime of the coating layers were evaluated by a cross-cutting method and salt spray test. The effects of manufacturing conditions on the protected gold mirror were seen and remedies for these effects were noted in order to improve the properties of the protected gold mirror in the drying process. The reflectance and lifetime of the protected gold mirror was influenced by manufacturing conditions, such as surface roughness and forming conditions of the anti-oxide layer, the adhesion layer, the reflecting layer and the protection layer. The results of this study showed that the protected gold mirror manufactured using a buffing method for pre-treatment resulted in the most effective reflectance. In addition, $Al_2O_3$ coating on an Al substrate as an anti-oxide layer was more effective than the anodizing process in the test of reflectance. Furthermore, the protected gold mirror manufactured by layers forming of various materials resulted in the most effective reflectance and lifetime when coated with $Al_2O_3$ as the anti-oxide layer, coated Cr as the adhesion layer, and coated $MgF_2$ as the protection layer.

• 한국터널지하공간학회 논문집
• /
• 제13권5호
• /
• pp.385-393
• /
• 2011

경제성장의 달성과 직선도로의 증가에 따라 터널은 전보다 더 많이 만들어졌다. 이러한 터널들의 입구 조명은 안전하고 편안한 운전을 위해 중요하다. 대부분의 터널 조명은 인공조명으로 많은 에너지를 사용한다. 본 연구에서는 터널의 조명 개선과 에너지 절약으로 반사거울 시스템을 적용하여 평가하였다. 반사거울 시스템을 적용하면 주광을 유입하여 터널 조명 환경을 개선할 수 있으며, 본 연구는 터널 인공조명 에너지의 절약을 위한 선행연구의 일환으로 진행되었다.

• 천문학회보
• /
• 제39권2호
• /
• pp.110.1-110.1
• /
• 2014

The optics of Space telescope is one of the major parts of space mission used for imaging observation of astronomical targets and the Earth. These kinds of space mission have a bulky and complex opto-mechanics with a long optical tube, but there are attempts have been made to observe a target with a small satellite in many ways. In this paper, we describe an optical design of a reflecting telescope for use in a CubeSat mission. For this design, we adopt the off-axis segmented method of astronomical observation techniques based on the Ritchey-Chr$\acute{e}$tien type telescope. The primary mirror shape is a rectangle with dimensions of $8cm{\times}8cm$, and a secondary mirror has dimensions of $2.4cm{\times}4.1cm$. The focal ratio is 3 which can obtain a $0.3{\times}0.2$ degree diagonal angle in a $1280{\times}800$ CMOS color image sensor with a pixel size of $3{\mu}m{\times}3{\mu}m$. This optical design can capture a ${\sim}4km{\times}{\sim}2.3km$ area of the earth's surface at 700 km altitude operation. Based on this conceptual design, we will keep trying to study more for astronomical observation with Attitude control system.