목적 : 현재 주목받고 있는 스마트 글라스와 같은 증강현실 기술은 배터리, 발열, 착용감 문제 등으로 사용자의 불편을 야기시킨다. 본 연구는 이러한 문제들을 해결하고 사용자 편의성을 극대화할 수 있는 새로운 NED 광학계 를 설계하고자 한다. 방법 : Waveguide 타입과 비구면 구성을 적용한 허상광학계로 NED 광학계를 설계하였다. Code V 소프트웨어 를 사용하였고, 경량화, 높은 시야각, 낮은 왜곡 수차 및 우수한 이미지 품질을 설계 목표로 하여 비순차 광학계를 구성하였다. 결과 : 설계된 광학계는 배율 증가, 포커싱, 수차 감소에 초점을 맞춘 첫 번째 파트와 빛의 손실을 최소화하는 Waveguide 타입의 두 번째 파트로 구성하여 고효율성과 높은 해상도를 나타내었다. 사용자에게 선명하고 편안한 시각적 경험을 보장하고, 컴팩트한 디자인으로 휴대성과 사용자 편의성이 동시에 고려된 광학계를 설계하였다. 결론 : 본 연구에서 개발된 Waveguide 타입과 비구면 광학계는 빛의 손실을 최소화하여 망막까지 효율적으로 전달함으로써 NED 기술의 성능을 크게 향상시켰다. 이는 사용자에게 더 높은 선명도와 생동감 있는 시각적 경험 을 제공하며, 향후 고해상도 광학 응용 분야에 큰 기여를 할 것으로 판단된다.

In this study, lanthanum boron silicate glasses were prepared with a composition of x Li2O-(60-x)B2O3-5CaO- 5BaO-7ZnO-10SiO2-10La2O3-3Y2O3 where x = 1,3,5,7, and 9 mol%. Each composition was melted in a platinum crucible under atmospheric conditions at 1,400 °C for 2 h. Clear glasses with a transmittance exceeding 85 % were fabricated. Their optical, thermal, and physical properties, such as refractive index, Abbe number, density, glass transition (Tg) and Knoop hardness were studied. The results demonstrated that refractive index was between 1.6859 and 1.6953 at 589.3 nm. The Abbe number was calculated using an equation for 589.3 nm (nd), 656.3 nm (nf) and 486.1 nm (nc) and was observed to be in the range from 57.5 to 62.6. As the Li2O content increased, the glass transition temperature of the optical glass decreased from 608 °C to 564 °C. If glass mold pressing is performed using a material with a low transition temperature and high mechanical strength, then the optical glasses developed in this study can be completely commercialized.

In this study, Barium Germanium glasses were prepared with a composition of xBaO-(72-x)GeO2-8La2O3-20ZnO where x = 16.0, 18.0, 20.0, 22.0 and 24.0 mol% respectively. Their physical and optical properties, such as refractiveness index, glass transition temperature (Tg), softening temperature (Ts), transmittance and Knoop hardness were studied. The results showed that refractive index, Tg, Ts and coefficient of thermal expansion (CTE) increased with increasing BaO concentration. The refractive index of all the prepared samples was observed between 1.7811 to 1.7881. The Abbe number was calculated by formula using nd (589.3 nm), nf (656.3 nm) and nc (486.1 nm) and observed to be between 38 to 40. The Abbe number of the prepared sample was similar to that of BaO and GeO2. The transmittance of the prepared glasses was observed to be between 80 ~ 82 % throughout the range from 200 nm to 800 nm. Knoop hardness divided into seven steps were measured 5 class (≥ 450 ~ < 550) of all prepared samples.

In this study, we tried to find out the most appropriate pre-processing method and to verify the feasibility of developing a low-price sensing system for predicting the hardy kiwis sugar content based on VNIRS and subsequent spectral analysis. A total of 495 hardy kiwi samples were collected from three farms in Muju, Jeollabukdo, South Korea. The samples were scanned with a spectrophotometer in the range of 730-2300 nm with 1 nm spectral sampling interval. The measured data were arbitrarily separated into calibration and validation data for sugar content prediction. Partial least squares (PLS) regression was performed using various combinations of pre-processing methods. When the latent variable (LV) was 8 with the pre-processing combination of standard normal variate (SNV) and orthogonal signal correction (OSC), the highest R2 values of calibration and validation were 0.78 and 0.84, respectively. The possibility of predicting the sugar content of hardy kiwi was also examined at spectral sampling intervals of 6 and 10 nm in the narrower spectral range from 730 nm to 1200 nm for a low-price optical sensing system. The prediction performance had promising results with R2 values of 0.84 and 0.80 for 6 and 10 nm, respectively. Future studies will aim to develop a low-price optical sensing system with a combination of optical components such as photodiodes, light-emitting diodes (LEDs) and/or lamps, and to locate a more reliable prediction model by including meteorological data, soil data, and different varieties of hardy kiwi plants.

We give a detailed description of the installation and operation of a double-station meteor detection system which formed part of a research & education project between Korea Astronomy Space Science Institute (KASI) and Daejeon Science Highschool. A similar system is currently not existing in South Korea. A total of six light-sensitive CCD cameras were installed with three cameras at SOAO and three cameras at BOAO observatory. A double-station observation of a meteor event enables the determination of the three-dimensional heliocentric orbit in space. This project was initiated in response to the Jinju reball event in March 2014. The cameras were installed in October/November 2014. The two stations are identical in hardware as well as software. Each station employes sensitive \Watec-902H2" cameras in combination with relatively fast f/1.2 lenses. Various elds of views were used for measuring dierences in detection rates of meteor events. We employed the SonotaCo UFO software suite for meteor detection and their subsequent analysis. The system setup as well as installation/operation experience is described and rst results are presented. We also give a brief overview of historic as well as recent meteor (fall) detections in South Korea. For more information please consult http://meteor.kasi.re.kr.

In order to guarantee reliability of the environmental testing on defense systems, it is important to use test equipment that meets requirements of the related test standards. Especially with regard to the rain test method in MIL-STD-810G w/change 1, the latest standard, it has been highly needed to introduce a novel technique and system to provide droplet-size and precipitation-rate conditions. In this study, droplet-diameter spectra of various nozzles were measured by a high-speed camera. Then, a pair of nozzles were selected based on the experimental results showing the spectra lie within the range from 0.5 mm to 4.5 mm, as suggested in the rain test method. Also, the flow-precipitation rate calibration system was developed to precisely correlate the precipitation rate measured in the chamber and the flow rate into the nozzle bank. In conclusion, the rain test equipment has been successfully developed fulfilling the requirements of the test standard.

목 적: 기존의 콘택트렌즈 분석기에서 1매의 렌즈를 삭제하여 시스템을 간소화하고, 수차를 감소시켜 콘택트렌즈 표면의 선명한 상을 얻는 저가격 고성능의 광학계를 최적화 설계하였다. 방 법: 기존의 콘택트렌즈 분석기의 광학적 성능 분석과 최적화 설계에 사용한 파장은 프라운호퍼 C, d, F선(0.656 ㎛, 0.587 ㎛, 0.486 ㎛)이며 기준파장은 d선으로 하였다. Full field는 object height를 5 mm로 설정하였다. 참고모델의 광학적 성능 분석과 분석기의 최적화 설계에는 Zemax 14.2 설계 프로그램을 사용하였다. 결 과: 최적화 설계한 콘택트렌즈 분석기는 기존의 콘택트렌즈 분석기보다 Spot diagram RMS radius는 42.51% 성능이 향상되었다. 상질에 영향을 주는 구면수차는 96.96%, 비점수차는 68.39%, 종 방향 색수차는 39.29%, 횡 방향 색수차는 95.97% 향상되었고, 상면만곡과 왜곡수차는 각각 82.09%와 66.05%로 수차 성능이 향상되었다. 결 론: 기존의 콘택트렌즈 분석기보다 적은 수차와 적은 렌즈 매수를 갖는 새로운 광학계를 설계하였다. 설계한 콘택트렌즈 분석기는 저가격, 고성능의 성능 최적화가 이루어졌다고 볼 수 있다.

ZnO nanoparticles in the size range from 5 to 15 nm were prepared by zinc-lithium-acetate system. The morphologies and structures of ZnO were characterized by TEM, XRD and FT-IR spectra. UV-visible results shows that the absorption of ZnO nanoparticles is blue shifted with decrease in particles size. Furthermore, photoluminescence spectra of the ZnO nanoparticles were also investigated. The ZnO nanoparticles have strong visible-emission intensity and their intensities depend upon size of ZnO nanoparticles.

목적: 백내장환자를 대상으로 비구면 단초점 인공수정체 삽입 후 시력과 시기능 변화를 분석하였다. 방법: 단안 또는 양안에 HOYA PC-60AD 비구면 단초점 인공수정체를 삽입한 백내장 환자 25명의 30안을 대상으로 수술 전, 수술 후 1일, 1주일, 1개월 및 3개월 후에 원거리 시력과 객관적인 시기능을 평가하고, 수술 3개월 후 인공수정체 삽입안의 시기능을 40대 이상의 정상안 18명(36안)과 비교하였다. 객관적인 시기능은 원거리 시력과 OQAS 장비를 이용하여 4 mm 동공크기에서 측정된 객관적 산란지수(objective scatter index, OSI), 변조전달함수(modulation transfer function, MTF) 및 Strehl ratio를 측정하여 평가하였다. 통계분석은 SPSS ver. 18.0로 대응표본 T 검정과 선형 회귀분석을 이용하여 비교하였고 유의수준은 p