• 한국기계가공학회지
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• 제6권1호
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• pp.7-12
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• 2007

The optic industry is a high value-added advanced technology industry combined with the precision machine industry and the digital electronics industry. The aspheric lens, one of optic parts, is a key technology having a significant influence on the performance of optic equipment. So this study relates to designing an aspheric lens to which a ray-tracing method is applied. In the ray-tracing method, a refractive index of material is used, which take an advantage that the location of a light source and incident angle can be fixed, unlike the ray back-tracing scheme.

• 한국안광학회지
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• 제3권1호
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• pp.263-267
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• 1998

Today's diopter of optical lens can reveal the derivation apparently compared with that of refraction measure lens. First, this is applicable when there is a difference in the shape and thickness basically and when the lens is used for a short distance. When measure and use it, an astigmatic difference is occurred by the discordant light passage. This is also applicable to optical lens with prism diopter lens and in some cases, must be corrected relating to the diopter incidently.

• 통합자연과학논문집
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• 제2권1호
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• pp.45-49
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• 2009

Electrochemical etching of heavily doped p-type silicon wafers (boron doped, <100> orientation, resistivity; $0.8-1.2m{\Omega}/cm$) with different current density resulting two different refractive indices resulted in DBR (Distributed Bragg Reflectors) porous silicon, which exhibited strong in-plane anisotropy of refractive index (birefringence). Dielectric stacks of birefringent porous silicon acting as distributed Bragg reflectors have two distinct reflection bands depending on the polarization of the incident linearly polarized light. This effect is caused by a three-dimensional (in plane and in depth) variation of the refraction index. Optical characteristics of DBR porous silicon were investigated.

• 한국광학회:학술대회논문집
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• 한국광학회 2008년도 동계학술발표회 논문집
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• pp.141-142
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• 2008

In order to develop a simple ray tracing model for simulating the radiation pattern of a LED, the propagation of a ray within the LED capsule was systematically evaluated by considering refraction and reflection from the capsule-air interface, multiple reflection within the capsule, and total internal reflection at the boundary. It was found that concentric ring shapes on the radiation pattern was formed by the rays multiple-reflected from the capsule surface, and that the strength of these rays were decreased rapidly as the number of multiple reflection is increased.

• 대한전자공학회논문지
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• 제19권5호
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• pp.5-11
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• 1982

슬라이드 글라스와 위에 1μm 가량의 산화막을 입힌 실리콘 웨이퍼 위에, 폴리우레탄이나 에폭시 등의 유기 물질을 스핀너 (spinner)로 코우팅시켜서 평판형 유전체 도파관(dielectric slab waveguide)을 제작하고, 프리즘으로 빛을 커플링 (coupling) 시켜서 광도파 현상을 화인했다. 실리콘 웨이퍼나 슬라이드 글라스 위에다 알루미늄이나 은(Ag)을 진공증착시킨 것을 기관으로 사용하여 금각판 도파관(metal clad waveguide)을 제작하고, 프리즘 2개로 커플링 (coupling), 디커플링 (decoupling)시켜서 모우드 라인(mode line)을 관찰했다. 포토리지스트 K. P. R.의 굴절율이 폴리우레탄의 굴절율보다 큰 점을 이용하여 2층 구조의 박막 프리즘을 제작하고 빛이 꺾이는 현상을 확인했다.

• 한국임상보건과학회지
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• 제4권2호
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• pp.550-555
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• 2016

Purpose. We compared with the refracting power and aberration according to the measurement change in illumination and the pupils area by using the auto refraction instruments. Methods. In this study it were examined 64 eyes without eye disease, 21.4 (${\pm}2.54$) age, 32 (male 10, female 22) patients. Experiments in general illumination using the auto refraction instruments (HRK-8000A, Huvitz, Korea) was measured in both eyes 3 times and after scotopic for 30 minutes in a dark room blocked the light was measured in the same way. Aberration were measured coma, spherical aberration, high and low order aberrations in a general illumination (3500 lux) and low illumination (5 lux) of the pupil area 3.96 mm and 5.96 mm. Results. In the general illumination for measuring of the pupil area, the refractive power, coma, spherical aberration and low order aberration was no significant difference. In the low illumination, spherical aberration of the pupil area was $0.005({\pm}0.015){\mu}m$ in a 3.96mm, $0.014({\pm}0.020){\mu}m$ in a 5.96 mm and appeared a significant difference(p = 0.003). In general and low illumination on the results of comparing the measured values of the refractive power and aberration at the pupil area 3.96 mm, high order aberrations was $0.205({\pm}0.145){\mu}m$ in general illumination, $0.132({\pm}0.075){\mu}m$ in low illumination and appeared a significant differences(p = 0.001). High order aberrations at the pupil area 5.96 mm was $0.278({\pm}0.244){\mu}m$ in general illumination, $0.150({\pm}0.092){\mu}m$ in low illumination and appeared a significant differences(p = 0.000). Conclusions. When the eye refractive power measured by the automatic refraction does not depend on the illumination conditions and size of the observation pupil area, it was found that aberrations are affected by the illumination and the observation pupil area. It was found that the eye examination chamber illumination to obtain accurate measurement produces better results to decrease than to increase.

• 한국염색가공학회지
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• 제3권3호
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• pp.57-68
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• 1991

Color vision 현상은 대상물질에 의해서 투과(transmission), 굴절(refraction), 반사(reflection)되어 나오는 광(light)이 망막(retina)에 비칠 때 시신경을 자극하여 뇌에 전달됨으로써 일어나는 하나의 감각현상(sensation)이다. 그러므로 그것은 인간의 감각상태, 광의 종류, 대상물질의 환경조건에 따라서, 즉 시각이 이루어진 그 순간에 인간의 눈이 어떻게 작용 하느냐에 달려있는 복잡한 현상 이다. 그래서 지금까지 발표된 20여개의 색채공간 중 그 어느 것도 인간의 감각량을 똑같이 표현할 수 없었던 것은 사실이다. 모든 자연현상이 그렇듯 인간도 개체마다 모두 다르고 대상물질 및 광에 관련된 너무 많은 요소(Factor)가 색지각 현상에 작용하기 때문에 이의 과학적 표현을 위해서는 단순화 및 normalization의 과정을 거치지 않으면 안되었던 것 같다. 지금까지 발표된 20여개의 color space중, perceptibility에 근거를 둔 유일한 color space인, Munsell color space의 해석에 Spline method 같은 수치 해석적 방법을 쓰지 않으면 안되는 그 이유를 제시하려 한다.

• 한국안광학회지
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• 제4권2호
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• pp.129-133
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• 1999

굴절이상인 근시안의 종류별 분포는 전체 대상자 100명 중 단순근시 50%, 근시성 복난시 16%, 근시성 단난시 15%, 혼합난시 19%의 순으로 나타났다. 양안 굴절이상인 근시의 분포는 -0.50~-2.00Dptr가 전체 대상자중 35%, -2.00~-6.00Dptr가 54%, -6.00Dptr이상이 11%로 나타났다. 연령별 근시성 굴절이상의 분포는 15세~20세가 54%, 21세~40세가 22%, 41~60세다. 16%, 61 세 이상이 10%였다. 근시성 굴절이상도의 직업분포는 학생(중, 고, 대학)이 61.5%, 사무직 13.5%, 주부 및 상업이 15%로 분포되어 나타났다. 하루중 굴절이상에 영향을 많이 미치는 시각때는 저녁인 오후 7시 이후가 45%로 가장 높게 나타났다. 그 이유는 오전에는 각막이 평평해져서 근시도가 줄어들고 오후에는 그 반대가 되어 Sph -0.50D의 차이가 나기 때문이며, 어두워질수록 동공이 확대되면서 각막이 주변부에서 굴절되는 빛의 굴절도가 큰 것이 이유가 된다. 계절별로는 땀의 배출로 인한 인체에서의 영양섭취와 배출의 부족함으로 인한 여름이 근시도수를 증가시켜 68%로 나타났다. 혈액형 별로는 A형과 B형이 34%로 비슷하게 분포되었으며, 남성은 활동적인 O형이 여성에 비해 근시도수가 높게 측정되었다.

• Journal of Periodontal and Implant Science
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• 제27권3호
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• pp.575-584
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• 1997

The quality of periodontal instrument cutting edge is a basic element of effective root planing procedure. Using instruments, the sharp edge is changed into blunt or beveled edge. With the blunt instrument, the periodontal treatment can't be carried into accuracy and effective. The study on the wear of periodontal curet is insufficient, there are few publications about the change of sharpness of cutting egde after using instrument and a certen reports were published on the study of scanning electron microscope(SEM) examination. In this study, to declare the number of strokes for sharpening of instruments, the changes of cutting edge is measured by the clinical methods, tactile sensitivity examination and refraction light-white line test after scaling strokes and root planing strokes. SEM test was added for defined the changes of cutting edges. The 7/8 Gracey curets that have been never used was tested. Maxillary molars which were extracted from the School of Dental Medicine, Dankook University was used. Subjected teeth had attachment loss more than 6 mm in bucca-lingual surface and sufficient calculus of a band type in cervical area. The strokes of curet were executed 3, 5, 7, 9, 11, 13 times on scaling stroke and 10, 15, 20, 25, 30, 35 times on root planing stroke. A resident has periodontal experience over 3 years carried out the clinical examinations those tactile sensitivity examination and refraction light-white line test 5 times. The case there being tactile sensitivity certenly is 2, the case being felt tactile sensitivity is 1, and the case there not being tactile sensitivity is 0. The visual examination was recorded as following. The case that refracted white line is not recognised is 2, the case that uncerten is 1, and the case that acknowledged is 0. The results were obtained as follows. 1. After scaling strokes, the tactile sensitivity was reduced after 11 strokes and disappeared in 13 strokes. 2. In tactile sensitivity after root planing procedures, sensitivity was reduced after 25 strokes and disappeared in 35 strokes. 3. In case of visual examination, the detection of refracted white line was increased after 9 strokes of scaling procedures and the accuracy of wear wasn't showed after root planing procedures. 4. In SEM, metal projection was observed on new periodontal curet cutting edge and it was disappeared after scaling procedures. 5. In SEM, the cutting edge was showed changing linear into an aspect of the surface after 5 strokes of scaling procedures and 10 strokes of root planing procedures and showed beveled edge in 11 strokes of scaling procedures, 25 strokes of root planing procedures. The results of 3-type examination indicated that the sharpening of curet should be performed after 11 strokes of scaling procedures and 25 strokes of root planing procedures.

• 대한기계학회논문집A
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• 제36권1호
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• pp.9-16
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• 2012

최근 태양광발전 시스템에서 태양광을 집광하는 광학기술이 접목된 집광기가 대두되고 있다. 본 연구에서는 광도파로 원리를 기반으로 한, 간단하면서 생산이 용이한 새로운 개념의 평면형 집광기를 제안하였다. 해당 집광기에서는 태양광 집광을 위하여 빛의 전반사와 굴절의 법칙에 의해 빛을 유도하는 마이크로 단위의 광학 패턴이 적용되었다. 본 집광기의 주요 설계변수로는 광도파 집광기의 기하집 광비 $R_c$와 마이크로 패턴의 두 각도 ${\Theta}_1$, ${\Theta}_2$를 선정하였다. 광학해석을 위한 시뮬레이션은 SPEOS로 수행되었으며 주요 설계변수의 변화에 따른 집광기의 광학효율을 예측하였다. 기하집광비 4, 5, 6에 대해서 광학효율 최대치가 각각 65.60%, 54.78%, 46.78%로 예측되었다. 집광기의 마이크로 패턴의 두 각도 ${\Theta}_1$, ${\Theta}_2$ 및 태양광 입사각에 따른 광학효율도 예측하였다.