• 헤리티지:역사와 과학
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• 제39권
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• pp.281-314
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• 2006

Several explanations exist about the usage of disk-shaped bronze implements in the ancient society. Some argue that they were used as mirrors, others suggest percussion instruments, and still others bronze ornaments. Differences between disk-shaped bronze implements and mirrors with multiple knobs are that the former have no visible design, only one handle, and a sharp curvature unlike the latter with smooth curvature. The question is whether disk-shaped bronze implements excavated from Korean peninsula have any light reflecting function. To answer this question, I carefully studied the concave surfaces of disk-shaped bronze implements excavated from Goejeong-dong, Tongso-ri and Hapsong-ri sites. The main findings are as follows: (1) The concave sides of the disk-shaped bronze implements excavated from Goejeong-dong and Tongso-ri sites were highly polished, and they were as reflective as bronze mirrors. (2) The concave side of the disk-shaped bronze implement from Hapsong-ri site was unpolished, and it was different from bronze mirrors. (3) As for the convex sides of the disk-shaped bronze implements, they did not appear to have been polished with care. Considering the above findings, the disk-shaped bronze implements excavated from Goejeong-dong and Tongso-ri sites belong to the stage where they could act as both mirrors and instruments. On the contrary, the disk-shaped bronze implement from Hapsong-ri site can belong to the stage where it lost the function of being a mirror as the result of maintaining only its function as an instrument. Even though disk-shaped implements had two functions, it can be considered that the light reflecting function expanded the role of a mirror with multiple knobs and the sound function helped the engraved round bronze implement to be converted into an eight-armed bronze rattle. Since it has been reported that shamans used bronze mirrors as percussion instruments in their performances in Korean peninsula and Siberia, I propose a reconsideration of the usage of mirrors in the ancient East Asia. Although the essential function of a mirror is to reflect light, other possible usages involving important functions need to be further investigated.

• International Journal of Contents
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• 제9권1호
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• pp.60-64
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• 2013

This study was performed for two of specific reasons, one is for exercise development for improving stroke patient's muscle power, balance and gait and, after verifying the effect of the exercise, the other is for showing that the appling this exercise was more effective on hemi-plegic stroke patients into the clinical trial. The subjects of this study were hemi-plegic patients by stroke, 51 patients were picked up, who were agreed with this research. Close kinetic chain leg exercise using mirrors was applied to study group I, Close kinetic chain leg exercise without mirrors was applied to study group II and general physical therapy was applied to comparison group. The results of this study are as follows. The difference of the groups, study group I showed more effective than study group II on checking rectus femoris, vastus lateralis, biceps femoris, Korean version of Berg Balance Scale, Center of pressure, Functional gait assessment. In this study, Close kinetic chain leg exercise showed more effective and significant on improving for muscle power, balance and gait on stroke patients. Especially, doing exercise using mirrors is considered as more effective method than without mirrors.

• 천문학회보
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• 제39권2호
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• pp.91.2-91.2
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• 2014

A near infrared wide-band high resolution spectrograph, immersion grating infrared spectrometer (IGRINS) has been jointly developed by the Korea Astronomy and Space Science Institute and the University of Texas at Austin. The compact white-pupil design of the instrument optics includes five cryogenic flat mirrors including a slit mirror, an input fold mirror, a dichroic mirror, and H&K camera fold mirrors. In this study, we introduce the optomechanical mount designs of the five cryogenic mirrors. In order to meet the structural stability and thermal requirements of the mount models, we conducted the design work with the aid of 3-dimensional computer modeling and the finite element analysis (FEA) method. We also present the actual fabricated parts and assemblies of the mounts and mirrors as well as their CAD models.

• Korean Journal of Geomatics
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• 제1권1호
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• pp.69-74
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• 2001

In conventional photogrammetry, three-dimensional coordinates are obtained from two consecutive images of a stationary object photographed from two exposure stations, separated by a certain distance. However, it is impossible to photograph moving objects from two stations with one camera at the same time. Various methods to overcome this obstacle were devised e. g. taking the left and right scenes simultaneously with one camera using a beam splitter attached to the front, thus creating a stereo scene in one image. A beam splitter consists of two outer mirrors and two inner mirrors. This paper deals with research where the optical principles of the beam splitter were evaluated based on light path phenomena between the outer mirrors and the inner mirrors. A mathematical model of the geometric configuration was derived for the beam splitter. This allows us to design and control a beam splitter to obtain maximum scale and maximum base-height ratio by stepwise application of the mathematical model. The results show that the beam splitter is a very useful tool for stereophotography with one camera. The optimum geometric configurations ensuring maximum scale and base-height ratio are closely related to inner and outer reflector sizes, their inclination angles and the offsets between the outer mirrors.

• 조명전기설비학회논문지
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• 제22권12호
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• pp.56-63
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• 2008

8각 미러를 이용한 원형 오링, 볼트, 플라스틱 가스켓의 측면 검사시스템을 개발하였다. 검사시스템은 1대의 CCD 카메라와 조명, 1, 2차 8각 미러로 이루어졌으며, 3종류 샘플의 영상 획득을 위해 조명과 미러를 조정하여 시스템을 구성하고 이에 대한 영상처리 알고리즘을 제안하였다. 제안된 알고리즘의 효율성은 각각의 제품에 대하여 실험을 통하여 입증하였고 검사속도는 독립형 카메라로 최대 0.2초 이내이었다. 이러한 검사 시스템은 다양한 원형제품의 측면검사에서 응용될 수 있다.

• 천문학회보
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• 제43권2호
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• pp.55.4-56
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• 2018

Linear Astigmatism Free - Three Mirror System (LAF-TMS) is the linear astigmatism free off-axis wide field telescope with D = 150 mm, F/3.3, and $FOV=5.51^{\circ}{\times}4.13^{\circ}$. We report the design and analysis results of its mirrors and optomechanical structures. Tolerance allowance has been analyzed to the minimum mechanical tolerance of ${\pm}0.05mm$ that is reasonable tolerance for fabrication and optical alignment. The aluminum mirrors are designed with mounting flexure features for the strain-free mounting. From Finite Element Analysis (FEA) results of mounting torque and self-weight, we expect 33 - 80 nm RMS mirror surface deformations. Shims and the L-bracket are mounted between mirrors and the mirror mount for optical alignment. The mirror mount is designed with four light-weighted mechanical parts. It can stably and accurately fix mirrors, and it also suppresses some of stray light.

• 한국광학회:학술대회논문집
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• 한국광학회 2007년도 하계학술발표회 논문집
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• pp.187-188
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• 2007

Four kinds of mirror substrates with same surface roughness were fabricated. On those substrates, a dielectric multi-layer coating with high reflectivity was deposited by ion beam sputtering technique. Most of the fused silica mirrors showed lower scattering than the ZERODUR mirrors one, which deposited on substrates similar in surface roughness. The ZERODUR mirrors scattering strongly depend on the micro-structure of $Ta_2O_5/SiO_2$ thin films wear deposited on ZERODUR substrates.

• 한국광학회지
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• 제9권2호
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• pp.92-95
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• 1998

본 논문에서는 비선형거울층(비선형 물질을 포함하고 있는 거울층)을 가진 비선형 etalon이 광쌍안정 특성을 가지며, 선형거울층을 가진 비선형 etalon보다 더 낮은 전력에서 스위치될 수 있음을 보였다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.336-339
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• 1995

There has been considerable interest in electrochromic devices because of its potential application in automobiles including mirrors and windows. The electrochromic(EC) mirror can automatically control the amount of glare produced by headlights or other light source on either inside or outside mirrors. Therefore, the EC mirror can be a better alternative to todays day-night mirrors for automobiles. In this paper we have fabricated all solid state EC mirrors with glass-ITO / a-WO$_3$/ polymer electrolyte / a-V$_2$O$\sub$5/ / ITO-glass / Al structure and investigated their spectral reflectance as a function of applied voltage.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2435-2439
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• 2005

In case of visual sensing systems with multiple mirrors, systematic errors need to be reduced by the system calibration and the mirror position adjustment in order to enhance system measurement accuracy. In this paper, a self calibration method is presented for a visual sensing system designed to measure the three-dimensional information in deformable peg-in-hole tasks. It is composed of a CCD camera and a series of mirrors including two pyramidal mirrors. By using an image of the inner pyramidal mirror taken by the system, the error parameters of the inner pyramidal mirror could be calibrated or adjusted. Also the influence of the plane mirrors is investigated.