• 한국공작기계학회논문집
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• 제13권4호
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• pp.30-36
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• 2004

The development of LD(Laser Diode) tester and its control system based on the graphical programming language(LabVIEW) is addressed. The ill tester is used to check the optic power and the optic spectrum of the LD Chip. The emitter size of LD chip and the diameter of the Detector(optic fiber and photo diode) are very small, therefore the test device needs high accuracy. But each motion part of the test device could not accomplish high accuracy due to the limit of the mechanical performance. So, an image processing with machine vision is proposed to compensate for the error. By adopting our method we can reduce the error of position within $\pm$5$\mu\textrm{m}$.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1663-1667
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• 2003

This thesis is on tile development of LD(Laser Diode) chip tester and the control system based on graphical programming language(LabVIEW) to control the equipment. The LD chip tester is used to test the optic power and the optic spectrum of the LD Chip. The emitter size of LD chip and the diameter of the receiver(optic fiber) are very small. Therefore, in order to test each chip precisely, this tester needs high accuracy. However each motion part of the tester could not accomplish hish accuracy due to the limit of the mechanical performance. Hence. an image processing with machine vision was carried out in order to compensate for the error. and also a load test was carried out so as to reduce tile impact of load on chip while the probing motion device is working. The obtained results were within ${\pm}$5$\mu\textrm{m}$ error.

• 한국전기전자재료학회논문지
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• 제22권3호
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• pp.248-251
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• 2009

We have investigated the effect of the quality of 1.3 um distributed feed back laser diode (DFB-LD) on the design of anti-reflection (AR) coatings. Optimal condition of AR coating to prevent internal feedback from both facets and reduce the reflection-induced intensity noise of laser diode was simulated with Macleod Simulator. Coating materials used in this work were ${Ti_3}{O_5}$ and $SiO_2$, of which design thickness were 105 nm and 165 nm, respectively. AR coating films were deposited by Ion-Assisted Deposition system. The electrical and optical properties of 1.3 um laser diode were characterized by Bar tester and Chip tester. Threshold current and slop-efficiency of DFB-LD were 27.56 mA 0.302 W/A. Far field pattern and wavelength of DFB-LD were $22.3^{\circ}(Horizontal){\times}24.4^{\circ}$ (Vertical), 1313.8 nm, respectively.

• Archives of Metallurgy and Materials
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• 제67권4호
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• pp.1465-1468
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• 2022

In this study, we investigated the effect of cladding on structural carbon steel (S45C) using 5%Cr-1.5%Mo-Fe powder (SKD61), which is expected to show economically efficient production of die-casting parts. The process conditions were performed under argon atmosphere using a diode laser source with specialized wavelength of 900-1070 nm, and the output conditions were 3, 4, and 5 kW, respectively. After the cladding was completed, the surface coating layer's shape and the microstructure were analyzed. The hardness test was carried out with Micro Vickers hardness tester under 500 gram-force along the normal line at the interval of 0.2 mm from the surface to core direction on the cross-sectional area. In addition, polarization curve test of the surface coating layer was performed to investigate the corrosion resistance characteristics.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.309-310
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• 2006

This paper is about the development of surface inspection of bearing inner and outer race using machine vision. Before this system is developed, most inspections are performed by workers' naked eye. To improve both the inconvenience and incorrectness, another new tester is introduced. This system has the three sections mainly. First one is the mechanism section which transfers bearing manufactured from previous process line to the testing process in plant. Another is the inspection system which is composed of two parts: computer vision and measurement system using laser diode which inspects the defects of the bearing inner or outer race. The other is the pneumatic cylinder part controlled by Programmable Logic Controller(PLC). The system which is developed shows favorable results, and that has the advantage of convenience and correctness compared to previous system.

• Journal of Oral Medicine and Pain
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• 제36권4호
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• pp.215-224
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• 2011

본 연구의 목적은 과민치아에 904 nm GaAs 다이오드 레이저를 조사하여 치료효과를 연구하여 과민 치아의 치료에 이러한 저수준 레이저 요법을 임상적으로 사용할 수 있는지 가능성을 파악하는 데 있다. 단국대학교 치과대학 부속치과병원 안면 동통 구강내과에 내원한 환자를 대상으로 하였으며, 각 환자는 치경부에 사아질이 노출된 치아가 적어도 좌우로 2개 이상의 짝이 되는 치아를 소유하였다. 본 연구에 사용된 치아는 모두 50 개로써 실험군 25개, 대조군 25 이었다. Tactile test, cold(ice stick) test, electrical pulp test 를 실험전, 실험 1주후, 2주후, 3주후, 4주후 모두 5회 시행하였다. 레이저조사는 첫방문시, 1주후, 2주후, 3주후 등 4회하되 모두 세가지 검사를 마친 후 시행하였다. 전기치수 검사 외 Tactile test와 cold test는 주관적 평가인 visual analogue scale을 사용하였다. 실험 결과, Tactile test에서 VAS 수치는 시간 경과에 따라 유의하게 감소하였으나 실험군과 대조군간에는 유의한 차이가 없었다. 전기치수 검사에서는 실험군의 과민도가 대조군에 비해 유의하게 높았으나 (높은 역치를 의미) 시간 경과시 유의한 변화는 볼 수 없었다. 온도 (cold) 검사에서는 레이저 조사후 실험군과 대조군 간의 차이뿐 만 아니라 시간 경과 시에도 유의하게 감소하였다. 이러한 결과를 보아 904 nm GaAs 레이저는 과민치아의 치료에 비가역적인 방법으로서 효과적으로 사용할 수 있으리라 사료된다.