• 제목/요약/키워드: LASER

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Laser Treatment in Restorative Dentistry

  • Shintani, Hideaki
    • 대한치과보존학회:학술대회논문집
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    • 대한치과보존학회 2001년도 추계학술대회(제116회) 및 13회 Workshop 제3회 한ㆍ일 치과보존학회 공동학술대회 초록집
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    • pp.556-556
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    • 2001
  • The application of the laser to the tooth hard tissue started from the removal of carious dentin with the laser performed by Goldman in 1964. With the development of the laser technology, the laser treatment with less descomfort such as pain, vibration, and noise, etc. has been attempted. Since it is difficult to give a suitable form for inlay restoration to a cavity prepared with laser, it has to be restored with adhesive resinous materials. However, various evaluation of adhesive properties of the resinous materials to lased tooth surface on the various conditions such as adgerent, irradiation condition, procedure of bond test, and adhesive materials used, etc. have been reported.(omitted)

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레이저 진단기법을 이용한 연소 가시화 기술 (Visualization of Combustion by Using Laser Diagnostic Techniques)

  • 정석호;원상희
    • 한국가시화정보학회지
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    • 제2권1호
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    • pp.52-56
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    • 2004
  • Several visualization techniques of laser diagnostics are presented for combustion phenomena, including Mie scattering for flow, Rayleigh and Raman scattering spectroscopy for major species, laser-induced fluorescence for minor species, and laser-induced incandescence for soot. These techniques have been applied to understand the various combustion phenomena more clearly, including buoyancy-dominant flow system, diffusion flam oscillation, laminar and turbulent lifted flames, flame propagation along a vortex ring, and soot zone characteristics. The usefulness of laser diagnostics on a better understanding of physical mechanism is demonstrated.

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레이저 가공 폴리머 마이크로 유체 장치 (Laser Process of Polymer Micro Fluidic Devices)

  • 김주한
    • 한국정밀공학회지
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    • 제23권2호
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    • pp.129-137
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    • 2006
  • Polymer micro-fluidic devices were fabricated with laser processes. A UV laser and a femto laser were used to machine polymer micro-fluidic structures directly. This laser direct machining process suits the need of rapid prototyping, as in many applications changes from the original design are often required. As examples, two polymer micro-systems were developed: a micro-check valve and a micro diffuser pump. The micro fluidic devices can be applied for many applications such as clinical diagnostics and drug delivery. Advantages and disadvantages using polymers as a material for micro-fluidic applications are discussed.

$CO_2$ 레이저를 이용한 자동차용 고장력 TRIP 강 용접의 용접부 품질 분류에 대한 연구 (A study on classification of weld quality in high tensile TRIP steel welding for automotive using $CO_2$ laser)

  • 박영환;박현성;이세헌
    • 한국레이저가공학회지
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    • 제5권3호
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    • pp.21-30
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    • 2002
  • In automotive industry, the studies about light weight vehicle and improving the productivity have been accomplished. For that, TRIP steel was developed and research for the laser welding process have been performed. In this study, the monitoring system using photodiode was developed for laser welding process of TRIP steel. With measuring light, neural network model for estimating bead width and tensile strength was made and weld quality classification algorithm was formulated with fuzzy inference method.

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Multiwavelength Erbium-doped Fiber Ring Laser with Adjustable Line Power using Variable Attenuators and DWDM

  • Lee, Hojoon
    • 한국광학회지
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    • 제25권3호
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    • pp.146-149
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    • 2014
  • The homogeneous line broadening in EDF leads to unstable lasing and strong mode competition. In this paper a multiwavelength fiber ring laser that overcomes these effects by using variable attenuators between the DWDM and $1{\times}N$ coupler, has been proposed. Fiber ring lasers with four and eight wavelength outputs are implemented, and we show that the output powers can be adjusted with stable operation. The EDF ring laser has one four-wavelength output and four of single wavelengths, with OSNR of 50 and 60 dB respectively.

레이저 트위저 라만 분광을 이용한 펨토초 광포획 동안의 적혈구 손상 분석 (Analysis of RBC Damage Using Laser Tweezers Raman Spectroscopy (LTRS) During Femtosecond Laser Optical Trapping)

  • 주성빈;표진우;장재영;이승덕;김법민
    • 한국광학회:학술대회논문집
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    • 한국광학회 2008년도 동계학술발표회 논문집
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    • pp.453-454
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    • 2008
  • femtosecond laser를 광원으로 하는 optical tweezers는 광포획 뿐만 아니라 비선형 현상을 발생시킬 수 있다는 장점을 가지고 있다. 그러나 높은 첨두 출력에 의하여 포획된 세포는 쉽게 손상되어 질 수 있다. 본 논문에서는 LTRS(Laser Tweezers Raman Spectroscopy)를 통하여 femtosecond laser와 CW laser에 의한 optical tweezers 상에서의 optical damage를 비교, 분석하였다.

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레이저를 이용한 유리기판의 미세가공(微細加工) (Micro-Processing of Glass Substrates Using a Laser)

  • 이천;풍전호일
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1994년도 하계학술대회 논문집 C
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    • pp.1425-1427
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    • 1994
  • Laser ablation of glass substrates (8K-7 and synthetic quartz) using a transversely excited atmospheric (TEA) $CO_2$ laser has been inverstigated to obtain high speed etching. The ablation occurs by local heating of a substrate with a focused TEA-$CO_2$ laser beam. The dependence of ablation rate on pulse count and repetition-rate of laser has been discussed.

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청록색 레이저를 이용한 수중영상 연구 (Underwater Imaging with a blue-green laser)

  • 이상훈;김근배;이광식;김달우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2000년도 하계학술대회 논문집 C
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    • pp.2180-2182
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    • 2000
  • Laser emission, a part of electromagnetic wave, has short propagation length in water, and the underwater applications of laser are limited. The acquisition of underwater imaging is possible only by using a blue-green laser since the blue-green range has relatively small absorption coefficient in water. We introduce the conditions of the laser required for underwater imaging and the attenuation characteristics of a blue-green laser used in water.

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$CO_2$ Laser Scribing법을 이용한 PDP용 격벽 제조 (Fabrication of Barrier Ribs for PDP by $CO_2$ Laser Scribing Method)

  • 안정식;이석영;김원용;전형조;이용호;김용석
    • 한국세라믹학회지
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    • 제37권1호
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    • pp.57-62
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    • 2000
  • In this study, an attempt was made to demonstrate the possibility of using laser scribing method in manufacturing the barrier ribs of plasma display panel. The scribing with a CO2 laser was conducted on the green tape produced by the doctor blade tape casting method. Among the processing parameters, the quenching gas pressure, shape of mask, and laser power were found to affect the depth and angle of the scibed barrier ribs.

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진공관 전원방식 30 W급 구리증기레이저 (A 30 W Copper Vapor Laser Using a Vacuum Tube Based Pulse Generator)

  • 진정태;차병헌;김철중;이흥호
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권12호
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    • pp.568-572
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    • 2003
  • A longitudinal discharge heated copper vapor laser with internal diameter 28 mm and discharge length 1.3 m has been constructed and tested. At the discharging voltage 15.2 kV, pulse repetition rate 10 kHz, buffer gas pressure 40 mbar, and internal temperature of the laser plasma tube $1520^{\circ}C$, it delivers more than 30 W average laser outputs.