• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 추계학술대회 논문집
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• pp.747-748
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• 2008

• Current Optics and Photonics
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• 제4권6호
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• pp.477-482
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• 2020

Recently, one of the authors has been reported an optically tunable fiber Bragg grating (FBG) with a photomechanical polymer. It was based on a typical FBG with a downsized diameter of 60 ㎛, coated with azobenzene-containing polymer material. Azobenzene is a well-known reversibly photomechanical stretchable material under ultraviolet (UV) light. The small part of the functional-coating region on the FBG absorbed UV light, which pulled the UV-exposed part of the grating. It was selectable as tunable FBG or tunable chirped FBG, by adjusting the position of UV exposure on the grating. As proof of concept for the tunable FBG device, the characteristics just including UV-induced center-wavelength shift and spectral-width changes of the device were reported. In this paper, we report for the first time that the microactuator makes it possible to control the spectral shape of the FBG reflection, according to the specifications (shape and intensity) of the UV beam that reaches the FBG coated with the azobenzene polymer. In addition, we provide the group-delay profiles for the chirped FBG, so that the sign of its dispersion (normal or anomalous) can be tailored by simply selecting the moving direction of the UV light's displacement in the experiment.

• 한국인쇄학회지
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• 제24권2호
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• pp.69-78
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• 2006

Proofing is one of the inspection operations of printing and can be considered a process control step. The three main kinds of proofs are press proofs, photomechanical proofs, and digital proofs. Photomechanical and digital proofs are also generally refered to as "off-press" proofs. Off-press color proofs are more economical than press proofs. Digital proofs offer fast production time along with a much lower cost per page. Hard-copy digital proofs can be output using thermal transfer printers, ink jet printers, and color laser copiers, as well as dye sublimation and electrophotographic technology. Ink jet method is commonly using because of the reasonal price. But ink jet system is difficult to reproduce an exact color proof. This research was carried out for the purpose of optimization of ink jet color proofing, using two kinds of ink jet printers with 6 colors (C, M, Y, K, mC, mM) and 4 colors (C, M, Y, K) system.

• Journal of Photoscience
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• 제2권1호
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• pp.31-35
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• 1995

Light signals in the form of intensity gradient, propagation direction, and wavelength elicit diverse mechanical responses ("photomechanical responese") in most organisms. The single cell ciliates, Stentor coeruleus and Blepharisma japonicum, are particularly sensitive to the light of visible wavelengths. In this paper, the way in which the seemingly sophisticated light signal transduction is triggered by the photosensory apparatus will be described in terms of the photoreceptor structure and photochemical function.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.609-610
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• 2011

• 대한기계학회논문집B
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• 제25권11호
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• pp.1483-1491
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• 2001

Enhancement of pulsed-laser ablation by an artificially deposited liquid film is presented. Measurements of ablation rate, ablation threshold, and surface topography arc performed. Correlation between material ablation and photoacoustic effect is examined by the optical beam deflection method. The dependence of ablation rate on liquid-film thickness and chemical composition is also examined. The results indicate that photomechanical effect in the phase explosion of liquid is responsible for the enhanced ablation. The low critical temperature of liquid induces explosive vaporization with localized photoacoustic excitation in the superheat limit and increases the ablation efficiency. Experiments were carried out utilizing a Q-swiched Nd:YAG laser at near-threshold laser fluences with negligible plasma effect (up to ∼100 MW/cm$^2$).

• Elastomers and Composites
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• 제47권4호
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• pp.282-291
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• 2012

최근 들어 광, 온도, pH, 전기, 자성, 압력 등과 같은 외부 환경의 작은 변화에도 반응하여 모양/부피가 변하거나 기계적, 광학적, 전기적, 화학적 특성 등이 가역적으로 바뀌는 스마트 소재에 대한 관심이 높아지고 있다. 이러한 스마트 소재들 중 광조사에 의해 소재의 다양한 특성을 가역적으로 제어할 수 있는 광응답 스마트 소재가 많은 관심을 받고 있다. 본 논문에서는 광에너지를 받아 기계적 에너지로 바로 전환되어 인공근육, 모터 등과 같은 액츄에이터 기능을 할 수 있는 광구동형 스마트 고분자 소재들에 대해 소개하고자 한다. 특히, 광구동형 스마트 고분자 소재 중에서도 마이크로와 매크로 스케일 변형이 가능한 아조벤젠을 함유한 비결정성 고분자, 액정 고분자, 자기 조립형 초분자에 대한 다양한 연구들에 대해 설명하고자 한다.