• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.2
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• pp.173-179
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• 1999

The effect of the surface activation treatment on the crystallization of the amorphous silicon film was investigated. The amorphous silicon film was deposited on the silica substrate with LPCVD technique. Wet blasting with silica slurry or exposure with Nd:YAG laser beam was applied on the amorphous silicon film before annealing for the crystallization. For the analysis of the crystallinity, XRD, Raman, and SEM were employed. In this investigation, the prior surface activation treatment like silica wet blasting or Nd:YAG laser beam exposure before annealing for the crystallization were found to be effective in the enhancement of the crystallization. It is believed that these treatment lower the activation energy required for the crystallization of the amorphous silicon film.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.4
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• pp.597-605
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• 2006

It is introduced that pit and fissure sealant is the most universal and effective to prevent occlusal dental caries. In processing of being applied the pit and fissure sealant, the various kinds of methods are developed to remove organic matters, plaque, microflora and debris in the pit and fissure for increasing the rates of maintain the sealant. Recently, the Er:YAG laser has been used as a new enamel surface treatment method. The purpose of this thesis is compared whether that enamel surface treatment method is superior to other methods or not. 1. 100mJ 5Hz Er:YAG lased enamel surface was similar to acid-etched enamel in SEM evaluation. 2, Mechanical preparation showed decreased microleakage when compared with acid-etching only, but no significant differences in both method. 3. After laser and acid-etching method showed decreased microleakage when compared with acid-etching only.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.176-177
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• 2005

PDMS는 생명공학 분야에서 중요한 기술적 폴리머이다. Nd:YAG레이저의 4고조파 ($\lambda$=266nm, pulse) 레이저를 사용하여 표면 처리를 하여 PDMS 표면의 습윤성과 접착성의 향상됨을 확인하였다. 식각한 PDMS는 샘물체의 미세회로에 사용될 수 있다. 본 논문은 레이저 빔의 주사속도를 변화시키며 PDMS를 레이저로 식각하며 PDMS의 식각 특성을 연구한다 식각 특성을 의존성이 가장 효과적인 주사 속도에 대한 의존성을 규명하고자 스테이지 컨트롤러의 속도를 변화시키며 실험하였다. 그리고 최적의 레이저 출력값을 알아내려고 레이저 출력값을 조절하며 실험 하였다. 단차측정기(알파스템)을 이용하여 식각형상과 식각 효율 등을 분석하였다.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2002.05a
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• pp.357-360
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• 2002

직물의 질감을 객관화시키는 연구는 고부가가치의 의류제품을 생산하고 판매하는데 매우 중요한 요소이다. 질감은 직물의 역학적 성질과 표면상태에 따라 좌우되며, 이의 측정방법 중에서 KES-F system이 가장 객관화되어 있다. KES-F system을 이용한 표면 거칠기 측정방법은 피아노선을 굴곡 시켜 일정한 힘을 가한 상태에서 직물의 표면을 문질러 측정하므로 직물의 표면을 문질러 측정하므로 직물 표면의 잔털이 눌려진 상태여서 질감해석을 위한 정확한 측정이 어렵다. 따라서 우리는 기하학적인 직물 표면의 거칠기를 표면의 변형없이 측정 가능한 레이저 센서를 사용하였다. 한편 직물의 주로 경사ㆍ위사로 짜여져 있어 이방성 성질을 가지고 있으므로 직물을 3방향으로 측정하여 해석하였다. 측정된 신호는 FET를 이용하여 일정한 주기의 표면형태를 구하고, 표면 높낮이의 평균, 최저값과 최고값을 구하여 표면의 특성을 얻었다. 직물 표면에 존재하는 잔털은 영상처리장치를 이용하여 양을 측정하였으며 표면의 거칠기 측정결과와 비교 분석하여 레이저 센서를 이용한 비접촉식 측정방법의 오차분석 및 표면 특징을 해석하였다.

• The Optical Journal
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• s.153
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• pp.47-62
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• 2014

${\blacksquare}$ 목적 * 우리나라 주력산업분야(자동차, 조선, 항공, 기계, 로봇, 반도체 등)에 절단, 가공, 용접, 리소그라피, 마킹, 열처리, 합성, 표면처리 등의 방식으로 활용되고, 융 복합산업(의료, 에너지, 영상, 군수, 신소재, 센서)에 광원으로 응용되는 산업용 고출력 레이저의 산업 생태계 분석을 통하여 기존 산업의 고부가화와 신산업의 경쟁력을 견인 ${\blacksquare}$ 주요현황 * (시장현황) 2011년부터 2014년까지 고출력 레이저의 시장규모는 4,452백만불(5조 463억원)에서 5,255백만불(5조 9,565억원)으로 연평균 5.7% 성장 전망 * (제품기술동향) 3세대 레이저인 광섬유 레이저와 고출력 다이오드 레이저, DPSS 레이저 등이 기술혁신을 거듭하면서 1, 2세대 레이저를 대체해 가면서 높은 수준의 성장을 거듭할 것으로 전망. 산업용레이저의 주요선진국 대비 국내 기술수준은 전체적으로 44.5%정도로 취약 * (기업동향) Coherent, Trumpf, Cymer, IPG Photonics, Rofin-Sinar 5개사가 전체시장의 55%이상을 점유하고 있으며 대부분 수직계열화를 통해 경쟁력 확보. 최근 중국의 Han's 사가 자국정부의 지원을 통해 급 부상 ${\blacksquare}$ 시사점 * 산업용 레이저를 이용한 응용기술 부분 투자가 과거에는 단기 경제적 성취는 이로웠으나, 현재에 이르러 레이저 혹은 레이저 시스템이 필요할 때마다 외국에서 관련 핵심부품, 모듈 등을 수입해야하는 실정에 이르렀음. 향후 레이저 국산화를 위한 노력과 함께 후방 소재.부품의 전략적 투자를 통해 산업의 건강한 선순환생태 환경을 조성하여 산업 경쟁력을 갖추어야 함.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.12
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• pp.1663-1668
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• 2011

Surface hardening treatment is required to improve the wear-resistance of press die because severe abrasion of die occurs during the drawing process in which the forming of the automotive body is completed and during the trimming process in which the unnecessary parts are cut. In this study, experiments on the laser surface treatment of press die are performed. Specimens are heat-treated separately at certain plate and edge position by using a diode laser to carry out suitable surface hardening treatment to reduce the wear during the drawing and the trimming processes, and the proper conditions for heat treatment are found. Spheroidal and flake graphite cast iron specimens are used, and the heat treatment characteristics of the two materials are compared. From the results of the study, it is confirmed that the heat treatment characteristics differed depending on the materials.

• Journal of the Institute of Convergence Signal Processing
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• v.8 no.1
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• pp.15-21
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• 2007

We propose a 3D modeling method for surface inspection of non-constant velocity moving object. 1'lie laser lines reflect tile surface curvature. We can acquire 3D surface information by analyzing projected laser lines on object. In this paper, we use multi-line laser to improve the single stripe method and high speed of single frame. Binarization and edge extraction of frame image were proposed for robust laser each line extraction. A new labeling method was used for laser line labeling. We acquired some feature points for image matching from the frame data and juxtaposed the frames data to obtain a 3D shape image. We verified the superiority of proposed method by applying it to inspect container's damages.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.201-206
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• 2006

A recent laboratory study has demonstrated improved caries lesion resistance with enamel that was exposed to $CO_2$ laser irradiation for very short time period. When topical fluoride treatment was performed before or after laser irradiation, reductions in dental caries. The purpose of this scanning electron microscopic(SEM) study and atomic force microscope study was to characterize surface alterations in tooth enamel after in vitro laser irradiation alone and combined topical fluoride treatment either before or after laser irradiation. The treatment effects of laser irradiation led to the formation of an irregular, mild porosities and fine fissures, also created granular materials. But when laser irradiation was followed by APF, the enamel surface had homogenous architecture. The result led to the caries resistance effects by these granular structures have been considered to represent redeposited mineral phases due to the mobilization of calcium, phosphate, and fluoride from lased enamel.

• Laser Solutions
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• v.17 no.2
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• pp.1-4
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• 2014

With the PEO(Plasma electrolytic oxidation) surface treatment, the oxide film of aluminum alloy is growing in a short time. The reflectance measurement to find the oxygen atoms in the oxide could be investigated. In order to form a thicker oxide film, the PEO surface treatment should be uniformly controlled in processing time.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.2
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• pp.9-17
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• 2020

In this study, the surface changes of titanium alloy using laser surface treatment and the surface analysis using laser-induced plasma spectroscopy were carried out. The laser surface treatment induced changes in surface roughness and the diffusion of atmospheric elements. Excessive melting or less melting caused roughness changes, but when moderate levels of energy were applied, a smoother surface could be obtained than the initial surface. In the process, the diffusion of atmospheric elements took place. To analyze the diffusion of atmospheric elements with respect to surface morphology, the surfaces were re-shaped with grinding. In this experimental conditions, the effect of plasma formation by surface roughness was identified. Compensated plasma signals for the material properties were obtained and analysed by removing the background plasma signal.