• Journal of Welding and Joining
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• 제12권3호
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• pp.71-81
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• 1994

Laser cutting is experiencing a rising worldwide acceptance in the industry. Expert systems are necessary for the systematic arrangement and searching of experimental data existing in journal papers, job handbooks, etc.. This paper proposes an expert system for the selection of the appropriate laser cutting variables from the available database. Optimum cutting conditions according to the given cutting velocity were searched and qualitative comments which are difficult to be used as database variables were shown at each velocity using the binary and fuzzy inference. These comments could be informative to unskilled operators of the laser cutting process. Typical cutting conditions of the mild steel and stainless steel were included and the working range and quality variations were displayed graphically. The proposed algorithm was implemented in an IBM compatible personal computer as an expert system for CO$_{2}$ laser cutting to derive the optimum cutting conditions by using the turbo prolog.

• Medical Lasers
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• 제10권4호
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• pp.246-249
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• 2021

The carbon dioxide (CO₂) laser is one of the treatment options used for xanthelasma palpebrarum. However, even if the full dermal layer is removed, the lesion can recur due to the residual lipid deposits. A 44-year-old male patient with xanthelasma on both upper eyelids was treated with a pulsed dye CO₂ laser. On the right upper eyelid, we carried out a CO₂ laser treatment until the yellowish plaque was almost invisible and the full thickness of the dermal layer was removed. On the left upper eyelid, the dermal layer was partially removed and an additional squeezing out of yellowish particles was done. The lesion treated by the squeezing out of lipid droplets showed better long-term results than the lesion treated up to the deeper dermal layer.

• Medical Lasers
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• 제8권2호
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• pp.90-93
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• 2019

The treatment of keloid and hypertrophic scars (HTSs) remains one of the most difficult challenges, with a high recurrence rate regardless of the method of treatment. The latest trend in scar management is a combined approach using multiple modalities that are individualized to the patient and that would provide successful results for keloid and HTSs. There are previous reports that stromal vascular fraction (SVF) is effective for scar remodeling. Based on these reports, we introduced the concept of a combination treatment using SVF injection and fractional ablative CO₂ laser. In this report, we present a 21-year-old woman who was involved in a car accident. A defect on her foot was covered with a skin graft, but the scars became elevated, which turned out to be HTSs. She was treated with a fractional ablative CO₂ laser for five sessions. A month later, SVF injection and fractional ablative CO₂ laser were conducted simultaneously. The result of a year's follow-up showed a flattened scar with resolution of pigment deposition. In conclusion, the combination treatment for HTSs with SVF injection and ablative fractional CO₂ laser is one of the modalities to achieve an excellent outcome for treating HTS.

• 한국레이저가공학회:학술대회논문집
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• 한국레이저가공학회 2001년도 춘계학술발표대회 논문개요집
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• pp.35-38
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• 2001

• 한국레이저가공학회:학술대회논문집
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• 한국레이저가공학회 1998년도 춘계학술발표대회 초록개요집
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• pp.12-14
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• 1998

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.409-412
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• 2004

In this paper, an integrated automation system of pattern design and $CO_2$ laser cutting for diving suits is presented. Pattern design includes grading which creates a full-size range from a base pattern. Tool path for laser cutting from the patterns is generated in G-code format. $CO_2$ Laser cutting machine is developed to help cut the patterns with accuracy and speed. Aluminum profiles, ball screws, and stepping motors are engaged into the machine as frame structure, transfer unit, and driving devices respectively. The developed system is tested in dry suit cutting, convincing it can be readily introduced in driving suits manufacturing with respect to cost and efficiency.

• 한국정밀공학회지
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• 제30권10호
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• pp.1017-1022
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• 2013

Currently, various optical fiber tips are used to deliver laser beam for endoscopic surgery. In this paper, we demonstrated multidirectional (forward and side) firing optical fiber tip using a femtosecond micromachining and $CO_2$ laser polishing technology. We controlled the edge width of optical fiber tip, by modulating the condition of $CO_2$ laser, to regulate the amount of side and forward emission. The distal end of the optical fiber with core/clad diameter of $400/440{\mu}m$ was microstructured with cone shape by using a femtosecond laser. And then the microstructured optical fiber tip was polished by $CO_2$ laser beam result in smoothing and specular reflection at the surface of the cone structure. Finally, we operated the LightTools simulation and good agreement was generally found between the proposed model and experimental simulation.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제53권1호
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• pp.36-40
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• 2004

A new laser Doppler velocimeter employing a $CO_2$ laser has been developed by using its photoacoustic effect. A change in the pressure of a discharge, induced by mixing of a returned wave with an originally existing wave inside the cavity, is employed to detect the Doppler frequency shift. We found that a Doppler frequency shift as much as 34 KHz was detected, and also a good linear relationship between the velocity and the Doppler frequency shift was obtained.

• 한국레이저가공학회지
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• 제16권2호
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• pp.12-15
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• 2013

In this paper, we controlled the edge angle of fiber by using $CO_2$ laser. In order to control the angle, tilting angle of fiber on stage and the number of scan repetition are adjusted, and laser power is fixed at 30 W in the experiment. In the polishing result, the edge angle of fiber can be changed from $4^{\circ}$ to $8^{\circ}$, as changing the tilting angle and the number of scan repetition. This $CO_2$ laser polishing can fabricate ball lenses with various curvatures and a sharp probe as well as the edge angled fiber.

• 한국광학회지
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• 제1권2호
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• pp.155-161
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• 1990

메틸알코올 레이저의 여기용으로 저속축류형의 가변파장 $CO_2$ 레이저를 제작하였다. 파장가변은 ZnSe Brewster 창과 반사 회절격자를 사용하였으며, 반사 회절격자는 Blaze wavelength 10.6$\mu\textrm{m}$, 100grooves/mm 인 평면형이다. 실험은 $CO_2$ 레이저의 연속발진 출력특을 살펴보고, $CO_2$ 레이저의 전 발진구간을 파장가변시켜 얻어진 출력분포를 $CO_2$ 레이저의 이득 곡선과 비교하였다. 연속발진 출력은 기체 혼합비 $CO_2: N_2$ : He=1:3:10, 전류 55mA, 압력 14 torr 일 때 100W를 얻었다. 가변된 파장은 10.4$\mu\textrm{m}$ 영역의 R(6)-R(38), P(6)-P(36), 9.4$\mu\textrm{m}$ 영역의 R (10)-R(32), P(10)-P(38)의 약 60여개의 회전선이 발진함을 확인하였고, 이 때의 파장은 9.3295$\mu\textrm{m}$에서 10.7648$\mu\textrm{m}$까지 변화하였다. 각 영역에서 얻어진 출력분포는 $CO_2$ 레이저의 이득곡선과 잘 일치하였고, 최대 출력은 20W 정도였다.