• Proceedings of the Korean Society of Computer Information Conference
• /
• 2014.07a
• /
• pp.427-428
• /
• 2014

화재발생 시 인명 안전을 위하여 초기의 화재감지가 매우 중요한 요인이다. 기존 연기감지기의 경우 일정한 조건만 맞으면 작동하기 때문에 비화재보의 우려가 높다. 특히 차량 매연도 연료가 연소되어 나오는 연기이므로 차량정체 시 트럭 등에서 발생하는 심한 매연에도 반응하여 오작동의 가능성이 높다. 이러한 기존 화재감지기의 문제점을 해결하기 위해 다양한 IR 레이저 기반 연기검출장치가 활용되고 있다. 하지만 IR 레이저 기반 연기검출장치는 100m 거리가 이격된 레이저 발광부와 수광부 구조에 따라 발광부 레이저광선의 각도변화에 따른 수광부 레이저 포인트 위치가 매우 민감하게 변화함에 따라 초기 레이저 포인트의 초점을 정확히 정합하고, 이후 보정하기 위한 고정밀 자동 초점 정합장치가 필요하다. 이에 본 논문에서는 레이저 투광부와 수광부를 분리하여 레이저 송신기, 수신기로 구성되는 고정밀 자동초점 정합장치를 설계하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.11
• /
• pp.2759-2764
• /
• 2014

Smoke detector is commonly used to reduce fire detection time. However, technical problems regarding its inaccuracy of laser beam-receiving point on the surface of the sensor associated with incoming interference are identified when the laser transmitter and receiver are installed at a distance of about 100m. In this paper, we propose the auto focus alignment algorithm with high precision to adjust tilting angle of lasers caused by environmental interference so that solve existing issues using multi-level worm gear set.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.10a
• /
• pp.499-500
• /
• 2014

화재발생 시 인명 안전을 위하여 초기의 화재감지가 매우 중요한 요인이다. 특히 도로터널, 지하철역사 등 광범위 폐쇄공간에서 연기에 의한 질식사 등 2차 피해의 발생위험이 높다. 이에 최근 광범위 공간에서 적외선 레이저를 활용한 원거리 연기검출 화재탐지기에 대한 연구가 진행되고 있다. 이러한 레이저 기반 원거리 연기검출장치는 이격(100m 이상) 설치되는 레이저 발신기와 수신기의 레이저 포인트가 정확히 정합되어야 한다. 아울러, 레이저 발신기와 수신기 사이의 거리에 비례하여 레이저 초점의 이동거리가 매우 민감하게 변화하므로 이를 정확히 정합하기 위한 고정밀 제어장치가 필요하다. 따라서 본 논문에서는 복수개의 레이저 발신모듈과 복수개의 조도센서(CdS)를 통해 초점의 정합을 자동 추적할 수 있는 알고리즘을 설계, 구현하였다. 이는 초기 레이저 초점의 설정과 이후 외부환경에 따른 초점의 틀어짐을 자동 보정하여 다양한 레이저 인식 장치에 적용될 것으로 사료된다.

• Proceedings of the Korean Society of Laser Processing Conference
• /
• 1998.11a
• /
• pp.6-9
• /
• 1998

• Proceedings of the KWS Conference
• /
• 2005.06a
• /
• pp.314-316
• /
• 2005

이 논문에서는 아크 용접시 발생하는 IR신호와 UV호의 상호 관계를 알아보려고 레이저 용접진단에 사용되는 IR-UV 센서 모니터링 시스템을 적용하였다. 그 결과 IR신호 크기는 용접폭에 관련이 있고, 펄스 형태의 UV신호는 IR신호 증가율이 임계값을 넘으면 나타나는 것을 알 수 있다.

• Biomedical Science Letters
• /
• v.6 no.3
• /
• pp.223-228
• /
• 2000

The purpose of this study was to find out the effect of He-Ne, IR laser therapy for 4 and 10 minutes on healing of septic arthritis. Sprague-Bawley rats (212.1$\pm$10 g) were randomly assigned to one control and three arthritis groups. Septic arthritis groups were divided into arthritis control, 4 or 10 minute laser therapy groups. Arthritis was experimentally induced by intraperitoneally administration of staphylococcus aureus in citrate buffer(pH 4.3). These result were obtained as follows: AST, LDH, ALP, CK activities and IgG concentration in 10 minute laser group were signifantly increased compare with those in the arthritis group. AST, LDH and CK activities in 4 minute laser group were significantly decreased compare with those in the arthritis group. We think that laser therapy in 4 minute may effective on the healing of septic arthritis. And we will have to study of the effect of laser therapy on healing mechanism, appropriate time of septic arthritis.

• Journal of Korean Physical Therapy Science
• /
• v.8 no.2
• /
• pp.1033-1038
• /
• 2001

This studies were to investigate the effects of low power Helium-Neon Infra-Red(He-Ne IR) laser on the changes of the chemical components in serum of the peripheral neuropathy in diabetic rats. The twenty one Spraque-Dawley adult male rats were assigned to the 3 groups: the control group(N=7), the diabetic group(n=7) and the laser group(n=7). The diabetic group was induced with a single intravenous injecion of 50mg/kg body weight streptozotocin dissolved to 0.01mol/L citrate buffer, pH 4.5. The experimental1asser group was irradiated low power He-Ne IR laser for 5 minutes every day during 21 days to the diabetic group. The results were as follows: 1. ALT was increased the laser treatment group than the diabetic group. but that was not significant. 2. AST was significantly increased the laser treatment group than the control group and the diabetic group. 3. LDH was significantly decreased the diabetic group and laser treatment group. 4. ALP was significantly increased the diabetic group and laser treatment group. 5. CHOL was significantly decreased the laser treatment group than the diabetic group. 6. TRIG was significantly increased the laser treatment group than the diabetic group. 7. CPK was significantly increased the laser treatment group than the control group and the diabetic group.

• Korean Journal of Optics and Photonics
• /
• v.8 no.4
• /
• pp.291-296
• /
• 1997

The slotted type of hollow copper cathode was constructed and tested for its geometric stability and usability for laser operation at 780nm. The peak output power of copper ion laser emission was measured for different operating conditions. The IR-laser power was dependent on the parameters of the geometry of the hollow cathodes, discharge current and gas fillings. The peak power decreased with increasing neon pressure over 60%. One reason for this decrease in output power may be conjectured as hier due to the decreasing population of the upper laser level. The copper ion laser transition at 780 nm populated at the 5p level. The hollow cathode copper ion laser is operated in He and Ne mixture by electric discharge excitation and could be operated for more than 100 hours with only a 35% drop in the output power(2.8mW cw for 9.6cm active length).

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.1
• /
• pp.37-42
• /
• 2012

LIFT (laser-induced forward transfer) is an advanced laser processing method used for selectively transferring micron-sized objects. In our study, this process was applied in order to deposit solder balls in microsystem packaging processes for electronics. Locally melted solder paste could be transferred to a rigid substrate using laser pulses. A thin glass plate with a solder cream layer was used as a donor film, and an IR laser pulse (wavelength = 1070 nm) was used to transfer a micron-sized solder ball to the receptor. Mass balance and energy balance were applied to analyze the shape and temperature profiles of the solder paste drops. The transferred solder bumps had measured diameters of 30-40 ${\mu}m$ and thicknesses of 50 ${\mu}m$ in our experiment. The limits and applications of this method are also presented.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2011.06a
• /
• pp.145-146
• /
• 2011