• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.05a
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• pp.816-819
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• 2000

Recently the styrofoam has been used fur material of press die pattern. The object of this research is to develope an automated laser system for manufacture of press die pattern which depends chiefly on handwork during its process. After converting 3-D CAD model into cross-sectional shape information, the unnecessary part of the section is vapored away by laser. The depth and width of cut are mainly under the control of laser power and beam feed rate. The optimum manufacturing conditions are obtained by preliminary experiments. It is necessary fur precise styrofoam pattern manufacturing to develope laser system which has sufficient motion accuracy and program or beam path generation and automatic control of this system.

• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2489-2491
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• 2003

In this study, we implement the laser pattern controller using function generator IC. Overall system consists of : (1) laser excitation circuit and laser tube, (2) two small mirrors to reflect laser beam on the screen, (3) two small motors for X, Y axis enabling each attached mirrors to rotate, (4) controller for motor control and user interface, (5) system power. We explain the architecture of the system and required theory to implement the system. Finally, experimental results are illustrated to show the performance of the system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1996.10a
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• pp.422-430
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• 1996

The automated scanning laser Doppler vibrometer (LDV) has been designed, and built to measure in-plane displacements associated with waves propagating on vibrating structures. Use of optical fibers allows the compact design of a laser probe head which can be scanned over the vibrating structures. An algorithm for automated self-alignment of the laser probe is developed. The system is completely automated for scanning over the structures, focusing two laser beams at each data point until the detected vibration signal is stable, and for recording and transferring the data to a system computer. The automated system allows one to get extensive data of the vibration field over the structures. The system is tested by scanning a piezoelectric cylindrical shell and a plate excited by a continuous signal and by a pulse signal, respectively. Results show that the automated scanning LDV system can be a useful tool to measure the in-plane vibration field and to detect the elastic waves propagating on the vibrating structures.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1271-1274
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• 1995

In this paper, design feature and operation characteristics of compact Ruby laser for plasma diagonostics are described. A linear Xe flashlamp and a single elliptical cavity are adopted as optical pumping system. With charging energy of 484J, the maximum output energy of 170mJ, laser pulse width $110{\mu}s$, and slope efficiency 0.09% were obtained. If Q-switch system is added to this laser, we suppose this laser will be quite enough for diagonizing plasma.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.911-914
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• 2007

We developed the laser annealing system using green laser of 261W(5kHz) and 75.5mJ/pulse(2kHz). We confirmed that this system makes it possible to form two kinds(large or uniformed grain) of poly-Si by changing its polarized directions. By using ${\mu}-crystal-Si$ as irradiated films, grain size uniformity is better than that using a-Si.

• Proceedings of the Optical Society of Korea Conference
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• 2001.08a
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• pp.154-155
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• 2001

A laser system for therapy of cancer is proposed in this paper. In order to accuracy and statistical output control we used the constant current control method and designed the power source to protect the resonator from the over -current, rush-current and electrical fault. The most important things are the radiation type for cancer therapy in laser system, we developed the radiation type of cw, pulse, and burst pulse. The experimental result show that laser beam power increase linearly from 100mW to 300mW for input current increasing and the exposure time.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.478-480
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• 2009

This experiment implemented a laser projection system that used the 2D MEMS scanner as the driving method for the display device. The 2D MEMS scanner, which can scan the images horizontally and vertically, was applied to drive the projection system using the interlaced scanning method. The laser was directly modulated to implement the grayscale and the images were WVGA resolution quality.

• The Journal of Pediatrics of Korean Medicine
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• v.26 no.4
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• pp.77-83
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• 2012

Objectives: The purpose of this study was to assess the effect of Extravascular Laser System on Osgood-Schlatter Disease Methods: In this study, we treated the 6 cases of children who were diagnosed with Osgood-Schlatter disease with Extravascular Laser System. 4 of them were treated with acupuncture as well, the other 2 were given with combined acupuncture and Blood-pricking Treatment. For evaluation, 6 children explained the degree of pain relief by comparing with degree of pain before treatment. Results: Extravascular Laser System for Osgood-Schlatter Disease resulted in a significant decline in the subjective pain degree. All of them were almost cured. The average treatment times was 6.7 times, and the average treatment period was 26.7days. Conclusions We report the good result of the efficacy of extravascular laser system on Osgood-Schlatter Desease. Cases in this study, however, were small in number. Therefore more study is required.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.05a
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• pp.41-45
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• 2006

The study on laser-ablation plasmas has been strongly interested in fundamental aspects of laser-solid interaction and consequent plasma generation. In particular, this plasma has been widely used for the deposition of thin solid films and applied to the semiconductors and insulators. In this paper, we developed and discussed the generation of carbon ablation plasmas emitted by laser radiation on a solid target, graphite. The progress of carbon plasmas by laser-ablation was simulated using Monte-Carlo particle model under the pressures of vacuum, 1 Pa, 10 Pa and 66 Pa. At the results, carbon particles with low energy were deposited on the substrate as the pressure becomes higher. However, there was no difference of deposition distributions of carbon particles on the substrate regardless of the pressure.

• Journal of the Optical Society of Korea
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• v.17 no.4
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• pp.323-327
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• 2013

A laser ultrasonic inspection system has the advantage of nondestructive testing. It is a non-contact mode using a laser interferometer to measure the vertical displacement of the surface of a material caused by the propagation of ultrasonic signals with the remote ultrasonic generated by laser. After raising the ultrasonic signal with a broadband frequency range using a pulsed laser beam, the laser beam is focused to a small point to measure the ultrasonic signal because it provides an excellent measurement resolution. In this paper, foreign materials are measured by a non-destructive and non-contact method using the laser ultrasonic inspection system. Mixed foreign material on the corroded part is assumed and the laser ultrasonic experiment is conducted. An ultrasonic wave is generated by pulse laser from the back of the specimen and an ultrasonic signal is acquired from the same location of the front side using continuous wave laser and Confocal Fabry-Perot Interferometer (CFPI). The characteristic of the ultrasonic signal of existing foreign material is analyzed and the location and size of foreign material is measured.