• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.6
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• pp.804-812
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• 2003

This paper introduces optical methods for in-situ measurement of surface temperature and pressure transient in thermal processes having nanosecond time scales. In the temperature measurement, a p -Si thin film whose refractive index is calibrated as a function of temperature is embedded beneath the sample surface and the photothermal reflectance is monitored for estimating the surface temperature. The pressure transients are measured using the photoacoustic optical deflection method. The experimental technique is used to analyze the nanosecond laser induced vaporization process that is central to numerous engineering and bio-medical applications. Based on the experimental results, discussions are made on the experimental technique and the physical mechanisms of laser-driven explosive vaporization phenomena.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.1.1-1.6
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• 2015

The restoration of extensive zygomatic complex defects is a surgical challenge owing to the difficulty of accurately restoring the normal anatomy, symmetry, proper facial projection and facial width. In the present study, an extensive post-traumatic zygomatic bone defect was reconstructed using a custom-made implant that was made with a selective laser melting (SLM) technique. The computer-designed implant had the proper geometry and fit perfectly into the defect without requiring any intraoperative adjustments. A one-year follow-up revealed a stable outcome with no complications.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1807-1809
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• 2002

In this study, asolid-state laser system adopting a firing time control(FTC) method in which three flashlamps are turned on consecutively was designed and fabricated to examine the pulse width and the pulse shape of the laser beams depending upon the changes in the lamp turn-on time. That is, this study shows a technology that makes it possible to make various pulse shapes by turning on three flashlamps consecutively on a real-time basis with the aid of a PIC one-chip microprocessor With this technique, the lamp turn-on delay time can be varied more diversely from 0 to 10 ms and the real-time control is possible with an external keyboard enabling various pulse shapes. In addition longer pulses can be more widely used for industrial processing and lots of medical purposes.

• Journal of the Korean Applied Science and Technology
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• v.12 no.2
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• pp.151-156
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• 1995

The influences of fluorophor, scatterer, absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by laser induced fluorescence spectroscopy. It has been found that the effects of optical properties in scattering media by the optical parameters(${\mu}_{s}$, ${\mu}_{a}$, ${\mu}_{t}$). The value of scattering coefficient ${\mu}_{s}$ is large by means of the increasing particles of scatterer, it has been found that the slope decays exponentially as a function of distance from laser source to detector. It may also aid in designing the best model for oil chemistry, laser medicine and application of medical engineering.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.309-310
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• 1998

Visual observation and subjective assessments lack the objective evaluation of laser therapy effects of the epidermal pigmented lesions. In this study, we proposed the two methods; One is CIE(Commission International d'Eclairage) $L^*,\;a^*,\;b^*$ coordinate system($L^*$ : brightness, $a^*$ : red(+) $\sim$green(-) content, $b^*$ : yellow(+) $\sim$blue(-) content), and the other is the relative color difference measurement. And we applied these two methods for quantitative evaluation of the laser therapy effects.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.76-77
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• 1998

In this paper, the authors have implemented a blood flow simulator and a blood flowmeter probe using self-mixing effect of the laser diode. The purpose of the blood simulator is to simulate microvascular blood flow in tissue. It consists of melinex film (thickness = $125{\mu}m$) which has similar optical characteristics to epidermis and porous polyethylene filter (Vyon, porosity 35%, mean pore size $50{\mu}m$, thickness=1 mm) which has similar optical characteristics to dermis. The blood flowmeter probe consists of laser diode(5 mW, 780 nm wavelength), CD lens(focal lenght 12 mm), current-to-voltage converter, highpass filter, and preamplifier. It doesn't need optical fiber, therefore, implementation of the probe is simpler than conventional probe using optical fiber.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.20 no.1
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• pp.25-30
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• 2009

Introduction: 585 nm Pulsed dye laser (PDL) laryngeal surgery is based on the photodynamic characteristics of selective photothermolysis and photoangiolysis and recently considered to be the treatment for a variety of benign laryngeal disease. Objective: To review the indications and outcome of office-based 585nm PDL surgery and summarize new developments. Method: Retrospective study involving 402 patients was performed, The PDL surgery could be applied to various laryngeal diseases such as laryngeal papilloma, vocal fold dysplasia, laryngeal granuloma, vocal polyp, capillarectasia, scarred vocal fold and sulcus vocalis. Results : The physiologic properties of the vascular specificity of PDL provide many advantages and appear to be effective for laryngeal treatment. The PDL resulted in precise, selective coagulation of the microvasculature without damage to the surrounding tissue. Therefore PDL surgery is safe and effective for office-based treatment of benign laryngeal disease and for all patients regardless of their overall medical condition. Conclusion: PDL surgery provides potential benefits and advantage for treating common benign laryngeal disease.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.459-460
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• 2005

The global consumption of aspheric surfaces will expand rapidly on the Electronics and Optical Components, Information and Communications, Aerospace and Defense, and Medical optics markets etc. We must research on market, technology forecast and analysis of aspheric surfaces that is a principle step of ultra precision machine technology with a base one of optical elements. Especially, F-theta lens is one of the important parts in LSU(Laser scanning unit) because it affects on the optical performance of LSU dominantly. The core is most of important to produce plastic F-theta lens by plastic injection molding method, which is necessary to get the ultra-precision aspheric and non-axisymmetric machine processing technology.

• Journal of the Korean Applied Science and Technology
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• v.16 no.4
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• pp.329-335
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• 1999

The influences of fluorophor, scatterer, and absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength. The molecular properties have been studied by laser induced fluorescence spectroscopy in phantom. It has been found that the effects of optical properties in scattering media could be investigated by the optical parameters(${\mu}_a$, ${\mu}_a$, ${\mu}_t$). Experimental and Monte Carlo Simulation method for modelling light transport in tissue was applied. The experimental results using a phantom were discussed and compared with those obtained through Monte Carlo Simulation. It may also aid in designing the best model for oil chemistry, medicine and application of medical engineering.

• Medical Lasers
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• v.9 no.2
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• pp.95-102
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• 2020

Phototherapy has a profound immunosuppressive effect and is widely used for the treatment of inflammatory skin diseases. Since allergic rhinitis (AR) shares several common pathologic features with atopic dermatitis, intranasal phototherapy is a novel approach for treating AR. Phototherapy reduces the antigen presenting capacity of dendritic cells, induces apoptosis of immune cells, and inhibits synthesis and release of pro-inflammatory mediators from inflammatory cells. The effectiveness of phototherapy for AR has been extensively researched: from in vitro studies to several clinical trials. Data indicates the potential of intranasal phototherapy as an alternative treatment for AR as well as other inflammatory mucosal diseases. In this review, we introduce the in vitro, in vivo studies, and clinical trials which demonstrated the effect of phototherapy on AR.