• Journal of Adhesion and Interface
• /
• v.23 no.2
• /
• pp.39-43
• /
• 2022

In optoelectronic devices including displays and solar cells that convert electricity into light or light into electricity, it is important to control optical behavior of light to improve device efficiency. Specifically, the control of internal emitting light in the OLEDs can induce more light to go out, improving luminous efficiency. In addition, the control of optical behavior of incident light in solar cells can increase optical path in the light absorption layer, increasing power-conversion efficiency. In this study, we generated wrinkles as a physical structure to control optical behavior of light and independently controlled their wavelength and height by changing stress relaxation time. To explore the effect of wavelength and height on optical behavior, we conducted UV/Vis spectroscopy analysis of wrinkles with various heights at a constant wavelength or various wavelengths at a comparable height, figuring out a wrinkle with high aspect ratio has more dispersive light and less straight light. It indicates that high aspect ratio is required to change the optical behavior and increase the optical path.

• Korean Journal of Optics and Photonics
• /
• v.21 no.5
• /
• pp.206-213
• /
• 2010

We fabricated and characterized a compact endoscopic catheter for optical coherence tomography. The optical delay line (ODL), composed of a cylindrical piezoelectric transducer (PZT) and an optical fiber, was operated with a 1 kHz sinusoidal driving wave in the time-domain. When the ODL was driven with a sinusoidal wave function, the axial scanning speed was 6 m/s and the axial acquisition rate was 2000 line/s at a depth of about 3 mm. Endoscopic OCT images of a human finger and earhole were successfully obtained with an image rate of ten frames per second.

• Korean Journal of Optics and Photonics
• /
• v.19 no.2
• /
• pp.144-149
• /
• 2008

Thermal distortion of the laser mirrors which are the Coude mirrors of the laser beam director and the wavefront error caused by the thermal distortion are studied. Coude mirrors consist of three relay mirrors and one fast steering mirror. The mirrors have reflectivity of 99.5% with respect to the laser wavelength of $3.8\;{\mu}m$, and absorption of 500 W per second. Thermal distortion and its related wavefront errors are studied with laser beam irradiation for 5 seconds. For the relay mirror, the wavefront error is 334 nm_PV, 98 nm rms and for fast steering mirror, $11.5\;{\mu}m$_PV, $3{\mu}m$ rms.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2013.05a
• /
• pp.901-902
• /
• 2013

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2003.10a
• /
• pp.103-106
• /
• 2003

In this work the novel potential epoxy resins, were synthesized and acrylated. Their structures were confirmed by means of FTIR, $^1H NMR, and^{13}/C NMR$ spectroscopies. Also, we were to note the effect of W curing on functional group changes of VE/UP blend system after UV curing.

• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.1394-1399
• /
• 2007

Recently, Study of 3D freeform fabrication method was working in the various applications. For example, in the powder base, it's laminated using a binding method or laser sintering method. However, these methods are not suitable in the office environments because it dust with powder that is bad for health. In this paper, we introduce a method of 3D freeform fabrication using a curing of photo-polymer resin and construct a system has multi printing head. A photo-polymer curing method has simply fabrication process and high strength of manufacturing part. However, this method has a problem on the multi print-head system. Because multi-printing system has a other printing method compare with a single printing system. Therefore, we experiment a single head 3D printing and proposed a 3D printing method using a multi-piezo head.

• Proceedings of the KIEE Conference
• /
• 2001.11c
• /
• pp.172-175
• /
• 2001

쾌속조형기술은 제품 설계나 기타 물체의 형상 데이터로부터 광경화성 수지, 금속 등 다양한 재료를 이용하여 수 시간 내에 실물 모형을 제작할 수 있는 기술이다. 쾌속조형기술은 주로 자동차나 제품의 모형제작에 주로 사용되어 왔다. 사이버메드에서는 인체에 대한 3차원 형상화 기술과 쾌속조형기술을 이용하여 개인별로 상이한 인체 골격에 대한 비교적 저렴한 비용으로 실물 모형을 제작할 수 있는 기술을 개발하여, 국내 및 일본의 병원에서 수술 계획 및 모형 수술에 직접 적용하고 있다. 이 논문은 쾌속 조형 기술, 인체의 3차원 형상화 기술의 개요와 그 동향, 그리고 이를 결합한 수술용 인체 골격모형의 제작 기술과 적용 사례에 대해서 기술하였다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2003.06a
• /
• pp.612-615
• /
• 2003

Maskless laser patterning process is developed using 3rd harmonic Diode Pumped Solid State Laser with near visible wavelength of 355 nm. Photo-sensitive curable polymer is irradiated by UV laser and developed using polymer solvent to obtain quasi-3D patterns. We performed basic experiments for the various process conditions such as laser power, writing speed, laser focus, and polymer optical property to gain the optimal conditions. Experimentally, the patterns of trapezoidal shape were manufactured into dimension of 8${\mu}{\textrm}{m}$ width and 5.4${\mu}{\textrm}{m}$ height. This process could be applied to fabricate a single mode waveguide without expensive mask projection method.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.25 no.2
• /
• pp.358-365
• /
• 2001

The purpose of this study was to investigate the relation between various aspects of multiple body image and clothing behavior i.e. individuality/self expression, body improvement, social approval, sex appeal. The data were collected from 498 female university students in Seoul and Kyong Ki Province and analyzed using factor analysis, Pearsons correlations, reliability test, analysis of variance, and multiple regression analysis. The results of this study were as follows: 1) Four dimensions of multiple body image were identified : appearance, body attractiveness, degree of fitness and atheletic skill. 2) Perception on appearance and fitness aspect of multiple body image has a positive correlation with all aspects of clothing behavior i.e. individuality/self expression, body improvement, social approval and sex appeal of clothing behavior. Body attractiveness and atheletic skill of multiple body image also had a positive correlation with individuality/self expression, and sex appeal.