• Journal of the Korean Ceramic Society
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• v.29 no.1
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• pp.48-52
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• 1992

Indium tin oxide (ITO) layers are of considerable interest on account of the combination of properties they provide high electrical conductivity, high infrared reflection with high solar energy transmission, high transmission in the visible range. We are concerned about the variation of the spectral transmittances and sheet resistances as the thickness of SiO2-ZrO2 barrier layer and ITO layers and heat treating conditions are changed. Transmittances and reflectivities were studied by measuring UV-VIS-NIR-, FT-IR spectroscopy. ITO films are crack free, homogeneous and of polycrystalline cubic structure. The microstructure of good ITO films shows a narrow grain size distribution and mean value of 100 nm. The selectivity of absorbing properties is improved by increasing the thickness of ITO films. The increase of sheet resistance of ITO films are due to the increase in the reaction between films and glass substrate.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.9 no.4
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• pp.53-58
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• 2010

In this paper, the output characteristics of PSD(Position Sensetive Detector) used in measurement system are described. Most of the precision measurment systems are accomplished by a laser diode(LD), a photo diode(PD) and PSD(Position Sensetive Detector), which are used in reflection of mirror or projection of infrared spectrometer. But it is especially restricted by resolution of PD and PSD in nano-measurement. A new inclined light methods into the PSD are employed in the surface measurement system for increasing the resolution. As the results, we can know that the output characteristics of detective senser (PSD) become more than 2 or 3 times by changing inclined angle(range: 5 degree) compared with common angle. In addition, the experiment results are confirmed that the change of inclined angle is not affecting to the linearity and repeating.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.268-268
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• 2013

Water molecules on a Ru(0001) surface are anomalously acidic compared to bulk water. The observation was made by conducting reactive ion scattering, reflection absorption infrared spectroscopy, and temperature-programmed desorption measurements for the adsorption of ammonia onto a water layer formed on Ru(0001). The study shows that the water molecules in the first intact $H_2O$ bilayer spontaneously release a proton to NH3 adsorbates to produce $NH_4{^+}$. However, such proton transfer does not occur for $H_2O$, OH, and H in a mixed adsorption layer or for $H_2O$ in a thick ice film surface.

• Proceedings of the KOSOMBE Conference
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• v.1993 no.05
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• pp.116-119
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• 1993

In this paper, we implemented a pulse wave type oximeter system that continuously measure the of oxyhemoglobin saturation of the arterial blood(SaO2) and pulse rate with non-invasively. We use the transmission type and reflection type transducer for comparison the percentage of hemoglobin oxgen saturation. The light Iron the two kind of LEDs is transmitted through the tissue, then received by a single photodiode with alternatively. By the phase sensitive detection circuit, the output of the photodiode is separated in to red and near infrared signal. We calculated a ratio of light transmittance between two kind of LEDs, and then, it is applied to the oxgen saturation coefficent calculation formular.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.165-166
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• 2007

특수 분장을 이용하여 매우 정교하게 제작된 가면을 쓴 얼굴 위변조의 경우 일반적인 밝기 영상으로는 검출이 용이하지 않다. 최근의 획기적인 특수 분장 기술 발전을 고려할 때 성공적인 얼굴 인식시스템 개발을 위해 가면을 쓴 얼굴 위변조 검출 연구는 매우 중요하다. 본 연구에서는 물질의 재질에 따른 반사율의 차이를 기반으로 가면을 착용하는 얼굴 위변조를 검출하는 방법을 제안한다. 우선 알비도(albedo)에 착안하여 여러 파장대의 조명에 대해 실험하였다. 실제 얼굴 인식 시스템의 적용 환경을 고려할 때 알비도를 단순히 빛의 반사량으로 간략화 할 수 있음을 보였고, 실험결과 850nm 적외선 조명이 적합하다는 결론을 얻었다.

• Journal of the Optical Society of Korea
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• v.8 no.1
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• pp.34-52
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• 2004

Over the past decade the experimental technique of THz time domain spectroscopy (㎔- TDS) has proved to be a versatile method for investigating a wide range of phenomena in the ㎔ or far infrared spectral region from 100 ㎓ to 5 ㎔. This paper reviews some recent results of the Ultrafast ㎔ Research Group at Oklahoma State University using ㎔-TDS as a characterization tool. The experimental technique is described along with recent results on ㎔ beam propagation and how ㎔ beam profiles arise from propagation of pulse fronts along caustics. To illustrate how spatio-temporal electric field measurements can determine material properties over a wide spectral range, propagation of ㎔ pulses through systems exhibiting frustrated total internal reflection (FTIR) are reviewed. Finally two potential metrology applications of ㎔-TDS are discussed, thin film characterization and non-destructive evaluation of ceramics. Although ㎔-TDS has been confined to the research laboratory, the focus on application may stimulate the adoption of ㎔- TDS for industrial or metrology applications.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.5-8
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• 1997

A study on the electrical conduction characteristics of the ultrathin organic films is one of the important factors for the development of molecular electronic devices. The Langmuir- Blodgett(LB) technique has recently been attracted interest as a method of the deposition ultrathin films. We hate fabricated N-docosyl N\`-methyl viologen-diTCNQ(DMVT) anion radical LB film and investigated the molecular orientation and electrical conduction characteristics. We have measured infrared transmission-reflection spectra. The alkyl chain is found to he well-ordered with the tilt angle of 13$^{\circ}$ with respect to the substrate surface normal and the TCNQ plane is tilted at 76$^{\circ}$ the surface normal. In ESR spectrum, we confirmed that a half-amplitude linewidth is clearly dependent on the incident angle, which indicates conducting species change. The in-plane conductivity of 31 lagers is approximately 1.33$\times$10$^{-6}$ S/cm. The ohmic behaviour was observed below 0.6 V, when current-voltage(I-V) characteristics was measured verically.

• Economic and Environmental Geology
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• v.22 no.1
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• pp.65-80
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• 1989

Strongly weathered granitic rocks are widely distributed in the south-eastern part of the Ganghwa island. Kaolinite developed during intense weathering on this granitic rocks have been studied mineralogically and chemically. Various weathering indexes were ca1culated on the basis of oxide. Those indexes are slightly varied with depth. It shows that the percentages of $Al_2O_3$ increase but that of $CaO+Na_2O+K_2O$ decrease as the weathering progress. These results indicate that day minerals, mainly kaolinite with the appreciable amount of halloysite, were formed by the weathering of feldspars in the granitic rocks. X-ray diffraction, differential thermal analysis, infrared spectrometry and electron microscopy were used to characterize and estimate crystallinity of the kaolinite. Generally, Kaolinite shows a less sharp basal reflection and relatively low dehydroxylation temperature, indicating disordered kaolinite. They usually occur aggregates as a vermicular kaolinites showing loose basal plane stacking arrangement.

• Journal of the Korean institute of surface engineering
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• v.39 no.4
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• pp.166-172
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• 2006

Metallized Polyimide films are extensively used as base materials in microelectronics, optical and automotive applications. However it is difficult to deposit metals on those because of their structural stabilities. In this work, polyimide films are modified by a wet process with alkalinemetalhydroxide and additives to introduce functional groups. The surface molecular structures of polyimide are investigated using X-ray photoelectron spectroscopy(XPS), fourier transform infrared reflection spectroscopy(FTIR-ATR), atomic force micro-scopic(AFM). XPS spectra and FTIR spectra show that the surface structure of polyimide is converted into potassium polyamate. AFM image and AFM cross-sectional analyses reveal the increased roughness on the modified surface of polyimide films. As a result, it is shown that the adhesion strength between polyimide surface and electroless nickel layer is increased by the nano-anchoring effect.

• Journal of the Korea Institute of Military Science and Technology
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• v.22 no.1
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• pp.81-92
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• 2019

Stealth means the reduction of all signature including the reflection/emission of radar, infrared, visible light and audio signals. Stealth aircraft can significantly improve the penetration capability, the combat survivability and the mission effectiveness. This paper presents the basic concept, the key elements and the application examples of stealth aircraft technology. Also it briefly describes the effect of the modern stealth aircraft on the future air warfare.