• Title/Summary/Keyword: Surface coverage

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A Study for Optimization Methodology of Unmanned System Architecture for Mine Countermeasure Based on Effectiveness (효과기반의 대기뢰전 무인화 체계 최적화 방안 연구)

  • Hong, Sungpyo;Yoon, Seonil;Choi, Bongwan;Oh, Hyunseung
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.37 no.2
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    • pp.62-69
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    • 2014
  • The capability and cost effectiveness of UUV and USV bring to underwater survey, target detection and identification operations have been widely demonstrated and accepted in recent years. Future USV systems may deploy UUVs to gain the advantage of higher area coverage rates through multiple and simultaneous operations. In this paper, we present an architecture of USV and UUV for mine countermeasure with results of measures on effectiveness.

Water vapor barrier properties of polymer-like amorphous carbon deposited polyethylene naphthalate film

  • Kim, Jeong-Yong;Park, Gyu-Dae;Song, Ye-Seul;Lee, Hui-Jin;Vu, Minh Canh;Kim, Seong-Ryong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.303.1-303.1
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    • 2016
  • Polymer-like amorphous carbon films were deposited on polyethylene naphthalate (PEN) substrate by plasma-enhanced chemical vapor deposition (PECVD) and their water vapor transmission rates (WVTR) were tested. propane was used as precursors. To make a polymer-like amorphous carbon film the deposition rate, surface roughness, light transmittance, and WVTR of the films were characterized as a function of the precursor feed ratio and plasma power. The water vapor transmission rates of bare PEN film and single layer PAC on PEN substrate were 6.95 g/m2/day and 0.3 g/m2/day, respectively. The superior property the water vapor permeability of thin layers of PAC was attributed to uniform coverage and good adhesion between PAC film and PEN substrate.

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Electronic Structure and Magnetic Moments of Copper-atom in/on GaN Semiconductor

  • Kang, Byung-Sub;Lee, Haeng-Ki
    • Journal of Magnetics
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    • v.15 no.2
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    • pp.51-55
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    • 2010
  • The electronic and magnetic properties of Cu-doped GaN with a Cu concentration of 6.25% and 12.5% are examined theoretically using the full-potential linear muffin-tin orbital method. The magnetic moment of Cu atoms decreases with increasing Cu concentration. The spin-polarization of Cu atoms is reduced due to the Cu d-d interaction depending on the distance between the nearest neighbouring Cu atoms. Cu atoms exhibits a clustering tendency in GaN. For Cu-adsorbed GaN thin films with a surface coverage of 0.25, the ferromagnetic state is found to be the energetically favourable state with an induced magnetic moment of $0.54\;{\mu}_B$ per supercell.

The electrochemical study on Viologen SA monolayer using QCM (수정진동자를 이용한 Viologen Self-Assembly 단분자막의 전기화학적 특성)

  • Kim, Jung-Myoung;Yoon, Hee-Chan;Song, Seung-Hun;Kwon, Young-Soo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.05b
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    • pp.21-23
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    • 2002
  • In this paper, the electrochemical behavior of Viologen self assembly monolayer has been investigated with QCM, which has been known as nano-gram order mass detector. The self assemvly process of Viologen was monitored using resonant frequency $({\Delta}F)$ and resonant resistance(R). QCM measurements indicated a mass adsorption for Viologen assembling on the gold sufrace with a frequency change about 135[Hz] and calculated its surface coverage($\Gamma$) to be $3.5273{\times}10^{-9}[mol/cm^{2}]$. Also reversible redox process was observed and analyzed with ionic interaction at the Viologen/solution interface using ${\Delta}F$.

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Adaptive Contrast Stretching for Land Observation in Cloudy Low Resolution Satellite Imagery

  • Lee, Hwa-Seon;Lee, Kyu-Sung
    • Korean Journal of Remote Sensing
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    • v.28 no.3
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    • pp.287-296
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    • 2012
  • Although low spatial resolution satellite images like MODIS and GOCI can be important to observe land surface, it is often difficult to visually interpret the imagery because of the low contrast by prevailing cloud covers. We proposed a simple and adaptive stretching algorithm to enhance image contrast over land areas in cloudy images. The proposed method is basically a linear algorithm that stretches only non-cloud pixels. The adaptive linear stretch method uses two values: the low limit (L) from image statistics and upper limit (U) from low boundary value of cloud pixels. The cloud pixel value was automatically determined by pre-developed empirical function for each spectral band. We used MODIS and GOCI images having various types of cloud distributions and coverage. The adaptive contrast stretching method was evaluated by both visual interpretation and statistical distribution of displayed brightness values.

A Study on Establishment of Brassiere Size and Clothing Pressure for the Twenties-aged Women (20대 여성의 브래지어 치수설정과 의복압에 관한 연구)

  • 박유신;임영자
    • Journal of the Korean Society of Costume
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    • v.52 no.8
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    • pp.15-27
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    • 2002
  • To set the measurements of bras for women in their 20s, considering the comfortableness in wearing and tightness, this paper conducted a questionnaire survey concerning breasts and bras as well as measurements of body and contact surface pressure. Easier and more accurate method of determining cup sizes based on the breast circumference is recommended to make up for the problem of current bra size system that can falsely measure cup sizes. Lower chest circumference was set at 5 cm equal intervals, and the breast circumference applicable to the cup size was set starting from the standard, 18 cm (A-cup), at 2 cm equal intervals, which gave the best coverage (88.1%).

증착온도가 CVD Cu 박막의 미세구조 및 전기비저항에 미치는 영향

  • 이원준;민재식;라사균;김동원;박종욱
    • Journal of the Korean Vacuum Society
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    • v.4 no.S1
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    • pp.118-128
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    • 1995
  • Copper(l) hexafluoroacetonate trimethylvinylsilane [Cu(hafac)(TMVS)]를 precursor로 사용하여 증착온도 $160~330^{\circ}C$ 범위에서 TiN 모재 위에 낮은 전기비저항값(~2 $\mu$$\Omega$.cm)을 갖는 CVD Cu 박막을 제조하였고, 증착온도에 따른 Cu 박막의 특성을 조사하여 증착온도가 Cu 박막의 미세구조와 전기비저항에 미치는 영향을 고찰하였다. Cu 증착의 활성화에너지는 표면반응제한지역(surface-reaction-limited region)에서 10.8 kcal/mol 이었다. 표면반응에 의해 증착속도가 결정되는 증착온도 $200^{\circ}C$ 이하에서 증착된 Cu 박막은 낮은 비저항값을 갖는 치밀한 박막이었고 step coverage 또한 우수하였다. 이에 반해 물질전달이 증착속도를 결정하는 증착온도 $200^{\circ}C$이상에서 증착된 Cu 박막은 연결상태가 불량한 구형의 결정립들로 이루어져 있어서 높은 비저항값과 거친 표면형상을 나타내었다. 이와 함께 증착온도에 따른 Cu 박막의 결정립 크기, 배향성 등도 조사하였다.

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Photoelectric Obsrvations of RS Canum Venaticorum

  • Lee, Yong-Sam;Jeong, Jang-Hae
    • Journal of Astronomy and Space Sciences
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    • v.1 no.1
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    • pp.55-65
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    • 1984
  • A total of 618 photoelectric observations (302 in yellow and 316 in bule) is made in 1982 at the Yonsei University Observatory. Except that of the secondary eclipse the homogeneous coverage of observations successfully secured B, V, and B-V light curves. Enhanced distortions in the light curves are appeared at the phases aroung $0.^P1$, which supports the wave-like migration period of 9.7 years(Rodono 1981). One epoch time of the primary minimum was made by combining the observations in three nights. This minimum time shows that the O-C values are still decreasing and there seems to indication of increasing. B and V light curves of the primary minimum are in strong asymmetry which show less luminous in the third and fourth contacts compared to those of the first and second ones. This asymmetry may be as a result of the reflection of the wave minimum at $0.^P1$, and B-V curve also shows asymmetry, redder at the third contact than the second one by about $0.^m04$. This color difference apperature distribution on the surface of cooler, larger component(KO IV star).

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Development of Al plasma assisted chemical vapor deposition using DMEAA (DMEAA를 이용한 알루미늄 PACVD법의 개발)

  • 김동찬;김병윤;이병일;김동환;주승기
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.10
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    • pp.98-106
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    • 1996
  • A thin film of aluminum for ultra large scale integrated circuits metalization has been deposited on TiN and SiO$_{2}$ substrates by plasma assisted chemical vapor deposition using DMEAA (dimenthylethylamine alane) as a precursor. The effects of plasma on surface topology and growth characteristics were investigated. Thermal CVD Al could not be got continuous films on insulating subsrate such as SiO$_{2}$. However, it was found that Al films could be deposited on SiO$_{2}$ substate without any pretreatments by the hydrogen plasma for pyrolysis of DMEAA. Compared to the thermal CVD, PACVD films showed much better reflectance and resistance on TiN and SiO$_{2}$ substrate. We obtained mirror-like PACVD Al film of 90% reflectance and resistance on TiN and SiO$_{2}$ substrates. We obtained mirror-like PACVD Al film of 90% reflectance on TiN substrate. Excellent conformal step coverage was obtained on submicron contact holes ;by the PACVD blanket deposition.

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Electrochemical spike oscillation st the Ni electrode interface (Ni 전극 계면에서 전기화학적 spike 발진)

  • 천장호;손광철;라극환
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.12
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    • pp.83-89
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    • 1996
  • The electrochemical spike oscillations at the nickel (Ni) electrode/(0.05M KHC$_{8}$H$_{4}$O$_{4}$) buffer solution (pH 9) interface have been studied using voltammetric and chronoamperometric methods. The nature of the periodic cathodic current spikes is the activation controlled currents due to the hydrogen evolution reaction and depends onthe fractioanl surface coverage of the adsorbed hydrogen intermediate or the cathodic potential. There is two kinds of the waveforms corresponding to two kinds of the cathodic current spike oscillations. The widths, periods, and amplitudes of the cathodic current spikes are 4 ms or 5ms, 151 ms or 302 ms, and < 30 mA or < 275 mA, respectively. The fast discharge and recombination reaction steps are 1.5 times and twice and faster than the slow discharge and recombination reaction steps. The fast and slow discharge and recombination reaction steps are 1.5 times and twice faster than the slow discharge and recombination reaction steps. The fast and slow discharge and recombination reactions corresponding to the fast and slow adsorption sites at the Ni cathode.

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