• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2003년도 춘계학술발표회 초록집
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• pp.53-53
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• 2003

Plasma polymerized organic thin films were deposited on Si(100) glass and metal substrates using thiophene and ethylcyclohexane precursors by PECVD method. In order to compare electrochemical properties of the as-grown thin films, the effects of the RF plasma power in the range of 30~100 W. AFM showed that the polymer films with smooth surface and sharp interface could be grown under various deposition conditions. Impedance analyzer was utilized for the determination of I-V curve for leakage current density and C-V for dielectric constants, respectively. To obtain C-V curve, we used a MIM structure of metal(Al)-insulator(plasma polymerized thin film)-metal(Pt) structure. Al as the electrode was evaporated on the thiophene films that grew on Pt coated silicon substrates, and the dielectric constants of the as-grown films were then calculated from C- V data measured at 1MHz. From the electrical property measurements such as I-V and C-V characteristics, the minimum dielectric constant and the best leakage current of thiophene thin films were obtained to be about 3.22 and $1{\;}{\times}10^{-11}{\;}A/cm^2$. However, in case of ethylcyclohexane thin films, the minimum dielectric constant and the best leakage current were obtained to be about 3.11 and $5{\;}{\times}10^{-12}{\;}A/cm^2$.

• 생물환경조절학회지
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• 제30권1호
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• pp.27-36
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• 2021

정전용량 수분측정 센서는 수경용 배지 양쪽에 구리 및 테플론으로 절연된 전극판(30cm×10cm)을 부착하여 배지의 넓은 부분에 걸쳐 측정하도록 개발되었다. 본 연구는 콘덴서형 정전용량 센서로부터 출력되는 정전용량 값을 배지 함수량으로 변환하는 것이다. 정량화 실험은 양액을 공급하면서 배지 물무게와 정전용량 변화를 측정하고 그 값을 비교하는 방식으로 수행되었다. 배지 함수량과 정전용량은 본 연구를 위해 특별히 개발된 소프트웨어와 함께 센서와 로드셀을 사용하여 20~30초마다 측정되었다. 상용 curve-fitting 프로그램을 이용하여 배지 함수량과 정전용량을 변수로 정전용량 값으로 배지 함수량을 추정하였다. 공급하는 물의 양이 증가하면 정전용량도 증가하는 경향을 보였다. 배지 내 물무게에 따른 정전용량에 대한 변동계수(coefficient of variation, cv)는 배지 내 물무게가 1.0kg 수준에서 다른 무게에 비해 높아 함수량 보정은 물무게를 1.7~6.0kg 수준에서 수행하였다. 정전용량과 물무게 사이의 상관 계수는 0.996이었고 보정식에 의해 정전용량으로 추정된 함수량은 로드셀로 측정한 배지 함수량과 비교하였다.

• Radiation Oncology Journal
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• 제6권1호
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• pp.85-91
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• 1988

한국에너지연구소 원자력병원 싸이클로트론에 의해 생산되는 중성자를 임상에 적용시키기 위해, 이의 물리적 특성을 알기 위하여 방사선선량 측정실험을 시행하였다. 여기서 얻은 결과를 외국의 다른 치료기관에서 얻은 데이타와 비교 분석하였다. 중심축 선상의 심부선량백분율, build-up곡선, open과 쐐기등선량 곡선의 값이 4MV와 6MV X-ray값의 중간에 위치하였다. 최대선량의 build-up은 피부아래 1.35cm에 위치했으며 입사 선량은 약 $40\%$였다. 출력인자는 $6\times6cm$의 조사야에서 0.894, $30\times30cm$의 조사야에서는 1.187이었다. 중성자선의 X-ray오염도는 $10\times10cm$ 조사야에서 심부 2cm에서 $4.9\%$였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.2222-2227
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• 2007

Newly structured metal-supported solid oxide fuel cell was fabricated and characterized by impedance analysis and galvanodynamic experiment. Using a cermet adhesive, thin ceramic layer composed of anode(Ni/YSZ) and electrolyte(YSZ) was joined with STS430 metal support of which flow channel was fabricated. $La_{0.8}Sr_{0.2}Co_{0.4}Mn_{0.6}O_3$ perovskite oxide was used as cathode material. Single cell performance was increased and saturated at operating time to 300hours at 800$^{\circ}C$ because of cathode sintering effect. The sintering effect was reinvestigated by half cell test and exchange current density was measured as 0.005A/$cm^2$. Maximum power density of the cell was 0.09W/$cm^2$ at 800$^{\circ}C$. Numerical analysis was carried out to classify main factors influencing the single cell performances. Compared to experimental IV curve, simulated curve based on experimental parameters such as exchange current density was in good agreement.

• 기본간호학회지
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• 제12권3호
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• pp.347-353
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• 2005

Purpose: The purpose of this study was to identify whether neck circumference might be correlated with other obesity indices and to determine the neck circumference cutoff level for obesity in female college students. Method: The data were obtained by measuring other anthropometric indices including BMI and neck circumference from 325 female college students in J city, Chungbuk Province. Receiver Operating Characteristic curve(ROC curve) analysis was used to find the optimal neck circumference cutoff level against BMI $25kg/m^2$. Results: The mean BMI was $21.4kg/m^2$, and the prevalence of obesity was 12.6%. Neck circumference was significantly correlated with body weight, BMI, waist circumference, hip circumference, waist to hip ratio, % body fat, triceps skinfold thickness, systolic and diastolic blood pressure. Neck circumference of 31.95cm was the best cutoff level for determining female students with a BMI over $25kg/m^2$, and the characteristic was acceptable with 97.6% sensitivity and 85.6% specificity. Conclusions: Neck circumference was strongly correlated with the other conventional obesity indices. Female college students with neck circumference over 31.95cm require an additional evaluation of obesity.

• 센서학회지
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• 제4권4호
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• pp.75-80
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• 1995

금속 alkoxide를 출발물질로 PZT-PNN 3성분계 압전박막을 제작하여, 박막의 결정성과 전기적 특성을 평가하였다. 박막의 X-RD 분석결과 $550^{\circ}C$ 소결온도에서 결정성이 가장 양호하였다. D-E 이력곡선의 관측 결과 항전계는 28.8 kV/cm, 잔유분극은 $18.3\;{\mu}C/cm^{2}$ 이었다. 박막의 진성파괴전압은 $76.0\;{\sim}\;27.0\;MV/m$이었고, 소결온도가 상승함에 따라 특성이 저하되었다. 박막의 비유전율은 조성비에 따라 (50:40:10)은 406, (50:30:20)은 1084, (45:35:20)은 723, (40:40:20)은 316이었다.

• 자원환경지질
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• 제13권3호
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• pp.159-166
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• 1980

A model study was conducted for the investigation of apparent resistivity variation along with electric resistivity variation of host rock and dip variation of bed. Experiments were carried out for the cases of horizontal and dipping beds in a water tank by using Wenner and Schlumberger arrays and by changing salinity of water. The ratios of resistivity values of the bed to that of brine were 1 : 10, 1 : 50, 1 : 100 and 1 : 500. Natural coally-shale of $55cm{\times}35cm{\times}3.5cm$ was used as a bed for experimental model, and brine as a host rock. Equi-resistivity curves and characteristic curves were obtained for each case of the experiment. The equi-resistivity curve was drawn both on the cross section parallel to strike of bed and longitudinal section perpendicular to it. The characteristic curve was drawn on the cross section. In the case of dipping bed of different dips, the curves are parallel to the boundary of the bed in the upper part of the bed, and are inclined to the opposite direction with the same angle of the dip of bed in the lower part. We can deduce, from the equi-resistivity curves, the location, shape and dip of the bed. It is shown in the characteristic curves that when the ratio of resistivity value of bed to that of host rock increases, the slope of curves becomes steeper, location of low-resistivity zone lower, and the width of it narrower. The slope of curves also becomes steeper when dip of bed increases. We can deduce, from the characteristic curves, the ratio of resistivity values between adjacent beds. It was found out from the experiments that electric resistivity method could be applicable to prospecting for underground geology with an electric resistivity contrast of 1 : 10. This fact strongly suggests that distinction of coal from coally-shale could be possible in a certain field condition.

• 한국의류산업학회지
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• 제25권3호
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• pp.315-323
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• 2023

In the diverse modern era, individuals are actively striving to develop and demonstrate their capabilities . As a means of cultivating interest in hanbok and differentiatedabilities , there exists a national qualification verification for hanbok technician. This study focuses on using Saekdong-jeogori pattern that is suitable for design and allows for accurate pattern production in a short time for beginners taking the practical test for hanbok technicians. We analyzed five experimental Saekdong-jeogori patterns, from which the final patterns for research were derived through appearance tests on the first table evaluation and the second outfit evaluation. The Saekdong-jeogori pattern-1 for research utilized the body values presented by beginners taking the hanbok technician qualification verification, while the rest were calculated or applied using equivalents. The godae point and armhole depth were calculated based on the chest circumference, and the armhole curve, sleeve shape, doryeon line, and sleeve-end were drawn, regardless of the changes in the figures, using equal parts. The Saekdong-jeogori pattern-2 provided activity by vertically lowering the side line from the end of the armhole, and the keotseop line was drawn by moving 1 cm from the width of the Kit to the armhole line. The seopko was raised 0.2 cm from the keotseop reference line and0.2cm , and was supplemented by its connection to a natural curve.

• Korean Chemical Engineering Research
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• 제48권6호
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• pp.784-790
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• 2010

고정층 반응기에서 비산재로부터 합성한 제올라이트와 4종류의 활성탄을 사용하여 질소 기류에서 아세톤, 벤젠, 톨루엔, 에틸벤젠 증기의 파과곡선을 측정하였다. 흡착실험은 101.3 kPa, $40^{\circ}C$에서 혼합 가스의 유량 $70cm^3/min$, 흡착제의 공급량 5 g, 그리고 VOCs 증기의 농도는 포화조의 온도를 $30^{\circ}C$로 하여 행하였다. 실험으로부터 얻은 파과곡선의 비선형해석으로부터 VOCs의 흡착과 흡착제의 비활성화를 동시에 고려한 비활성모델의 흡착속도상수와 비활성속도상수를 구하여 문헌의 다른 흡착등온모델과 비교하였다. 검토한 모델 중 비활성모델이 실험결과와 가장 일치하였고 다음으로 Freundlich, DRK 모델 순으로 높은 상관관계를 나타내었다. 또한 파과곡선으로부터 구한 흡착제의 흡착용량은 VOC의 끓는점이 증가할수록 감소하였으며, 증기압이 증가할수록 증가하였다.

• 한국진공학회지
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• 제11권4호
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• pp.230-234
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• 2002

고온 급속 열처리를 행한 $LiNbO_3Si$/(100) 구조를 가지고 여러 가지 전극을 사용하여 금속/강유전체/반도체 커패시터를 제작하였으며, 제작한 커패시터의 비휘발성 메모리 응용 가능성을 확인하였다. MFS 커패시터의 C-V 특성 곡선에서는 LiNbO$_3$박막의 강유전성으로 인한 히스테리시스 특성이 관측되었으며, 1 MHz C-V 특성 곡선의 축적 영역에서 산출한 비유전율은 약 25 이었다. Pt 전극을 사용하여 제작한 커패시터에서는 인가 전계 500 kV/cm 범위에서 $1\times10^{-8}$ A/cm 이하의 우수한 누설전류 특성이 나타났다. midgap 부근에서의 계면 준위 밀도는 약 $10^{11}\textrm{cm}^2$.eV 이었으며, 잔류분극 값은 약 1.2 $\muC/\textrm{cm}^2$ 였다. Pt 전극과 A1 전극 모두 500 kHz 주파수의 바이폴러 펄스를 인가하면서 측정한 피로 특성에서 $10^{10}$ cycle 까지 측정된 잔류 분극 값이 초기 값과 같았다.