• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1992년도 춘계학술대회 논문집
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• pp.114-116
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• 1992

ITO/TiO$_2$/Se solar cell were fabricated by vacuum deposition method, the Se and TiO$_2$were deposited on the ITO/Glass. Prior to the electrical properties of film, the provide Te between the ITO and the Se film were deposited by substrate temperature 20[$^{\circ}C$] and evaporation time 15[min], next time TiO$_2$ were treated by rf-magnetron sputtering in substrate temperature 250[$^{\circ}C$]. Fabricated ITO/TiO$_2$/Se solar cell were as follows : Open Voltage V$\_$oc/=848[mV], Short Circuit Current I$\_$sc/=10.79[mA/$\textrm{cm}^2$]. Fill Factor FF=0.518, energy conversion efficiency η=4.74[%] under the illumination of AM 1.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권10호
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• pp.4160-4176
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• 2015

Data compression like image and video compression has come a long way since the introduction of Compressive Sensing (CS) which compresses sparse signals such as images, videos etc. to very few samples i.e. M < N measurements. At the receiver end, a robust and efficient recovery algorithm estimates the original image or video. Many prominent algorithms solve least squares problem (LSP) iteratively in order to reconstruct the signal hence consuming more processing time. In this paper non-iterative threshold based recovery algorithm (NITRA) is proposed for the recovery of images and videos without solving LSP, claiming reduced complexity and better reconstruction quality. The elapsed time for images and videos using NITRA is in ㎲ range which is 100 times less than other existing algorithms. The peak signal to noise ratio (PSNR) is above 30 dB, structural similarity (SSIM) and structural content (SC) are of 99%.

• Bulletin of the Korean Chemical Society
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• 제7권1호
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• pp.73-77
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• 1986

Data on the concentration of Na, K, Sc, Cr, Fe, Co, Cu, Ga, Rb, Cs, Ba, La, Ce, Sm, Eu, Tb, Lu, Hf, Ta, and Th obtained by neutron activation analysis have been used to characterize Korean porcelainsherds by multivariate analysis. The mathematical approach employed is principal component analysis (PCA). PCA was found to be helpful for dimensionality reduction and for obtaining information regarding (a) the number of independent causal variables required to account for the variability in the overall data set, (b) the extent to which a given variable contributes to a component and (c) the number of causal variables required to explain the total variability of each measured variable.

• Current Photovoltaic Research
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• 제6권4호
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• pp.94-101
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• 2018

Light elevated temperature induced degradation (LeTID) was noted as an issue in multi-crystalline silicon solar cells (MSSC) by Ram speck in 2012. In contrast to light induced degradation (LID), which has been researched in silicon solar cells for a long time, research about both LeTID and the mechanism of LeTID has been limited. In addition, research about LeTID in single-crystalline silicon solar cells (SSSC) is even more limited. In order to improve understanding of LeTID in SSSC with a passivated emitter rear contact (PERC) structure, we fabricated four group samples with boron and oxygen factors and evaluated the solar cell characteristics, such as the cell efficiency, $V_{oc}$, $I_{sc}$, fill factor (FF), LID, and LeTID. The trends of LID of the four group samples were similar to the trend of LeTID as a function of boron and oxygen.

• 한국해안해양공학회지
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• 제19권2호
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• pp.151-161
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• 2007

동해안 검조소 조위자료를 이용하여 비조석 성분을 추출하고, 추출된 비조석 성분을 이용하여 통계적인 특성 분석을 수행하였다. 분석대상 검조소는 속초, 묵호, 후포, 포항, 울산, 울릉도이며, 분석기간을 1년부터 가용한 자료기간까지 증가시켜 가며 비조석 성분의 분산 및 왜곡도 계수의 통계정보(최대값, 최소값, 평균, 표준편차) 변차를 분석하였다. 또한, 분석기간에 따른 통계정보의 변화범위를 분석한 결과, ${\pm}5%$ 범위의 분산 신뢰구간을 확보하기 위하여 필요한 분석기간은 전체적으로 12년 이상 정도로 파악되었으며, ${\pm}0.1$ 범위의 왜곡도 계수 신뢰구간 확보에 필요한 분석기간은 울릉도의 6년 이상을 제외하고는 모두 12년 이상으로 파악되었다. 한편, 자기상관함수 및 스펙트럼 분석을 수행한 결과, 절대적인 변화량에 차이는 있으나 변화경향은 모든 지점이 매년 유사한 것으로 파악되었다.

• 한국진공학회지
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• 제16권5호
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• pp.388-396
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• 2007

KSTAR (Korea Superconducting Tokamak Advanced Research) 전류인입선(CL; Current Lead)은 4.5 K의 저온에서 운전되는 초전도 버스라인과 300 K의 실온에서 운전되는 MPS (Magnet Power Supply)를 전기적으로 연결하는 장치이다. 초기 플라즈마 발생시험을 위하여 TF (Toroidal Field) 및 PF (Poloidal Field) 리드박스에 전류인입선이 설치된다. TF 자석용 CL은 17.5 kA급 4 개의 CL에 최대 35 kA의 DC 전류가 인가되며, PF 자석용은 13 kA급 14 개의 CL에 350초간 $20\;{\sim}\;26\;kA$의 펄스 전류가 인가된다. 각각의 전류인입선은 TF 및 PF 자석에 전류를 인가하기 위한 버스라인이 연결되어 있으며, 전류인입선을 통해 초전도 버스라인으로 전달되는 전도열 및 전류인가시 발생되는 주울(Joule) 열을 차단하기 위한 헬륨냉매 제어시스템이 KSTAR 주장치와는 별도로 설치되어 있다. 리드박스 내 외부의 배관 및 제어시스템 설치완료 후 고진공 배기, 헬륨 누설검사, 전류인입선 유량 검사 및 액체질소 냉각시험을 실시하여 장치의 성능검증을 완료하였다.

• 한국광학회지
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• 제2권3호
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• pp.139-148
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• 1991

광섬유를 사용하여 미소 교류자기장 (200Hz-2kHz) 감지를 위한 광섬유 간섭계 자기센서시스템을 구성하였다. 자왜효과(magnetostriction effect)가 큰 비정질 metallic glass(2605SC)를 광섬유에 부착하여 자기장 감지부를 제작하고 방향성 결합기 metallic glass(2605SC)를 광섬유에 부착하여 자기장 감지부를 제작하고 방향성 결합기(directional coupler)를 사용한 광섬유 일체식(all-fiber type)으로 Mach-Zehnder 간섭계를 구성하여 외부 자기장의 변화를 간섭계의 위상변화로 변환시켜 그 크기를 측정하였다. 온도변화, 진동 등 주위환경에서 오는 불규칙한 신호에 의한 간섭계의 신호소멸(signal fading) 문제는 능동 위상추적방법(active phase tracking method)으로 간섭계의 기준 광통로(reference arm)에 위치한 위상 변조기에 보상신호를 되먹임으로써, 직각조건(quadrature condition)을 이루어 안정시켰다. 측정 결과 metallic glass의 주파수 반응특성은 900Hz-2kHz 대역에서 거의 비슷한 경향을 보였으며 최대 감도를 나타내는 직류 바이어스 자기장은 3.5 Oe 였다. 미소 교류자기장에 대한 간섭계의 출력은 $\pm$0.5 Oe 범위 안에서 좋은 선형성을 보였다. 1 kHz 교류자기장에 대한 scale factor S는 8.0 rad/Oe 이었으며 최소감지자기장은 $3X10^{-6} Oe/\sqrt{Hz}$(1Hz detection bandwidth)이었다.

• 대한물리의학회지
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• 제13권2호
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• pp.61-68
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• 2018

PURPOSE: This study aimed to examine the effects of self-stretching (SS) and joint mobilization (JM) on pain, craniovertebral angle (CVA), autonomic system function in chronic cervical pain patient with forward head posture (FHP). METHODS: A total of 30 male college students were selected as study subjects, and were divided into Group I (general physical therapy; GPT, n=10), Group II (GPT+SS, n=10), Group III (GPT+JM, n=10). All groups were evaluated three times a week for 4 weeks. Pain was measured by visual analogue scale (VAS), CVA was measured using digital goniometer and autonomic system function (heart rate; HR, skin conductivity; SC, LF norm, HF norm, LF/HF ratio) was measured by Biofeedback ProComp Infiniti. After 4 weeks, paired t-test was used to compare the changes within the group and one way ANOVA was used to compare those between the groups. RESULTS: In Group I, VAS was significantly decreased. In Group II and III was a significantly change in all items. In comparison between Group I and II was a difference in all items except HR. In comparison between Group I and III was a difference in all items. In comparison between Group II and III was a difference in VAS, LF norm and LF/HF ratio. CONCLUSION: This study showed that SS and JM can effectively reduce pain and normalize the autonomic system function.

• 정신신체의학
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• 제5권1호
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• pp.97-107
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• 1997

As a preliminary step to develop the Daily stress Inventory(DSI) for assessing minor stressors frequently experienced in everyday lift. We examined the reliability and validity of the DSI. The Daily Stress Inventory(DSI), the Beck Depression Inventory(BDI), the State-Trait Anxiety Inventory(STAI), the Social Readjustment Rating Scale(SRRS) and the Minnesota Multiphasic Personality Inventory(MMPI) were administered to 111 college students. Compared with the weekly DSI Event, Impact and I/E ratio scores of the American college students, the weekly event and I/E ratio scores of the Korean college students were significantly higher but weekly Impact score was lower. The internal consistency reliability of the DSI as computed by Cronbach alpha was .98. The DSI I/E ratio scores were significantly correlated with the scores of State Anxiety$({\gamma}=.27)$ and Trait Anxiety${\gamma}=.24)$, but not with BDI scores. And the SSRS scores were not significantly correlated to the DSI Event or Impact and In ratio scores. Significant correlations were revealed between the DSI Impact scores and the Sc and Ma scales of the MMPI. And the correlation between the DSI I/E ratio scores and the L, D, Hy, Pd and Pa scales of the MMPI was also significant. But no significant correlation was found between the DSI Event scores and all the scales of the MMPI. This study suggests that the DSI can be a reliable and valid tool to assess the minor stress frequently experienced in everyday life future study should be directed to obtain normative data based on more varied and larger population. Especially gathering additional evidences for the validity of the DSI using other minor stressor scale will be required.

• Imaging Science in Dentistry
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• 제40권2호
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• pp.63-68
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• 2010

Purpose : To compare the CT numbers on 3 cone-beam CT (CBCT) images with those on multi-detector CT (MDCT) image using CT phantom and to develop linear regressive equations using CT numbers to material density for all the CT scanner each. Materials and Methods : Mini CT phantom comprised of five 1 inch thick cylindrical models with 1.125 inches diameter of materials with different densities (polyethylene, polystyrene, plastic water, nylon and acrylic) was used. It was scanned in 3 CBCTs (i-CAT, Alphard VEGA, Implagraphy SC) and 1 MDCT (Somatom Emotion). The images were saved as DICOM format and CT numbers were measured using OnDemand 3D. CT numbers obtained from CBCTs and MDCT images were compared and linear regression analysis was performed for the density, $\rho$ ($g/cm^3$), as the dependent variable in terms of the CT numbers obtained from CBCTs and MDCT images. Results : CT numbers on i-CAT and Implagraphy CBCT images were smaller than those on Somatom Emotion MDCT image (p<0.05). Linear relationship on a range of materials used for this study were $\rho$=0.001H+1.07 with $R^2$ value of 0.999 for Somatom Emotion, $\rho$=0.002H+1.09 with $R^2$ value of 0.991 for Alphard VEGA, $\rho$=0.001H+1.43 with $R^2$ value of 0.980 for i-CAT and $\rho$=0.001H+1.30 with $R^2$ value of 0.975 for Implagraphy. Conclusion: CT numbers on i-CAT and Implagraphy CBCT images were not same as those on Somatom Emotion MDCT image. The linear regressive equations to determine the density from the CT numbers with very high correlation coefficient were obtained on three CBCT and MDCT scan.