대면적 기판의 투명 전극용 SnO₂ 박막 증착을 위한 APCVD 공정

김병국,김현수,김형준,박준우,김윤석,박승호,Kim, Byung-Kuk,Kim, Hyunsoo,Kim, Hyoung June,Park, Joonwoo,Kim, Yoonsuk,Park, Seungho 대한기계학회 2013 대한기계학회 논문집. Transactions of the KSME. C, 산업기술과 혁신 Vol.1 No.1

$SnO_2$ (tin oxide) 박막은 물리적, 전기적 성질이 우수하여 첨단산업의 다양한 분야에서 널리 응용/개발되고 있다. 이의 응용대상은 다양한 센서, 윈드쉴드(windshield) 윈도우의 히팅 요소, 태양전지, flat panel diplay에서의 투명전극을 들 수 있다. 본 연구에서는 대면적 기판에 대한 APCVD 공정개발을 위하여 실험용 2세대 크기의 유리기판에 $SnO_2$ 박막증착 실험을 수행하였다. 증착 온도가 증가함에 따라 증착 두께가 두꺼워지고 이에 따라 면저항은 감소, 투과도는 감소, 연무도 (haze)는 증가함을 확인하였다. 증착을 위한 전구체인 $SnCl_4$의 유량이 증가함에 따라 증착 두께 역시 증가하고 이에 따라 면저항은 감소한다. 그러나 투과도와 연무도는 $SnCl_4$ 유량의 영향을 거의 받지 않는다는 것을 확인하였다. Tin oxide thin-films have been widely applied in various fields of high-technology industries due to their excellent physical and electric properties. Those applications are found in various sensors, heating elements of windshield windows, solar cells, flat panel displays as tranparent electrodes. In this study, we conducted an experiment for the deposition of $SnO_2$ on glass of 2nd Gen. size for the effective development of large-scale backplanes. As deposition temperatures or flow rates of the $SnCl_4$ as a precursor changed, the thickness of tin oxide thin-films, their sheet resistances, transmittances, and hazes varied considerably.

시승격기준의 강화방안

김병국,이정엽 ( Ki Ork Kim,Jung Yeob Yi ) 한국지방행정연구원 1990 地方行政硏究 Vol.5 No.3

내가 왔던 길, 그리고 새로이 시작하는 길.

김병국,Kim, Byeong-Guk 한국수자원학회 2022 물과 미래(한국수자원학회지) Vol.55 No.10

배터리로 구동되는 이동 로봇의 에너지 소모 최소화를 위한 3-구간 속도 제어

김병국,김종희,Kim Byung-Kook,Kim Chong-Hui 제어로봇시스템학회 2006 제어·로봇·시스템학회 논문지 Vol.12 No.3

Energy of wheeled mobile robot is usually supplied by batteries. In order to extend operation time of mobile robots, it is necessary to minimize the energy consumption. The energy is dissipated mostly in the motors, which strongly depends on the velocity profile. This paper investigates various 3-step (acceleration - cruise - deceleration) speed control methods to minimize a new energy object function which considers the practical energy consumption dissipated in motors related to motor control input, velocity profile, and motor dynamics. We performed an analysis on the energy consumption various velocity profile patterns generated by standard control input such as step input, ramp input, parabolic input, and exponential input. Based on these standard control inputs, we analyzed the six 3-step velocity profile patterns: E-C-E, P-C-P, R-C-R, S-C-S, R-C-S, and S-C-R (S means a step control input, R means a ramp control input, P means a parabolic control input, and E means an exponential control input, C means a constant cruise velocity), and suggested an efficient iterative search algorithm with binary search which can find the numerical solution quickly. We performed various computer simulations to show the performance of the energy-optimal 3-step speed control in comparison with a conventional 3-step speed control with a reasonable constant acceleration as a benchmark. Simulation results show that the E-C-E is the most energy efficient 3-step velocity profile pattern, which enables wheeled mobile robot to extend working time up to 50%.

Stimulation of Lysergic Acid Alkaloid Production in Submerged Cultures of Claviceps paspali by Arsenate

김병국,Kim, Byong-Kak,Kelleher, William J.,Schwarting, Arthur E. 생화학분자생물학회 1972 한국생화학회지 Vol.5 No.1

라이써직산 알카로이드를 생성하는 발효에서 맥각균 Claviceps paspali의 성장과정중 경시적으로 발효액을 분석하여 본바, 가장 높은 농도의 알카로이드를 생성하는 발효액에서 인산이 가장 신속히 소모됨을 알았다. 인산대사가 비산에 의해 방해된다는 점에 착안하여 일종의 인산결핍상태를 만들 목적으로 배양액에다 비산나트륨을 첨가하였다. 인산의 0.02 및 0.05 몰 농도에 해당하는 비산을 첨가하였을때 알카로이드 생성이 100% 까지 증가하는 결과를 나타내었다. 폐지의 정상농도의 10배의 인산을 사용한 실험에서, 알카로이드의 생성증가에 중요한 영향을 미치는 것은 비산의 절대농도가 아니라 인산 대 비산의 비 임을 알게 되었다. 인산 농도만을 증가시켰을 때(정상 농도의 20배까지), 알카로이드 생성이 상당히 증가되는 결과를 초래하였다. 맥각균의 인산 섭취의 범위와 속도에 대한 비산의 영향을 측정하였다. 전자 수송 혹은 산화적 인산화 또는 두 가지 모두를 저지하는 수종의 억제제 중에서 다이나이트로훼놀만이 알카로이드 생성을 촉진시키는 데 유효하였다. Analysis of the culture filtrates of lysergic acid alkaloid-producing fermentations at intervals during growth of the cultures showed that phosphate is most rapidly depleted from the medium in fermentations that produce the highest levels of alkaloid. In view of the known interference with phosphate metabolism by arsenate, sodium arsenate was added to the culture medium with the intent of creating, in effect, a phosphate deficiency. The addition of arsenate at levels between one-fiftieth and one-twentieth the molar concentration of phosphate resulted in increases in alkaloid production up to 100 per cent. Experiments with ten-times the usual concentration of phosphate showed that the ratio of arsenate to phosphate rather than the absolute concentration of arsenate was most significant in obtaining this effect. Increasing the concentration of phosphate alone (up to twenty times the usual concentration) resulted in substantial increases in alkaloid production. The effect of arsenate on both the rate and the extent of phosphate uptake was determined. Among several inhibitors of electron transport and/or oxidative phosphorylation, only the un coupler of oxidative phosphorylation (dinitrophenol) was effective in increasing alkaloid production.

UVB 에 의한 홍반반응 및 색소반응의 Dose - response Angle과 피부의 자외선 감수성 지표들과의 상관관계에 관한 연구

김병국,박석범,윤재일 ( Byoung Kook Kim,Seok Beom Park,Jai Il Youn ) 대한피부과학회 1997 대한피부과학회지 Vol.35 No.6

Background: There are many predictors of sensitivity to UVR, but controversies exist about their objectivity, correlation bet,ween them, and applicability to various races. Objective : In 42 healthy volunteers, we assessed the validaty of dose response angle of erythe ma(DRAE) and delayed tanning(DRADT) after UVB irradiation, and also evaluated the correlation hetween dose-response angb s and other predictors of UV sensitivity. Methods : We measured erythema and melanin index using reflectance spectrophotometer aft,er irradiation of UVB on the back of 42 males. When the erythema index and melanin index were plotted against UV doses for each patient, a dose response curve was obtained. Linear regression analysis was used to calculate the slope of those curves for erythema and delayed tanning, which were called DRAE and DRADl respectively. Also we checked predictots of UV sensitivity such as skin type, MED, MMD, consiitutional and facult,ative skin color, then analyzed the relation be tween dose response angles and other predictors. Results : Statistically significa it linear regression lines were obtained from 41 subjects regar d- ing to erythema and frorn 31 subjects regarding to delayed tanning. As for the relationship he tween the pvedictors of UV senitivity, only the MED correlated well with DRAE. Conclusion : We found that dose response angles, especially DRAE, were an objective and adequate predictor of cutaneous LJV sensitivity, but could not find validity of skin type and skin color in Koreans. A more organized study with a larger number of subjects is needed to clarify the usefulness of the predictors. (Korean J Dermatol 1997;35(6): 1177-1183)

오존노출 후 백서 기도점막의 형태학적 변화

김병국,나기상,신시옥,Kim, Byung-Kook,Rha, Ki-Sang,Shin, See-Ok 대한기관식도과학회 2000 大韓氣管食道科學會誌 Vol.6 No.1

Objectives : This study was designed to compare the morphological changes in the nasal, tracheal and main bronchial mucosa in rats exposed to 0, 0.3, 0.6, 0.9 and 1.2 ppm ozone for 7 days, 6 hours per day. Materials and Methods : We observed the nasal, tracheal and main bronchial mucosa in rats exposed to 0, 0.3, 0.6, 0.9 and 1.2 ppm ozone for 7days, 6hours per day with LM, SEM and TEM. Results : In light microscopy, influx of inflammatory cells, epithelial hyperplasia, loss of cilia and increased goblet cells were observed in all rats except those exposed to 0.3 ppm. these findings increased with the increase of ozone concentration, but there were no significant differences among the nasal, tracheal and main bronchial mucosa in rats exposed to the same ozone concentration. In scanning electron microscopy, a loss of cilia was observed in rats exposed to 0.3 ppm in some sections and 0.6 ppm and 1.2 ppm in all sections. In transmission electron microscopy, vacuolization of epithelial cells was observed in rats exposed to 0.3 ppm in some sections and 0.6 ppm in all sections. These results suggest that electron microscopic observation is necessary to study morphology of airway mucosa in rats exposed to ozone below 0.3 ppm. And also the morphological changes in nasal septal epithelium may reflect those of tracheal and bronchial epithelium after high concentration ozone-exposure.

근육세포 분화에 대한 TGF-β1과 OP-1의 억제 효과

김병국,정성수,Kim, Byung-Gook,Jung, Sung-Su 대한안면통증구강내과학회 2001 Journal of Oral Medicine and Pain Vol.26 No.1

In order to investigate the effect of Transforming growth factor ${\beta}1$(below TGF-${\beta}1$) and osteogenic protein-1(below Op-1) onto the myogenic differentiation, C2C12 satellite myoblastic cell line was cultured and treated with both growth factors. At first morphological changes with microscopical examination were examined, and isolated total RNA to analyse mRNA expression of bone marker proteins, muscle regulatory proteins, TGF-${\beta}$ receptor and their ligands by Northern blot analysis. And cellular proliferative inducibility of both growth factors was also tested to C2C12 cells. Incubating the cell with $5ng/m{\ell}$ of TGF-${\beta}1$ until 4 days almost inhibited multinucleated myotube formation expressing muscular regulatory proteins, and induced decreasing Id proteins. However, no osteoblastic phenotypes was induced by TGF-${\beta}1$ in C2C12 cells. The mRNA expression of TGF-${\beta}$ receptors with TGF-${\beta}1$ was conversed after 48 hours cultured. Type I TGF-${\beta}$ receptor was seemed to play a role in negative signalling for inhibition of myogenic differentiation. OP-1 dose dependently induced ALP activity, osteopontine production and bone sialoprotein production at concentrations above $100ng/m{\ell}$ and osteocalcin production at concentrations above $300ng/m{\ell}$. The concentration of OP-1 required to induce these osteoblastic phenotypes was the same as that required to almost completely inhibit myotube formation. Incubation with above $100ng/m{\ell}$ OP-1 suppressed the expression of mRNA for muscular egulatory proteins from 2 days after incubation. Expression of Id-1, 2, 3 mRNA were stimulated by OP-1 at concentration above $300ng/m{\ell}$. When C2C12 cells were treated with both growth factors, TGF-${\beta}1$ potentiated the inhibitory effect of OP-1 on myotube formation and expression of mRNA for myogenin at 12 days. And TGF-${\beta}1$ reduced osteocalcin and bone sialoprotein production induced by OP-1 at 12 days in C2C12 cells. Both growth factor had no mitogenic effect. These results indicate that OP-1 converts the differentiation pathway of C2C12 myoblasts into that of osteoblastic lineage cells and it's not heritable, but TGF-${\beta}1$ does not and has reversible inhibitory activity on the myogenic differentiation. TGF-${\beta}1$ and OP-1 play a role in myogenic differentiation via different mechanism between them.

SOD방법을 이용한 저가 EFG 리본 실리콘 태양전지의 효율 향상에 관한 연구

김병국,임종엽,저호,오병진,박재환,이진석,장보윤,안영수,임동건,Kim, Byeong-Guk,Lim, Jong-Youb,Chu, Hao,Oh, Byoung-Jin,Park, Jae-Hwan,Lee, Jin-Seok,Jang, Bo-Yun,An, Young-Soo,Lim, Dong-Gun 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.3

The high cost of crystalline silicon solar cells has been considered as one of the major obstacles to their terrestrial applications. Spin on doping (SOD) is presented as a useful process for the manufacturing of low cost solar cells. Phosphorus (P509) was used as an n-type emitters of solar cells. N-type emitters were formed on p-type EFG ribbon Si wafers by using a SOD at different spin speed (1,000~4,000 rpm), diffusion temperatures ($800^{\circ}C{\sim}950^{\circ}C$), and diffusion time (5~30 min) in $N_2+O_2$ atmosphere. With optimum condition, we were able to achieve cell efficiency of 14.1%.

저가 다결정 EFG 리본 웨이퍼의 표면 반사도 특성 최적화

김병국,이용구,저호,오병진,박재환,이진석,장보윤,안영수,임동건,Kim, Byeong-Guk,Lee, Yong-Koo,Chu, Hao,Oh, Byoung-Jin,Park, Jae-Hwan,Lee, Jin-Seok,Jang, Bo-Yun,An, Young-Soo,Lim, Dong-Gun 한국전기전자재료학회 2011 전기전자재료학회논문지 Vol.24 No.2

Ribbon silicon solar cells have been investigated because they can be produced with a lower material cost. However, it is very difficult to get good texturing with a conventional acid solution. To achieve high efficiency should be minimized for the reflectance properties. In this paper, acid vapor texturing and anti-reflection coating of $SiN_x$ was applied for EFG Ribbon Si Wafer. P-type ribbon silicon wafer had a thickness of 200 ${\mu}m$ and a resistivity of 3 $\Omega-cm$. Ribbon silicon wafers were exposed in an acid vapor. Acid vapor texturing was made by reaction between the silicon and the mixed solution of HF : $HNO_3$. After acid vapor texturing process, nanostructure of less than size of 1 ${\mu}m$ was formed and surface reflectance of 6.44% was achieved. Reflectance was decreased to 2.37% with anti-reflection coating of $SiN_x$.