질소 및 셀레늄 분위기 열처리가 나노 입자 Cu(In, Ga) Se₂ 광흡수층의 치밀화에 미치는 영향

김기현(Kim, Ki-Hyun),안세진(Ahn, Se-Jin),전영갑(Chun, Young-Gab),박병옥(Park, Byun-Ok),윤경훈(Yoon, Kyung-Hoon) 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.06

나노 입자 분무 기법을 이용한 Cu(In,;Ga)Se₂ (CIGS) 광흡수층 제조 기법은 고진공 장치를 사용하지 않는다는 점에서 대면적 저가형 CIGS 태양전지 양산에 적합한 차세대 기술로 인식되고 있다. 그러나 일반적으로 스프레이 된 상태의 CIGS충 자체는 태양전지 제조에 적합하지 않은데 이는 스프레이 막의 다공성 구조 때문이다. 본 연구에서는 나노입자 분무 기법을 이용하여 증착한 CIGS 광흡수층막을 질소 또는 셀레늄 분위기에서 열처리함으로써 태양전지 제조에 적합한 치밀한 구조의 CIGS 광흡수충을 제조하고자 하였다. 실험 결과, 질소 분위기 500?C의 온도에서 1시간 열처리하여도 CIGS 나노 입자의 성장은 거의 일어나지 않는 것으로 나타났다. 반면 셀레늄 분위기 500?C의 온도에서 30분 열처리시 입자 크기가 1{mu}m이상인 치밀한 광흡수층을 얻을 수 있었다. 본 결과는 CIGS 나노 입자의 입자 성장 반응에서 열에너지 단독에 의한 표면 에너지 감소 효과는 미미하며 셀레늄 증기의 역할이 더욱 크다는 것을 의미하는 것이다.

2단 IMDCT Recursive 구조를 이용한 MPEG-2 AAC 복호화기의 필터뱅크 구현

박세기,강명수,오신범,이채욱 대구대학교 정보통신연구소 2003 情報通信硏究 Vol.2 No.1

MPEG-2 AAC(Advanced Audio Coding)는 높은 압축율과 고음질의 특성을 갖는 멀티채널 오디오 압축 표준으로 알려져 있고, 대우 낮은 비트율에서 방송 음질 수준의 오디오를 제공하기 위해서 고해상도 필터뱅크(high-resolution filter bank), 예측기법(prediction), 허프만 부호화(Huffman coding) 등을 결합하여 사용한다. MPEG-2 AAC 필터뱅크에서 부화화기와 복호화기에서 각각 수행하는 MDCT(Modified Discrete Cosine Transform)/ IMDCT(Inverse MDCT) 연산은 특히 많은 연산을 필요로 한다. 본 논문에서는 MPEG-2 AAC 실시간 복호화 시스템을 하드웨어로 구현시 IMDCT의 연산에 적합한 2단 IMDCT의 Recursive 구조를 제안한다. 그리고 메모리와 연산속도, 하드웨어의 복잡도를 기존에 제안된 알고리듬과 비교하였다. MPEG-2 Advanced Audio Coding(AAC) is the uideb used audio standard and offers the high-quality multi-channel surround audio AAC algonthm combines the coding efficiency of a high-resolution filter bank, prediction techniques, and Huffman coding to achieie the broadcast-qualitv audio at very low data rates The foruard and inperse modified discrete transform(MDCT) are two of the most computational) 1 intensive operation in the MPEG-2 AAC In this paper, we propose the suitable recursive structure at IMDCT process for MPEG-2 AAC real-time decoder, and compared the memory, the computation speed and complexity of hardware with the proposed algonsms

전치부 반대교합아동의 발음장애에 관한 음향적 연구

박정삼,손동수,이상훈,김진태,한세현,장기택,김종철 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.2

It has widely known for speech problem in patients with malocclusion,but there have been insufficient studies on degrees of serverity.Patients with openbite and CIⅢ malocclusion usually have speech problem.It has widly known that fricative /s/ is pronunciated most abnomally in CIⅢ malocclusion than any other consonant.Therefore 20 childen with anterior crossbite selected for control group.7 sounds such as /사(sa),서(sδ),소(so),수(su),스(sω),시(si),세(se)/ were recorded,and the formants and formants ratio were measured by using Sensimetric Speech Station,which is speech analyzing program in IBM pc. The results were as follows: 1.In anterior crossbite group,F1 of all 7 sounds were significantly higher than normal anterior relationship group(P<0.05). 2.There were no significant difference in F2 between two groups except/소(so),수(su)/(P>0.05). 3.In anterior crossbite group,F2/F1 ratio of all 7 sounds were significantly smaller than normal anterior relationship group(P<0.05). 4.There were no significant difference in accordance with tongue position(P>0.05).

뇌경색후 발생한 Cortical Spreading Depression과 뇌경색 범위에 관한 실험적 연구

박윤관,이승민,김세훈,이기찬,주정화,이훈갑 대한신경외과학회 1996 Journal of Korean neurosurgical society Vol.25 No.3

Cortical Spreading Depression(CSD) is a transient depression of neuronal activity that spreads across the cortical surface and is associated with profound changes in blood flow, extracellular ion concentration. Direct Current(DC) potentials and cell membrane potentials. One of the electrophysiological disturbance in the periinfarct surrounding is spontaneous occurrence of repeated CSD like DC shifts associated with increased energy demand. Due to restricted blood flow to the periinfarct border zone, elevated metabolic demand is potentially harzardous. So the authors designed this experiment to verify the correlation between periinfarct cortical spreading depression and ischemic volume following permanent middle cerebral artery (MCA) occlusion in rats. Sprague-Dawley rats(n=27) were anesthetized with 0.5∼1% halothane, and artificially ventilated through a tracheal cannula. Arterial pressure, blood gases and body temperature were controlled. The middle cerebral artery(MCA) was occluded distally to the lenticulostriate branches. Measurements of CSD activity were made for 4 hours in each animal. Infarct volume was determined 6 hours later in 2, 3, 5-triphenyl tetrazolium chloride(TTC)-stained sections. For 4 hours after MCA occlusion, the CSDs were found in all experimental animals with a range of 2∼9 times. Those CSDs wer of varying duration, : "small"(<1 min) and "big"(> 1 min) SDs and mean of total duration of SD was 10.5±10.3 min during 4 hours of MCA occlusion. Neuropathological evaluation of brain infarct in the rats, which had been allowed to survive for 6 hours after MCA occlusion showed a mean volume of 89.7±45.3㎣. Serial observation of duration of CSD showed progressive prolongation only in 8 rats. The rest of them(n=19) did not show any prolongation. Neither the prolongation of duration of CSD nor the frequency of CSD in the penumbral zone correlated with the volume of infarct. However total duration of CSD was slightly related with the infarct volume after 6 hours of the permanent MCA occlusion(r=0.414, p=0.0318).

Microform Cleft Lip 환자의 분류에 따른 수술적 치료

박철수,엄기일,황세휘,안덕균,김잉곤 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.3

The microform cleft lip is the mildest expression of cleft lip and nose deformity, but it has no specific definition, classification, and few methods have been reported for its correction. It is characterized by deformity of the nostril, skin striae of the upper lip, notching of peaked Cupid's bow, deformity of the vermilion, and anomaly of the upper lateral incisior and alveolar ridge on the affected region. Sixty-three microform cleft lip patients were operated on between Dec. 1993 and Sep. 1998 in our department(29 males and 34 females). The age of the patients ranged from 5 months to 30 years(Mean 9 years). We classified and treated the microform cleft lip as follows: Class Ⅰ: Cleft lip nose with very slight lip deformity Class Ⅱ: Minimal lip deformity without vermilion notching ClassⅢ: Mild lip deformity with slight vermilion notching. The goals in the correction of a microform cleft lip are to obtain an esthetically pleasing upper lip and nose, and to reestablish muscle continuity for improved function. To attain these goals, we used the above classification and satisfactory results were obtained by treating the microform cleft according to the classification.

근적외선을 이용한 두개강내 혈종의 진단

박정율,홍기선,김상대,김세훈,임동준,조태형 대한체열학회 2003 대한체열진단학회지 Vol.3 No.1

腎疾患에서의 Cellulose Acetate 電氣泳動分劃에 對한硏究

宋基昌,朴在允,車德源,金昌世 朝鮮大學校 醫學硏究所 1979 The Medical Journal of Chosun University Vol.- No.-

Cellulose acetate electrophoretic studies of renal diseases were performed and the follo- wing results were obtained 1) The mean values for the electrophoretic fractions of serum protein in nephrotic syn- drome mere 1.18±0.48gm/100㎖(28.65±8.03%), 0.25±0.19 gn/100㎖ (5.05±3.17%)1.46±0.57 gn/100㎖(35.95±12.83%), 0.72±0.28 gn/100㎖(17.32±5.39%), and 0.56±0.21gm/100㎖(13.45±4.47%), respectively, for the albnmi, α_l-, α_2-, β-, and γ- globulin fractions. It was found that decrensed both albumin 2.11gm/100㎖(19a17%), and γ-glo-bulin, 0.94gm/100㎖(7.83%), fractions were more marked than in control groups. While α_2-globulin fraction was markedly increased, 0.7gm/100㎖(25.37%), to compare in control group. 2) The correlation coefficient between albumin and α_2-globulin fractions in nephrotic syndrome was γ=-0.84 and regression equation, was y=-1.34x-74.40. 3) The A/G ratio was markedly reversed as 0.40±0.16. 4) The mean values for the electrophoretic fractions of serum proteins in nonnephrotic syndrome, i. e. , acute and chronic glomerulonephritis, renal failure, pyelonephritis, and renal stones, were 2.35±0.59gm/100㎖(40.74±8.54%), 0.27±0.13gn/100㎖(4.65±1.98%), 0.78±0.25gm/100㎖(13.30±2.84%), 0.93±0.28gm/100㎖(15.75±4.33%), and 1.43±0.58gm/100㎖(24.14±8.14%), respectively, for the albumin, α_l-, α_2-, β-, and γ- globulin fractions. It was found that decreased albumin and increased α_l-globulin fractions were marked than in control group. 5) In the biochemical data in nephrotic syndrome it was found that serum cholesterol was increased. 2.5 times than in control group. In non-nephrotic syndrome group it was found that increased concentration of serum K and markedly increased concentration of serum creatinine(4.5 times) and BUN(3 times) were shown.

SM20C摩擦鎔接시 鎔接部 가공에 따른機械的 性質 硏究

이세경,박천봉,민택기 충남대학교 공업교육연구소 2005 論文集 Vol.27 No.1

This study examined mechanical properties according to the change of outer circumference in the friction welding of SM20C, which is one of carbon steel for machine structures used in steel pipes, steel rods, steel plates, bolts, rivets, etc., and SM20C stock with 10 hollow at the center. Welding conditions were fixed at RPM of 2,000, friction pressure of 60㎫, friction time of 1.4 seconds, upset pressure of100㎫ and upset time of 2.0 seconds. The obtained of this study are as follows. According to the tensile strength test, the maximum tensile strength was 585㎫ when the change of outer circumference was 1mm and it corresponds to 94% of 624㎫, the tensile strength of the base material. The result of measuring hardness, hardness appeared to increase at 5mm and then decrease for welding interface, and it was maximum 250HV at D=5mm of the solid shaft. High hardness was observed around 0.5mm of vertical distance from the welding section and relatively low hardness was observed around 2mm. The result of a bending test, the maximum bending strength was 7.701㎫ at L = 5mm in the solid shaft, which is 130% of the bending strength of the base material. The result of examining microstructure, the microstructure grew finer with the change of outer circumference against the welding surface. Namely, as it was closer to the center in the solid shaft, but the microstructure grew finer and then coarser in the hollow shaft.

腎疾患에서의 Cellulose Acetate 電氣泳動分劃에 對한 硏究

宋基昌,朴在允,車德源,金昌世 順天鄕大學校 1979 의대논문집 Vol.4 No.-

Cellulose acetate electrophoretic studies of renal diseases were performed and the following results were obtained : 1) The mean values for the electrophoretic fractions of serum protein in nephrotic syndrome were 1.18±0.48gm/100㎖(28.65±8.03%), 0.25±0.19gm/100㎖(5.05±3.17%)1.46±0.57gm/100㎖(35.95±12.83%), 0.72±0.28gm/100㎖(17.32±5.39%), and 0.56±0.21gm/100㎖(13.45±4.47%), respectively, for the albumi, a₁-, a₂-, β-, and r- globulin fractions. It was found that decrensed both albumin 2.11 gm/100㎖(19a17%), and r-globulin, 0.94gm/100.㎖(7. 83%), fractions were more marked than in control groups. While α₂-globlllin fraction was markedly increased, 0.7gm/100㎖(25.37%), to compare in control group. 2) The correlation coefficient between albumin and α₂-globulin fractions in nephrotic syndrome was r= -0.84 and regression equation was y= -1.34x+74.40. 3) The A/G ratio was markedly reversed as 0.40±0.16. 4) The mean values for the electrophoretic fractions of serum proteins in nonnephrotic syndrome, i. e., acute and chronic glomerulonephritis, renal failure, pyelonephritis, and renal stones, were 2.35±0.59gm/100㎖(40.74±8.54%), 0.27±0.13gm/100㎖(4.65±1.98%), 0.78±0.25gm/100㎖(13.30±2.84%), 0.93±0.28gm/100㎖(15.75±4.33%), and 1.43±0.58gm/100㎖(24.14±8.14%), respectively, for the albumin, a₁-, a₂-, β-, and r-globulin fractions. It was found that decreased albumin and increased α₁--globulin fractions were marked than in control group. 5) In the biochemical data in nephrotic syndrome it was found that serum cholesterol was increased 2.5 times than in control group. In non-nephrotic syndrome group it was found that increased concentration of serum K and markedly increased concentration of serum creatinine(4.5 times) and BUN(3 times) were shown.

손상지수를 이용한 포장도로 평가모형의 제안

이기세,박광규 大田大學校 産業技術硏究所 1996 산업기술연구소 論文集 Vol.7 No.1

Upon using the newly constructed pavement for a long time, the efficiency of the pavement which was constructed based on the proper design procedure will be dropped with times. Thus, it is going to be hard to keep the designed performance of a constructed pavement continuously. To meet the designed performance of the pavement which is lowered by undertaking repeated traffic loadings for a long time it can be a critical to rehabilitate effectively existing pavement at proper time to give always structurely and functionally stable pavement. To rehabilitate a pavement using a selected method at a optimum time, the pavement performance model may be needed to determine the time and the method for rehabilitation. In this paper a pavement performance models was developed and provided. It is the pavement performance model with roughness index and other distresses as independent variables.