광섬유 Sagnac 간섭계를 이용한 초음파의 비접촉식 감지

이정주,장태성,이승석,김영길,권일범,이왕주,Lee, Jeong-Ju,Jang, Tae-Seong,Lee, Seung-Seok,Kim, Yeong-Gil,Gwon, Il-Beom,Lee, Wang-Ju 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.9

This paper describes a fiber optic sensor suitable for non-contact detection of ultrasonic waves. This sensor is based on a fiber optic Sagnac interferometer. Quadrature phase bias between two interfering laser beams in Sagnac loop is introduced by a polarization controller. A stable quadrature phase bias can be confirmed by observing the interferometer output versus phase bias. This method eliminates a digital signal processing for detection of ultrasonic waves using Sagnac interferometer. Interference intensity is affected by the frequency of ultrasonic waves and the time delay of Sagnac loop. Collimator is attached to the end of the probing fiber to focus the light beam onto the specimen surface and to collect the reflected light back into the fiber probe. Ultrasonic waves produced by conventional ultrasonic transducers are detected. This fiber optic sensor based on Sagnac interferometer is very effective for detection of small displacement with high frequency such as ultrasonic waves used in conventional non-destructive testing.

호피 시 착지방법에 따른 하지 강성도

이정주,손종상,김정윤,김영호,Lee, J.J.,Son, J.S.,Kim, J.Y.,Kim, Y.H. 대한의용생체공학회 2011 의공학회지 Vol.32 No.2

The purpose of the present study was to analyze the lower stiffness over the difference between soft and stiff landings during hopping. Five male subjects performed hopping on two legs at 2.5 Hz. During the experiments, 3D motion capture system was used to obtain the kinematic data and two force plates were synchronized to calculate the kinetic data. We determined lower extremity stiffness of the knee and ankle from kinetic and kinematic data. Leg stiffness was approximately 1.2-times significantly higher in stiff landing than in soft landing_ There was no significant difference in knee joint stiffness between soft and stiff landings. Ankle joint stiffness was approximately 1.34-times significantly higher in stiff landing than in soft landing. These results suggest that humans adjust lower extremity stiffness over the comparison of two different landing methods we evaluated.

간유(肝兪).중완(中脘)의 대계(大?) 약침(藥鍼)이 급성 산화적 간손상에 미치는 효과

이정주,문진영,Lee Jeong-Joo,Moon Jin-Young 경락경혈학회 2003 대한침구의학회지 Vol.9 No.1

Objectives : Circii Herba has been used as a natural drug for the treatment of stress digestive system disease. The aim of this study is to investigate the role of Circii Herba aqua-acupuncture solution (CHAS) in experimental oxidative liver injury. Methods : In order to investigate the effects of CHAS on acute liver injury, male ICR mice were pretreated with CHAS(0.2 ml/mouse/day) at the loci of BL18 and CV12 for 6days, starved for 24hrs, and administerated acetaminophen(500 mg/kg, i.p.). After acetaminophen administeration, mice were sacrificed, and the liver was removed, rinsed with ice-cold $1.15{\%}$ KCI buffer, and homogenized at $4^{\circ}C$. Fractions(fraction Ⅰ, Ⅱ, Ⅲ) were isolated by differential centrifugation. Lipidperoxide, total SH, and glutathione(GSH) levels were measured in the Fraction Ⅰ. In addition, activities of hepatic enzyme, such as catalase, glutathione peroxidase(GSH-Px) were measured in the Fraction Ⅱ, and glutathione S-transferase(GST) was measured in the Fraction Ⅲ. Results : In vivo treatment of CHAS(BL18 and CV12) showed effective inhibition of acetaminophen induced lipid peroxidation, and showed elevations of total SH, GSH level, catalase, GSH-Px, GST activities. Conclusions : These results suggested that CHAS might suppress the formation of oxidative metabolites, and prevent acetaminophen induced hepatotoxicity.

수재해 정보관리 및 서비스를 위한 공간, 비공간 정보 자료 개념 설계

이정주,김동영,정영훈,황의호,채효석,Lee, Jeong-Ju,Kim, Dong-Young,Jung, Young-Hun,Hwang, Eui-Ho,Chae, Hyo-Sok 한국농공학회 2016 한국농공학회논문집 Vol.58 No.2

This study conducted a basic design of system and interface which provide both of spatial and non-spatial data for water hazard information management. This helps to decide directions of the future integrated water hazard information platform and possible technical examinations of the web-based system for the realization of the prototype. For user friendly system, this study did a survey to investigate the data format, service environment, image processing level and visualization type that users prefer. Also, authorization range was set up by type of the user group. In the water hazard information platform, the data and analysis algorithm were classified by the fields. Furthermore, the platform was consisted with six block systems according to the function and the interface and designed to flexibly mount or modify the additional functions. For a basic design of the data exchange method and protocols, a prototype was constructed by using the spatial information web service technology. The portal service system to visualize and provide spatial data was designed by the WMS/WFS type of OGC standard interface and the FTP/HTTP interface type through open source GIS software for server environment.

세제 농도에 따른 세척력과 세제성분의 잔류

이정주,김유겸,Lee, Jung-Ju,Kim, You-Kyum 한국섬유공학회 2011 한국섬유공학회지 Vol.48 No.2

Selected standard methods for washing machines: agitating type; horizontal drum type. Market detergents: standard powder detergent; powder detergent; liquid detergents. Standard soiled clothes composed of five types, including the various contaminants from the actual life of soiled clothes, respectively. When washing with the standard course for a washing machine and using the standard, recommended amount of detergent product, the detergency for the agitating-type washing machine and standard soiled clothes increased by approximately 25%, on average, compared to the case of -30% use, and increased by 2% compared to the case of +60% use, respectively. When the horizontal drum-type washing machine was used, detergency increased by approximately 28%, on average, compared to -30% use, and increased by 12% compared to +100% case. Accordingly, the detergency when using the standard amount of detergent increased by approximately 27% on average, and increased by approximately 7% compared to the cases of +60%~+100% use. Moreover, the residue of the detergent components was extremely small, but proportional nonetheless to detergent concentration.

韓國人 隔離集團의 遺傳學的 硏究

이정주,Lee, Chung Choo 한국통합생물학회 1978 동물학회지 Vol.21 No.1

서울, 강남구 서수동 일대가 격리된 集團이기 때문에 ankyloglossia가 높은 빈도로 나타났는지를 간접적으로 究明하고저 실시한 연구에서 다음과 같은 결과를 얻었다. 이 集團의 PTC 味覺 値에 관한 分布相은 他集團과 대개 일치하였다. 그러나 味盲者의 빈도는 남자가 여자보다 有意하게 높았으며 ankyloglossia가 남자에서 많이 발생한 현상과 비슷하였다. 그러나 味盲과 anakyloglossia가 어떤 상호관계가 있는지는 알 수 없었다. 舌運動의 rolling과 folding과 되는 경우는 서울의 他集團과 비교할 때 그頻度가 낮은 편이었다. twisting이 되는 경우는 남녀에 따라 차이가 심하였다. 色感異常의 頻度는 6.21%로 다른 集團보다 약간 높았다. 이와같은 결과로 보아 이 集團은 遺傳的으로 격리된 集團으로 추측되며, 舌動的, PTC 味覺 및 ankyloglossia 사이의 관계와 ankyloglosia의 遺傳樣式등은 앞으로 더 追究해야 할 문제로 생각된다. This study has been carried out with the object of researching into the situation of the genetic isolation of a Korean population located near Seoul. The results obtained are summarized as follows: In general, the distribution of P.T.C. threshold values in the population is close to that of the Seoul population. But the nonataster frequency of male in the population is higher than that of female, and this is in agreement with the status of ankyloglossia frequency in male. However the relationship between the two traits has not been clarified. The gene frequencies of rolling and folding of tongue are slightly lower than that of the Seoul population. The gene frequency conditioning the ability to twist the tongue is lower in the male than in the female. The color-blindness is 6.21 percent, and it is slightly higher than that of other Korean population. All considered, the studied population might be regarded to have been kept in genetic isolation.

외상무홍채증과 동반된 무수정체안에서 흑색횡격막 인공수정체 삽입에 대한 장기 임상경험

이정주,이상준,김신동,Jung Joo Lee,M,D,Sang Joon Lee,M,D,Shin Dong Kim,M,D 대한안과학회 2008 대한안과학회지 Vol.49 No.2

`Purpose: This is a report on the long-term follow-up of patients who had received black diaphragm intraocular lens implantation after traumatic aniridia. Methods: This is a retrospective study on the long-term follow-up for more than 50 months of six patients who had received black diaphragm intraocular lens implantation after traumatic aniridia. Results: An improvement in visual acuity of more than two letters, according to the Snellan chart, occurred in three out of six eyes that were available for follow-up studies after an average period of 7 years and 8 months (50-115 months) after the operation, and no visual acuity decline groups were present. Early complications of black diaphragm intraocular lens implantation consisted of cystoid macular edema and transient intraocular pressure rise. The complications late occurred included bullous keratopathy in four eyes, glaucoma in three eyes, and exotropia in three eyes. We performed penetrating keratoplasty in two of the four eyes suffering from bullous keratopathy, and an Ahmed valve implantation in two of the three eyes suffering from glaucoma. There were signs of reduced visual acuity in four eyes due to complications of the surgery. Conclusions: The authors of this report recommend care in use of black diaphragm intraocular lens implantation, by studies done with an average follow-up period of 7 years and 8 months post operatively. Also reported were severe complications with this treatment such as bullous keratopathy and glaucoma.`

자동차 브레이크 마찰재용 비침상형 육티탄산칼륨의 합성 연구

이정주,이나리,피재환,김종영,김정주,Lee, Jung Ju,Lee, Na-Ri,Pee, Jae-Hwan,Kim, Jong-Young,Kim, Jeong-Joo 한국재료학회 2017 한국재료학회지 Vol.27 No.3

We synthesized potassium hexatitanate, ($K_2Ti_6O_{13}$, PT6), with a non-fibrous shape, by acid leaching and subsequent thermal treatment of potassium tetratitanate ($K_2Ti_4O_9$, PT4), with layered crystal structure. By controlling nucleation and growth of PT4 crystals, we obtained splinter-type crystals of PT6 with increased width and reduced thickness. The optimal holding temperature for the layered PT4 was found to be ${\sim}920^{\circ}C$. The length and width of the PT4 crystals were increased when the nucleation and growth time were increased. After a proton exchange reaction using aqueous 0.3 M HCl solution, and subsequent heat treatment at $850^{\circ}C$, the PT4 crystal transformed into splinter-type PT6 crystals. The frictional characteristics of the friction materials show that as the particle size of PT6 increases, the coefficient of friction (COF) and wear amounts of both the friction materials and counter disc increase.

대학에 대한 새로운 사회의 요구

이정주,Lee, Jeong-Ju 한국대학교육협의회 2004 大學敎育 Vol.127 No.-

우리의 가장 좋은 자원은 인적자원이다. 대학이 이 풍부한 인적자원을 지식근로자로 육성할 때 우리는 세계시장에서 다시 경쟁력을 회복할 수 있게 될 것이다. 청년실업문제는 노동정책의 문제가 아니라 대학교육 개혁의 문제로 인식되어야 하는 것이다.

진공증착법에 의해 제작된 Cd₂GeSe₄와 Cd₂GeSe₄:Co²⁺ 박막의 물리적 특성

이정주,성병훈,이종덕,박창영,김건호,Lee, Jeoung-Ju,Sung, Byeong-Hoon,Lee, Jong-Duk,Park, Chang-Young,Kim, Kun-Ho 한국진공학회 2009 Applied Science and Convergence Technology Vol.18 No.6

$Cd_2GeSe_4$ and $Cd_2GeSe_4:Co^{2+}$ films were prepared on indium-tin-oxide(ITO)-coated glass substrates by using thermal evaporation. The crystallization was achieved by annealing the as-deposited films in flowing nitrogen. X-ray diffraction spectra showed that the $Cd_2GeSe_4$ and the $Cd_2GeSe_4:Co^{2+}$ films were preferentially grown along the (113) orientation. The crystal structure was rhomohedral(hexagonal) with lattice constants of $a=7.405\;{\AA}$ and $c=36.240\;{\AA}$ for $Cd_2GeSe_4$ and $a=7.43\;{\AA}$ and $c=36.81\;{\AA}$ for $Cd_2GeSe_4:Co^{2+}$ films. From the scanning electron microscope images, the $Cd_2GeSe_4$ and $Cd_2GeSe_4:Co^{2+}$ films were plated, and the grain size increased with increasing annealing temperature. The optical energy band gap, measured at room temperature, of the as-deposited $Cd_2GeSe_4$ films was 1.70 eV and increased to about 1.74 eV and of the as-deposited $Cd_2GeSe_4:Co^{2+}$ films was 1.79 eV and decreased to about 1.74 eV upon annealing in flowing nitrogen at temperatures from $200^{\circ}C$ to $500^{\circ}C$. The dynamical behavior of the charge carriers in the $Cd_2GeSe_4$ and $Cd_2GeSe_4:Co^{2+}$ films were investigated by using the photoinduced discharge characteristics technique. 진공증착법으로 $Cd_2GeSe_4$와 $Cd_2GeSe_4:Co^{2+}$ 박막을 ITO(indium tin oxide) 유리 기판 위에 제작하였다. 결정화는 증착된 박막들을 질소분위기의 전기로에서 열처리함으로서 이룰 수 있었다. X-선 회절 분석에 의하여 증착된 $Cd_2GeSe_4$와 $Cd_2GeSe_4:Co^{2+}$ 박막의 격자상수는 $a\;=\;7.405\;{\AA}$, $c\;=\;36.240\;{\AA}$와 $a\;=\;7.43\;{\AA}$, $c\;=\;36.81\;{\AA}$로서 능면체(rhombohedral) 구조이었고, 열처리 온도를 증가함에 따라 (113)방향으로 선택적으로 성장됨을 알 수 있었다. 열처리 온도를 증가시킴에 따라 입계 크기가 점차 커지고 판상구조로 결정화 되었다. 실온에서 측정한 광학적인 에너지 띠 간격은 열처리 온도의 증가에 따라 $Cd_2GeSe_4$ 박막의 경우 1.70 eV ~ 1.74 eV로 증가하였고, $Cd_2GeSe_4:Co^{2+}$ 박막의 경우 1.79 eV ~ 1.74 eV로 감소하였다. $Cd_2GeSe_4$와 $Cd_2GeSe_4:Co^{2+}$ 박막 내의 전하운반자들의 동역학적 거동을 광유기 방전 특성(PIDC : photoinduced discharge characteristics) 방법으로 조사하였다.