리튬 미소전지용 $LiCoO_2$ 박막양극의 전기화학적 특성에 미치는 기판의 영향

이종기,이승주,백홍구,이성만,Lee Jong-Ki,Lee Seung-Joo,Baik Hong-Koo,Lee Sung-Man 한국전기화학회 2000 한국전기화학회지 Vol.3 No.3

기판의 변화가 박막전극의 전기화학적 특성에 미치는 영향을 조사하기 위해 박막 $LiCoO_2$ 양극을 alumina, chemically etched-Si그리고 flat-Si기판 위에 증착하였다. Alumina기판의 경우 산소 분위기, $800^{\circ}C$ 30분간 열처리 후 내부에 균열이 존재하는 매우 큰 결정이 형성되었으나 flat-Si 기판의 경우에는 미세하며 균일한 결정이 관찰되었다. Flat-Si 기판 위에 증착된 박막은 alumina또는 식각된 Si 기판의 경우에 비하여 peak potential증감 및 고 전류밀도 방출 능면에서 매우 우수한 특성을 나타내었으며 이는 열처리 후 형성된 결정립의 크기, 표면 형상 및 전류 집전체의 전기저항 차이에 기인한 것으로 생각되었다. In order to investigate the substrate effect on the electrochemical properties of thin-film electrode, $LiCoO_2$ was deposited onto the alumina, chemically etched-Si and flat-Si substrates. After annealing at $800^{\circ}C$ in $O_2$ for 30min, the film deposited on the alumina consisted of large particles with several cracks, whereas the film deposited on the flat-Si substrate was composed of very small and uniform particles. The films deposited on the flat-Si showed improved electrochemical properties such as peak potential divergence and rate-capability, over those deposited on the alumina and chemically etched-Si substrate, which can be attributed to the differences of the particle size surface morphology, and the electrical resistance of the current collector.

흰쥐에 경구 및 정맥투여시 에피가로카테친이 니모디핀의 생체이용률에 미치는 영향

이종기,최준식,최동현,Lee, Chong-Ki,Choi, Jun-Shik,Choi, Dong-Hyun 대한약학회 2011 약학회지 Vol.55 No.4

The purpose of this study was to investigate the effect of epigallocatechin gallate (EGCG) on the pharmacokinetics of nimodipine in rats. Pharmacokinetic parameters of nimodipine were determined in rats after oral and iv administration of nimodipine with or without EGCG and also the effect of EGCG on the cytochrome P450 (CYP) 3A4 and P-glycoprotein (P-gp) activity were evaluated. EGCG inhibited CYP3A4 and P-gp activity. EGCG significantly increased the area under the plasma concentration-time curve (AUC) and peak plasma concentration ($C_{max}$) of nimodipine. The absolute bioavailability (AB%) and relative bioavailability (RB%) of nimodipine by EGCG were increased by 16% and by 48%, respectively, compared to the control. In contrast, EGCG did not affect the intravenous pharmacokinetics of nimodipine. Based on these results, the increased bioavailability of nimodipine might be due to inhibition of CYP3A4 in the small intestine and/or in the liver and inhibition of P-gp in the small intestine by EGCG.

시판 노르플록사신 정계의 생체내 이용률

이종기,조삼상,Lee, Chong Ki,Cho, Sam Sang 한국임상약학회 1996 한국임상약학회지 Vol.6 No.2

This study was attempted to investigate the dissolution rate and the bioavailability after oral administration of commercially available norfloxacin tablets in rabbits. The dissolution test was conducted in artificial gastric juice using basket method with for norfloxacin preparations (A, B, C and D) which were chemically equivalent. The results were as follows ; The dissolution rate was increased in the order of four different brand A>D>B>C. Area under the plasma concentration curve and peak plasma concentration were increased in the order of brand A>D>B>C. Absorption rate constant and peak time were increased in the order of brand B>A>C>D, and there was a little difference in elimination rate constant and biological half-life. The correlation of the dissolution rate and relative bioavailability showed significant linear relationship. From the results of this experiment, the bioavailability of norfloxacin tablets in rabbits may be predicted from the results of dissolution rate studies.

Functional Assessments of Spodpotera Cell-expressed Human Erythrocyte-type Glucose Transport Protein with a Site-directed Mutagenesis

이종기,Lee, Chong-Kee 대한의생명과학회 2008 Biomedical Science Letters Vol.14 No.2

The baculovirus/insect cell expression system is of great value in the study of structure-function relationships in mammalian glucose-transport proteins by site-directed mutagenesis and for the large-scale production of these proteins for mechanistic and biochemical studies. In order to exploit this, the effects of substitution at the highly conserved residue glutamine 282 of the human erythrocyte-type glucose transporter have been examined by in vitro site-directed mutagenesis. The modified human transport protein has been expressed in Spodoptera frugiperda 21 cells by using the recombinant baculovirus AcNPV-GTL. To assess the functional integrity of the expressed transporter, measurements of the transport inhibitor cytochalasin B binding were performed, involving the membranes prepared from 4 days post infection with no virus, with wild-type virus or AcNPV-GTL virus. Data obtained showed that there was little or no D-glucose-inhibitable binding in cells infected with the wild type or no virus. Only the recombinant virus infected cells exhibited specific binding, which is inhibitable by D- but not by L-glucose. However, there was a notable reduction in the affinity for the potent inhibitor cytochalasin B when binding measurements of AcNPV-GTL were compared with those of AcNPV-GT, which has no substitution. It is thus suggested that although the modified and unmodified human transporters differed slightly in their affinity for cytochalasin B, the glutamine substitution did not interfere the heterologous expression of the human transporter in the insect cells.

Web 3D 가상도시 구축

이종기,임일식,김병국,Lee, Jong-Ki,Lim, Il-Sik,Kim, Byung-Guk 한국공간정보학회 2003 개방형지리정보시스템학회 논문지 = Journal of the Korea Open Geogr Vol.5 No.1

실세계의 분석에서부터 3D 가상도시를 구축하는 GIS는 매우 빠르게 발전하고 있다. 3D 가상도시는 GIS 기술, 컴퓨터그래픽스 기술, 가상현실 기술, 공간 데이터베이스 기술에 의해 컴퓨터 속에 구현이 되는 도시를 말한다. 본 연구에서는 수치지도를 이용하여 실세계 지도좌표를 포함한 3차원 지형 기본맵을 구축하였다. 그리고 높이값을 가진 건물과 3차원 지형 기본맵을 통합하여 Cyber City를 구축하였다. 여기에 Server/Client 시스템을 이용하여 3차원 Cyber City 웹서비스 실시하였다. 기존의 이미지 또는 벡터 기반의 웹서비스방식보다 벡터와 이미지의 합성인 하이브리드(Hybrid)방식으로의 개선을 제안하였고, 공간검색 속성검색 기능을 제공함으로써 기존의 Web 3D 기술의 단순한 가시화의 한계를 넘어 Web 3D GIS로의 발전방향을 제시하였다. The GIS which is analysis of the real world to construction of 3D virtual city develop s in rapid growth. 3D virtual city is simulated by use of a GIS, Computer graphics, virtual reality and Spatial database. In this paper 3D topographical basemap which have the geographic coordinate of world was constructed by digital map. And build the Cyber city with combining the building that have elevation and 3D topographical basemap. By using server/client system for the cyber city. 3D cyber city web service implemented. We proposed the hybrid base web service method rather than the image or vector base web service. By the spatial and attribute search in the 3D Cyber City, overcome the existing simple visibility of Web 3D technology, and exhibited development direction to the Web 3D GIS.

수직 Bridgman 법에 의한 CdTe 단결정 성장에 관한 연구

이종기,김욱,백홍구 ( Jong Ki Lee,Wook Kim,Hong Koo Baik ) 한국주조공학회 1990 한국주조공학회지 Vol.10 No.4

N/A The single crystal of CdTe was grown by modified 6 zone Bridgman method under the conditions of excess Te and excess Cd. To prevent the constitutional supercooling, the crystal growth was done under the temperature gradient of 17℃/㎝ in front of the solid /liquid interface and the growth rate was 3㎜/hr. The grain morphologies and the growth mechanism were investigated in excess Te and excess Cd conditions. The grain size of excess Te crystal was increased with an increase of the distance from the tip but, in the case of excess Cd crystal, single crystal was not obtained because of the cavities due to the excess Cd vapors so that the grain size was not increased with an increase of the distance from the tip. In addition, the growth of single crystal of CdTe was done with repeated necking ampoule. It was found that the necking had no effects on the grain selection because the cavities trapped in the necking portion acted as heterogeneous nucleation sites.

흰쥐에서 모린이 니페디핀의 약물동태에 미치는 영향

이종기,최준식,Lee, Chong-Ki,Choi, Jun-Shik 대한약학회 2007 약학회지 Vol.51 No.3

The aim of this study was to investigate the effect of morin on the pharmacokinetics of nifedipine in rats. The pharmacokinetic parameters of nifedipine were measured after the oral administration of nifedipine (5 mg/kg) in the presence or absence of morin (1.5, 7.5 and 15 mg/kg, respectively). Compared to the control groups, the presence of 7.5 mg/kg and 15 mg/kg of morin significantly (p<0.05) increased the area under the plasma concentration-time curve (AUC) of nifedipine by 48.5${\sim}$68.2%, and the peak concentration (C$_{max}$,) of nifedipine by 59.9~84.2%. The absolute bioavailability(AB%) of nifedipine was significantly (p<0.05) increased by 21.5${\sim}$24.5% compared to the control (14.5%). While there was no significant change in the time to reach the peak plasma concentration (T$_{max}$) and the terminal half-life (T$_{1/2}$) of nifedipine in the presence of morin. It might be suggested that morin altered disposition of nifedipine by inhibition of both the first-pass metabolism and p-glycoprotein (P-gp) efflux pump in the small intestine of rats. In conclusion, the presence of morin significantly enhanced the oral bioavailability of nifedipine, suggesting that concurrent use of morin or morin-containing dietary supplement with nifedipine should require close monitoring for potential drug interaction.

오픈소스 Moodle 학습관리시스템 기반의 협동학습 운영 사례에 관한 연구 - 사용자의 협동학습지원을 중심으로 -

이종기,Lee, Jong-Ki 서비스사이언스학회 2016 서비스연구 Vol.6 No.4

오픈소스는 스마트폰의 등장과 함께 놀라운 확산을 하고 있다. 이러닝 분야의 오픈소스인 Moodle 학습관리시스템은, 상용프로그램인 Blackboard를 제외하고 전 세계적으로 가장 많이 사용되고 있는 학습관리시스템이다. 그 이유 중 하나는 교육공학의 이론적 기초가 되며, 이러닝의 핵심 원칙이라 할 수 있는 구성주의 원칙에 따른, 협동학습과 상호작용이 잘 지원되도록 설계되어, 높은 교육적 효과와 장점을 가지기 때문이다. 본 연구에서는 오픈소스인 Moodle 학습관리시스템을 이용한 협동학습 운영 사례를 중심으로, 사용자의 협동학습을 지원하는 구체적 내용을 소개하고, 사례를 통하여 나타난, Moodle 학습관리시스템 협동학습의 장점과 특이점을 살펴본다. 연구 결과 PC와 스마트폰 환경에서 동시에 구현된, Moodle 학습관리시스템의 팀 프로젝트 협동학습을 통하여, 협동학습의 재미와 유용성을 확인하고, 학습자체의 중요성을 넘어 관계의 중요성이 학습자의 협동학습동기를 유발시킨다는 것을 사례를 통하여 확인할 수 있다. Open source has an amazing spread with the advent of smartphones. Open-source Moodle in e-learning areas are free of LMS (Learning Management System) and the most widely used worldwide, except for the black board commercial programs. One reason is well designed to support collaborative learning and interaction based on constructivist principles, which is the core principle of e-learning in particular that the theoretical basis of educational technology has a high educational effectiveness and benefits. This study examines the operational practices of collaborative learning using open source learning management system Moodle program. It introduces specific information to support the user of the collaborative learning. It looks at the advantages and singularity of collaborative learning in e-learning through examples shown. The purpose of this study is the importance of the relationship between learners and the importance of self-learning of collaborative learning through collaborative learning in a knowledge repository of Moodle. In addition, collaborative learning outcomes are is based on the motivation of learners and playfulness.

융합시대의 통신과 방송의 보편적서비스 정립방안에 관한 연구

이종기(Joong-Ki Lee),이상우(Sang-Woo Lee),이봉규(Bongkyu Lee) 한국언론학회 2009 한국언론학보 Vol.53 No.3

濟州道 草地開發에 있어서 土壤學的 問題點

李鍾基(Chong Ki Lee),李根常(Keun Sang Lee) 한국토양비료학회 1975 한국토양비료학회지 Vol.8 No.3