실시간 분광 엘립소메트터를 이용한 a-Si박막의 crystallization현상 연구

오영록,최은호,이기용,방경윤,안일신,김옥경 한양대학교 이학기술연구소 2004 이학기술연구지 Vol.7 No.

실시간 측정과 in-situ 측정을 하기 위해 실시간 분광 엘립소메트터 (real-time spectroscopic rotating compensator ellipsometer) 를 제작 방법을 연구하였다. 높은 온도 에서 얻어지는 Poly-Silicon은Glass에 변형이 생기므로 저온에서의 Poly-Silicon을 만들기 위하여 ni기판에 a-Si 박막을 성장 시킨후 그위에 투명전극을 올려 300℃ 이하의 저온에서 Ni과 투명전극에 전기장을 걸어 주었을때 a-Si이 Poly-Silicon 으로 바뀌는 crystallization 현상을 직접 제작한 ellipsometer 를 이용하여 실시간으로 관찰하였다. We make real-time spectroscopic rotating compensator ellipsometer for real time measurement and in-situ measurement. We study a method to make Poly silicon after depositing amomhous silicon thin film by dc sputter system at different temperature and pressure. Amorphous silicon films of 30㎚ thickness were deposited on the Ni substrate, and then ITO films of 20㎚ thickness were deposited on the a-Si films. The sampie were crystallized below 300℃ in the electric field applied between the Ni and ITO.

흉막삼출의 유무에 따른 쯔쯔가무시증 환자간의 비교

권세훈,김형호,강지인,하재하,한경택,이재록,김동민,권용은,윤성호,이승일 朝鮮大學校 附設 醫學硏究所 2007 The Medical Journal of Chosun University Vol.32 No.1

Scrub typhus is a potentially fatal infectious disease caused by the organism Orientia tsutsugamushi. Clinical manifestations are fever, skin rash, eschar and varying degree of respiratory distress. The pleural effusion in scrub typhus is rare and secondary to the destruction of vascular endothelium. Because the respiratory symptoms are generally mild and the pleural effusion in scmb typhus is rare than in interstitial pneumonia, there are few comments about the characteristics of scmb typhus with pleural effusion. So we made the comparative study of scmb typhus patients between with pleural effusion and without pleural effusion. 연구배경 치명적일 수 있는 감염질환 중 하나인 쯔쯔가무시중(Scrub typhus)에서 드문 흉막삼출을 동반한 환자에 대한 고찰은 다른 문헌에서도 자주 언급되지 않았다. 따라서 본 저자들은 흉막삼출이 있는 경우와 없는 경우에 따른 쯔쯔가무시중 환자들을 비교하고자 하였다. 방법 2003년에서 2006년까지 조선대학교 병원 내과에 입원중인 환자 중 쯔쯔가무시중 진단을 받은 총 109명의 환자를 대상으로 하여 흉부 X선 검사 및 혈청학적 검사(CPK, LDH, ESR, CRP, AST, ALT, ADA), 혈액학적 검사(WBC, PLT) 및 백분율 검사등을 실시하였다. 결과 흉막삼출이 있는 환자들의 경우 흉막 삼출이 없는 환자들에 비해 ESR 수치가 통계학적으로 의의있게 높았다(p-vaule < 0.05). 결론 흉막삼출 유무에 따른 쯔쯔가무시중 환자간의 비교에 있어 ESR 수치가 통계학적인 의의를 가졌다.

Fully nonlinear time-domain simulation of a backward bent duct buoy floating wave energy converter using an acceleration potential method

Lee, Kyoung-Rok,Koo, Weoncheol,Kim, Moo-Hyun The Society of Naval Architects of Korea 2013 International Journal of Naval Architecture and Oc Vol.5 No.4

A floating Oscillating Water Column (OWC) wave energy converter, a Backward Bent Duct Buoy (BBDB), was simulated using a state-of-the-art, two-dimensional, fully-nonlinear Numerical Wave Tank (NWT) technique. The hydrodynamic performance of the floating OWC device was evaluated in the time domain. The acceleration potential method, with a full-updated kernel matrix calculation associated with a mode decomposition scheme, was implemented to obtain accurate estimates of the hydrodynamic force and displacement of a freely floating BBDB. The developed NWT was based on the potential theory and the boundary element method with constant panels on the boundaries. The mixed Eulerian-Lagrangian (MEL) approach was employed to capture the nonlinear free surfaces inside the chamber that interacted with a pneumatic pressure, induced by the time-varying airflow velocity at the air duct. A special viscous damping was applied to the chamber free surface to represent the viscous energy loss due to the BBDB's shape and motions. The viscous damping coefficient was properly selected using a comparison of the experimental data. The calculated surface elevation, inside and outside the chamber, with a tuned viscous damping correlated reasonably well with the experimental data for various incident wave conditions. The conservation of the total wave energy in the computational domain was confirmed over the entire range of wave frequencies.

SAN 환경에서의 공유파일 시스템을 위한 광역 버퍼관리기의 설계 및 구현

이경록(Kyoung-Rok Lee),김은경(Eun-Kyung Kim),정병수(Byeong-Soo Jeong) 한국정보과학회 2002 한국정보과학회 학술발표논문집 Vol.29 No.1A

최근에는 ATM, Fast Switched LAN, Fiber Channel과 같은 고속의 네트워크의 발달로 인해 분산 환경의 네트워크 파일 시스템에서 디스크를 접근하는 속도보다 원격지 클라이언트의 메모리를 접근하는 속도가 현저하게 증가되었다. 실제로 이와 같은 고속 네트워크 환경을 기반으로 하여 각 서버와 저장 장치를 분리하여 대용량 데이터를 관리하는 SAN(Storage Area Network)과 같은 새로운 네트워크 저장 시스템이 출연하고 있다. 본 논문에서는 이와 같은 새로운 분산 네트워크 파일 저장 시스템 환경에서 필수적으로 고려되어야 하는 광역 버퍼관리기를 설계 및 구현하였다. 본 논문에서 구현된 광역 버퍼 관리기는 크게 데이터 룩업과 버퍼리스트 관리 부분으로 나누어 구성되어 있으며, 이를 위한 적절한 자료 구조와 시스템 내에 있는 각 호스트간의 버퍼블록정보 유지를 위한 방안 및 기존 운영체제의 커널내 버퍼 관리기와 통합하는 방안을 제시한다.

피에조일렉트릭 프린터 헤드 구동을 위한 집적화된 고전압 펄스 발생 회로의 설계

이경록(Kyoung-Rok Lee),김종선(Jong-Sun Kim) 한국조명·전기설비학회 2011 조명·전기설비학회논문지 Vol.25 No.2

This paper presents an integrated variable amplitude high voltage pulse generation circuit with low power and small size for driving industrial piezoelectric printer heads. To solve the problems of large size and power overhead of conventional pulse generators that usually assembled with multiple high-cost discrete ICs on a PCB board, we have designed a new integrated circuit (IC) chip. Since all the functions are integrated on to a single-chip it can achieve low cost and control the high-voltage output pulse with variable amplitudes as well. It can also digitally control the rising and falling times of an output high voltage pulse by using programmable RC time control of the output buffer. The proposed circuit has been designed and simulatedd in a 180[nm] Bipolar-CMOS-DMOS (BCD) technology using HSPICE and Cadence Virtuoso Tools. The proposed single-chip pulse generation circuit is suitable for use in industrial printer heads requiring a variable high voltage driving capability.

화자분류를 위한 유성음 분리에 관한 연구

이경록(Kyoung Rok Lee) The Research and Information Service 2013 남부대학교 논문집 Vol.13 No.-

본 논문에서는 화자 분류 및 추적을 위한 전처 리 단계로서 입력 음성 에서 유성음을 분리하는 것에 대하여 실 험하였다. 유성음 분리를 위한 적절한 특징 파라미터로 특이점, ZCR, HZCRR, SDV를 선택하고 실험목적에 맞게 최종 판별과정을 보완하였다. 테스트 DB는 화자변화 패턴을 고려 해서 만들어진 1분 길이의 실제 뉴스 파일로서 242개의 유성음 구간이 존재 한다. 실험결과 MDR에서는 ZCR이 7.4%로 가장 좋은 결과를 보였고, FAR에서는 HZCRR이 32.6%로 가장 좋은 결과를 보였다. MDR, FAR 양쪽을 모두 고려하면 ZCR이 MDR 7.4%, FAR 37.6%로 가장 양호한 결과를 보였고 SDV는 MDR 23.1%, FAR 58.6%로 가장 낮은 결과를 보였다.

Darapladib Binds to Lipoprotein-Associated Phospholipase A2 with Meaningful Interactions

Do, Kyoung-Rok,Kim, Chul,Chang, Byungha,An, Seong Soo A.,Shin, Jae-Min,Yea, Sang-Jun,Song, Mi-Young,No, Kyoung Tai,Lee, Jee-Young Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.1

Lipoprotein-associated phospholipase A2 (Lp-$PLA_2$) is a crucial enzyme in atherosclerosis as a potential drug target. The most remarkable Lp-$PLA_2$ inhibitory drug is Darapladib. We determined the binding pose of Darapladib to Lp-$PLA_2$ through docking study. Darapladib formed two hydrogen bonding interactions with the side chain of Tyr160 and Gln352 and several pi-pi interactions with aromatic and aliphatic hydrophobic residues of Lp-$PLA_2$. It is known that the dietylpropan-amine moiety of Darapladib has influence on the improvement of its oral bioavailability and we supposed this in our docking results.

지방육종으로 오인된 후복막강에서 기원한 거대 지방종 1예

이경록 ( Kyoung Rok Lee ),서태진 ( Tae Jin Seo ),조준호 ( Jun Ho Cho ),김형일 ( Hyung Il Kim ),허영회 ( Young Hoi Hur ),조성범 ( Sung Bum Cho ),이완식 ( Wan Sik Lee ),주영은 ( Young Eun Joo ) 대한소화기학회 2010 대한소화기학회지 Vol.55 No.6

Lipomas are the most common benign tumors of adipose tissue among adults. Lipomas can occur almost anywhere in the trunk, extremities, mediastinum, and pelvis, but retroperitoneal lipomas are extremely rare. It should be distinguished from well differentiated liposarcoma in order to provide the appropriate treatment and follow up. We experienced a case of 60-year-old patient with large retroperitoneal lipoma mimicking liposarcoma causing palpable abdominal mass and pain. Abdominal computerized tomography (CT) showed 33×22 cm sized bulky fat-containing mass with contrast enhanced solid portion in right retroperitoneum. Positron emission tomograpgy (PET) revealed increased 18F-FDG uptake at solid portion shown in abdominal CT. Imaging studies confirmed a high index of suspicion on liposarcoma. Laparotomy showed a large encapsulating tumor arising from retroperitoneum with fat necrosis. Pathologic examination of resected specimen revealed normal mature adipocytes without atypical cells, compatible with lipoma. (Korean J Gastroenterol 2010;55:394-398)

Effect of different grinding burs on the physical properties of zirconia

Kyung-Rok Lee,Han-Cheol Choe,Yu-Ri Heo,Jang-Jae Lee,Mee-Kyoung Son 대한치과보철학회 2016 The Journal of Advanced Prosthodontics Vol.8 No.2

PURPOSE Grinding with less stress on 3Y-TZP through proper selection of methods and instruments can lead to a long-term success of prosthesis. The purpose of this study was to compare the phase transformation and physical properties after zirconia surface grinding with 3 different grinding burs. MATERIALS AND METHODS Forty disc-shaped zirconia specimens were fabricated. Each Ten specimens were ground with AllCeramic SuperMax (NTI, Kahla, Germany), Dura-Green DIA (Shofu Inc., Kyoto, Japan), and Dura-Green (Shofu Inc., Kyoto, Japan). Ten specimens were not ground and used as a control group. After the specimen grinding, XRD analysis, surface roughness test, FE-SEM imaging, and biaxial flexural strength test were performed. RESULTS After surface grinding, small amount of monoclinic phase in all experimental groups was observed. The phase change was higher in specimens, which were ground with Dura-Green DIA and AllCeramic SuperMax burs. The roughness of surfaces increased in specimens, which were ground with Dura-Green DIA and AllCeramic SuperMax burs than control groups and ground with Dura-Green. All experimental groups showed lower flexural strength than control group, but there was no statistically significant difference between control group and ground with Dura-Green DIA and AllCeramic SuperMax burs. The specimens, which were ground with Dura- Green showed the lowest strength. CONCLUSION The use of dedicated zirconia-specific grinding burs such as Dura-Green DIA and AllCeramic SuperMax burs decreases the grinding time and did not significantly affect the flexural strength of zirconia, and therefore, they may be recommended. However, a fine polishing process should be accompanied to reduce the surface roughness after grinding.

Determination of coronal electron density distributions by DH type II radio bursts and CME observations

Jae-Ok Lee,Yong-Jae Moon,Jin-Yi Lee,Kyoung-Sun Lee,Rok-Soon Kim 한국천문학회 2015 天文學會報 Vol.40 No.1