SLALOM을 이용한 전광 직렬-병렬 데이터 형식 변환기

이성철,이기철,이석,박진우,Lee, Sung-Chul,Lee, Ki-Chul,Lee, Seok,Park, Jin-Woo 한국광학회 2002 한국광학회지 Vol.13 No.5

In this paper, we propose new simple schemes for all-optical serial-to-parallel and parallel-to-serial data format converters based on a semiconductor laser amplifier in a loop mirror (SLALOM) for all-optical data processing. They have the advantages of simple and easily expandable structure, efficient operation and easy implementation. We implement the proposed all-optical data converters. and experimentally demonstrate their operation. 본 논문에서는 SLALOM(Semiconductor Laser Amplifier in a Loop Mirror)을 사용하여 광신호를 직렬 데이터 형식에서 병렬 데이터 형식으로 또는 병렬 데이터 형식에서 직렬 데이터 형식으로 데이터 형식을 전광으로 변환할 수 있는 전광 직렬-병렬 데이터 형식 변환기의 구조가 제안되었다. 이 구조들은 간단하고 확장이 쉽고 효율적으로 동작하며 쉽게 구현될 수 있다. 제안된 데이터 형식 변환기를 구현하여 동작을 실험적으로 입증하였다.

유관 압박나사를 이용한 거골하 관절유합술

이성철,정홍근,전지용,유제욱,Lee, Sung-Chul,Jung, Hong-Geun,Chun, Ji-Yong,Yu, Je-Wook 대한족부족관절학회 2005 대한족부족관절학회지 Vol.9 No.1

Purpose: To analyze the overall clinical outcome, overall assessment, and patient's satisfaction rate of subtalar arthrodesis using the cannulated compression screw. Materials and Methods: This study is based on 17 patients, 17 feet who underwent subtalar arthrodesis using the cannulated compression screw from March, 1997 to March, 2004 with at least 1 year follow-up. The average follow-up period was 33.0 months (12 to 72 months). Functional results were assessed using the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot (AOFAS) score, and Visual Analysis Scale (VAS) pain score, patients' returning to previous occupation and patients' satisfaction rate were also evaluated. Results: The mean AOFAS scores at final follow-up were 80.4 points (range $66{\sim}92$). The satisfactory rates were as follow. Thirteen patients (76.4%) were at least satisfied with surgical result at final follow-up. Patients' VAS pain score was average 2.8 points ($1{\sim}6$). Fourteen (82.3%) patients returned to previous job at mean postoperative period of 11.3 months (range 3-18 months). Patients' work efficiency after returning to previous occupation was 68.7% (range $33{\sim}100%$). There were 9 complications which were 3 cases of sural nerve injury, 1 case of valgus malunion, and 5 cases of the hindfoot residual pain. Conclusion: We obtained the satisfactory functional results with relatively high patient satisfaction rate of 76%. So we conclude that subtalar arthrodesis using the cannulated compression screw is a reliable method for addressing the painful end-stage subtalar osteoarthritis and unreconstructible comminuted calcaneal fractures. However we also found out that average 11 months were necessary for patients to return to their job.

가와사끼 병에 합병된 간기능 이상소견에 대한 임상적 및 병리조직학적 소견

이성철,차한,나송이,김희섭,박호진,신미경,Lee, Sung-Chul,Tchah, Hann,Na, Song-Yi,Kim, Hee-Sup,Park, Ho-Jin,Shin, Mi-Kyeong 대한소아소화기영양학회 2000 Pediatric gastroenterology, hepatology & nutrition Vol.3 No.1

Purpose: The aim of this research is to examine the abnormal liver function complicated with Kawasaki disease (KD) and to analyze its clinical characteristics and complications. Methods: Ninty eight cases were diagnosed as having KD, among which thirty four cases had abnormal alanine aminotransferase (ALT) (>30 IU/L). These abnormal ALT cases were evaluated in terms of age and sex distribution, major symptoms, complications, laboratory and histopathologic findings. Results: Male to female ratio was 2.4:1 and most patients (91.2%) were under 5 years of age. Cervical lymphadenopathy was observed in 3 cases (8.8%); and recurred cases were two (5.8%). Average fever duration was 8 days; average length of hospitalization was 9 days; and average recovery period was 13 days. Immediately after admission, positive CRP was observed in 31 cases (91.2%), leukocytosis (> $10,000/mm^3$) in 26 cases (76.0%), thrombocytosis (> $450,000/mm^3$) in 7 cases (20.6%), and anemia (<10 gm/dl) in 7 cases (20.6%), respectively. GB hydrops or cholecystitis were noted in 3 cases (8.8%), abnormal ECG finding in 1 case (2.9%), coronary dilatation or aneurysm in 2 cases (5.9%). Liver biopsy was done in four cases and revealed mild infiltration of lymphocytes on the portal area and mild bile duct proliferations. Conclusion: The abnormal liver function was noted in 34.7% of KD patients, and subsided all within one month. But the liver function test should be checked closely in patients of the abnormal liver function test complicated with KD despite of its good prognosis.

Allergic Purpura에 합병된 Acute Pancreatitis 1례

이성철,김화자,차한,박호진,Lee, Sung-Chul,Kim, Hwa-Ja,Tchah, Hann,Park, Ho-Jin 대한소아소화기영양학회 1999 Pediatric gastroenterology, hepatology & nutrition Vol.2 No.1

저자들은 복통, 구토, 혈변을 주소로 입원한 6세 여아에서 allergic purpura에 급성 췌장염이 병발된 1례를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Allergic (Henoch-Schonlein) purpura is a nonthrombocytopenic purpura that affects small nonmuscular vessels with involvement of skin, gastrointestinal tract, joint, and kidney. Pancreatitis has rarely been reported as a complication of H-S purpura. In 1965, hemorrhagic pancreatitis as a complication of H-S purpura was reported by Toskin. We experienced one case of pancreatitis complicated with H-S purpura: pancreatic head enlargement was noted in small bowel series and abdominal sonogram with increased serum amylase level (160 U/dL) in a 6-year-old female child who complained of abdominal pain, vomiting, bloody stool, and petechiae on lower extremities.

실린더형 MoSi₂계 발열체의 유도가열 적용

이성철,김요한,명재하,김배연,Lee, Sung-Chul,Kim, Yo Han,Myung, Jae-ha,Kim, Bae-Yeon 한국화학공학회 2019 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.57 No.4

본 연구에서는 슬립캐스팅 성형법을 이용하여 실린더형 $MoSi_2$계 세라믹 서스셉터를 개발하여 고온 유도가열에 적용시켰다. $MoSi_2$계 소재는 SHS법(Self-propagating High-temperature Synthesis)으로 합성하였고 XRD 분석을 통해 합성된 상과 결정구조를 확인하였다. 합성된 소재로 실린더 성형체를 제작하기 위해 슬립캐스팅을 진행하였고 슬립의 고형분 함량 및 유지시간을 조절하여 실린더 성형체의 두께를 제어하였다. 최종적으로 성형체 소결을 통해 유도가열 발열체를 제작하였고 열처리과정 중 표면에 형성된 $SiO_2$층은 SEM/EDS 분석을 통해 확인하였다. 서스셉터로서의 가열성능을 평가하기 위해 유도가열기로 일정한 출력을 인가하였을 때 $(Mo,W)Si_2$ 실린더 서스셉터의 표면온도를 측정하여 출력 2 kW를 인가하였을 때 발열특성을 분석하였으며, 서스셉터 표면의 최고 온도는 $1457^{\circ}C$, 평균 승온속도는 $19^{\circ}C/s$로 우수한 가열 특성을 나타냈다. In present study, the cylindrical susceptor by the slip casting method was designed to apply high-temperature induction heating by using $(Mo,W)Si_2$ ceramics. $MoSi_2$-based materials were synthesized by SHS (Self-propagating High-temperature Synthesis) method. The phase and crystal structure of $MoSi_2$-based materials were confirmed by XRD analysis. The shape of cylindrical mold was synthesized for various thickness by using the slip casting method. Finally, the susceptor for induction heating was processed by sintering and heat treatment to form $SiO_2$ layer, which was confirmed on the surface of susceptor by SEM/EDS analysis. To evaluate the heating performance of $(Mo,W)Si_2$ cylinder susceptor, we measured the maximum surface temperature and heating rate in comparison with the rod heating element under constantly applied power. The induction heating of the $(Mo,W)Si_2$ cylinder showed excellent heating performance, reaches the maximum temperature of $1457^{\circ}C$, with the average heating rate of $19^{\circ}C/s$ at 2 kW

유한요소법에 의한 박판곡선부채의 좌굴해석

이성철,Lee, Sung Chul 대한토목학회 1991 대한토목학회논문집 Vol.11 No.2

A computer program for the linear elastic buckling anlalysis of thin walled members is developed using a 3-node triangular shell element. The element has real stiffness value for a kinematic degree of freedom associated with rotation about the surface normal at each node. The validity of the present computer program is demonstrated through the plate buckling analysis and the lateral-torsional buckling analysis of a straight beam. Then, simply supported circular arches subjected to uniform bending are analyzed and the results are compared with existing solutions. 평면내에서의 비틀림에 대한 강성도를 갖는 3절점 삼각형 shell요소를 사용하여 박판으로 이루어진 곡석 또는 직선부재의 선형 탄성좌굴 해석을 위한 컴퓨터 프로그램을 개발 하였다. 판의 좌굴 해석과 보의 횡 비틈 좌굴해석을 통하여 본 프로그램의 타당성을 입증하였고, 이를 순수 휨을 받는 양단의 단순지지된 원호 아치의 좌굴해석에 적용시켜 그 결과들을 다른 연구 결과들과 비교 검토하여 보았다.

설계인자 보정방법에 의한 사출성형기어의 캐비티 설계

이성철,김충현,권오관,허용정,Lee, Sung-Chul,Kim, Choong-Hyun,Kwon, Oh-Kwan,Huh, Yong-Jeong 대한기계학회 1996 大韓機械學會論文集A Vol.20 No.10

As plastics shrink when changing from a molten to a solid state, mold cavities must by made larger than the product specification, In making molded gears, the teeth in the cavity must be carefully compensated for shrinkage so that the teeth of gears will have the correct profile. Two compensation methods are widely used in the cavity design. One is the compensation of a module and the other is the modification of a pressure angle and profile shifting coefficient. These methods, however, do not provide a gear cavity with all disign parameters for gears and several parameters are determined by experience. In this paper, the new design technique, namely the compensation method of design parameters, was proposed , which is based on the three kinds of shrinkage rates obtained from the measuring data of the prototype of molded gears. Using the shrinkage rates in the tip circle, tooth heigth and tooth thickness, we calculate the whole design parameters of a gear cavity. Thus, the gear cavity is considered as a complete gear with the compensated module, pressure angle, profile shifting coefficient, clearance coefficient and back lash amount so that the formula of gears can be applied to the cavity design effectively. Experimental results show that more precision molded gears can be made by using the proposed design method.

타원형 기어의 와이어커팅을 위한 설계

이성철,Lee, Sung-Chul 한국트라이볼로지학회 2007 한국트라이볼로지학회지 (Tribol. Lubr.) Vol.23 No.4

The CAD model of a elliptical gear for wire cutting has been developed. The rolling contact of pitch ellipses whose rotation axes coincide with their focus has been analyzed, and the perimeter of the pitch ellipse has been divided into equal-length segments by the number of teeth. A master tooth profile, which is a composite curve of circular arcs that represents involute, has been introduced. The elliptical gear has been designed by imposing the master tooth on the divided points of the pitch ellipse, and a full fillet has been achieved between neighbour teeth. Thus, the whole profile of an elliptical gear is a composite curve of arcs only, and consequently NC codes for wire cutting can be easily generated. Furthermore, a computer simulation program is developed to verify the mesh of the elliptical gear.

조화사회와 농민공의 현실: 영화 <미꾸라지도 물고기다>를 중심으로

이성철 ( Sung Chul Lee ),이치한 ( Chi Han Lee ) 한국외국어대학교 외국학종합연구센타 중국연구소 2009 中國硏究 Vol.45 No.-

고도근시의 망막하출혈

이성철(Sung Chul Lee),조강원(Kang Won Cho),김남수(Nam Soo Kim) 대한안과학회 1996 대한안과학회지 Vol.37 No.4