초고속 데이터에 대한 전광(全光) 파장변환기 구현

이승우,이정렬,엄진섭 강원대학교 정보통신연구소 2002 정보통신논문지 Vol.6 No.-

Generally, it is announced that RZ pattern gives a better transmission performance than NRZ pattern in ultra-high speed transmission above 10Gbps. A wavelength converter for RZ data which can controls XPM in SOA by using polarization controller within optical fiber loop mirror is proposed and demonstrated. The proposed structure needs only one polarization dependent SOA for implementation compared to previous XPM ones and makes the cost down. And it provides wavelength converted signals with non-inverted and inverted pattern into outputs respectively.

NOLM 구조를 이용한 데이터 속도 가변 펄스 발생기

이승우,윤경모,이용기,엄진섭 강원대학교 정보통신연구소 2003 정보통신논문지 Vol.7 No.-

This paper describes a tunable data rate pulse generator using the NOLM structure. This can induce the change of pulse rate by the control of PC (Polarization Controller) which located in NOLM. We measured very stable NRZ pulse sequences of three rates (200Mbps, 400Mbps, 800Mbps), and also obtained 100ps pulse width under the same condition.

구강외과 수술용 스텐트 기반 영상유도 수술 시스템의 개발

이우진,김대승,이원진,이삼선,최순철,허민석,허경회,김명진,이지호 대한구강악안면방사선학회 2009 Imaging Science in Dentistry Vol.39 No.3

Purpose : The purpose of this study was to develop a stent-based image guided surgery system and to apply it to oral and maxillofacial surgeries for anatomically complex sites. Materials and Methods : We devised a patient-specific stent for patient-to-image registration and navigation. Threedimensional positions of the reference probe and the tool probe were tracked by an optical camera system and the relative position of the handpiece drill tip to the reference probe was monitored continuously on the monitor of a PC. Using 8 landmarks for measuring accuracy, the spatial discrepancy between CT image coordinate and physical coordinate was calculated for testing the normality. Results : The accuracy over 8 anatomical landmarks showed an overall mean of 0.56±0.16 mm. The developed system was applied to a surgery for a vertical alveolar bone augmentation in right mandibular posterior area and possible interior alveolar nerve injury case of an impacted third molar. The developed system provided continuous monitoring of invisible anatomical structures during operation and 3D information for operation sites. The clinical challenge showed sufficient accuracy and availability of anatomically complex operation sites. Conclusion : The developed system showed sufficient accuracy and availability in oral and maxillofacial surgeries for anatomically complex sites. (Korean J Oral Maxillofac Radiol 2009; 39 : 149-56)

파트너십에 의한 지하철 입구 공간의 쌈지공원 설계 및 시공

김승환,강현우,손용욱,박승범,남정칠,이기철,차민준 東亞大學校 建設技術硏究所 2009 硏究論文集 Vol.32 No.2

A pocket park is valued in securing green space in downtown and improving urban view in the aspect of natural and environmental values, and it signifies a lot as the center of local residents’ community and harmony as well. Since subway exits and surroundings that have high portions in taking up street space due to lack of green space in downtown aren't made full use of, valuable pocket park place. Dangni Pocket Park of subway exits is a park completed with cooperative works and partnership by students, specialists, administrative organizations, businesses and civilian organizations, etc. without support of special budget. The study site was finally chosen to the space between exit No.1 of Dangni subway station, after analyzing the surrounding circumstances, availability and accessibility of the space among the several subway station exits of Saha, Dangni, and Hadan Station in Busan Metropolitan city. For the designing process, The Citizens organization for Million Amenity Park performed the planning and project proceeding, and 19 design drafts were proposed during the class of landscape architecture in Dong-a University. Design review panel members discussed to select the best draft in practical and authentical, and the related experts reviewed and revised to present the final design plan. The construction was conducted was performed under the cooperation between the civil, authorities, and industrial organizations, among which Saha District office managed for the waste treatment and maintenance matters. The graduates of landscape architecture department of Dong-a University and related industrial enterprises supplied landscape materials and related labors, were supported by 20 members of GPM, one of clubs of Dong-a University volunteered durig the most of construction progress, completing the Pocket Park of subway exits through partnership.

폴리머 콘크리트 복합체를 이용한 교통안전 시설물 개발

이명호,이재철,이승우,서장일,박세희 강원대학교 부설 석재복합신소재 제품연구센터 2004 석재연 논문집 Vol.9 No.-

폴리머 콘크리트 복합체를 이용하여 악천후에도 시인성이 좋고 주위의 경관과 어울리는 자동점멸 표지병을 개발하였다. 아날로그 회로에 비해 설계상의 난해한 점이 있으나 상대적으로 간편한 디지털 회로를 사용하여 자동점멸 회로를 구성하였으며, 작업의 능률을 높이고 개발비를 줄이기 위하여 OrCAD를 사용한 Simulation을 실시후 회로를 구성하였다. 표지병의 시공시와 같은 환경에서의 실험에서는 디지털회로의 작은 전류와 표지병간의 거리, 전선의 저항으로 인하여 클럭 및 클리어 신호에 전압강하와 상승/하강 시간의 증가가 나타났다. 표지병은 전자회로와 함께 설치되어야 하므로 방수성을 고려하여 표지병과 전자회로를 일체형으로 설계하였다. 실제 시공시의 환경에서 시행한 실험에서 나타난 문제점을 검토하였으며, 향후 연구방향에 관하여 고찰하였다. Using polymer concrete composite, the automatic-on/off road marker that is well distinguished in a bad weather condition of rainy or foggy day and is well harmonized with. Digital circuit that is hard to design but simpler than an analog circuit is used in designing the automatic-on/off circuit, and it order to raise the working efficiency and lower the development cost, OrCAD, a simulation tool of electric circuit, was used in simulating the circuit. In an experiment conducted under the circumstance of practical application, voltage drop and raising/lowering time increment in the clock and the clear signals are occurred because of small current of digital circuit and resistance of electrical line. Because that the road marker is assembled with the digital circuit, it is designed as one assembled unit by considering water proof. Some problems occurred in the experiment and the future work are discussed.

초고속 광대역 파장 가변 광섬유 링 레이저 구현

이정렬,이승우,엄진섭 강원대학교 정보통신연구소 2002 정보통신논문지 Vol.6 No.-

In this paper, we demonstrate a tunable wavelength erbium-doped fiber ring laser. It's tuning interval can be controlled as fine as hundreds of picosecond by using a tunable filter of Fiber Reflection Mach-Zehnder Interferometer with gain-transparent SOA within one arm. And a wavelength tuning range over 17㎚ can be achieved by adjusting the power of 1310㎚ pump light into SOA. Narrow linewidth less than 0.08㎚ and SMSR of more than 30dB is obtained with single-mode operation.

폴리머 콘크리트를 이용한 환경친화형 호안블럭 개발

이영호,이재철,이승우,서장일,박세희 강원대학교 부설 석재복합신소재 제품연구센터 2003 석재연 논문집 Vol.8 No.-

폴리머 콘크리트를 이용하여 호안블럭을 디자인하고 제작하였다. 제품의 표준화를 위하여 '폴리머 복합체를 이용한 호안블럭 제조용 시방서'를 작성하였다. 폴리머 콘크리트의 우수한 물리적 성질을 이용하고 환경 친화적인 호안블럭을 제작하기 위하여 중앙에 원형 홀이 있는 I형, 원형, 반원형 호안블럭을 디자인하였다. 중앙의 홀은 바닥재로 채워질 수 있도록 했으며 인공적인 색상보다는 주위의 환경과 어울리도록 식물을 조경할 수 있도록 하였다. 또한, 시판중인 호안블럭과 호환이 되도록 크기를 결정하였으며 자외선 흡수제를 첨가하여 제작하였다. 시방서에서 제시하는 방법으로 휨강도 및 흡수율을 측정하였다. Polymer concrete was used to produce the stone block. In order to make the blocks standardize, 'Specifications for Producing Stone Block using Polymer Concrete' was suggested I-type, circular type and semi-circular type of stone blocks were designed and produced, in which a circular hole was made to utilize the excellent physical properties of the polymer concrete and to produce the eco-friendly stone block. Instead of using artificial color, the hole was designed to be filled with the ground soil and then grass can be planted to make the blocks harmonize with surroundings. The dimensions of blocks were determined to fit the cement concrete block on the market and the ultra violet absorber was added in producing the blocks. Flexural strengths and absorption of the polymer concrete blocks were measured by the method regulated in the specification.

SOA내에서의 XPM,FWM을 이용한 WDM 시스템 파장변환기 구현

정광원,이정렬,이승우,엄진섭 강원대학교 정보통신연구소 2001 정보통신논문지 Vol.5 No.-

In this paper, a new type of wavelength converter using XPM within a loop-mirror is proposed and demonstrated. The proposed structure decreases hardware components for implementation of XPM wavelength converter and makes it possible to get non-inverted and inverted output signals simultaneously. Also, we generate wideband pumping mode series for FWM wavelength conversion scheme and propose the effective filtering method for selecting converted wavelength from FWM outputs. The results show that the pumping mode range is over 30nm within 5dB power fluctuation, and that a pumping and a prove wave can be removed successfully by using both of Michelson interferometer and polarization controller.

광굴절 MgO:LiNbO3 결정의 2광파 혼합 특성

김준태,신승호,이승우,차성도 강원대학교 정보통신연구소 1998 정보통신논문지 Vol.2 No.-

The signal beam gains of 4% mol MgO doped LiNbO3 crystal were measured with two wave mixing geometry at room temperature. The experimental investigations have been carried out to obtain gain coefficients as a function two beam's incident angle 2θ, beam ratioβand the angleφof pump beam with respect to the c-axis. The experimental results are analyzed with diffusion only transport mechanism, and two beam coupling and absorption coefficient of the crystal obtained by using curve fitting method are presented.

임신 중 파열된 담관낭종 1예

강병철,김영우,정혜경,이선영,이한주,손혜영,성순희,김승철 대한소화기학회 2000 대한소화기학회지 Vol.35 No.2

Choledochal cysts are congenital dilatation of the biliary tree occurring predominantly in female. Most of the cases are diagnosed during childhood, and its presentation during pregnancy or postpartum period is rare. Choledochal cysts during pregnancy are frequently associated with complication due to the concealment of the mass by enlarged uterus. Rupture of cyst is a rare complication that occurs spontaneously in most cases. We experienced a case of ruptured choledochal cyst during pregnancy in a 28-year-old primigravida. It occurred at 32 weeks of pregnancy. A premature newborn was delivered by normal vaginal delivery. The choledochal cyst was excised, and reconstruction was carried out by Roux-en-Y choledochojejunostomy. Although choledochal cysts occurring in pregnancy are rare, it is important to be aware of the condition because a missed or delayed diagnosis may be catastrophic for both mother and child.