IVF-ET Program에서 Blastocyst 배아의 발생에 관한 연구 - II. 난구세포 공동배양에 의한 Blastocyst 배아의 발생

이석원,윤산현,윤혜균,조현진,허용수,윤혜진,박세필,이원돈,임진호,Lee, Suk-Won,Yoon, San-Hyun,Yoon, Hye-Gyun,Cho, Hyon-Jin,Heo, Yong-Soo,Yoon, Hye-Jin,Park, Se-Pill,Lee, Won-Don,Lim, Jin-Ho 대한생식의학회 1998 Clinical and Experimental Reproductive Medicine Vol.25 No.1

This study was carried out to investigate the development rates of human embryos co-cultured with cumulus cells to each blastocyst stage. Human zygotes were co-cultured on cumulus cell monolayer in YS medium supplemented with 20% hFF. On day 2, if patient had four or more "good" embryos (regular blastomeres without fragmentation), embryos were further cultured for 72hrs. Blastocysts on day 5 were classified into early blastocyst (ErB), early expanding blastocyst (EEB), middle expanding Blastocyst (MEB), and expanded blastocyst (EdB) on the basis of their morphological aspects of trophectoderm cells and blastocoele. Subsequently, maximum 3 of best blastocysts were transferred in 486 cycles. The results in this study were as follows: Patients who had four or more "good" embryos on day 2 were 498 persons, but patients whose embryos could not be transferred due to failure in development to the blastocyst stage on day 5 were 12 persons (2.4%). The development rate of embryos to the blastocyst stage was 58.2% (2,885/4,957) on day 5, and the rates that developed to the ErB, EEB, MEB, and EdB stage were 15.0% (743/4,957), 14.9% (739/4,957), 14.4% (714/ 4,957), and 13.9% (689/4,957), respectively. Total 1366 blastocysts were transferred in 486 cycles (mean number=2.81). The implantation rate and the ongoing implantation rate obtained by observing the number of G-sac and FHB were 29.9% (409/1,366) and 22.5% (308/1,366), respectively. The clinical pregnancy rate was 51.2% (249/486), and the ongoing pregnancy rate' was 39.1% (190/486). Among women showing ongoing pregnancy, women with singleton were 50% (95/190), women with twin were 37.9% (72/190), and women with triplet were 12.1% (23/190). Although triplet pregnancy rate in this study was high such as 12.1%, because many blastocysts with high viability were produced in our co-culture system using cumulus cells on day 5, we really believe that a multiple pregnancy except twin should not occur by selecting good embryos for maximum two blastocyst transfer. These results demonstrate that autologous cumulus cells may be used for the production of blastocysts with high developmental competence, and the use of autologous cumulus cells to be collected easily, and to be treated conveniently at OPU must be an effective means for obtaining high implantation and pregnancy rate.

시간지연 시스템의 응답특성 개선을 위한 제어기 설계

이석원,양승현,Lee, Suk-Won,Yang, Seung-Hyun 한국조명전기설비학회 2005 조명·전기설비학회논문지 Vol.19 No.7

시간지연이 존재하는 시스템의 제어기 설계에 많이 사용되는 Smith Predictor는 플랜트와 모델이 완전히 일치해야만 특성방정식에서 시간지연을 제거 할 수 있기 때문에 실제 공정에서는 적용하기가 매우 어렵다. 본 논문에서는 Smith Predictor의 모델을 플랜트와 일치한 식이 아닌 시간지연을 포함한 2차식 형태로 제안하여 큰 시간지연에서의 응답특성을 향상 시켰다. PI 제어기의 적분상수의 범위를 제안하였다. The practical control problems for the lime-delay system is considered. The delay-free characteristics of the Smith Predictor is available only when both the process and it's model are exactly matched. So it does not used widely in practical industrial processes. In this paper, using the 2nd-order plus dead time model in place of the plant model of the Smith Predictor, the proposed controller shows the improved performance in case of the very long time delay. And the range of integral constant of the PI controller is also proposed.

동적인 채널할당을 이용한 결합형 주문형 비디오 서비스

이석원,박승권,Lee Suk Won,Park Sung-Kwon 한국통신학회 2005 韓國通信學會論文誌 Vol.30 No.1a

주문형 비디오 시스템의 설계에 있어 가장 중요하게 고려되고 있는 것은 사용되는 채널의 수를 일정하게 유지하면서 자입자의 대기시간을 줄이는 방법이다. 이러한 연구의 한 시도로 근래에 실시간 주문형 비디오와 유사주문형 비디오의 장점을 결합하는 결합형 주문형 비디오에 대한 연구가 활발히 이루어지고 있다. 결합형 주문형 비디오에 대한 연구는 결국 어떻게 유니캐스트 채널을 사용하는 사용자들을 그룹화하여 멀티캐스트 채널을 사용하도록 할 것인가에 대한 연구이다. 본 논문에서는 동적인 채널을 이용하여 시청자의 대기시간을 기존의 방식에 비해 효율적으로 줄일 수 있는 결합형 주문형 비디오를 제안하겠다. 모의실험 결과 제안된 방식은 10개의 비디오를 100의 채널을 이용하여 0.5 requests/second의 도착률로 서비스할 경우 Unified Video-on-Demand 비해 $551{\%}$의 성능향상을 보였다. 본 논문은 동적채널 할당을 이용하여 채널을 해제하고 다시 사용하는 과정, 성능 모델, 모의실험을 제시한다. In designing a video-on-demand (VoD) system, the major challenge may be how to reduce the channels concurrently used maintaining the client's waiting time. For this reason, the various architectures which integrate the multicast streams with the unicast streams were suggested in order to improve channel efficiency in recent years. In combining multicast with unicast, the ways to group the unicast channels together are important so that clients can share the multicast transmission channels. This paper proposes a hybrid video-on-demand system which gathers the unicast channels in new ways and shares multicast transmission channels efficiently by using dynamic channel allocation architecture. The numerical results demonstrate that the proposed architecture in some case achieves performance gain of $551{\%}$ compared to existing architecture. This paper presents procedure of channel release and reuse, performance analysis, and simulation results of the dynamic channel allocation architecture.

임플랜트 주위 연조직세포의 세포-기질 접착

이석원,류인철,한종현,이재봉,Lee Suk-Won,Rhyu In-Chul,Han Chong-Hyun,Lee Jai-Bong 대한치과보철학회 2006 대한치과보철학회지 Vol.44 No.1

The importance of soft tissue response to implant abutments has become one of the major issues in current implant dentistry. To date, numerous studies have emphasized on maintaining connective tissue barriers in quantity, as well as in quality fir the long term success of dental implants. The cells mainly consisting the soft tissue around dental implants are fibroblasts and epithelial cells. The mechanism of the fibroblasts adhesions to certain substrata can be explained by the 'focal adhesion' theory. On the other hand, epithelial cells adhere tn the substratum via hemidesmosomes. The typical integrin-mediated adhesions of cells to certain matrix are called 'cell-matrix adhsions'. The focal adhesion complex of fibroblasts, in relation to the cell-matrix adhsions, consists of the extracellular matrix(ECM) such as fibronectin, the transmembrane proteins such as integrins, the intracellular cytoplasmic proteins such as vinculin, talin, and more, and the cytoskeletal structures such as filamentous actin and microtubules. The mechanosensory function of integrins and focal adhesion complexes are considered to play a major role in the cells adhesion, migration, proliferation, differentiation, division, and even apoptosis. The '3-D matrix adhesions' defined by Cukierman et al. makes a promising future for the verification of the actual process of the cell-matrix adhesions in vivo and can be applied to the field of implant dentistry in relation to obtaining strong soft tissue attachment to the implant abutments.

임베디드 웹 서버를 이용한 자동차용 모니터링 및 제어기 개발에 관한 연구

이석원,양승현,Lee, Suk-Won,Yang, Seung-Hyun 한국조명전기설비학회 2005 조명·전기설비학회논문지 Vol.19 No.2

In this paper, Web server is built up using PXA255, 32bit RISC processor with porting Embedded Linux and GoAhead HTTP(Hyper Text Transfer Protocol) web server, and the system which can monitor and control the environment and condition for AICC(Automatic Intelligent Cruise Control) is realized For sensing the operation condition and change of vehicle the desired data is derived by interfacing ECU(Electric Control Unit) and Embedded system and the rpm of engine is controlled by step motor connected to throttle valve. 본 연구에서는 임베디드 리눅스와 HTTP(Hypertext Transfer Protocol) 웹 서버인 GoAhead를 포팅한 32비트 RISC프로세서인 PXA255를 이용하여 웹 서버를 구축하고, 웹 서버를 기반으로 자동차의 순항제어나 무인 운전을 위한 일련의 환경과 상황을 모니터링하고 제어할 수 있는 시스템을 구현하였다. 자동차의 동작 상태와 변화를 감지하기 위해서 ECU와 임베디드 시스템을 인터페이스 시켜 필요한 데이터를 추출하고, 스로를 밸브에 스텝모터를 연결하여 자동차의 엔진을 회전시켜 자동차의 무인 이동을 제어한다.

총의치 환자 만족도의 영향요인

이석원,정문규,Lee Suk-Won,Chung Moon-Kyu 대한치과보철학회 2005 대한치과보철학회지 Vol.43 No.5

Statement of problem: In spite of the progress in techniques and materials in complete denture prosthodontics, patients still complain of discomfort after the insertion of complete dentures. For the last several decades many prosthodontists tried to find factors influencing patient complete denture satisfaction, however the reported results became a controversy. Purpose: The purpose of the present study was to verify the factors influencing patient satisfaction with complete dentures using multiple regression analysis. Materials and methods: 33 patients who visited the department of prosthodontics, dental hospital of Yonsei University, 4 to 6 weeks after the complete denture delivery, were asked to complete the questionnaires on complete denture satisfaction, social variables and psychological variables. The Prosthodontists who treated the patients with complete dentures were also asked to complete the questionnaires on evaluation of patients' oral condition and technical quality of dentures. The factors influencing patients' satisfaction with their complete dentures were analyzed using multiple regression analysis. Results: Among the patients' sociodemographic variables. the variables of relationship with children, economic status, housing condition, other people's opinions of dentures and gender were the influential factors on patients' satisfaction with complete dentures. Patients showing the symptoms of depression, one of the psychological variables, were dissatisfied with their complete dentures. In spite of the good oral condition, patients were dissatisfied with complete dentures, where-as the technical quality of dentures did not influence patients' complete denture satisfaction. Conclusion : According to the results above, patients' sociodemographic and psychological variables rather than clinical variables including oral condition and technical quality of dentures were the influential factors on complete denture satisfaction. The results of this study may not only enable prosthodontists to predict the success and failure of complete denture treatment, but also help both prosthodontists and patients be informed of the essentials of increasing satisfaction with complete dentures.

일반논문 : 실업자 직업훈련 사업의 분포적 효과: 분위수 회귀식을 사용한 분석

이석원 ( Suk Won Lee ) 서울대학교 한국행정연구소 2006 行政論叢 Vol.44 No.4

적극적 노동시장 정책의 효과성 평가 : 실험적 평가방법의 유용성과 활용방안

이석원(Suk Won Lee) 한국행정학회 2001 韓國行政學報 Vol.35 No.1

N/A N/A

ATM망의 가입자망으로서 MCNS DOCSIS MAC의 성능분석

이석원(Suk-won Lee),이태형(Tae-young Lee),박승권(Sung-kwon Park) 한국통신학회 1999 한국통신학회 학술대회논문집 Vol.1999 No.11

장애인의 생산성과 의무고용제도

이석원 ( Suk Won Lee ) 한국정책학회 2007 韓國政策學會報 Vol.16 No.4