원발성 장 림프관 확장증 1례

황대환,한정우,김지홍,한석주,홍순원,Hwang, Dae Hwan,Han, Jung Woo,Kim, Ji Hong,Han, Seok Joo,Hong, Soon Won 대한소아소화기영양학회 2004 Pediatric gastroenterology, hepatology & nutrition Vol.7 No.2

Primary intestinal lymphangiectasia is a congenital lymphatic disorder in which intestinal lymphatic channels are dilated and ruptured resulting in loss of protein, lipid, and lymphocyte into the intestine or peritoneum. As a result, hypoalbuminemia, generalized edema, diarrhea are clinically manifested. We report a case of primary intestinal lymphangiectasia with generalized edema which occurred in a 7-year old boy who was treated with lipid restriction diet with medium chain triglyceride oil supplement.

ATM 망에서의 멀티미디어 통신단말 시스템 망접합부의 구성 ( ATM Network Interface Module for Multimedia Communication Terminal )

황대환,최진상,김선자 한국통신학회 1995 한국통신학회 학술대회논문집 Vol.14 No.2

광대역ISDN상의 다지점 멀티미디어 통신서비스 I부:DAVIC 표준 STB에서의 대화형 멀티미디어통신

황대환,이종형,박영덕,조규섭 한국통신학회 1998 한국통신학회논문지 Vol.23 No.4

The Digital Audio-Visual Council(DAVIC) that was established to develop useful multimedia communication services has completed the specifications for providing on-demand services such as Movie on Demand(MoD), Teleshopping and accepting Internet service. And then they are proceeding the works to suport converstional communcation services like Plain Old Telecphone Service(POTS), Video telephone, Video teleconferencing. In this paper, we prpose an efficient terminal architecture which can provide conversational multimedia communication services on DAVIC Set-Top Box (STB) environments. To apply the implemented conversational terminal to the multipoint communication environment, we considered the factors of Qurlity of Services(QoS) that determine grade of conversational communication service. We also present the inter-working scheme and that system structure to satisfy QoS by using new MPEG video bridge which gurantees end to end delay requirements as major element of QoS for achieving the real time communication and does not accompany visual quality degradation.

서비스 통합형 ATM 멀티미디어 통신단말

황대환,이종형,박영덕,조규섭 한국통신학회 1998 한국통신학회논문지 Vol.23 No.4

In this paper, we propose an architecture of multimedia communication terminal that can e used in broadband ISDN environments. To design and implement the multimedia communication terminal, we analyzed the structure of multimedia terminals and the types of services which is recommended by public and private standard or ganization, such as ITU-T, Digital Audio-Visual Council(davic) and ATM Forum. The multifunctional communication terminal designed in this paper could allow inter-working between existing communication terminals on the heterogeneousnetwork and accept current and advanced multimedia communication application flexible. An implemented terminal is consisted of the multimedia processing board and the ATm interface board that is installed in PCI bus on personal computer. The integrated service multimedia communication terminal that is implemented supports retrieval, distributive and conversational communication service simultaneously. And then we performaned functional module test according to the individual communication services.

멀티미디어 네트워킹을 위한 압축 신호상에서 동영상 처리 : 압축 동영상 비트율 변환

황대환,조규섭,황수용 한국통신학회 2001 한국통신학회논문지 Vol.26 No.11

Interoperability and inter-working in the various network and media environment with different technology background is very important to enlarge the opportunity of service access and to increase the competitive power of service. The ITU-T and advanced counties are planning ahead for provision of GII enabling user to access advanced global communication services supporting multimedia communication applications, embracing all modes of information. In this paper, we especially forced the heterogeneity of end user applications for multimedia networking. The heterogeneity has several technical aspects, like different medium access methods, heterogeneous coding algorithms for audio-visual data and so on. Among these elements, we have been itemized bit rate shaping algorithm on the compressed moving video. Previous manipulations of video has been done on the uncompressed signal domain. That is, compressed video should be converted to linear PCM signal. To do such a procedures, we should decode, manipulate and then encode the video to compressed signal once again. The traditional approach for processing the video signa1 has several critical weak points, requiring complexity to implement, degradation of image quality and large processing delay. The bit rate shaping algorithm proposed in this paper process the manipulation of moving video on the completely compressed domain to cope with above deficit. With this algorithms. we could realized efficient video bit rate shaping and the result of software simulation shows that this method has significant advantage than that of pixel oriented algorithms.

Array Processor 방식의 실시간 MPEG 비디오 브리지 설계

황대환,조규섭,Hwang, Dae-Hwan,Cho, Kyu-Seob 한국정보처리학회 1998 정보처리논문지 Vol.5 No.8

근접한 프로세서간 통신방식에 관한 연구

황대환,박영덕,김선형,조규섭,박병철 한국통신학회 1987 韓國通信學會論文誌 Vol.12 No.6

Giving a high degree of intelligence to the electronic equipments such as communication system is the general trend of nowadays. Therefore the multi-processor will be required in a single system and the switch gives an example of it. In this paper, "Reserved Bus" is proposed as the interprocessor communication method applicable to such system which has multi-processor in the limited space. The performance of proposed method is also analyzed. analyzed. 앞으로의 전자기기 특히 통신기기에서는 고도의 지능화가 요구되어지고 있다. 따라서 단일시스템 내에서도 이러한 지능화를 위해 대수의 프로세서가 요구되어질 것이며 이의 대표적인 예가 교환기라 하겠다. 본 논문에서는 이와 같은 환경 즉, 제한된 공간내 다수의 프로세서가 근접되어 잇는 시스템에 적응할 수 있는 IPC(Inter Processor Communication)방식으로 "통신예약버스"를 제안하였으며 이에 대한 성능을 분석하였다.성능을 분석하였다.

단일 기관에서 진단받은 가와사끼병 환아 1,000례의 통계학적 분석

황대환,신경미,최경민,최재영,설준희,김동수 대한소아청소년과학회 2005 Clinical and Experimental Pediatrics (CEP) Vol.48 No.4

Purpose : To find the risk factors associated with coronory artery lesions, non-responsiveness to intravenous immunoglobulin(IVIG) treatment, and recurrences in Kawasaki disease patients. Methods : We retrospectively analyzed 1,000 Kawasaki disease patients who were admitted to Yonsei University Medical Center from September 1990 to December 2003. We compared between responder and non-responder groups to IVIG treatment as well as between relapsed and non-relapsed groups, and as to the relapsed group, we also compared variables between patients in their first and second attack states. Finally, factors associated with longer-fever duration from disease onset were evaluated. Results : Longer fever durations before and after IVIG treatment, male sex, lower Hgb and Hct level, higher WBC count and segmented WBC proportion, and higher CRP and Harada's score were related with coronary artery lesions. Non-responsiveness was related to higher WBC count, segmented WBC proportion, CRP, SGPT, Harada's score, and pyuria. Moderate-to-severe coronary artery dilatations and recurrences were more commonly seen among the non-responder group. No significant predictive factors for recurrence were found. In the relapsed group, lower WBC count, CRP, and shorter fever duration from disease onset were observed in their second attack state. Fever duration from disease onset showed positive correlation with WBC count, CRP, and Harada's score and negative correlation with Hgb levels. Conclusion : Higher WBC count, CRP, and higher Harada's score were related to both higher incidences of coronary artery lesions and non-responsiveness to IVIG treatment, and these factors were also related with longer fever duration. Non-responders to IVIG treatment showed higher recurrence rate and more moderate-to-severe coronary artery dilatations than responders. 목 적 : 가와사끼병 환아의 특성과 관상동맥 이상, IVIG에 대한 비반응 및 병의 재발 등에 대해 관련된 인자를 찾아보고자 하였다.방 법 : 1990년 9월부터 2003년 12월까지 본원에 내원, 가와사끼 병으로 진단받고 IVIG을 투여한 1,000명을 대상으로 후향적으로 분석하였다. 내원시 관상동맥 확장군과 관상동맥 정상군을 비교하였고 IVIG 1회 투여에 대한 반응군과 비반응군 및 재발군과 비재발군의 비교도 시행하여 두 군간에 의미있는 요인을 찾아보려고 하였으며 재발된 환아를 대상으로 처음 발병시와 두 번째 발병시의 각종 자료를 분석하였고 두 군간에 관상동맥 이상이 생기는 정도도 비교해 보았다. 또한 첫 IVIG을 투여하기 전까지의 발열기간과 상관비례하는 인자를 알아보려 하였다.

가와사끼병 환자에서 분리한 CD14양성 세포에서 Toll-like Receptor-2의 발현

황대환 대한소아청소년과학회 2005 Clinical and Experimental Pediatrics (CEP) Vol.48 No.3

Objective:Toll like receptor(TLR) is known to be involved in innate immunity. Many microbial antigens stimulate TLR, and as a result of intracellular signal transduction, they activate nuclear factor-kB which produces diverse inflammtory cytokines. Until now, many research topics in Kawasaki disease focused on cytokine increasement. In this study, we aim to reveal TLR increasement which might be associated with initiation of inflammatory response. Methods:We obtained the peripheral blood of ten patients who were diagnosed with Kawasaki disease in Yonsei University College of Medicine from March 2003 to August 2003, as well as those of a febrile control group and the same number of a normal control group. Flow cytometry was done in all samples for quantification of TLR-2 expression in CD14 positive monocyte. And we also extracted total RNA of periphral monocyte and quantificated expression of TLR-2 mRNA by RT- PCR. Results:The expression of TLR-2 in Kawasaki disease increased significantly compared with the normal control group but not when compared with the febrile control group. And the expression decreased slightly in the subacute phase of Kawasaki disease compared with the acute phase, but this was statistically insignificant. mRNA expression of TLR-2 in peripheral blood monocyte also increased in the acute phase of Kawasaki disease. Conclusion:Expression of TLR-2 in Kawasaki disease increased when compared with the normal control group, which means that innate immunity is associated with the pathogenesis of Kawasaki disease 목 적 : 본 연구에서는 가와사끼병에서 toll-like receptor (TLR)의 발현정도를 살펴 염증반응이 유발되기 시작하는 기전에 대해 접근하고자 하였다. 방 법 : 2003년 3월부터 8월까지 연세의료원에서 가와사끼병으로 진단 받은 환아 10명과 발열대조군 10명 및 정상대조군 10 명의 말초혈액을 얻은 후 유세포분석기(flow cytometry)를 시행하여 CD14 양성인 단핵구에서의 TLR-2 발현정도를 측정하였다. 또한 말초 혈액 단핵구의 total RNA를 분리한 후 역전사 중합효소 연쇄반응(RT-PCR)을 시행하여 TLR-2의 mRNA 발현을 살펴보았다. 결 과 : 환자군에서의 TLR-2 발현은 정상대조군보다 통계적으로 유의하게 증가되어 있었으나 임상경과에 따른 양상을 보면 급성기보다 아급성기에서 감소하였지만 통계적으로 유의한 차이는 보이지 않았고 환자군과 발열대조군의 TLR-2 발현도 의미있는 차이를 보이지 않았다. 또한 급성기 환자군의 말초혈액 단핵구에서 TLR-2의 mRNA 발현이 증가되어 있었다.결 론:TLR-2의 발현은 가와사끼병 환자에서 정상대조군과 비교하여 증가되어 있었으며 이는 TLR 및 이를 통한 선천성 면역계(innate immunity)가 가와사끼병의 병인과 연관될 수 있음을 시사한다. 앞으로 TLR의 발현이 가와사끼병에서의 염증유발에 있어 구체적으로 어떤 역할을 하는지에 대한 연구가 더 필요할 것으로 사료된다.

멀티미디어 네트워킹을 위한 압축 신호상에서 동영상 처리

황대환(Hwang, Dae hwan),이종형(Lee, Jong Hyeong) 한국통신학회 2000 한국통신학회 학술대회논문집 Vol.2000 No.11