• Proceedings of the Safety Management and Science Conference
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• 2002.05a
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• pp.151-159
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• 2002

Real-Time Linux를 이용하여 실시간 운영체제가 요구하는 특성과 요구조건을 분석하고 이러한 요구조건에 부합하도록 리눅스를 하드웨어에 이식하고 하드웨어에 이식하기 위한 방법을 제시하였다. 다른 상용 실시간 운영체제 (RTOS)와는 달리 리눅스는 특정 하드웨어를 지원하기 위한 별도의 개발환경을 제공하지 않는다. 이에 개발환경을 구축하고 부트로더를 개발하기 위해 목표 시스템에 부합하도록 리눅스 커널을 이식하였다. 또한 응용 개발의 유연성을 제공하기 위하여 램디스크를 이용한 파일 시스템을 지원하도록 하였으며, GPIO(general purpose I/O)를 통한 디바이스 드라아버를 제작하는 등의 실험을 통해 시스템의 안정성을 검증하였다 실험에서는 StrongArm SAl110 마이크로프로세서를 이용하였으며 이 실험을 통해 실시간 운영체제로서의 리눅스의 활용 가능성을 확인하였다.

• Journal of the Korea Computer Graphics Society
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• v.11 no.4
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• pp.11-20
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• 2005

본 논문에서는 모션데이터의 재사용성을 높이기 위해 '유추적 이식(analogic transplanting)'이라는 새로운 방법을 제시한다. 일반적으로 사람 또는 동물의 동작에서 각 관절은 상호 연관성을 가지고 움직인다. 그러므로 신체를 몇 부분으로 나누었을 때 나누어진 한 부분의 유사성을 바탕으로 다른 부분과의 결합 가능성을 유추할 수 있게 된다. 본 연구에서는 신체 부분의 의미적 유사성을 판단하기 위해 주성분분석법과 클러스터링 기법을 사용하였다. 유추적 이식 방법은 매우 자연스러운 동작을 합성할 수 있으며, 충돌을 피할 수 있는 단순하고 저비용의 방법을 제공하며, 물리적 요소를 고려하지 않아도 결과적으로 매우 안정된 동작을 풍부하게 생성해 낸다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.25-27
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• 2001

설계 재활용을 위하여서는, 반도체 지적 소유권(Intellectual property)의 표준화와 더불어 레이아웃 자동 이식에 관한 연구와 상품화가 필수적이다. 본 논문은 반도체 설계 형식 중에서 생산 공정과 밀접한 레이아웃 형식의 회로도면 처리를 자동화하여 설계와 생산 시간을 혁신적으로 단축하기 위한 연구이다. 레이아웃 형식은 특성상 도형(폴리곤)으로 구성되어 있으며, 레이아웃 형태에서 다양한 도형의 중첩이 반도체의 트랜지스터, 저항, 캐피시터를 표현함으로써, 반도체 지적소유권의 한 형식으로 자주 활용되고 있다. 본 논문은 반도체 레이아웃 이식 소프트웨어 시스템의 내부 기능에 관한 설명과 처리 능력과 속도를 높이기 위한 알고리즘의 제안과 벤치마킹 결과를 보여 주고 있다. 비교 결과, 자원의 최적 활용(41%)으로 대용량의 처리 가능성을 보여 주고 있으며, 처리 속도는 평균 27배로써 이전의 벤치마킹 회로를 더욱 크게 하여 그 결과를 보여 주고 있다. 이러한 비교 우위는 본 논문에 포함된 소자 처리 알고리즘과 그래프를 이용한 컴팩션 알고리즘에 기인한다. 지면상의 연유로, 참고1에서는 기능 설명을, 본 논문은 알고리즘의 구현에 관한 설명을 중점적으로 기술한다.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.482-491
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• 2004

Background: The xenogenic or allogenic valves after in Vitro repopulation with autologous cells or in vivo repo-pulation after acellularization treatment to remove the antigenicity could used as an alternative to synthetic polymer scaffold. In the present study, we evaluated the process of repopulation by recipient cell to the acellu-larized xenograft treated with NaCl-SDS solution and grafted in the right ventricular outflow tract. Material and Method: Porcine pulmonary valved conduit were treated with. NaCl-SDS solution to make the grafts acellularized and implanted in the right ventricular outflow tract of the goats under cardiopulmonary bypass. After evaluating the functions of pulmonary valves by echocardiography, goats were sacrificed at 1 week, 1 month, 3 months, 6 months, and 12 months after implantation, respectively. After retrieving the implanted valved conduits, histopathologic examination with Hematoxylin-Eosin, Masson' trichrome staining and immunohistochemical staining was performed. Result: Among the six goats, which had been implanted with acellularized pulmonary valved conduits, five survived the expected time period. Echocardiographic examinations for pulmonary valves revealed good function except mild regurgitation and stenosis. Microscopic analysis of the leaflets showed progressive cellular in-growth, composed of fibroblasts, myofibroblasts, and endothelial cells, into the acellularized leaflets over time. Severe inflammatory respon-se was detected in early phase, though it gradually decreased afterwards. The extracellular matrices were regenerated by repopulated cells on the recellularized portion of the acellularized leaflet. Conclusion: The acellularized xenogenic pulmonary valved conuits were repopulated with fibroblasts, myofibroblasts, and endothelial cells of the recipient and extracellullar matrices were regenerated by repopulted cells 12 months after the implantation. The functional integrity of pulmonary valves was well preserved. This study showed that the acellularized porcine xenogenic valved conduits could be used as an ideal valve prosthesis with long term durability.

• Journal of Chest Surgery
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• v.39 no.9 s.266
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• pp.714-717
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• 2006

Heart and kidney transplantation has made great progress in the modern era. Coupled with the growing successes in individual solid organ transplantation, there has also been an increase in the number of multiple organ transplants, such as heart-kidney transplantation. This trend has been in part due to a better understanding of immunobiology, advances in surgical technique and postoperative care, and an often-common pathologic association between dual-organ failure. This pathologic course is representative for end-stage heart failure leading to secondary renal dysfunction or failure, or for end-stage renal failure as a cause for (uremic) cardiomyopathy. However, refractory cardiac failure has long been considered a contraindication to kidney transplantation. Additionally, cardiac transplantation has been denied for patients with end-stage renal disease. Over recent years, combined heart-kidney transplantation has been offered to select patients who were once denied transplantation. We report the first experience of combined heart-kidney transplantation with one year follow-up results.

• KSBB Journal
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• v.19 no.3
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• pp.210-214
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• 2004

Whole liver transplantation, the currently available treatment of end-stage liver disease, has limitations including serious donor shortage, fatal surgical complications, risk of allograft rejection, and the requirement of life-long immunosuppression. In this study, we investigated the possibility of reconstructing liver tissues in vivo by implanting fetal hepatocytes on polymer scaffolds as a potential method to replace the current treatments. Fetal hepatocytes were freshly isolated from mice and seeded onto porous mesh scaffolds fabricated from polyglycolic acid, a biodegradable synthetic polymer. The seeded scaffolds were implanted into peritoneal cavity of athymic mice for one week. As a control, fetal hepatocytes were implanted without scaffold. One week after transplantation, liver-like tissues formed. Histological and immunohistochemical analyses indicated that the hepatocyles and liver tissue structures (bile ducts) were present in the newly formed tissues. In the control group, no transplanted hepatocytes were observed. Theses preliminary results suggest that liver tissues may be regeneration by transplanting fetal hepatocytes on polymer scaffolds.

• Clinical and Experimental Pediatrics
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• v.51 no.1
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• pp.67-72
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• 2008

Purpose : In this study, we retrospectively analyzed the clinical outcomes of patients who underwent allogeneic hematopoietic stem cell transplantation (HSCT) grafted from HLA-matched parents. Methods : Seven children with acute leukemia (4 acute lymphoblastic leukemia, 3 acute myeloid leukemia) in first complete remission received allogeneic HSCT from their respective parents at the St. Marys Hospital between April, 1999 and October, 2005. The median age of patients at transplantation was 5 years (range, 1-11 years; 2 male, 5 female) and the median age of donors was 35 years (range, 30-41 years; 5 male, 2 female). We investigated the clinical outcomes such as engraftment, acute and chronic graft-versus-host disease (GVHD), transplant-related morbidity and mortality, relapse and survival. Results : Median time from transplantation to last follow-up was 69.5 months (range, 18.8-96.5 months). All patients were successfully engrafted, with a median time of 11 days (range, 10-16 days) and 26 days (range, 13-39 days) for neutrophil and platelet recovery, respectively. Grade II acute GVHD occurred in 3, and grade III acute GVHD in 1 of 7 recipients. Extensive chronic GVHD developed in 2, and limited chronic GVHD in 1 of 7 recipients. Death from transplant-related complications occurred in 1, and relapse occurred in 1 of 7 recipients. Estimated 5-year overall survival was $83{\pm}15%$. Conclusion : The clinical outcomes of recipients who underwent HSCT from HLA-matched parents were comparable to those of patients who received HSCT grafted from HLA-matched sibling donors in childhood leukemia. HLA typing of parents, as well as siblings will increase the likelihood of finding an HLA-matched family donor for patients who need HSCT.

• Journal of Korean Orthopaedic Sports Medicine
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• v.7 no.1
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• pp.15-18
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• 2008

Chrisman-Snook 술식은 광범위한 절개 및 비복 신경 손상 우려 등과 함께 기술적으로 복잡하다고 여겨지고 있으나, 단비골건을 전부 희생하지 않고 전거비 인대와 종비 인대를 함께 재건하면서 동시에 이식건의 등장성을 확보할 수 있어 술 후 환자의 만족도가 비교적 높고 재발 가능성이 적은 훌륭한 술식으로 사료된다.

• 건강소식
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• v.34 no.11
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• pp.42-43
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• 2010

우리나라 장기기증자는 선진국에 비교해 크게 부족하다. 이로 인해 실낱같은 희망을 걸고 장기이식 순서를 기다리는 대기자는 매년 증가하고 있다. 장기기증은 간이나 신장질환자의 치료에 투입되는 엄청난 의료비용을 줄여준다. 생명나눔 차원뿐만 아니라 사회적 비용 감소에도 기여하는 것이다. 외국의 장기기증 현황을 알아봄으로써 국내 적용 가능성을 점쳐보고자 한다.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.2 no.1
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• pp.27-33
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• 2009

Generally, implantable microphone has been implanted in the temporal bone for implantable middle ear hearing devices (IMEHDs). In this case, the microphone's membrane can be damaged and can be generated biological noise. In order to overcome the these problems, the location of implanted microphone should be changed. As an alternative, the microphone can be implanted in the external auditory canal. However, the sound emission can be produced because of vibration transducer toward reverse direction from the tympanic membrane to the external auditory canal. In this paper, an amount of the emitted sound is measured using a probe microphone as the changing the position of microphone in the external auditory canal of a physical ear model, which is similar to acoustical and vibratory properties of the human ear. Through the measured value, the location of the microphone was assumed in the external auditory canal. According to the analysis, the microphone input sound can be decreased when microphone position become more distance from the tympanic membrane in the auditory canal. However, the external auditory canal is not appropriated to implantable microphone position, because sound emission is not completely eliminated.