• 벤처창업연구
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• 제11권5호
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• pp.29-43
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• 2016

창업 성공률을 제고하고 실패 가능성을 낮추는 경영전략으로써'린 스타트업'은 2011년 에릭 리스의 책 출간 이후 줄곧 주목을 받아왔다. 전 세계적인 유니콘 스타트업의 등장과 창업 초기기업에 보다 효과적인 성장 방법론으로써의 린 스타트업에 대한 관심 고조에도 불구하고 한국에서는 체계적인 관련 이론연구와 사례 축적이 미진한 상황이다. 경영학의 진정한 발전은 이론과 그것을 기반으로 한 다양한 사례와의 접목이 이루어질 때 가능하다. 이에 본 논문에서는 서비스 개발 초기부터 린 스타트업의 개념이 적용되었고 서비스와 고객 개발의 전 과정에서 린 개념이 적극적으로 도입된 한국기업 '카닥'의 사례를 발굴하고 고찰하였다. 본 연구를 통해 알게 된 사실은 다음과 같다. 첫째, 린 스타트업 적용을 위해서는 우선 린 스타트업을 적용하려는 경영진, 팀원 들이 모두 그 개념을 깊이 이해하고 적용의 필요성에 공감해야 한다. 둘째, 수많은 논의보다 빠른 MVP(최소요건제품)의 출시가 우선이다. 셋째, 효과적인 학습을 하기 위해서는 적합한 분석툴과 핵심지표(Key Metrics) 선정이 무엇보다 중요하다. 넷째, 만들기-측정-학습(Build-Measure-Learn)의 사이클을 통해 지속적으로 측정하고 배워 제품/시장 적합성(Product/Market Fit)이 검증되었다면 과감히 규모를 확장해야 한다. 다섯째, 신규사업 진출도 철저히 린 하게 해야 한다. 카닥은 현재 신규사업으로 확장을 꾀하는 중으로 이 역시 린 스타트업 방법론을 철저히 적용하여 시범서비스(MVP)로 그 가능성을 타진해 본 후 투자를 본격화 한다. 본 연구는 린 스타트업에 관련한 기존 개념의 논의와 더불어 그 적용사례가 축적되고 있는 외국과 비교해, 한국 기업의 사례연구가 절대적으로 부족한 현 상황에서 한국의 대표적인 린 스타트업 활용 사례를 고찰하였다는 점에서 의의가 있다고 할 수 있다. 본 연구가 린 스타트업 방법론의 국내 적용과 향후 관련 연구에 하나의 디딤돌이 되기를 바란다.

• 한국게임학회 논문지
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• 제4권4호
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• pp.11-18
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• 2004

과거의 온라인 게임은 일대일 접속으로 두 사람만이 데이터를 주고받으며 게임 할 수 있었으나 현재의 온라인 게임은 MMORPG라고 해서 수만 명의 사람들이 동시에 접속이 가능하다. 특히 우리나라는 세계 어느 나라에서 찾아 볼 수 없는 네트워크 인프라를 확보하고 있다. 거의 모든 가정에 초고속 인터넷 통신망이 설치되어 있으며 높은 인구 밀도는 이런 인프라의 형성을 가속화하는 것을 가능하게 했다. 하지만 이러한 온라인 게임의 급격한 증가는 제한적인 인터넷의 통신용량에 대하여 트래픽의 증가로 이어지고 온라인 게임이 접속이 불안정해지거나 접속이 다운되는 상태로 이어질 가능성이 높다. 이러한 문제를 해결하기 위해 각 게임 서버를 보다 확충함으로서 해결할 수 있으나 그럴 경우 고비용을 필요로 하게 된다. 본 논문에서는 이러한 문제점을 해결하고자 현재의 온라인 게임에서 사용되고 있는 컨텐츠별로 나누어진 게임 서버들을 지 역 클러스터 링 형태로 연결하고, 부하 균등화(Load Balancer)서버로써 특정한 게임 서버의 부하를 감소시키고 게임 서버의 성능 향상과 효율적인 게임 서버 운용을 위하여 부하 균등화 기법을 제안한다. 본 논문에서는 그룹별 각각 다른 서비스를 하고 CPU 사용율의 자원정보를 이용하여 효율적으로 부하를 균등화하는 기법을 제안한다. 각각 서로 다른 게임을 서비스하는 그룹들은 컨텐츠들에 대한 수정, 삭제, 추가 등 자원 정보 변경으로 인하여 깨어질 수도 있는 자원 정보 일관성을 유지하기 위해 네트워크 파일 시스템에 연결되어 운영된다. 성능 실험을 통해 기존의 RR방식과 LC방식보다 제안한 방식이 각각 12%와 10%의 응답시간 향상을 보여주었다.기간효과를 별도로 취급하기는 쉽지 않다.이즈의 영향이 가장 클 것으로 판단된다. 항원성시험에서 casein으로 피하 감작할 경우 푸른색 반점이 나타났으나 효소처리구에서는 이러한 반점이 나타나지 않아 충분히 항원성이 저감화 되었음을 확인하였다. 행동을 평가하는데 있어 적정한 신뢰도와 타당도를 가지고 있었으며 임상 장면에서 아동의 행동 문제에 대한 평가 및 진단에 유용하게 사용될 수 있을 것으로 보인다.식적인 형태소-음소 상응 규칙 적용 능력 모두에서 장애를 보였으며, 거울상 반전 오류 등 시각적 정보 처리 기능의 장애도 나타내었다. 이들 장애는 단어/비단어 읽기 검사와 글자기호감별검사를 통해 신뢰할 수 있고 타당성 있게 구분하고 평가할 수 있었다.치료 시 고려해야 할 것이다.순차처리항목과 계산능력에서 유의하게 높았고(p<.05), KEDI-WISC를 이용한 평가에서는 ADHD- HI형은 대상수가 소수여서 비교할 수 없었으며, ADHD-C형과 ADHD-Ⅰ형 사이에 유의한 차이는 보이지 않았다. CPT, WCST, SST를 이용한 신경심리학적 실행기능의 비교에서 아형간 계량적인 차이는 있었으나 통계적으로 유의한 차이는 보이지 않았다. 결 론：결론적으로 ADHD 세 아형은 임상적으로 뚜렷한 차이를 보였지만, 실행기능상 유의한 차이를 발견할 수 없었다. 향후 보다 잘 고안 된 연구와 발달중인 아동에 적절한 신경심리 평가 도구의 개발을 통해 결과를 보완해야 할 것으로 사료된다.었으나, 주의력에서는 전두엽의 실행능력(executive function)과 관련되는 검사들에서 산소흡입이 특이한 효과를 보여준다는 것이 확인되었고, 기억능력에서는 단기기억능력 평가에서 산소흡입군이

• 정보처리학회논문지D
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• 제15D권2호
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• pp.223-234
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• 2008

최근 웹 서비스 분야는 기업내외의 효율적인 통합 환경을 제공해 주면서 웹 서비스의 도입을 원하는 업체가 증가하고 있다. 또한 웹 서비스가 발전하면서 새로운 비즈니스 모델이 등장하고, 웹 서비스로 인해 국내 기업 환경 및 e-비즈니스 환경이 변화하고 있다. 유사한 기능을 제공하는 웹 서비스가 증가함에 따라 사용자의 요구에 가장 적합한 서비스를 찾는 방법이 더욱 중요시 되고 있다. 많은 유사한 웹 서비스들 가운데 하나를 선택해야 할 때, 서비스 사용자는 일반적으로 웹 서비스의 품질 정보를 필요로 하게 된다. 그러나 웹 서비스의 광고 QoS 정보는 항상 신뢰성이 있지는 않다는 문제점이 있다. 서비스 제공자가 더 많은 사용자들을 끌어들이기 위해 부정확한 QoS 정보를 게시하거나, 게시된 QoS 정보가 오래 되었을 수도 있다. 따라서 현재의 사용자들이 웹 서비스로부터 받는 QoS를 평가하고 이러한 평가를 공유하는 중개자의 존재는 새로운 사용자들에게 가치 있는 정보를 제공할 수 있다. 본 논문에서는 서비스 사용자의 입장에서 사용자가 원하는 최적의 품질을 제공하는 서비스를 찾도록 도와주는 에이전트 기반 품질 브로커 아키텍처를 제안한다. 동적으로 웹 서비스를 선정하는 아키텍처를 사용자에 제공함으로서 사용자의 품질 요구 변경 문제를 해결할 수 있다. 즉 사용자는 품질 브로커 서버에 연결된 UDDI 브라우저를 통해 최적의 품질 척도를 제공하는 서비스를 검색할 수 있다. 또한 각 서비스의 품질척도 값 결정에는 사용자 개입이 최대한 배제된다. 기존 선정 아키텍처에서는 사용자의 주관적 서비스 등급 선정으로 객관적 평가가 어려웠으나, 에이전트가 사용자 위치에서 모니터링 한 바인딩 정보를 통한 품질 척도 값 결정으로 객관성을 확보할 수 있다. 즉, 제공자들이 제공하지 못하는 서비스의 QoS 정보를 사용자측 에이전트들의 피드백으로 인한 QoS 정보 공유로 해결하고자 한다.

• 한국가정과교육학회지
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• 제29권4호
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• pp.161-193
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• 2017

본 연구의 목적은 고등학교 교육과정에서 활용할 수 있는 가정교과 기반의 예비부모교육 프로그램을 개발하고 평가하여, 예비부모인 고등학생 학습자들이 훗날 우리 사회의 주역이 될 미래세대를 현명하게 보살필 수 있는 성숙한 부모가 되는데 필요한 역량을 갖추도록 하며 동시에 현재 정부가 추진하고 있는 부모교육 활성화 방안의 청소년 대상 예비부모교육을 실행하는 데 도움이 되는 기초자료를 제공하는데 있다. 본 연구의 예비부모교육프로그램 개발 및 평가 과정은 일반적체제설계모형인 ADDIE 모형을 따랐으며, ADDIE모형 중 실행단계(Implement)를 제외한 분석, 설계, 개발, 평가의 4가지 과정을 거쳐 이루어졌다. 먼저, 분석 단계에서는 프로그램 내용요소 추출과 프로그램 개발의 시사점을 얻기 위해 관련 선행연구와 2015 개정 중 고등학교 "기술 가정" 교육과정 문서를 대상으로 분석이 이루어졌다. 그 결과 가정교과 이 외의 분야에서 연구되어 온 예비부모교육의 9 가지 주제(1.자기이해, 2.예비부모의 성, 3.결혼, 4.임신과 출산, 5.부모됨, 6.부모역할, 7.부모 자녀관계, 8.부모와 가족, 9.부모와 사회)와 해당 내용요소들은 이미 가정교과 교육과정에 모두 포함되어 있음을 확인하였으며, 9가지 주제 이외에 가정교과만의 독자적인 주제(1.생애설계, 2.가정생활 내 의 식 주 실천역량, 3.가정생활과 자녀안전, 4.가족문화)와 해당 내용요소들을 별도로 확인함으로써 예비부모교육 시행에 있어 가정교과가 지닌 강점(청소년과 가정과 사회를 바라보며 부모교육 내용 뿐만 아니라 식 의 주 소비 생활 전반을 포함하는 총체적 관점의 교육과 실제로 부모 준비를 실천하게 하는 교육)을 확인하였다. 둘째, 프로그램 개발을 위한 설계는 가정교과와 예비부모교육 간의 접점을 찾고 이를 프로그램 구성요소(목적, 개발방향, 주제, 내용요소, 학습목표, 학습활동)에 반영하는 과정을 통해 이루어졌다. 이 연구의 예비부모교육 프로그램은 미래세대를 현명하게 길러낼 수 있는 성숙한 부모가 지녀야 할 관련 지식, 태도, 가치관, 실천적 문제 해결 능력을 고등학생 학습자가 갖추도록 지원하는 것을 일차 목적으로 두며, 부모됨의 준비 관점에서 학습자가 현재 생활 점검 및 개선을 통해 생활자립능력을 갖추도록 하는 것을 이차목적으로 둔다. 궁극적으로 이 두 가지 목적 달성을 통해 학습자가 장차 부모로서 살아갈 가정생활 영역과 개인적 성취와 관련된 직업생활 영역 그리고 사회 발전에 기여할 수 있는 민주시민으로서의 삶의 영역간의 균형을 이뤄 이를 조화롭게 영위할 수 있는 성숙한 부모로의 성장을 돕고자 하였다. 프로그램 개발방향은 '전체 전개', '내용구성', '교수 학습법 구성'으로 크게 세 가지 측면에서 설정되었다. 프로그램의 주제는 총 11개로 '1. 부모 됨: 부모가 된다는 건', '2. 배우자선택: 행복한 부부관계, 자녀에게 주는 최고의 선물', '3. 임신과 출산: 새로운 생명과의 감동적인 만남', '4. 신생아 돌봄: 24시간 신생아 돌봄', '5. 영유아자녀돌봅: 사랑스러운 나의 아기와의 관계, 애착', '6. 유아기 자녀 돌봄: 별에서 온 내 아이, 유아기 자녀 돌보기', '7. 부모와 건강가정: 건강가정 속 부모와 자녀', '8.부모 자녀 관계: 현명한 부모, 자녀와 효과적으로 상호작용하기', '9. 가정생활 내 자녀안전: 가정생활 속 안전관리자, 부모', '10. 영유아 돌봄 실습', '11. 지역사회 양육지원서비스 개발 실습'이다. 프로그램의 들어갈 최종 내용요소들은 분석단계에서 추출된 내용요소들을 11개 주제와의 관련성을 토대로 분배된 후 선정되었다. 학습목표와 학습활동은 해당 주제와 내용요소를 반영하여 구상되었으며, 특히 프로그램의 학습활동은 1) 부모 됨 관련 실천적 문제를 포함한 사례 활용, 2) 학습한 지식과 기술을 활용한 지역사회 교류활동, 3) 부모 됨 관련 학습내용을 활용한 실생활 프로젝트 활동, 4) 고등학생 학습자의 현재 삶의 긍정적인 변화를 유도하는 활동, 그리고 5) 자녀 발달을 지원하는 가정교과 내 의 식 주 실습활동을 주요 특징으로 한다. 셋째, 프로그램의 개발은 앞서 설정된 설계에 따라 이루어졌으며, 이에 총 11개 주제에 따른 17차시 분량에 해당하는 교수 학습과 정안 및 학습자료가 개발되었다. 개발된 교수 학습과정안은 수업흐름 및 교사 참고자료를 포함하며, 수업 도입부에 가상의 자녀로부터 수업관련 메시지를 받는 것을 시작으로, 정리단계에서는 받은 메시지에 대한 답장의 형태로 해당 차시의 내용 정리 및 예비부모로서의 다짐을 하는 것을 기본 틀로 하였다. 학습자료는 학습활동을 위해 필요한 각종 계획서나 보고서 양식을 포함하며, 정규교육과정에서의 교과서와 같은 역할을 하도록 구체적으로 작성되었다. 넷째, 개발된 프로그램의 평가는 프로그램 개발과정과 결과물 두 가지 측면에 대해 가정교과 전문가 13인으로부터 5점 리커트형 설문지를 활용하여 이루어졌다. 개발과정에 대한 기초분석 평가결과 평균 4.61점, 내용타당도 지수 97.4%였으며, 프로그램 결과물에 대한 평가결과는 평균 4.37점 내용타당도 지수 86.9%였다. 이와 같은 값은 이 연구 프로그램의 개발과정과 그 결과물에 대한 타당도가 상당히 높은 수준에서 확보됐음을 나타내며, 이에 이 연구의 가정교과 기반의 예비부모교육 프로그램은 고등학생 학습자를 대상으로 하는 예비 부모 교육 프로그램으로 타당하고 적합하다는 결론을 내릴 수 있다.

• 지능정보연구
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• 제19권2호
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• pp.177-189
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• 2013

스마트교육에서 디지털교과서의 역할은 학습자와 대면하는 교육미디어로써 그 중요성은 재론의 여지없다. 이러한 디지털교과서는 학습자의 편의와 더불어 교수자, 콘텐츠 제작자, 유통업자를 위하여 표준화되어야 활성화되고 산업화될 수 있다. 본 연구에서는 다음과 같은 3가지 목표를 지향하는 디지털교과서 표준화 방안을 모색한다. (1) 디지털교과서는 온-오프 수업을 모두 지원하는 혼합학습 매체의 역할을 해야 하며, 특별한 전용뷰어 없이 표준을 준수하는 모든 EPUB 뷰어에서 실행가능 해야 하며, 기존의 이러닝 학습 콘텐츠와 학습관리시스템를 활용할 수 있도록 하며, 디지털 교과서를 사용하는 학습자의 정보를 추적 관리할 수 있는 트랙킹기능이 있으면서도, 오프라인 동안의 정보를 축적하여 서버와 통신할 수 있는 기능도 필요하다. 디지털교과서의 표준으로서 EPUB을 고려하는 이유는 디지털교과서가 책의 형태를 가져야 하는데 이를 위해서 따로 표준을 정할 필요가 없으며, EPUB 표준을 채택함으로써 풍부한 콘텐츠, 유통구조, 산업기반을 활용할 수 있기 때문이다. (2) 디지털교과서는 오픈소스를 적극 활용하여 저비용으로 현재 사용가능한 서비스를 구성하여 표준과 더불어 실제 실행 가능한 프로그램으로 제시되어야 하며, 관련 학습 콘텐츠가 오픈마켓의 형태로 운영될 수 있어야 한다. (3) 디지털교과서는 학습자에게 적절한 학습 피드백을 제공하기 위하여 모든 학습활동 정보를 축적하고 관리될 수 있는 인프라를 표준에 따라 구축하여 교육 빅데이터 처리의 기반을 제공하여야 한다. 이북 표준인 EPUB 3.0을 기반으로 하는 오픈 디지털교과서는 (1) 학습활동 정보를 기록하고 (2) 이 학습활동 지원을 위한 서버와 통신하여야 한다. 현재 표준으로 정해져 있지 않은 이북의 기록과 통신 기능을 EPUB 3.0의 JavaScript로 구현하여 현재 EPUB 3.0 뷰어에서도 활용하면서 이를 차세대 이북 표준 또는 교육을 위한 이북 표준(EPUB 3.0 for education)으로 제안하여 향후 제정된 표준 이북 뷰어에서는 JavaScript없이도 처리되도록 하는 전략이 필요하다. 향후 연구는 제안한 오픈 디지털교과서 표준에 의한 오픈소스 프로그램을 개발하고, 개발된 오픈 디지털교과서의 학습활동정보를 활용한 새로운 교육서비스 방안(교육 빅데이터 활용방안 포함)을 제시하는 것이다.

• 대한의용생체공학회:의공학회지
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• 제6권2호
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• pp.1-8
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• 1985

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70$\pm$1.32mmHg/min)compared to CF dialyzers(4.32$\pm$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500, 550, 570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500, 550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100, 300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3, 000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.SpO2 with Plethysmograph.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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• pp.17-17
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• 1993

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.

• 대한간호학회지
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• 제22권1호
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• pp.81-115
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• 1992

The problem addressed by this study was to determine the effect of nurse - patient agreement on the means to achieve nursing goals in the early postpartum period of primiparous mothers. It was hypothesized that the experimental treatment would result in hegher self-confidence and satisfaction in maternal role performance. This purpose was to contribute to the planning of nursing care to enhance self- confidence and satisfaction in maternal role performance and to the development of relevant nursing theory. Especially, the early postpartum period is crucial toward in recovery from childbirth and attainment of the maternal role. Maternal role attaintment is a complex social and cognitive process of stimulus -response accomplished by learning. Most women attain the maternal role sucessfully. But, some primiparous mothers experience difficultites in attainment of the maternal role due to lack of experience and knowledge. Self-confidence and satisfaction in maternal role performance are important factors in attainment and adjustment to the maternal role (Mercer, 1981a, 1981b ; Lederman, Weigarten, and Lederman, 1981 :Bobak and Jensen, 1985). Nursing is defined as behaviors of nurses add patients that attain nursing goals through action, reaction, interaction, and transaction. For attainment of nursing goals, active participating transactions must occur by agreement on the means to achieve those goals through nurse -patient mutual goal setting and establishment of their active relationships(King, 1981, Ha, 1977). Based on King's theory of goal attainment (1981), this stuy was planned as a non-equivalent control group, non -synchronized quasi -experimental design using agreement on the means to achieve nursing goals in early postpartum as the experimental treatment. The data were collected from July 20 to Sep. 1, 1991 by questionnaires with 60 primiparous mothers planing to breast feed after normal deliveries at W hospital in Pusan, Korea. The subjects were divided into a control group(conventional group) -those admitted from July 20 to Aug. 12, and an experimental group(agreement group) - those admitted from Aug. 13 to Sep. 1. The instument for agreement on the means to nursing goals in the early postpartum period included five steps - identification of disturbances of problems through action, reaction, and interaction with primiparous mothers : mutual early postpartal nursing goal setting : exploration of the means to achieve goals ; agreement on the means (self- care, ealry maternal -infant contact, performance of mothering behavior, and communicating about the infant's behavior and health condition) : implementation of the means. This instrument was developed on the basis of King's elements that lead to transactions in nurse-patient interactions. Lederman et al's (1981) scale for Confidence in ability to cope with tasks of motherhood and Lederman et al's(1981) scale for Mother's satisfaction with motherhood and infant care were used to measure self-confidence and satisfaction in maternal role performance ·with the subjects immediately after admission and on the day of discharge. Self-care performance in the experimental group was measured by self -evaluation tool developed by the investigator from the literature concerned. The tools to measure Pelf-confidence and satisfaction in maternal role performance, and the tool to measure self-evaluation of self-care performance were tested for internal reliability. Cronbach's Alphas were 0.94, 0.94, and 0.63. The data were analysed by using in S.P.S.S. computerized program and included percentage, x²-test, t-test, ANOVA, and Pearson Correlation Coefficient. The conclusions obtained from this study are summerized as follows : 1. The degree of self-confidence in maternal role performance of the total subjects group measured before the experimental treatment was above average with a mean score of 2.77(range 2.14-3.64). Out of 14 items, those with relatively high mean scores were ‘I would like to be a better mother than I am’(3.95), and ‘I have my doubts about whether I am a good mother’(2.87). Those with low mean scores were ‘I know that my baby wants most of the times’(2.28), ‘When the baby cries, I can tell what she /he wants’(2.37), and ‘I have confidence in my ability to care for the baby’(2;50). That is, the self - confidence of Primiparous mothers was considerably high in mothering, but rather low in activities concerning the infant care and understanding of the infant behavior. The degree of satisfaction in maternal role performance of the total subjects group measured before the experimental treatment was high with a mean score of 3.18(range 1.92-3.92). Out of 13 items, those with relatively high mean scores were ‘I am glad 1 had this baby now’(3.75), ‘I play with the baby between feedings when s/he is awake and quiet’(3.67), and ‘I enjoy being a mother’(3.27). Those with low mean scores were ‘I am upset about having too many responsibilities as a mother’(2.78), ‘It bothers me to get up for the baby at night’(2.82), and ‘I get annoyed if the baby frequently interrupts my activities’.(2.82), That is, the satisfaction of primiparous mothers was considerably high in mothering and infant care, but rather low in restraints in time or on the mother's self accomplishment and development. 2. Agreement on the means to achieve nursing goals in the early postpartum period included process of mutual goal setting, exploration of the means to achieve goals, and ahreement in concert means to achieve goals based on the mothers' condition, concerns, self-perception of the nurse - patient interactions. In the process of agreement, there was agreement that the means to achieve goals should be through trust and establishment of active relationships with the nurse through identification of problems according to planned nursing goals and active interaction, such as explanations, teaching, changing of opinions, acceptance or rejection of explanations, and proposing of questions. Therefore agreement on the means to achieve nursing goals in the early postpartum period appears to be an effective nursing intervention for primiparous mothers. 3. The degree of self- confidence in maternal role performance of the exprimental group was higher than that of the control group(t＝3.95, p＜0.01). Out of 14 items, those with higher score in the experimental group were ‘I would like to be a better mother than I am’(t＝1.93, p＜0.05), ‘I know that my baby wants most of the times’(t＝2.75, p＜0.01), ‘When the baby cries, 1 can tell what she/he wants’(t＝2.10, p＜0.05), ‘I have confidence in my ability to care for the baby’(t＝3.72, p＜0.01), ‘I trust my own judement in deciding how to care for the baby’(t＝1.96, p＜0.05), ‘I feel that I know my baby and what to do for him /her’(t＝2.44, p＜0.01), ‘I am concerned about being able to meet the baby's needs’(t＝2.87, p＜0.01), ‘I know what my baby likes and dislikes’(t＝3.26, p＜0.01), ‘I don't know to care for the baby as well as I should’(t＝2.07, p＜0.05), and ‘I am unsure about whether I give enough attention to the baby’(t＝3.04, p＜0.01), That is, the degree of self-confidence in mothering, activities concerning infant care, and understanding of infant behavior of the experimental group was higher than that of the control group. Therefore, the first hypothesis, that the degree of self-confidence in maternal role performance of the experimental group would be higher than that of the control group, was supported(t＝3.95, p＜0.01). 4. The degree of satisfaction in the maternal role performance of the exprimental group was higer than that or the control group(t＝2.31, p＜0.05). Out of 13 items, those with higher score in the experimental group were ‘I am glad I had this baby now’(t＝2.29, p＜0.05), ‘I enjoy taking care of the baby’(t＝2.4g, p＜0.01), ‘It is boring for me to care for the baby and do the same thing over and over’(t＝2.87, P＜0.01), ‘I am unhappy with the amount of time I have for activities other than childcare’(t＝2.51, p＜0.01), and ‘When bathing and diapering the baby, I would like to be doing something else’(t＝2.43, p＜0.01). That is, the degree of satisfaction in mothering, infant care, and restraints in time of on the mother's self accomplishment and development in the experimental group was higher than that of the control group. Therefore, the second hypothesis, that the degree of satisfaction in maternal role performance of the experimental group would be higher than that of the control group, was supported(t＝2.31, p＜0.05). 5. The third hypothesis, that the higher the degree of satisfaction in materenal role performance, the higher the degree of self-confidence in materenal role performance in the experimental group, was supported (r＝0.57, p＜0.01)

• 한국유통학회지:유통연구
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• 제17권2호
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• pp.63-92
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• 2012

본 연구는 소비자가 지각하는 유통업체의 위치기반 모바일 쇼핑정보 서비스에 대한 정보의 상황관련성과 정보자극에 대한 PAD 감정변수들(환기, 지배력, 즐거움) 간의 상호 인과관계와 이용의도에 대한 이들의 효과를 실증 연구 하였다. 미국 내 모바일 이용자를 대상으로 무작위 표본추출법에 근거하여 추출되었고, 총 335명의 사용가능한 응답이 수거되었다. 분석결과, 환기와 상황관련성은 즐거움에 정(+)의 영향을 주었으나 지배력은 즐거움에 유의한 영향력을 나타내지 않았다. 즐거움은 이용의도에 정(+)의 영향을 주었다. 본 연구를 통해 위치기반 모바일 서비스에 대한 소비자의 인지적 반응과 감정적 반응을 통합적으로 살펴보았으며, PAD 감정차원간의 체계적인 관계를 규명하였다. 연구결과를 바탕으로 모바일 쇼핑서비스 개발자, 유통업체, 그리고 마케팅 실무자를 위한 시사점을 논의하였으며, 연구의 한계점과 더불어 향후 연구 방향을 제시하였다.

• 인터넷정보학회논문지
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• 제14권6호
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• pp.71-84
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• 2013

컴퓨터 시스템 운용 간에 발생하는 많은 정보들이 기록되는 로그데이터는 컴퓨터 시스템 운용 점검, 프로세스의 최적화, 사용자 최적화 맞춤형 제공 등 다방면으로 활용되고 있다. 본 논문에서는 다양한 종류의 로그데이터들 중에서 은행에서 발생하는 대용량의 로그데이터를 처리하기 위한 클라우드 환경 하에서의 MongoDB 기반 비정형 로그 처리시스템을 제안한다. 은행업무간 발생하는 대부분의 로그데이터는 고객의 업무처리 프로세스 간에 발생하며, 고객 업무 프로세스 처리에 따른 로그데이터를 수집, 저장, 분류, 분석하기 위해서는 별도로 로그데이터를 처리하는 시스템을 구축해야만 한다. 하지만 기존 컴퓨팅환경 하에서는 폭발적으로 증가하는 대용량 비정형 로그데이터 처리를 위한 유연한 스토리지 확장성 기능, 저장된 비정형 로그데이터를 분류, 분석 처리할 수 있는 기능을 구현하기가 매우 어렵다. 이에 따라 본 논문에서는 클라우드 컴퓨팅 기술을 도입하여 기존 컴퓨팅 인프라 환경의 분석 도구 및 관리체계에서 처리하기 어려웠던 비정형 로그데이터를 처리하기 위한 클라우드 환경기반의 로그데이터 처리시스템을 제안하고 구현하였다. 제안한 본 시스템은 IaaS(Infrastructure as a Service) 클라우드 환경을 도입하여 컴퓨팅 자원의 유연한 확장성을 제공하며 실제로, 로그데이터가 장기간 축적되거나 급격하게 증가하는 상황에서 스토리지, 메모리 등의 자원을 신속성 있고 유연하게 확장을 할 수 있는 기능을 포함한다. 또한, 축적된 비정형 로그데이터의 실시간 분석이 요구되어질 때 기존의 분석도구의 처리한계를 극복하기 위해 본 시스템은 하둡 (Hadoop) 기반의 분석모듈을 도입함으로써 대용량의 로그데이터를 빠르고 신뢰성 있게 병렬 분산 처리할 수 있는 기능을 제공한다. 게다가, HDFS(Hadoop Distributed File System)을 도입함으로써 축적된 로그데이터를 블록단위로 복제본을 생성하여 저장관리하기 때문에 본 시스템은 시스템 장애와 같은 상황에서 시스템이 멈추지 않고 작동할 수 있는 자동복구 기능을 제공한다. 마지막으로, 본 시스템은 NoSQL 기반의 MongoDB를 이용하여 분산 데이터베이스를 구축함으로써 효율적으로 비정형로그데이터를 처리하는 기능을 제공한다. MySQL과 같은 관계형 데이터베이스는 복잡한 스키마 구조를 가지고 있기 때문에 비정형 로그데이터를 처리하기에 적합하지 않은 구조를 가지고 있다. 또한, 관계형 데이터베이스의 엄격한 스키마 구조는 장기간 데이터가 축적되거나, 데이터가 급격하게 증가할 때 저장된 데이터를 분할하여 여러 노드에 분산시키는 노드 확장이 어렵다는 문제점을 가지고 있다. NoSQL은 관계형 데이터베이스에서 제공하는 복잡한 연산을 지원하지는 않지만 데이터가 빠르게 증가할 때 노드 분산을 통한 데이터베이스 확장이 매우 용이하며 비정형 데이터를 처리하는데 매우 적합한 구조를 가지고 있는 비관계형 데이터베이스이다. NoSQL의 데이터 모델은 주로 키-값(Key-Value), 컬럼지향(Column-oriented), 문서지향(Document-Oriented)형태로 구분되며, 제안한 시스템은 스키마 구조가 자유로운 문서지향(Document-Oriented) 데이터 모델의 대표 격인 MongoDB를 도입하였다. 본 시스템에 MongoDB를 도입한 이유는 유연한 스키마 구조에 따른 비정형 로그데이터 처리의 용이성뿐만 아니라, 급격한 데이터 증가에 따른 유연한 노드 확장, 스토리지 확장을 자동적으로 수행하는 오토샤딩 (AutoSharding) 기능을 제공하기 때문이다. 본 논문에서 제안하는 시스템은 크게 로그 수집기 모듈, 로그 그래프생성 모듈, MongoDB 모듈, Hadoop기반 분석 모듈, MySQL 모듈로 구성되어져 있다. 로그 수집기 모듈은 각 은행에서 고객의 업무 프로세스 시작부터 종료 시점까지 발생하는 로그데이터가 클라우드 서버로 전송될 때 로그데이터 종류에 따라 데이터를 수집하고 분류하여 MongoDB 모듈과 MySQL 모듈로 분배하는 기능을 수행한다. 로그 그래프생성 모듈은 수집된 로그데이터를 분석시점, 분석종류에 따라 MongoDB 모듈, Hadoop기반 분석 모듈, MySQL 모듈에 의해서 분석되어진 결과를 사용자에게 웹 인터페이스 형태로 제공하는 역할을 한다. 실시간적 로그데이터분석이 필요한 로그데이터는 MySQL 모듈로 저장이 되어 로그 그래프생성 모듈을 통하여 실시간 로그데이터 정보를 제공한다. 실시간 분석이 아닌 단위시간당 누적된 로그데이터의 경우 MongoDB 모듈에 저장이 되고, 다양한 분석사항에 따라 사용자에게 그래프화해서 제공된다. MongoDB 모듈에 누적된 로그데이터는 Hadoop기반 분석모듈을 통해서 병렬 분산 처리 작업이 수행된다. 성능 평가를 위하여 로그데이터 삽입, 쿼리 성능에 대해서 MySQL만을 적용한 로그데이터 처리시스템과 제안한 시스템을 비교 평가하였으며 그 성능의 우수성을 검증하였다. 또한, MongoDB의 청크 크기별 로그데이터 삽입 성능평가를 통해 최적화된 청크 크기를 확인하였다.