• 지능정보연구
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• 제25권1호
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• pp.43-61
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• 2019

최근 4차 산업혁명과 함께 인공지능 기술에 대한 연구가 활발히 진행되고 있으며, 이전의 그 어느 때보다도 기술의 발전이 빠르게 진행되고 있는 추세이다. 이러한 인공지능 환경에서 양질의 지식베이스는 인공지능 기술의 향상 및 사용자 경험을 높이기 위한 기반 기술로써 중요한 역할을 하고 있다. 특히 최근에는 인공지능 스피커를 통한 질의응답과 같은 서비스의 기반 지식으로 활용되고 있다. 하지만 지식베이스를 구축하는 것은 사람의 많은 노력을 요하며, 이로 인해 지식을 구축하는데 많은 시간과 비용이 소모된다. 이러한 문제를 해결하기 위해 본 연구에서는 기계학습을 이용하여 지식베이스의 구조에 따라 학습을 수행하고, 이를 통해 자연어 문서로부터 지식을 추출하여 지식화하는 방법에 대해 제안하고자 한다. 이러한 방법의 적절성을 보이기 위해 DBpedia 온톨로지의 구조를 기반으로 학습을 수행하여 지식을 구축할 것이다. 즉, DBpedia의 온톨로지 구조에 따라 위키피디아 문서에 기술되어 있는 인포박스를 이용하여 학습을 수행하고 이를 바탕으로 자연어 텍스트로부터 지식을 추출하여 온톨로지화하기 위한 방법론을 제안하고자 한다. 학습을 바탕으로 지식을 추출하기 위한 과정은 문서 분류, 적합 문장 분류, 그리고 지식 추출 및 지식베이스 변환의 과정으로 이루어진다. 이와 같은 방법론에 따라 실제 지식 추출을 위한 플랫폼을 구축하였으며, 실험을 통해 본 연구에서 제안하고자 하는 방법론이 지식을 확장하는데 있어 유용하게 활용될 수 있음을 증명하였다. 이러한 방법을 통해 구축된 지식은 향후 지식베이스를 기반으로 한 인공지능을 위해 활용될 수 있을 것으로 판단된다.

• 비교문화연구
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• 제25권
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• pp.695-721
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• 2011

본 연구는 결혼이주여성들이 출신국의 문화에 대한 자부심을 가지고 한국문화를 공부하기 위해 자신의 출신국 지역문화 스토리텔링(자기문화 스토리텔링) 활용 표현교육 모형을 제안하고자 한다. 이를 통해 결혼이주여성들이 자신의 문화에 대한 자부심을 가지고 한국문화를 공부할 수 있을 것으로 기대한다. 본 연구는 결혼이주여성들의 자기문화 스토리텔링 활용 표현교육 5단계 모형을 활용하여 한국어 고급 학습자 49명에게 한국어 쓰기와 말하기 활동을 주목하였다. 그 중 일본 출신 A씨의 한국어 쓰기 및 말하기 표현교육 사례를 중심으로 각 단계별 활동 결과물을 제시했다. 활동 결과 제시의 방법은 내러티브 기술법을 사용하였다. 본 연구에서 자기문화 스토리텔링은 스토리텔링의 '대중성', '상호작용성', '참여성'을 중심으로 구성하였다. 자기문화 스토리텔링은 결혼이주여성에게 출신국의 문화에 대한 쓰기와 말하기의 재구성을 포함한다. 이를 통해 결혼이주여성들은 자기문화에 대한 자부심 함양과 정체성의 확립에 긍정적인 변화가 있었을 뿐만 아니라 한국어 및 한국문화 이해도가 높아진 것을 확인할 수 있었다.

• Asia pacific journal of information systems
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• 제24권2호
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• pp.233-253
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• 2014

Can the stock market really be predicted? Stock market prediction has attracted much attention from many fields including business, economics, statistics, and mathematics. Early research on stock market prediction was based on random walk theory (RWT) and the efficient market hypothesis (EMH). According to the EMH, stock market are largely driven by new information rather than present and past prices. Since it is unpredictable, stock market will follow a random walk. Even though these theories, Schumaker [2010] asserted that people keep trying to predict the stock market by using artificial intelligence, statistical estimates, and mathematical models. Mathematical approaches include Percolation Methods, Log-Periodic Oscillations and Wavelet Transforms to model future prices. Examples of artificial intelligence approaches that deals with optimization and machine learning are Genetic Algorithms, Support Vector Machines (SVM) and Neural Networks. Statistical approaches typically predicts the future by using past stock market data. Recently, financial engineers have started to predict the stock prices movement pattern by using the SNS data. SNS is the place where peoples opinions and ideas are freely flow and affect others' beliefs on certain things. Through word-of-mouth in SNS, people share product usage experiences, subjective feelings, and commonly accompanying sentiment or mood with others. An increasing number of empirical analyses of sentiment and mood are based on textual collections of public user generated data on the web. The Opinion mining is one domain of the data mining fields extracting public opinions exposed in SNS by utilizing data mining. There have been many studies on the issues of opinion mining from Web sources such as product reviews, forum posts and blogs. In relation to this literatures, we are trying to understand the effects of SNS exposures of firms on stock prices in Korea. Similarly to Bollen et al. [2011], we empirically analyze the impact of SNS exposures on stock return rates. We use Social Metrics by Daum Soft, an SNS big data analysis company in Korea. Social Metrics provides trends and public opinions in Twitter and blogs by using natural language process and analysis tools. It collects the sentences circulated in the Twitter in real time, and breaks down these sentences into the word units and then extracts keywords. In this study, we classify firms' exposures in SNS into two groups: positive and negative. To test the correlation and causation relationship between SNS exposures and stock price returns, we first collect 252 firms' stock prices and KRX100 index in the Korea Stock Exchange (KRX) from May 25, 2012 to September 1, 2012. We also gather the public attitudes (positive, negative) about these firms from Social Metrics over the same period of time. We conduct regression analysis between stock prices and the number of SNS exposures. Having checked the correlation between the two variables, we perform Granger causality test to see the causation direction between the two variables. The research result is that the number of total SNS exposures is positively related with stock market returns. The number of positive mentions of has also positive relationship with stock market returns. Contrarily, the number of negative mentions has negative relationship with stock market returns, but this relationship is statistically not significant. This means that the impact of positive mentions is statistically bigger than the impact of negative mentions. We also investigate whether the impacts are moderated by industry type and firm's size. We find that the SNS exposures impacts are bigger for IT firms than for non-IT firms, and bigger for small sized firms than for large sized firms. The results of Granger causality test shows change of stock price return is caused by SNS exposures, while the causation of the other way round is not significant. Therefore the correlation relationship between SNS exposures and stock prices has uni-direction causality. The more a firm is exposed in SNS, the more is the stock price likely to increase, while stock price changes may not cause more SNS mentions.

• 지능정보연구
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• 제20권1호
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• pp.133-148
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• 2014

최근 다양한 정보채널들의 등장으로 인해 빅데이터에 대한 관심이 높아지고 있다. 이와 같은 현상의 가장 큰 원인은, 스마트기기의 사용이 활성화 됨에 따라 사용자가 생성하는 텍스트, 사진, 동영상과 같은 비정형 데이터의 양이 크게 증가하고 있는 것에서 찾을 수 있다. 특히 비정형 데이터 중에서도 텍스트 데이터의 경우, 사용자들의 의견 및 다양한 정보를 명확하게 표현하고 있다는 특징이 있다. 따라서 이러한 텍스트에 대한 분석을 통해 새로운 가치를 창출하고자 하는 시도가 활발히 이루어지고 있다. 텍스트 분석을 위해 필요한 기술은 대표적으로 텍스트 마이닝과 오피니언 마이닝이 있다. 텍스트 마이닝과 오피니언 마이닝은 모두 텍스트 데이터를 입력 데이터로 사용할 뿐 아니라 파싱, 필터링 등 자연어 처리기술을 사용한다는 측면에서 많은 공통점을 갖고 있다. 특히 문서의 분류 및 예측에 있어서 목적 변수가 긍정 또는 부정의 감성을 나타내는 경우에는, 전통적 텍스트 마이닝, 또는 감성사전 기반의 오피니언 마이닝의 두 가지 방법론에 의해 오피니언 분류를 수행할 수 있다. 따라서 텍스트 마이닝과 오피니언 마이닝의 특징을 구분하는 가장 명확한 기준은 입력 데이터의 형태, 분석의 목적, 분석의 결과물이 아닌 감성사전의 사용 여부라고 할 수 있다. 따라서 본 연구에서는 오피니언 분류라는 동일한 목적에 대해 텍스트 마이닝과 오피니언 마이닝을 각각 사용하여 예측 모델을 수립하는 과정을 비교하고, 결과로 도출된 모델의 예측 정확도를 비교하였다. 오피니언 분류 실험을 위해 영화 리뷰 2,000건에 대한 실험을 수행하였으며, 실험 결과 오피니언 마이닝을 통해 수립된 모델이 텍스트 마이닝 모델에 비해 전체 구간의 예측 정확도 평균이 높게 나타나고, 예측의 확실성이 강한 문서일수록 예측 정확성이 높게 나타나는 일관적인 성향을 나타내는 등 더욱 바람직한 특성을 보였다.

• 지능정보연구
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• 제21권1호
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• pp.143-159
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• 2015

불확실한 환경변화에 대처하고 장기적 전략수립을 위해 기업에게 있어서 IT 트렌드에 대한 예측은 오랫동안 중요한 주제였다. IT 트렌드에 대한 예측을 기반으로 새로운 시대에 대한 인식을 하고 예산을 배정하여 빠르게 변화하는 기술의 추세에 대비할 수 있기 때문이다. 해마다 유수의 컨설팅업체들과 조사기관에서 차년도 IT 트렌드에 대해서 발표되고는 있지만, 이러한 예측이 실제로 차년도 비즈니스 현실세계에서 나타났는지에 대한 연구는 거의 없었다. 본 연구는 현존하는 빅데이터 기술을 활용하여 서울지역을 중심으로 지난 8개월동안(2013년 5월1일부터 2013년12월31까지) 정보통신산업진흥원과 한국정보화진흥원에서 2012년 말에 발표한 IT 트렌드 토픽이 언급된 21,589개의 트윗 데이터를 수집하여 분석하였다. 또한 2013년에 나라장터에 올라온 프로젝트들이 IT트렌드 토픽과 관련이 있는지 상관관계분석을 실시하였다. 연구결과, 빅데이터, 클라우드, HTML5, 스마트홈, 테블릿PC, UI/UX와 같은 IT토픽은 시간이 지날수록 매우 빈번하게 언급되어졌으며, 이 같은 토픽들은 2013년 나라장터 공고 프로젝트 데이터와도 매우 유의한 상관관계를 가지고 있는 것을 확인할 수 있었다. 이는 전년도(2012년)에 예측한 트렌드들이 차년도(2013년)에 실제로 트위터와 한국정부의 공공조달사업에 반영되어 나타나고 있는 것을 의미한다. 본 연구는 최신 빅데이터툴을 사용하여, 유수기관의 IT트렌드 예측이 실제로 트위터와 같은 소셜미디에서 생성되는 트윗데이터에서 얼마나 언급되어 나타나는지 추적했다는 점에서 중요한 의의가 있고, 이를 통해 트위터가 사회적 트랜드의 변화를 효율적으로 추적하기에 유용한 도구임을 확인하고자 할 수 있었다.

• 지능정보연구
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• 제25권4호
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• pp.105-122
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• 2019

텍스트 데이터가 특정 범주에 속하는지 판별하는 문장 분류에서, 문장의 특징을 어떻게 표현하고 어떤 특징을 선택할 것인가는 분류기의 성능에 많은 영향을 미친다. 특징 선택의 목적은 차원을 축소하여도 데이터를 잘 설명할 수 있는 방안을 찾아내는 것이다. 다양한 방법이 제시되어 왔으며 Fisher Score나 정보 이득(Information Gain) 알고리즘 등을 통해 특징을 선택 하거나 문맥의 의미와 통사론적 정보를 가지는 Word2Vec 모델로 학습된 단어들을 벡터로 표현하여 차원을 축소하는 방안이 활발하게 연구되었다. 사전에 정의된 단어의 긍정 및 부정 점수에 따라 단어의 임베딩을 수정하는 방법 또한 시도하였다. 본 연구는 문장 분류 문제에 대해 선택적 단어 제거를 수행하고 임베딩을 적용하여 문장 분류 정확도를 향상시키는 방안을 제안한다. 텍스트 데이터에서 정보 이득 값이 낮은 단어들을 제거하고 단어 임베딩을 적용하는 방식과, 정보이득 값이 낮은 단어와 코사인 유사도가 높은 주변 단어를 추가로 선택하여 텍스트 데이터에서 제거하고 단어 임베딩을 재구성하는 방식이다. 본 연구에서 제안하는 방안을 수행함에 있어 데이터는 Amazon.com의 'Kindle' 제품에 대한 고객리뷰, IMDB의 영화리뷰, Yelp의 사용자 리뷰를 사용하였다. Amazon.com의 리뷰 데이터는 유용한 득표수가 5개 이상을 만족하고, 전체 득표 중 유용한 득표의 비율이 70% 이상인 리뷰에 대해 유용한 리뷰라고 판단하였다. Yelp의 경우는 유용한 득표수가 5개 이상인 리뷰 약 75만개 중 10만개를 무작위 추출하였다. 학습에 사용한 딥러닝 모델은 CNN, Attention-Based Bidirectional LSTM을 사용하였고, 단어 임베딩은 Word2Vec과 GloVe를 사용하였다. 단어 제거를 수행하지 않고 Word2Vec 및 GloVe 임베딩을 적용한 경우와 본 연구에서 제안하는 선택적으로 단어 제거를 수행하고 Word2Vec 임베딩을 적용한 경우를 비교하여 통계적 유의성을 검정하였다.

• 지능정보연구
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• 제22권2호
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• pp.127-142
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• 2016

딥러닝은 인공신경망(neural network)이라는 인공지능분야의 모형이 발전된 형태로서, 계층구조로 이루어진 인공신경망의 내부계층(hidden layer)이 여러 단계로 이루어진 구조이다. 딥러닝에서의 주요 모형은 합성곱신경망(convolutional neural network), 순환신경망(recurrent neural network), 그리고 심층신뢰신경망(deep belief network)의 세가지라고 할 수 있다. 그 중에서 현재 흥미로운 연구가 많이 발표되어서 관심이 집중되고 있는 모형은 지도학습(supervised learning)모형인 처음 두 개의 모형이다. 따라서 본 논문에서는 지도학습모형의 가중치를 최적화하는 기본적인 방법인 오류역전파 알고리즘을 살펴본 뒤에 합성곱신경망과 순환신경망의 구조와 응용사례 등을 살펴보고자 한다. 본문에서 다루지 않은 모형인 심층신뢰신경망은 아직까지는 합성곱신경망 이나 순환신경망보다는 상대적으로 주목을 덜 받고 있다. 그러나 심층신뢰신경망은 CNN이나 RNN과는 달리 비지도학습(unsupervised learning)모형이며, 사람이나 동물은 관찰을 통해서 스스로 학습한다는 점에서 궁극적으로는 비지도학습모형이 더 많이 연구되어야 할 주제가 될 것이다.

• 한국수학교육학회지시리즈A:수학교육
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• 제63권2호
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• pp.123-138
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• 2024

본 연구는 S대학 <인공지능을 위한 기초수학[Math4AI]> 강좌의 교수·학습과정에서 맞춤형 챗GPT를 개발하여 활용한 경험을 공유한다. 연구진은 ① 먼저 강좌 맞춤형 챗GPT (https://math4ai.solgitmath.com/)를 개발하였다. 이때 챗GPT가 부정확한 정보를 주지 않도록 수년간의 해당 강좌 주요 데이터(교재, 실습실, 토론 기록, 코드 등)를 우선적으로 학습하는 챗GPT의 기능을 적용하였다. ② 학생들이 교재를 스스로 학습하다 궁금한 부분이 생기면, 맞춤형 챗GPT 인터페이스를 통해 자연어로 수학 용어, 정리, 예제, 열린 문제 번호, 핵심어 등을 질문하여 도움을 얻을 수 있도록 하였다. 그러면 챗GPT는 관련된 주요 문제나 용어, 그리고 이전 학생들의 토론에 기반한 몇 가지 샘플 답안 또는 토론 내용과 함께 사용되었던 코드 샘플을 제공한다. ③ 학생들이 챗GPT를 통해 얻은 내용을 스스로 윤문하여 공유하고, 상호 토론하면서, 교재에서 제시하는 주요 개념과 열린 문제의 대부분을 이해하도록 하였다. ④ 학기 말에는 그간 본인이 얻은 열린 문제들에 대한 학습기록을 모아 PBL (Problem-Based Learning) 보고서로 제출하고, 발표하여 강좌를 수료하도록 하였다. 이러한 방식은 학생들이 학습을 포기하지 않고 한 단계 앞으로 더 나아갈 추진력과 동기를 주며, 궁극적으로 각각의 문제를 스스로 해결하는 자기 주도적 학습을 도울 수 있다. 또한 학생들 각자의 수준에 맞추어 실시간으로 최적화된 조언을 제시하므로 강좌뿐만 아니라 대학수학교육 전반에 대한 학생별 맞춤형 교육(personalized education)을 제공할 수 있다. 즉, 학생들이 담당교수(또는 조교)와 AI 조교의 도움으로 실시간 답변과 효과적인 조언을 받을 수 있게 됨을 의미한다. 이는 양질의 조교 부족에 대한 고민을 추가 비용 없이 획기적으로 해결할 수 있다. 본 연구는 강좌의 교수·학습과정에 교재 맞춤형 챗GPT를 접목한 것으로, 인공지능(AI) 기술을 기타 대학수학 과목들(미적분학, 선형대수학, 이산수학, 공학수학, 기초통계학 등)과 초·중·고 수학교육에 적용할 수 있는 새로운 방법을 제시한다. 특히 AI 기술을 적용하여 이전 수강생들의 학습기록(열린 문제 풀이, 토론 자료, 코드 등)을 참고하며, 각자 실습한 결과를 공유 및 상호 토론하여 문제를 해결하는 방식은, 다양한 전공의 학생들이 내용을 더 효과적으로 이해하고, 본인 전공 관련 문제 해결 능력을 향상시키는 데 획기적인 도움을 줄 것으로 예상된다. 또한 교재 맞춤형 챗GPT와 함께 자기주도적인 학습을 경험토록 하는 교수학습 방법은 평생 교육(lifelong learning, extension school, extension college, extended college) 또는 평생학습의 관점에서 중요하다.

• 지능정보연구
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• 제20권2호
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• pp.109-122
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• 2014

현재 우리는 소셜 네트워크 서비스(Social Network Service, 이하 SNS) 상에서 수많은 데이터를 만들어 내고 있다. 특히, 모바일 기기와 SNS의 결합은 과거와는 비교할 수 없는 대량의 데이터를 생성하면서 사회적으로도 큰 영향을 미치고 있다. 이렇게 방대한 SNS 데이터 안에서 사람들이 많이 이야기하는 이슈를 찾아낼 수 있다면 이 정보는 사회 전반에 걸쳐 새로운 가치 창출을 위한 중요한 원천으로 활용될 수 있다. 본 연구는 이러한 SNS 빅데이터 분석에 대한 요구에 부응하기 위해, 트위터 데이터를 활용하여 트위터 상에서 어떤 이슈가 있었는지 추출하고 이를 웹 상에서 시각화 하는 트위터이슈 트래킹 시스템 TITS(Twitter Issue Tracking System)를 설계하고 구축 하였다. TITS는 1) 일별 순위에 따른 토픽 키워드 집합 제공 2) 토픽의 한달 간 일별 시계열 그래프 시각화 3) 토픽으로서의 중요도를 점수와 빈도수에 따라 Treemap으로 제공 4) 키워드 검색을 통한 키워드의 한달 간 일별 시계열 그래프 시각화의 기능을 갖는다. 본 연구는 SNS 상에서 실시간으로 발생하는 빅데이터를 Open Source인 Hadoop과 MongoDB를 활용하여 분석하였고, 이는 빅데이터의 실시간 처리가 점점 중요해지고 있는 현재 매우 주요한 방법론을 제시한다. 둘째, 문헌정보학 분야뿐만 아니라 다양한 연구 영역에서 사용하고 있는 토픽 모델링 기법을 실제 트위터 데이터에 적용하여 스토리텔링과 시계열 분석 측면에서 유용성을 확인할 수 있었다. 셋째, 연구 실험을 바탕으로 시각화와 웹 시스템 구축을 통해 실제 사용 가능한 시스템으로 구현하였다. 이를 통해 소셜미디어에서 생성되는 사회적 트렌드를 마이닝하여 데이터 분석을 통한 의미 있는 정보를 제공하는 실제적인 방법을 제시할 수 있었다는 점에서 주요한 의의를 갖는다. 본 연구는 JSON(JavaScript Object Notation) 파일 포맷의 1억 5천만개 가량의 2013년 3월 한국어 트위터 데이터를 실험 대상으로 한다.

• 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.