• 지능정보연구
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• 제18권4호
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• pp.59-77
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• 2012

기업의 성장성, 수익성, 안정성, 활동성, 생산성 등에 대한 다양한 분석이 은행, 신용평가기관, 투자자 등 많은 이해관계자에 의해 실시되고 있고, 이에 대한 다양한 경영분석 지표들 또한 정기적으로 발표되고 있다. 본 연구에서는 이러한 경영분석 지표를 이용하여 어떤 기업이 가까운 미래에 유상증자를 실시하는지를 데이터마이닝을 통해 예측하고자 한다. 본 연구를 통해 어떠한 지표가 유상증자 여부를 예측하는데 도움이 되는가를 살펴 볼 것이며, 그 지표들을 이용하여 예측할 경우 그 예측의 정확도가 어느 정도인지를 분석하고자 한다. 특히 1997년 IMF 금융위기 전후로 유상증자를 결정하는 변수들이 변화하는지, 그리고 예측의 정확성에 분명한 차이가 존재하는지 분석한다. 또한 유상증자 실시 시기를 경영분석 지표 발표 후 1년 내, 1~2년 내, 2~3년 내로 나누어 예측 시기에 따라 예측의 정확성과 결정 변수들의 차이가 존재하는지도 분석한다. 658개의 유가증권상장법인의 경영분석 데이터를 이용하여 실증 분석한 결과, IMF 이후의 유상증자 예측모형이 IMF 이전의 예측모형에 비해 예측 정확도가 높았고, 학습용 데이터의 예측 정확도와 검증용 데이터의 예측 정확도 차이도 IMF 이후가 낮게 나타났다. 이러한 결과는 IMF 이후 재무자료의 정확도가 높아졌고, 기업에게 유상증자의 목적이 더욱 명확해졌다고 해석될 수 있다. 또한 예측기간이 단기인 경우 경영분석 지표 중 안전성에 관련된 지표들의 중요성이 부각되었고, 장기인 경우에는 수익성과 안전성뿐만 아니라 활동성과 생산성 관련지표도 유상증자를 예측하는 데 중요한 것으로 파악되었다. 그리고 모든 예측모형에서 산업코드가 유상증자를 예측하는 중요변수로 포함되었는데 이는 산업별로 서로 다른 유상증자 유형이 존재한다는 점을 시사한다. 본 연구는 투자자나 재무담당자가 유상증자 여부를 장단기 시점에서 예측하고자 할 때 어떠한 경영분석지표를 고려하여 분석하는 것이 바람직한지에 대한 지침을 제공하는데 그 의의가 있다.

• 지능정보연구
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• 제24권1호
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• pp.167-181
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• 2018

지난 10여 년간 딥러닝(Deep Learning)은 다양한 기계학습 알고리즘 중에서 많은 주목을 받아 왔다. 특히 이미지를 인식하고 분류하는데 효과적인 알고리즘으로 알려져 있는 합성곱 신경망(Convolutional Neural Network, CNN)은 여러 분야의 분류 및 예측 문제에 널리 응용되고 있다. 본 연구에서는 기계학습 연구에서 가장 어려운 예측 문제 중 하나인 주식시장 예측에 합성곱 신경망을 적용하고자 한다. 구체적으로 본 연구에서는 그래프를 입력값으로 사용하여 주식시장의 방향(상승 또는 하락)을 예측하는 이진분류기로써 합성곱 신경망을 적용하였다. 이는 그래프를 보고 주가지수가 오를 것인지 내릴 것인지에 대해 경향을 예측하는 이른바 기술적 분석가를 모방하는 기계학습 알고리즘을 개발하는 과제라 할 수 있다. 본 연구는 크게 다음의 네 단계로 수행된다. 첫 번째 단계에서는 데이터 세트를 5일 단위로 나눈다. 두 번째 단계에서는 5일 단위로 나눈 데이터에 대하여 그래프를 만든다. 세 번째 단계에서는 이전 단계에서 생성된 그래프를 사용하여 학습용과 검증용 데이터 세트를 나누고 합성곱 신경망 분류기를 학습시킨다. 네 번째 단계에서는 검증용 데이터 세트를 사용하여 다른 분류 모형들과 성과를 비교한다. 제안한 모델의 유효성을 검증하기 위해 2009년 1월부터 2017년 2월까지의 약 8년간의 KOSPI200 데이터 2,026건의 실험 데이터를 사용하였다. 실험 데이터 세트는 CCI, 모멘텀, ROC 등 한국 주식시장에서 사용하는 대표적인 기술지표 12개로 구성되었다. 결과적으로 실험 데이터 세트에 합성곱 신경망 알고리즘을 적용하였을 때 로지스틱회귀모형, 단일계층신경망, SVM과 비교하여 제안모형인 CNN이 통계적으로 유의한 수준의 예측 정확도를 나타냈다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권1호
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• pp.124-136
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• 2002

As an official journal of the Asian-Australasian Association of Animal Production Societies (AAAP), the Asian-Australasian Journal of Animal Sciences (AJAS) was born in February 1987 and the first issue (Volume 1, Number 1) was published in March 1988 under the Editorship of Professor In K. Han (Korea). By the end of 2001, a total of 84 issues in 14 volumes and 1,761 papers in 11,462 pages had been published. In addition to these 14 volumes, a special issue entitled "Recent Advances in Animal Nutrition" (April, 2000) and 3 supplements entitled "Proceedings of the 9th AAAP Animal Science Congress" (July, 2000) were also published. Publication frequency has steadily increased from 4 issues in 1988, to 6 issues in 1997 and to 12 issues in 2000. The total number of pages per volume and the number of original or review papers published also increased. Some significant milestones in the history of the AJAS include that (1) it became a Science Citation Index (SCI) journal in 1997, (2) the impact factor of the journal improved from 0.257 in 1999 to 0.446 in 2000, (3) it became a monthly journal (12 issues per volume) in 2000, (4) it adopted an English editing system in 1999, and (5) it has been covered in "Current Contents/Agriculture, Biology and Environmental Science since 2000. The AJAS is subscribed by 842 individuals or institutions. Annual subscription fees of US$ 50 (Category B) or US$ 70 (Category A) for individuals and US$ 70 (Category B) or US$ 120 (Category A) for institutions are much less than the actual production costs of US$ 130. A list of the 1,761 papers published in AJAS, listed according to subject area, may be found in the AJAS homepage (http://www.ajas.snu.ac.kr) and a very well prepared "Editorial Policy with Guide for Authors" is available in the Appendix of this paper. With regard to the submission status of manuscripts from AAAP member countries, India (235), Korea (235) and Japan (198) have submitted the most manuscripts. On the other hand, Mongolia, Nepal, and Papua New Guinea have never submitted any articles. The average time required from submission of a manuscript to printing in the AJAS has been reduced from 11 months in 1997-2000 to 7.8 months in 2001. The average rejection rate of manuscripts was 35.3%, a percentage slightly higher than most leading animal science journals. The total number of scientific papers published in the AJAS by AAAP member countries during a 14-year period (1988-2001) was 1,333 papers (75.7%) and that by non- AAAP member countries was 428 papers (24.3%). Japanese animal scientists have published the largest number of papers (397), followed by Korea (275), India (160), Bangladesh (111), Pakistan (85), Australia (71), Malaysia (59), China (53), Thailand (53), and Indonesia (34). It is regrettable that the Philippines (15), Vietnam (10), New Zealand (8), Nepal (2), Mongolia (0) and Papua New Guinea (0) have not actively participated in publishing papers in the AJAS. It is also interesting to note that the top 5 countries (Bangladesh, India, Japan, Korea and Pakistan) have published 1,028 papers in total indicating 77% of the total papers being published by AAAP animal scientists from Vol. 1 to 14 of the AJAS. The largest number of papers were published in the ruminant nutrition section (591 papers-44.3%), followed by the non-ruminant nutrition section (251 papers-18.8%), the animal reproduction section (153 papers-11.5%) and the animal breeding section (115 papers-8.6%). The largest portion of AJAS manuscripts was reviewed by Korean editors (44.3%), followed by Japanese editors (18.1%), Australian editors (6.0%) and Chinese editors (5.6%). Editors from the rest of the AAAP member countries have reviewed slightly less than 5% of the total AJAS manuscripts. It was regrettably noticed that editorial members representing Nepal (66.7%), Mongolia (50.0%), India (35.7%), Pakistan (25.0%), Papua New Guinea (25.0%), Malaysia (22.8%) and New Zealand (21.5%) have failed to return many of the manuscripts requested to be reviewed by the Editor-in-Chief. Financial records show that Korea has contributed the largest portion of production costs (68.5%), followed by Japan (17.3%), China (8.3%), and Australia (3.5%). It was found that 6 AAAP member countries have contributed less than 1% of the total production costs (Bangladesh, India, Indonesia, Malaysia, Papua New Guinea and Thailand), and another 6 AAAP member countries (Mongolia, Nepal and Pakistan, Philippine and Vietnam) have never provided any financial contribution in the form of subscriptions, page charges or reprints. It should be pointed out that most AAAP member countries have published more papers than their financial input with the exception of Korea and China. For example, Japan has published 29.8% of the total papers published in AJAS by AAAP member countries. However, Japan has contributed only 17.3% of total income. Similar trends could also be found in the case of Australia, Bangladesh, India, Indonesia, Malaysia and Thailand. A total of 12 Asian young animal scientists (under 40 years of age) have been awarded the AJAS-Purina Outstanding Research Award which was initiated in 1990 with a donation of US$ 2,000-3,000 by Mr. K. Y. Kim, President of Agribrands Purina Korea Inc. In order to improve the impact factor (citation frequency) and the financial structure of the AJAS, (1) submission of more manuscripts of good quality should be encouraged, (2) subscription rate of all AAAP member countries, especially Category B member countries should be dramatically increased, (3) a page charge policy and reprint ordering system should be applied to all AAAP member countries, and (4) all AAAP countries, especially Category A member countries should share more of the financial burden (advertisement revenue or support from public or private sector).

• 지능정보연구
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• 제20권1호
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• pp.149-161
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• 2014

공공 서비스의 수출의 경우 수출 절차와 대상 선정에 따른 다양한 문제가 발생하며, 공공 서비스 수출 플랫폼은 이러한 문제점들을 해결하기 위하여 사용자 중심의 유연하고, 개방형 구조의 디지털 생태계를 조성할 수 있도록 구현되어야 한다. 또한 공공서비스의 수출은 다수의 이해당사자가 참여하고 여러 단계의 과정을 거쳐야 하므로 사용자의 이해 종류와 탐색 컨설팅 협상 계약 등 수출 프로세스 단계별로 맞춤형 플랫폼 서비스 제공이 필수적이다. 이를 위해서 플랫폼 구조는 도메인과 정보의 정의 및 공유는 물론 지식화를 지원할 수 있어야 한다. 본 논문에서는 공공서비스 수출을 지원하는 플랫폼을 위한 온톨로지 모형을 제안한다. 서비스 플랫폼의 핵심 엔진은 시뮬레이터 모듈이며 시뮬레이터 모듈에서는 온톨로지를 사용하여 수출 비즈니스의 여러 컨텍스트들을 파악하고 정의하여 다른 모듈들과 공유하게 된다. 온톨로지는 공유 어휘를 통하여 개념들과 그들 간의 관계를 표현할 수 있으므로 특정 영역에서 구조적인 틀을 개발하기 위한 메타 정보를 구성하는 효과적인 도구로 잘 알려져 있다. 공공서비스 수출 플랫폼을 위한 온톨로지는 서비스, 요구사항, 환경, 기업, 국가 등 5가지 카테고리로 구성되며 각각의 온톨로지는 요구분석과 사례 분석을 통하여 용어를 추출하고 온톨로지의 식별과 개념적 특성을 반영하는 구조로 설계한다. 서비스 온톨로지는 목적효과, 요구조건, 활동, 서비스 분류 등으로 구성되며, 요구사항 온톨로지는 비즈니스, 기술, 제약으로 구성 된다. 환경 온톨로지는 사용자, 요구조건, 활동으로, 기업 온톨로지는 활동, 조직, 전략, 마케팅, 시간으로 구성되며, 국가 온톨로지는 경제, 사회기반시설, 법, 제도, 관습, 인프라, 인구, 위치, 국가전략 등으로 구성된다. 수출 대상 서비스와 국가의 우선순위 리스트가 생성되면 갭(gap) 분석과 매칭 알고리즘 등의 시뮬레이터를 통하여 수출기업과 수출지원 프로그램과의 시스템적 연계가 이루어진다. 제안하는 온톨로지 모형 기반의 공공서비스 수출지원 플랫폼이 구현되면 이해당사자 모두에게 도움이 되며 특히 정보 인프라와 수출경험이 부족한 중소기업에게 상대적으로 더 큰 도움이 될 것이다. 또한 개방형 디지털 생태계를 통하여 이해당사자들이 정보교환, 협업, 신사업 기획 등의 기회를 만들 수 있을 것으로 기대한다.

• 한국농림기상학회지
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• 제8권1호
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• pp.1-9
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• 2006

동계기온의 지속적인 상승에도 불구하고 낙엽과수의 동해발생빈도는 줄지 않고 있지만, 동해 경감을 위해 필수적인 사전경보시스템에 대한 연구는 미흡한 실정이다. 본 연구에서는 급격한 기후변화에 적응하지 못하는 기존의 '최저기온 의존 동해경보시스템'을 보완하기 위해 생물계절이론에 근거한 휴면심도를 동해위험도 판정의 추가기준으로 제시한다. 평년 기온자료와 생물계절모형에 근거한 휴면심도의 경시변화양상은 낙엽과수의 교과서적인 내동성 변화추세와 일치하였다. 개별 연도의 기온자료에 의해 추정된 휴면심도는 연차 변이가 현저하였으며 동일 연도 내 지역간 변이도 확인할 수 있었다. 전북 김제시 백구면 Campbell Early 주산지 10개 포도원을 대상으로 소기후모형과 인근 기상관서 기후자료에 의해 연도별 최저기온을 복원하고, 최저기온 발생일의 휴면심도를 생물계절모형으로 추정하였으며, 동해정도를 조사하였다. 최저기온휴면심도 피해율 사이의 관계를 분석하여 동해위험도 판정식을 작성하고, 이를 근거로 경북 영천, 충북 옥천, 충남 아산, 경기 화성 등 4개 포도 주산지 시군에 대해 1971-2000 평년의 동해위험지도를 30 m 공간해상도로 제작하였다. 화성지역의 경우 1996년의 동해사례에 의해 동해위험지도의 신뢰성을 부분적으로 검증할 수 있었다. 월동기간 중 실측기온자료에 의해 임의날짜의 휴면심도를 추정하고, 기상청 예보기온을 소기후모형에 의해 30m해상도의 국지기온 예상분포도로 변환한 다음, 내일 아침의 동해가능성을 동해위험도 판정식에 의해 판정할 수 있는 실시간 동해경보시스템을 설계하였다. 이 시스템의 실제 운영을 위해 필요한 프로그램을 작성하고 하드웨어를 갖추어 기상청 국가농업기상센터에 이전, 설치하였다. 산출되는 최저기온 및 동해위험정보는 표준지리정보로 가공되어 기상청 농업 기상정보서비스를 통해 시범적으로 제공될 예정이다.되지 않았으며 상처에 의하여서도 전혀 반응을 하지 않았다. 고에서는 이와 같은 비상통신과 관련하여 수행하고 있는 국외 비상통신 관련표준화 현황 및 해외 주요국가 별 구축 동향에 대해서 기술한다.급식성과는 급식경험 기간과 음(-)의 상관관계를, 아침식사횟수와는 양(+)의 상관관계를 보였으며, 서비스 품질의 특성 영역은 각 영역들에 대한 급식성과 점수가 높을수록 다른 영역의 급식성과 점수가 높은 유의적인(p <0.01) 양(+)의 상관관계를 보였다. 이상의 결과를 살펴볼 때, 균형된 영양공급이 다른 어느 시기보다 더 중요한 우리의 청소년들의 학교급식에 대한 만족도를 높이기 위해서 다음과 같은 제언을 하고자 한다. 먼저, 학교급식에 대한 식단 작성 시 학생들이 학교에서 제공되기 원하는 식단에 대한 의견을 받고 그 의견에 대한 결과를 게시하여 학생들이 제공되기 원하는 식단을 급식 시 제공하여 학생들이 식단선택에 동참할 수 있는 기회를 주는 것이 바람직하겠다. 또한 영양사는 학급의 반대표와의 정기적인 모임을 가짐으로서 학생들의 불만사항 및 개선 요구사항에대해 서로 의견을 교환하여 설문지조사가 아닌 직접적인 대화를 하여 문제점을 파악하고자 하는 적극적인 자세가 필요하겠다. 특히 아침식사의 결식 빈도가 높았고 이는 급식성과에 부정적인 영향을 줄 뿐 아니라 학교에서 제공하는 음식의 섭취정도에도 영향을 주고 있으므로 학생들에게 학부모와 전담교사 및 학교영양사는 학생들에게 이상적인 아침식사에 대한 교육은 물론이고 아침식사를 실천할 수 있도록 다양한 방안에 대해 함께 연구해야 하겠다. 정부차원에서 학교급식에 아침식사 프로그램을 도입할 수 있는 방안을 연구하고, 아침을 결식하는 학생이 학교에서 수업시작 하기 전에 간단한 식사를 할 수 있는 정책 도입이 필요하다acid의 생성량(生成量)을 측정(測定)하였는데 periodate의 소비량(消費量)은

• 지능정보연구
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• 제26권2호
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• pp.105-129
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• 2020

본 연구는 부도위험 예측을 위해 K-IFRS가 본격적으로 적용된 2012년부터 2018년까지의 기업데이터를 이용한다. 부도위험의 학습을 위해, 기존의 대부분 선행연구들이 부도발생 여부를 기준으로 사용했던 것과 다르게, 본 연구에서는 머튼 모형을 토대로 각 기업의 시가총액과 주가 변동성을 이용하여 부도위험을 산정했으며, 이를 통해 기존 방법론의 한계로 지적되어오던 부도사건 희소성에 따른 데이터 불균형 문제와 정상기업 내에서 존재하는 부도위험 차이 반영 문제를 해소할 수 있도록 하였다. 또한, 시장의 평가가 반영된 시가총액 및 주가 변동성을 기반으로 부도위험을 도출하되, 부도위험과 매칭될 입력데이터로는 비상장 기업에서 활용될 수 있는 기업 정보만을 활용하여 학습을 수행함으로써, 포스트 팬데믹 시대에서 주가 정보가 존재하지 않는 비상장 기업에게도 시장의 판단을 모사하여 부도위험을 적절하게 도출할 수 있도록 하였다. 기업의 부도위험 정보가 시장에서 매우 광범위하게 활용되고 있고, 부도위험 차이에 대한 민감도가 높다는 점에서 부도위험 산출 시 안정적이고 신뢰성 높은 평가방법론이 요구된다. 최근 머신러닝을 활용하여 기업의 부도위험을 예측하는 연구가 활발하게 이루어지고 있으나, 대부분 단일 모델을 기반으로 예측을 수행한다는 점에서 필연적인 모델 편향 문제가 존재하고, 이는 실무에서 활용하기 어려운 요인으로 작용하고 있다. 이에, 본 연구에서는 다양한 머신러닝 모델을 서브모델로 하는 스태킹 앙상블 기법을 활용하여 개별 모델이 갖는 편향을 경감시킬 수 있도록 하였다. 이를 통해 부도위험과 다양한 기업정보들 간의 복잡한 비선형적 관계들을 포착할 수 있으며, 산출에 소요되는 시간이 적다는 머신러닝 기반 부도위험 예측모델의 장점을 극대화할 수 있다. 본 연구가 기존 머신러닝 기반 모델의 한계를 극복 및 개선함으로써 실무에서의 활용도를 높일 수 있는 자료로 활용되기를 바라며, 머신러닝 기반 부도위험 예측 모형의 도입 기준 정립 및 정책적 활용에도 기여할 수 있기를 희망한다.

• 지능정보연구
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• 제27권1호
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• pp.1-21
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• 2021

글로벌 경영환경 변화로 기술개발과 시장니즈의 불확실성이 커지고 기업 간 상호 경쟁이 심화되면서 개별 기업들의 연구개발 활동에 대한 관심과 요구가 증가하고 있다. 이러한 환경변화에 대응하기 위하여 연구개발 기업들은 설비투자에 더욱 신중을 가하면서 연구개발의 질적인 경쟁력을 제고시키기 위한 수단 중 하나로 연구개발 투자를 강화하고 있다. 결과적으로 설비나 연구개발 투자 요소는 연구개발 기업들의 입장에서는 미래 불확실성을 떠안아야하는 부담이 될 수 밖에 없다. 단지 연구개발 역량을 제고시키기 위한 수단으로 연구개발 투자를 증가시키는 경영 전략은 기업성과측면에서 불확실성이 높은 것이 사실이다. 본 연구에서는 데이터마이닝 기법을 활용하여 기업들의 연구개발 역량에 영향을 주는 특성들을 기술경영능력, 연구개발능력, 그리고 기업분류 속성 관점에서 탐색하고 이러한 개별 요인들이 연구개발 역량의 수준에 따라 나타나는 특성들을 탐색하였다. 이를 위해서 국내 연구개발 기업 전체를 대상으로 증거데이터에 근거해 군집분석과 실험결과를 제시하였다. 상기의 3개 관점마다 세부 평가지표를 각각 7개, 2개, 4개로 구성하여 해당 영역에서의 개별적인 수준을 정량적으로 측정하고자 하였다. 기술경영능력과 연구개발능력의 경우 현행 기술력 평가기관들이 주도적으로 활용하고 있는 소항목 평가지표를 참조하였으며, 이때 정량적으로 자료 확보가능한지 여부를 고려하여 최종적인 세부 평가지표를 새롭게 구성하였다. 기업분류 속성의 경우에는 가장 기본적인 기업 분류 프로파일 정보를 고려하여 구성하였다. 특히 연구개발 역량수준의 동질성 파악을 위해서 기술경영능력과 연구개발능력의 세부평가지표를 활용하여 개별기업별 종합점수를 부여하였으며, 이때 역량수준을 5개의 등급으로 분류하여 군집분석 결과와 비교하였다. 분석된 군집과 역량수준 등급과의 비교평가에 따른 의미를 부여하기 위해서 군집별로 연구개발 역량수준이 높은 경향과 낮은 경향이 존재하는 군집들을 탐색하였다. 이후 해당 군집에서 세부 평가지표에 따른 특징들을 분석하였다. 이와 같은 연구수행 방법을 통해 연구 개발 역량수준이 높은 군집이 2개, 낮은 군집이 1개로 분석되었으며, 나머지 2개의 군집들은 역량수준이 거의 높은 발생 빈도로 유사하게 나타났다. 결과적으로 본 연구에서는 역량수준이 높은 2개 군집과 낮은 1개의 군집들을 대상으로 세부 평가지표에 따른 개별적 특징들을 분석하였다. 본 연구의 결과가 제시하고 있는 시사점은 기술변화 속도와 시장수요의 변화에 효과적으로 대응할 수 있는 전문 경영자의 교체주기가 빠를수록 연구개발 역량 제고에 기여할 가능성이 높다는 점이다. 개인기업의 경우에 법인기업으로의 전환을 통해 연구개발 인력들의 기업에 대한 소속감을 제고시킴으로써 연구개발 역량의 투입강도를 높일 필요가 있으며, 조직적 측면에서도 팀단위의 조직구성을 통해 책임과 권한의 정확성을 제공할 필요가 있다는 점이다. 기술상용화 실적건수나 기술인증건수는 역량제고에 기여하는 경우와 그렇지 않은 경우 모두 발생되고 있어, 경영자 입장에서 연구개발 역량제고를 위한 중요 인자로 검토하는데 한계가 있는 것으로 확인되었다. 마지막으로 실용신안출원의 경험 여부는 연구개발 역량에 중요한 영향을 미치는 요인으로 파악되어, 연구개발 역량 제고를 위해서는 실용신안출원 장려를 위한 동기부여를 제공할 필요성을 확인하였다. 이처럼 본 연구결과는 개별 기업들의 연구개발 역량 제고를 위한 기업 경영전략의 중요한 시사점을 제공할 수 있을 것으로 기대된다.

• 지능정보연구
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• 제23권3호
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• pp.155-175
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• 2017

최근 독감 예측이나 당선인 예측, 구매 패턴, 투자 등 다방면에서 웹검색 트래픽 정보. 소셜 네트워크 내용 등 거대한 데이터를 통해 사회적 현상, 소비 패턴을 분석하는 시도가 이전보다 늘어났다. 구글, 네이버, 바이두 등 인터넷 포털 업체들의 웹검색 트래픽 정보 공개 서비스와 함께 웹검색 트래픽 정보를 활용하여 소비자나 사용자와 관련된 연구가 실시되기 시작했다. 웹검색 트래픽 정보를 활용한 사회 현상, 소비 패턴 분석을 연구는 많이 수행되었으나, 그에 비해서 도출된 여행 수요 모델을 토대로 의사결정을 위한 실질적 대책 수립으로 이어지는 연구는 많이 진행되지 않은 실정이다. 관광산업은 상대적으로 많은 고용을 가능하게 하고 외자를 유치하는 등 고부가가치를 창출하여 경제 전체에 선순환 효과를 일으키는 중요한 산업이다. 그 중에서도 국내 입국외래객중 수년간 2위와의 큰 차이로 1위를 차지해왔던 중국 국적의 관광객 '유커' 및 그들이 지출하는 1인당 평균 관광 수지는 한국 경제에 매우 중요한 한 부분이다. 관광 수요의 예측은 효율적인 자원 배분과 합리적인 의사 결정에 있어서 공공부문 및 민간부문 모두 중요하다. 적절한 관광 수요 예측을 통해서 한정된 자원을 더욱 효과적으로 활용하여 더욱 많은 부가가치를 창출하기 위한 것이다. 본 연구는 중국인 인바운드를 예측하는 방법에 있어, 이전보다 더 최신의 트렌드를 즉각적으로 반영하고 개인들의 집합의 관심도가 포함되어 예측 성능이 개선된 방법을 제안한다. 해외여행은 고관여 소비이기 때문에 잠재적 여행객들이 입국하기 전 웹검색을 통해 적극적으로 자신의 여정과 관련된 정보를 취득하기 위한 활동을 한다. 따라서 웹검색 트래픽 수치가 중국인 여행객의 관심정도를 대표할 수 있다고 보았다. 중국인 여행객들이 한국 여행을 준비하는 단계에서 검색할만한 키워드를 선정해 실제 중국인 입국자 수와 상관관계가 있음을 검증하고자 하였다. 중국 웹검색 엔진 시장에서 80%의 점유율을 가지는 중국 최대 웹검색 엔진 '바이두'에서 공개한 웹검색 데이터를 활용하여 그 관심 정도를 대표할 수 있을 것이라 추정했다. 수집에 필요한 키워드의 선정 단계에서는 잠재적 여행객이 여정을 계획하고 구체화하는 단계에서 일반적으로 검색하게 되는 키워드 후보군을 선정하였다. 키워드의 선정에는 중국 국적의 잠재적 여행객 표본과의 인터뷰를 거쳤다. 트래픽 대소 관계 확인 결과에 따라서 최종 선정된 키워드들을 한국여행이라는 주제와 직접적인 연관을 가지는 키워드부터, 간접적인 연관을 가지는 키워드까지 총 세 가지 레벨의 카테고리로 분류하였다. 분류된 카테고리 내의 키워드들은 바이두'가 제공하는 웹검색 트래픽 데이터 제공 서비스 '바이두 인덱스'를 통해 웹검색 트래픽 데이터를 수집했다. 공개된 데이터 페이지 특성을 고려한 웹 크롤러를 직접 설계하여 웹검색 트래픽 데이터를 수집하였고, 분리되어 수집된 변수에는 필요한 변수 변환 과정을 수행했다. 자동화 수집된 웹검색 트래픽 정보들을 투입하여 중국 여행 인바운드에 대한 유의한 영향 관계를 확인하여 중국인 여행객의 한국 인바운드 여행 수요를 예측하는 모형을 개발하고자 하였다. 정책 의사결정 및 관광 경영 의사결정 같은 실무적 활용을 고려하여 각 변수의 영향력을 정량적으로 설명할 수 있고 설득이 명료한 방법인 다중회귀분석방법을 적용해 선형 식을 도출하였다. 수집된 웹검색 트래픽 데이터를 기존 검증된 모형 독립변인들에 추가적으로 투입함으로써 전통적인 독립변인으로만 구성된 연구 모형과 비교하여 가장 뛰어난 성능을 보이는 모형을 확인하였다. 본 연구에서 검증하려는, 웹검색 트래픽으로 대표되는 독립변인을 투입한 최종 도출된 모형을 통해 중국인 관광 수요를 예측할 때 유의한 영향을 끼치는 웹검색 트래픽 변수를 확인할 수 있다. 최적 모형 설명력을 가지는 모형을 기반으로 최종 회귀 식을 만들었고 이를 '유커마이닝' 시스템 내부에 도입하였다. 데이터 분석에서 더 나아가 도출된 모형을 직관적으로 시각화하고, 웹검색 트래픽 정보를 활용하여 도출할 수 있는 인사이트를 함께 보여주는 데이터 분석 기반의 '유커마이닝' 솔루션의 시스템 알고리즘과 UX를 제안하였다. 본 연구가 제안하는 모형과 시스템은 관광수요 예측모형 분야에서 웹검색 트래픽 데이터라는 정보 탐색을 하는 과정에 놓인 개인들의 인터랙티브하고 즉각적인 변수를 활용한 새로운 시도이다. 실무적으로 관련 정책결정자나 관광사, 항공사 등이 활용 가능한 실제적인 가치를 가지고, 정책적으로도 효과적인 관광 정책 수립에 활용될 수 있다.

• 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)
• /
• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
• /
• pp.17-17
• /
• 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.