• 한국정보처리학회논문지
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• 제5권12호
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• pp.3047-3062
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• 1998

본 논문은 ITU-T에서 제안한 영상회의 시스템에서 오디오/비디오 스트림 데이터를 회의 참여자에 송수신하거나 또는 수신된 멀티미디어 데이터들에 대한 QoS 정보를 송신측에 피드백 하기 위해 제공되는 RTP/RTCP 프로토콜(RFC1889,1890)에 관한 설계 및 구현에 관해 기술한다. RTP는 인코더로부터 전달된 오디오/비디오 데이터를 고정 포맷으로 패킷화하여 모든 회의 참여자에 멀티캐스팅하고, RTCP모듈은 RTP와 함께 연동되면서 수신 패킷을 모니터하여 지연, 지연변이 및 패킷 손실 등의 QoS 값들을 검출하고, 이를 비-정기적으로 송신측에 피드백하도록 구현하였다. 이들 프로토콜은 Windows NT에서 멀티쓰래드 방식으로 구현되었으며, 하위 프로토콜로 socket I/F를 통해서 U에/IP-Multicast를 이용하였다. 또한, 인터넷 환경에서 영상회의 시스템을 수행했을 때 나타나는 여러 QoS 값들을 검출하여 분석하였다. 시험은 오디오 데이터 전송을 이용하였으며 통신 부하가 심한 시간 구간에서 지연과 지연 변이는 음성 인식에 대체로 허용 범위에 충족되나 다량의 패킷 손실에 따른 품질 저하를 분석할 수 있었으며, 대부분의 손실된 패킷들은 비-연속적인 특성을 갖는 것으로 나타났다.

• 한국방사선학회논문지
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• 제4권1호
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• pp.11-17
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• 2010

요석은 고대 인류부터 지금 현재 인류까지 끊임없이 인간을 괴롭히고 있는 질병중의 하나이다. 하지만 딱히 예방법이 없어 문제가 생기면 비뇨기과적 치료가 절대적으로 필요한 질병이다. 이런 요석의 가장 큰문제점은 상당한 통증 과 구토, 발열등을 유발한다는 것이다. 통증은 요관을 통과 할 때나 요관이 요석으로 인한 심한 경련이 일어날 때 크게 일어난다. 이 통증은 마약성분이 강한 펜타닐 이나 페치딘 같은 강한 진통제에도 잘 잡히지 않는 경향이 있어 신속한 검사와 치료가 요구된다. 본 논문에서는 ESWL(Extracorpereal Shock Wave Lithotripsy)을 이용한 요석 치료시 특히 분쇄율은 낮고 환자의 통증은 심한 Proximal ureteral stone 과 Mid ureteral stone에 대해 각각의 여러 조건을 적용하여 최적의 치료방법과 최고의 분쇄율에 대하여 실험 과 연구를 하여 보았다. 실험결과 Proximal과 Mid ureter에 위치한 stone은 호흡에 의한 충격파의 적중률이 낮아 분쇄율이 distal ureter보다 낮았으나 방전interval을 줄임으로써 분쇄율을 높일 수 있었고, 낮은 방전 Power로 여러번 분쇄하는 것보다는 높은 방전 Power와 적절한 방전횟수로 분쇄를 하였을 때 ureter도 보호하면서 분쇄율이 높다는 것을 알 수 있었다.

• 한국재난정보학회 논문집
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• 제17권4호
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• pp.684-693
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• 2021

연구목적: 아두이노를 이용하여 실시간 대지저항 데이터를 취득할 수 있는 스마트 대지저항 측정장치를 개발하여 낙뢰 등 이상전압으로부터 안전한 설비환경을 구축하는것에 목적이 있다. 연구방법: 본 논문은 아두이노와 전력선 통신(PLC) 체계를 갖춘 대지저항 취득 및 분석 시스템을 개발하여 설계모델과 적용사례를 연구하였다. 경남지역의 풍력발전 단지 내 일부 부지를 테스트 베드로 선정하여 신기술을 적용한 실시간 대지저항 데이터를 취득하였다. 전극배열은 웨너(Wenner) 4전극배열과 슐렘버거(Schlumberger) 전극배열을 혼용한 스마트 전극배열을 채택하였다. 연구결과: 본 기술의 특징은 첫 번째로 스마트 다 전극의 깊이를 각기 다르게 편성해 층간에 특이성을 가지는 지층 구조에도 취득 데이터의 오차범위를 축소하였다. 두 번째로 스마트 접지전극에서 취득한 대지저항 데이터의 정보를 사물인터넷으로 실시간 송·수신이 가능하도록 IT융합 기술을 적용하였다. 마지막으로 규칙적인 관리 체계를 구축하고 Server에 축적된 빅 데이터를 분석하여 다양한 요소들의 변화추이를 확인할 수 있으며, IT융합 환경에 최적의 접지 알고리즘과 접지시스템 설계 모델링이 가능하다. 결론: 본 기술은 4차 산업 시대에 근간이 되는 도시 기반시설에 낙뢰로 인한 서지(Surge)의 피해를 줄이고 최적화된 접지시스템 모델을 설계하여 사용자의 안전과 생명을 보호 할 것이다. 또한 순수 국산 기술력의 지적재산권을 확보하여 포스트 코로나 시대에 팬데믹으로 정체되어있는 우리산업의 일자리 창출과 활기를 불어넣는 효과도 기대된다.

• 보건교육건강증진학회지
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• 제2권1호
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• pp.3-50
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• 1984

The levels of health knowledge, attitude and practice of housewives considerably effect to the health of households, communities and the nation. This study was designed to grasp the levels of health knowledge, attitude and practice of houswives and analyse the various factors effecting to health in order to provide health education services as well as materials for effective formulation and implementation of health policy to improve the health of the nation. This study has been conducted through interviews by trained surveyers for 4,281 housewives selected from 4,500 households throughout the country for 40 days during July 11-August 20, 1983. The results of survey were analysed by stepwise multiple regression and path analysis are summarized as follows; 1. Based on the measurement instrument applied to this study, the levels of health knowledge, attitude and practice of housewives were extremely low with 54.5 points out of 100 points in full. Higher level with 72 points and above was approximately 21 percent and lower level with 39 points and below was approx. 24 percent. The middle level was approx. 55 percent. In order to implement health programs successively, health education should be more strengthened and to improve the level of health knowledge, attitude and practice (KAP) of the nation, political consideration as a part of spiritual reformation must be concentrated on health. 2. The level of health knowledge indicated the highest points with 57.3 the level of attitude was the second with 55.0 points and the practice level was the lowest with 50.0 point. Therefore, planning and implementation of health education program must be based on the persuasion and motivation that health knowledge turn into practice. 3. Housewives who had higher level of health knowledge, showed their practice level was relatively lower and those who had middle or low level of it practice level was the reverse. 4. Correlations among health knowledge, attitude and practice (KAP) were generally higher and statistically significant at 0.1 percent level. Correlation between total health KAP level and health knowledge was the highest with r=.8092. 5. Health KAP levels showed significant differences according to the age, number of children, marital status, self-assessed health status and concern on health of the housewives interviewed (p<0.001) 6. Health KAP levels also showed significant differences according to the education level, economic status, employment before marriage and grown-up area of the housewives interviewed. (p<0.001) 7. Heath KAP levels showed significant differences according to health insurance benificiary and the existence of patients in the family. (p<0.001). 8. Health KAP levels showed significant differences according to distance to government organizations, schools, distance to health facilities, telephone possession rate, television possession rate, newspaper reading rate and activities of Ban meeting and Women's club. (p<0.001) 9. Health KAP levels showed significant differences according to electric mass communication media such as television, radio and village broadcasting etc. and printed media such as newspaper, magazine and booklets etc., IEC variables such as individual consultation and husband-wife communication, however, there was no significance with group training. 10. Health KAP of the housewives showed close correlation with personal characteristics variables, i.e., education level (r=.5302), age (r=-.3694) grown-up area (r=.3357) and employment before marriage. In general, correlation of health knowledge level was higher than the levels of attitude or practice. In case of health concern and health insurance, correlation of practice level was higher than health knowledge level. 11. Health KAP levels showed higher correlation with community environmental characteristics, Ban meeting and activity of Women's club, however, no correlation with New-village movement. 12. Among IEC variables, husband-wife communication showed the highest correlation with health KAP levels and printed media, electric mas communication media and health consultation in order. Therefore, encouragement of husband-wife communication and development of training program for men should be included in health education program. 13. Mass media such as electric mass com. and printed media were effective for knowledge transmission and husband-wife communication and individual consultation were effective for health practice. Group training was significant for knowledge transmission, however, but not significant for attitude formation or turning to health practice. To improve health KAP levels, health knowledge should be transmitted via mass media and health consultation with health professionals and field health workers should be strengthened. 14. Correlation of health KAP levels showed that knowledge level was generally higher than that of practice and recognized that knowledge was not linked with attitude or practice. 15. The twenty-five variables effecting health KAP levels of housewives had 41 per cent explanation variances among which education level had great contribution (β=.2309) and electric mass com. media (β=.1778), husband-wife communication (β=.1482), printed media, grown-up area, and distance to government organizations in order. Variances explained (R²) of health KAP were 31%, 15%, and 30% respectively. 16. Principal variables contributed to health KAP were education level (β=.12320, β=.1465), electric mass comm. media (β=.1762, β=.1839), printed media, (β=.1383, β=.1420) husband-wife communication (β=.1004, β=.1067), grown-up area and distance to government organizations, in order. Since education level contributes greatly to health KAP of the housewives, health education including curriculum development in primary, middle and high schools must be emphasized and health science must be selected as one of the basic liberal arts subject in universities. 17. Variences explained of IEC variables to health KAP were 19% in total, 14% in knowledge, 9% in attitude, and 10% in health practice. Contributions of IEC variables to health KAP levels were printed media (β=.3882), electric mass comm media (β=.3165), husb-band wife com. (β=.2095,) and consultation on health (β=.0841) in order, however, group training showed negative effect (β=-.0402). National fund must be invested for the development of Health Program through mass media such as TV and radio etc. and for printed materials such as newspaper, magazines, phamplet etc. needed for transmission of health knowledge. 18. Variables contributed to health KAP levels through IEC variables with indirect effects were education level (Ind E=0.0410), health concern (Ind E=.0161), newspaper reading rate (Ind E=.0137), TV possession rate and activity of Ban meeting in order, however, health facility showed negative effect (Ind E=-.0232) and other variables showed direct effect but not indirect effect. 19. Among the variables effecting health KAP level, education level showed the highest in total effect (TE=.2693) then IEC (TE=.1972), grown-up city (TE=.1237), newspaper reading rate (TE=.1020), distance to government organization (TE=.095) in order. 20. Variables indicating indirect effects to health KAP levels were; at knowledge level with R²=30%, education level (Ind E=.0344), newspaper reading rate (Ind E=.0112), TV possession rate (Ind E=.0689), activity of Ban meeting (Ind E=.0079) in order and at attitude level with R²=13%, education level (Ind E=. 0338), activity of Ban meeting (Ind E=.0079), and at practice level with R²=29%. education level (Ind E=.0268), health facility (Ind E=.0830) and concern on health (Ind E=.0105). 21. Total effect to health KAP levels and IEC by variable characteristics, personal characteristics variables indicated larger than community characteristics variables. 22. Multiple Correlation Coefficient (MCC) expressed by the Personal Characteristic Variable was .5049 and explained approximately 25% of variances. MCC expressed by total Community environment variable was .4283 and explained approx. 18% of variances. MCC expressed by IEC Variables was .4380 and explained approx. 19% of variances. The most important variable effected to health KAP levels was personal characteristic and then IEC variable, Community Environment variable in order. When the IEC effected with personal characteristic or community characteristic, the MCC or the variances were relatively higher than effecting alone. Therefore it was identified that the IEC was one of the important intermediate variable.

• 한국방사선학회논문지
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• 제10권4호
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• pp.255-261
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• 2016

PET/CT 촬영에서 정량분석에 영향을 주는 다양한 인자 중 현재 상품화된 CT 조영제와 MRI 조영제의 종류별 각 성분의 특성에 따른 SUV의 변화를 비교 분석하고자 하였다. 실험장비는 Discovery 690 PET/CT(Ge)와 NEMA NU2-1994 PET phantom를 이용하였고, 팬텀에 증류수 2/3를 채워 넣은 후 방사성동위원소(18F-FDG 37 MBq)와 각각의 CT와 MRI 조영제를 순차적으로 주입하여 팬텀을 고르게 교반하고 다시 증류수를 가득 채운 후 기포가 생기지 않게 하였다. 방출스캔은 FDG 또는 FDG와 혼합한 조영제를 넣고 40분에 15분 동안 스캔하였으며, 투과스캔은 CT로 관전압 120 kVp, 관전류 40 mA, 회전시간 0.5 sec, 단면두께 3.27 mm, DFOV 30 cm의 조건으로 스캔하였다. 분석방법으로 정량분석은 각각 10, 15, 20, 25, 30번째 slice에서 region of interest (ROI)를 설정하여 각각 SUVmean, SUVmax를 구하였다. 결과적으로 순수 FDG 영상과 비교에서 MRI 조영제를 혼합한 3종류의 영상 모두에서 SUVmean가 높게 측정되었으나 통계적 유의성은 없었고, SUVmax 에서는 유의한 결과를 얻었다. 또한 4종류의 CT 조영제 영상은 SUVmean, SUVmax 모두 유의한 결과를 얻었다. PET/CT는 영상의 정확도를 위해 감쇠 보정은 다양한 방법으로 시행되고 있지만 CT와 MRI 조영제는 감쇠보정 시 영상의 왜곡에 의한 진단적 가치를 저하시킬 수 있다. 이러한 이유로 진료 당일 여러 종류의 검사를 시행하기 전 반드시 선행되어야 할 검사를 선별하여 서로 영향을 주지 않도록 함으로서 고객에게 차별화된 양질의 의료서비스를 제공해야 한다.

• 핵의학기술
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• 제14권2호
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• pp.21-25
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• 2010

PET/CT검사에 있어서 CT는 해부학적인 정보를 제공할 뿐 아니라 PET영상에 대한 감약 정보를 제공하는 역할을 하고 있다. CT의 감약차를 이용하는 것으로서 검사 부위에 존재하는 여러 가지 변수에 의해 그 정도가 달라질 수 있다. 이것은 현재 본 원에서 PET/CT검사 시에 팔을 몸 옆에 두고 검사하는 것에도 적용할 수 있으며, 이에 본 논문에서는 일부 타 병원에서 시행하고 있는 팔을 머리 위로 올리고 검사하는 방법과 함께 CT값의 변화에 따른 표준섭취계수의 변화를 비교 연구했다. NEMA 1994 PET 모형의 삽입체와 모형의 부피를 고려하여 4:1의 비율로 $^{18}F$-FDG를 주입하였다. 먼저 테플론 삽입체 두 개를 NEMA 1994 PET 모형의 양 옆에 고정시켜 팔을 내리고 있는 상태를 가정하여 영상을 얻었으며 테플론 삽입체를 제거하여 팔을 머리 위로 올린 상태를 가정하여 영상을 얻었다. 앞의 과정을 거쳐 얻은 영상을 재구성 하여 Volume Viewer를 이용해 한 영상면 당 5개의 관심 체적을 설정했고 각 측정값을 평균하여 얻어낸 CT값과 표준섭취계수로 그 변화를 측정하였다. 측정된 값과 폐 관련 암환자의 간에 관심 영역을 설정하고 측정한 값을 비교하여 실제 임상 영상에서의 차이를 측정하였다. 모형 실험결과 테플론 삽입체를 부착하였을 때보다 테플론 삽입체를 부착하지 않았을 때 CT값이 -5.8 HU에서 0 HU으로 평균 5.8 HU 증가하였고 표준섭취계수는 24.64에서 24.29로 평균 0.35 감소하였다. 축방향 균일도는 0.064에서 0.052로 평균 0.012 감소하였다. 환자 실험결과 팔을 내리고 검사하였을 때보다 팔을 머리 위로 올리고 검사하였을 때 CT값은 54.1 HU에서 59.9 HU로 평균 5.8 HU 증가하였고 표준섭취계수는 2.02에서 1.85로 평균 0.17 감소하였다. 테플론 삽입물을 부착한 상태로 검사할 때 보다 테플론 삽입물을 부착하지 않은 상태로 검사할 때 CT값은 증가하고 표준섭취계수는 감소하는 양상을 보였다. 이러한 현상이 일어나는 이유는 감약의 정도와 표준섭취계수의 상관관계에서 찾을 수 있다. CT값이 증가할수록 감약 계수는 비례하여 증가하는데 이것은 결국 CT값이 증가될수록 감약이 증가된다고 볼 수 있다. 따라서 팔에 의해 감약이 과다하게 측정될 수 있으므로 결국 표준섭취계수의 증가로 이어진다고 판단된다. 하지만 그 값의 차이가 매우 적어 진단적으로 유의한 범위라고 볼 수 없다. 팔을 머리 위로 올리고 검사하는 자세가 어깨 및 팔에의 $^{18}F$-FDG섭취와 환자의 고통을 야기하게 된다는 점들을 종합하여 고려해 보았을 때, PET/CT검사 시에는 팔을 내리고 검사하는 것이 합리적이나, 환자의 상태 및 영상의 질적 측면을 고려하여 결정하여야 하겠다.

• 대기
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• 제21권4호
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• pp.429-438
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• 2011

The climatology of surface UV radiation for Seoul, presented in Cho et al. (1998; 2001), has been updated using measurement of surface erythemal ultraviolet (EUV) and total ultraviolet (TUV) irradiance (wavelength 286.5~363.0 nm) by a Brewer Spectrophotometer (MK-IV) for the period 2004~2010. The analysis was also carried out together with the broadband total (global) solar irradiance (TR ; 305~2800 nm) and cloud amount to compare with the UV variations, measured by Seoul meteorological station of Korean Meteorological Agency located near the present study site. Under all-sky conditions, the day-to-day variability of EUV exhibits annual mean of 98% in increase and 31% in decrease. It has been also shown that the EUV variability is 17 times as high as the total ozone in positive change, whereas this is 6 times higher in negative change. Thus, the day to day variability is dominantly caused rather by the daily synoptic situations than by the ozone variability. Annual mean value of daily EUV and TUV shows $1.62kJm^{-2}$ and $0.63MJm^{-2}$ respectively, whereas mean value of TR is $12.4MJm^{-2}$ ($143.1Wm^{-2}$). The yearly maximum in noon-time UV Index (UVI) varies between 9 and 11 depending on time of year. The highest UVI shows 11 on 20 July, 2008 during the period 2004~2010, but for the period 1994~2000, the index of 12 was recorded on 13 July, 1994 (Cho et al., 2001). A 40% of daily maximum UVI belongs to "low (UVI < 2)", whereas the UVI less than 5% of the maximum show "very high (8 < UVI < 10)". On average, the maximum UVI exceeded 8 on 9 days per year. The values of Tropospheric Emission Monitoring Internet Service (TEMIS) EUV and UVI under cloud-free conditions are 1.8 times and 1.5 times, respectively, higher than the all-sky measurements by the Brewer. The trend analysis in fractional deviation of monthly UV from the reference value shows a decrease of -0.83% and -0.90% $decade^{-1}$ in the EUV and TUV, respectively, whereas the TR trend is near zero (+0.11% $decade^{-1}$). The trend is statistically significant except for TR trend (p = 0.279). It is possible that the recent UV decrease is mainly associated with increase in total ozone, but the trend in TR can be attributed to the other parameters such as clouds except the ozone. Certainly, the cloud effects suggest that the reason for the differences between UV and TR trends can be explained. In order to estimate cloud effects, the EUV, TUV and TR irradiances have been also evaluated for clear skies (cloud cover < 25%) and cloudy skies (cloud cover ${\geq}$ 75%). Annual mean values show that EUV, TUV and TR are $2.15kJm^{-2}$, $0.83MJm^{-2}$, and $17.9MJm^{-2}$ for clear skies, and $1.24kJm^{-2}$, $0.46MJm^{-2}$, and $7.2MJm^{-2}$ for cloudy skies, respectively. As results, the transmission of radiation through clouds under cloudy-sky conditions is observed to be 58%, 55% and 40% for EUV, TUV and TR, respectively. Consequently, it is clear that the cloud effects on EUV and TUV are 18% and 15%, respectively lower than the effects on TR under cloudy-sky conditions. Clouds under all-sky conditions (average of cloud cover is 5 tenths) reduced the EUV and TUV to about 25% of the clear-sky (cloud cover < 25%) values, whereas for TR, this was 31%. As a result, it is noted that the UV radiation is attenuated less than TR by clouds under all weather conditions.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 춘계학술대회 논문집
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• pp.5-9
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• 2004

본 연구에서 고분해능 측정과 저가격화 및 소형으로 제작이 가능하여 전세계적으로 많은 연구가 진행중인 광섬유를 이용한 광영상단층촬영기를 연구하였다. 광영상단층촬영기의 기돈원리로는 마이켈슨 간섭계를 이용한 것이다. 시스템의 구성으로는 광원은 분해능 및 측정범위를 고려하여 1,300nm 중심파장을 가지며 대역폭이 35nm인 상용제품의 SLD(Superluminersent diode)를 사용하였으며, 샘플내부의 영상을 검출하기 위한 간섭신호 검출방법은 기준거울이 선형적으로 이동하여 광경로를 일치하는 광지연선로를 구성하였다. 그리고 간섭계는 단일모드 광섬유를 이용하여 기본적인 마이켈슨 간섭계를 구성하였으며, 스캐너는 시준기를 이용하여 샘플에 대한 초점을 고정하도록 하였으며, 스템모터를 이용하여 스텝모터를 이용하여 샘플에 대한 횡단방향으로 이동하여 샘플의 2차원 단층영상을 측정하도록 하였다. 수광부는 소신호인 간섭신호를 검출하기 위하여 감도가 뛰어나면 잡음특성이 우수한 800~1,700nm 측정범위의 광검출기를 사용하였다. 신호처리부에서 간섭신호의 포락선 신호만을 검출하기 위하여 증폭 및 필터링 하여 A／D 변환을 거친 후 제작된 영상검출 프로그램을 이용하여 단층영상을 나타내도록 하였다. 측정결과 분해능은 약 30$\mu\textrm{m}$로서 이론식과 일치함을 확인하였으며, 탁구공의 단층영상을 측정하였다. 기본적인 마이켈슨 간섭계를 이용한 OCT시스템은 되돌아오는 간섭광의 절반이 광원부로 향하여 간섭신호의 절반이 손실되므로 검출기에서 검출된 신호가 미약하여 단층영상의 대비도를 떨어뜨린다. 이러한 문제점을 해결하기 위하여 간섭계 구성의 개선이 필요하다. 또한 측정시간을 단축하기 위하여 광지연선로의 개선으로 통해 짧은 시간내 당층영상을 얻을 수 있도록 하여야 할 것이다.기로 확장 가능한 PCS 단말기를 사용해서 위치추적을 하는 시스템이다. 이러한 시스템을 선정하게된 배경은 단말기아 망 이용료의 가격이 저렴하여 현실적으로 트럭이 쉽게 부착할 수 있다는 장점이 있으며 나아가 인터넷 단말기를 활용하여 차량과 관제센터사이에 메시지 전송 등 부가적인 서비스가 가능하기 때문이다.비교한 결과 토사 유출 억제효과는 한지형과 나지형잔디들의 혼합형(MixtureIII)과 자생처리구(MixtureV), Italian ryegrass와 자생식물의 혼합형(MixtureIV)등에서 비교적 낮은 수치를 토사유출량을 기록하였다. 이러한 결과는 자생식물들이 비록 초기생육속도는 외래도입초종에 떨어지지만 토사유출의 억제효과면에서는 이들 외래초종에 필적할 수 있음을 나타낸다고 할 수 있겠다.중량이 약 115kg/$m^2$정도로 나타났다.소 들(환경의 의미, 사람의 목적과 지식)보다 미학적 경험에 주는 영향이 큰 것으로 나타났으며, 모든 사람들에게 비슷한 미학적 경험을 발생시키는 것 이 밝혀졌다. 다시 말하면 모든 사람들은 그들의 문화적인 국적과 사회적 인 직업의 차이, 목적의 차이, 또한 환경의 의미의 차이에 상관없이 아름다 운 경관(High-beauty landscape)을 주거지나 나들이 장소로서 선호했으며, 아름답다고 평가했다. 반면에, 사람들이 갖고 있는 문화의 차이, 직업의 차 이, 목적의 차이, 그리고 환경의 의미의 차이에 따라 경관의 미학적 평가가 달라진 것으로 나타났다.corner$적 의도에 의한 경관구성의 일면을 확인할수 있지만 엄밀히 생각하여 보면 이러한 예의 경우도 최락의 총체적인 외형은 마찬가지로 $\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $

• 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
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• 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.