• 한국정보전자통신기술학회논문지
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• 제10권5호
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• pp.469-475
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• 2017

소프트웨어 개발시행 과정에서 소프트웨어 신뢰성은 매우 기본적이고 필수적인 문제 중에 하나이다. 소프트웨어 고장현상을 파악하기 위하여 비동질적인 포아송 과정에서 순간 고장률인 강도함수가 고장시간에 독립적으로 일정하거나, 증가형 혹은, 감소형 추세를 가질 수 있다. 본 논문에서는 소프트웨어 설계 과정에서 강도형태가 감소패턴을 따르는 랜들리 수명분포와 증가하다가 감소하는 어랑수명 분포를 활용한 소프트웨어 신뢰속성 모형에 대하여 신뢰도 장단점에 관한 연구를 하였다. 소프트웨어 고장현상을 파악하기 위하여 모수추정은 최우추정법을 적용하였다. 따라서, 본 논문에서는 소프트웨어 고장시간 자료를 적용하여 소프트웨어 신뢰도를 비교하고, 평가하였다. 그 결과, 랜들리 모형이 어랑분포 모형보다 신뢰도가 상승하는 것으로 나타났으나, 어랑분포 모형에서는 형상모수가 높을수록 높은 신뢰도를 나타내는 추세를 보였다. 본 논문를 통하여 소프트웨어 기획 부서에서는 특정한 수명분포와 형상모수를 활용함으로서 소프트웨어 고장분석을 활용한 소프트웨어 신뢰성 모형에 대한 신뢰성 속성을 적용한 데이터 및 기본 지식을 제공함으로서 소프트웨어 설계에 실질적인 도움을 줄 수 있다.

• 한국환경생태학회지
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• 제25권1호
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• pp.91-101
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• 2011

본 연구는 저토심 옥상녹화에 적용 가능한 초본류 및 지피식물을 중심으로 식물의 광합성작용을 통한 $CO_2$ 흡수량과 증발산량을 정량화하여 도시미기후 관점에서의 옥상녹화식물의 환경성능을 평가하고자 하였다. 이를 위해 옥상녹화용 초본류 7종을 대상으로 적외선 $CO_2$ 가스 분석기에 의한 $CO_2$ 교환 속도 분석을 통해 각 식물의 $CO_2$ 흡수량과 증발산량을 측정하였다. 실험기간은 생장이 활발해지기 시작하는 5월부터 11월까지 매월 2반복 측정하였고, 주변 환경에 예민한 초본류의 특성상, 환경변수가 고정된 실내에서 광도의 변화를 주어 실시하였다. $CO_2$ 흡수량과 증발산량을 산출한 결과 단위엽면적당 $CO_2$ 흡수량은 초본류 중 구절초가 $21.47{\times}10^{-6}g/cm^2/s$, 매발톱꽃이 $12.74\;g{\times}10^{-6}g/cm^2/s$로 높은 흡수율을 보였고, 켄터키블루그래스도 $16.20{\times}10^{-6}g/cm^2/s$로 비교적 높았다. 단위엽면적당 증발산량은 켄터키블루그래스가$8.75{\times}10^{-5}g/cm^2/s$로 가장 많았고, 다음은 매발톱꽃 $8.66{\times}10^{-5}g/cm^2/s$, 구절초 $8.58{\times}10^{-5}g/cm^2/s$ 순으로 나타났다.

• 한국산학기술학회논문지
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• 제21권2호
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• pp.511-520
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• 2020

지구온난화로 인해 하절기 폭염현상과 열대야가 강해짐에 따라, 도시공원 등 녹지공간의 열환경 개선에 대한 연구가 활발히 진행 중이다. 하지만, 녹지의 식재패턴과 바람의 세기로 인해 변화하는 도시 열환경 개선 연구는 아직까지 미흡한 실정이다. 본 연구는 공공 휴게 녹지공간의 온도분석 및 온도의 변화요인을 파악하는데 목적이 있다. 대상지로는 전남대학교 민주마루 앞 광장을 설정하였다. 대상지의 피복상태, 식재형태를 조사 후, 온도, 습도, 풍향, 풍속 등을 측정하여 요인들을 분석하였다. 측정기준은 기상청 기준 오후 2시에 전운량 30% 이하, 습도 90% 이하, 온도는 최고온도 30℃ 이상인 날로 지정하였다. 온도 실측은 크게 1차 실측과 2차 실측으로 구분하여 측정하였다. 1차 실험은 2018년 6월 1일부터 6월 21일까지 30도를 기준일로 6일간, 2차 실험은 2018년 7월 27일부터 8월 1일까지 35도를 기준으로 3일간 측정을 실시하였다. 온도분포에 가장 큰 영향을 미치는 요인은 증발산과 바람에 의한 열 이동으로 판단된다. 온도변화요인으로는 피복유형, 풍속/풍향, 식재유형 등이 있었다. 피복유형에서 목본 식재지는 저온역으로, 초지와 아스팔트 포장은 고온역으로 구분되었다. 풍속/풍향에서는 3.5m/s 이상의 바람이 불어올 때 남풍에서 1.2도, 서풍에서 0.7도, 북풍에서 0.4도, 동풍에서 0.5도씩 순간온도가 저감되었다. 식재유형에서는 녹지량이 많고, 바람의 영향을 많이 받는 형태일수록 온도가 저감되었다. 온도변화요인을 알아보기 위해 등온선을 작성하여, 풍향과 수목식재 위치 관계를 파악하였다.

• 한국수자원학회논문집
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• 제36권4호
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• pp.533-545
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• 2003

본 연구에서는 설마천 유역에서 관측된 여러 강우-유출사상을 분석하여, 각 사상마다 GIUH의 특성속도를 추정하고, 이를 분석하여 그 변동특성을 살펴보았다. 특히, 본 연구에서는 강우의 특성에 따른 특성속도의 변화에 초점을 맞추어 분석하였다. 설마천 유역의 순간단위도는 HEC-1모형을 이용하여 유도하였으며, 이렇게 유도된 순간 단위도의 첨두유량과 첨두시간을 GIUH의 그것과 비교함으로서 특성속도가 계산될 수 있도록 하였다. 각 강우사상별 특성속도는 GcIUH 및 강우의 여러 특성과 비교분석하였다. 이 과정을 통하여 얻은 결과를 정리하면 다음과 같다. (1) GIUH의 특성속도는 GcIUH의 그것보다 변동정도가 크고 아울러 약간 크게 산정되었으나 그 경향은 유사한 것으로 파악되었다. (2) 총유효우량(또는, 평균유효우량)이 GIUH의 특성속도를 상대적으로 잘 설명함을 파악할 수 있었다. 이는 회귀분석의 결과로 나타나는데 그 결정계수가 0.6 전후로 크게 나타났다. (3) 반대로 강우의 지속 기간이나 최대강우강도는 GIUH의 특성속도를 결정하는데 큰 영향을 끼치지 못하고 있음을 파악하였다. 회귀분석 결과 결정계수는 최대 0.3을 넘지 않았다. (4) 본 연구에서 분석한 강우사상들의 경우 GIUH의 특성속도의 분포가 평균 0.402m/s 표준편차0.173 m/s인 정규분포를 따르는 것으로 나타났으며, 주로 0.4∼0.5 m/s 사이에 대부분의 값이 위치하는 것으로 나타났다. 그 변동계수는 0.43정도로 유출의 경우(대략 1.0 정도)에 비해 훨씬 적은 변동특성을 나타냄을 확인할 수 있었다.

• 한국산학기술학회논문지
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• 제17권5호
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• pp.717-722
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• 2016

본 논문은 고장발생 초기 고장전류의 크기에 따라 피크전류제한 기능을 갖도록 하나의 철심에 기존 1차 코일과 2차 코일이 병렬로 연결된 초전도 소자 1과 추가적인 철심을 사용하여 3차 권선에 초전도 소자 2가 연결된 자기결합형 초전도한류기를 제안하였다. 이중 철심을 이용하여 코일 1과 코일 2간 병렬로 연결한 자기결합형 초전도한류기가 고장발생시 피크전류를 초전도 소자 1만이 분담하는 것을 확인할 수 있었다. 그 이유는 초기 사고전류의 순간적인 요소가 커서 초전도 소자 1이 ?치되어 작동하였으나, 코일 3에 흐르는 전류가 임계전류를 초과하지 않았고, 이로 인해 초전도 소자 2가 ?치되어 작동하지 않았기 때문이다. 사고 시 피크전류를 순차적인 초전도 소자로 제한하기 위해서는 코일 1이 낮은 자기인덕턴스 값을 갖고 있으면서도 코일 2보다 코일 3이 보다 높은 자기인덕턴스 값을 갖도록 설계해야 할 것이다. 또한, 고장 발생 초기 사고전류의 크기를 결정하는 고장조건 중의 하나인 1차 코일과 2차 코일간의 권선비가 0.25일 때 두 SFCL의 전류제한 및 회복특성에 대한 검증을 선로단락실험을 통해 분석되었다. 이 단락실험의 분석결과, 가극결선인 경우가 감극결선한 경우보다도 전류제한 및 회복특성이 더욱 우수함을 확인할 수 있었다.

• 한국전통조경학회지
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• 제35권4호
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• pp.126-133
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• 2017

본 연구는 조경기술기반 LID 시스템 적용에 따른 선릉 정릉 권역의 우수유출변화를 수문학적 관점에서 분석하였으며, 연구결과를 다음과 같이 정리할 수 있다. 첫째, 광화문 침수가 발생한 2011년 7월 27일 기준 최대순간강우량은 27일 10시에 기록된 183mm/hr로 시간당 최대강우량 57.5mm/hr에 비해 3배 이상의 강우강도가 10분간 집중된 것으로 확인되었다. 둘째, 토심기준 시나리오에서 담심 1,500mm의 경우 첨두유출량 제어가 가능하여 해당 조경기술기반 LID 시스템 적용 시 선릉 정릉 권역의 수해취약성을 개선할 수 있을 것으로 판단된다. 셋째, 담심 기준 시나리오에서 모든 토심 모형에서 첨두유출량 제어가 이루어지지 않았으나, 최초 우수유출을 토심 기준 시나리오에 비해 4시간 10분의 추가적인 지연효과를 기록하였다. 초기 우수유출저감에는 토심, 첨두유출량에는 담심이 상대적으로 중요한 지표로 해석되었다. 이를 통해 문화재 보호권역 내 경관친화적인 생태적 요소를 시스템화하여 적용할 경우 예상되는 수해방재효과를 이론적으로 확인할 수 있었다.

• 한국수산과학회지
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• 제25권4호
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• pp.282-290
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• 1992

한국근해 참조기의 지난 20여년 동안의 어획자료를 사용하여 잉여생산량 모델에 의해 추정된 MSY를 비교하여 보면, Shaefer와 Fox 모델에 의하여 추정된 값들은 각각 37,000mt와 33,450mt였고, Zhang 모델에 의하여 자원량과 순간어획사망계수를 적용시킨 MSY는 45,328mt, 자원량과 어획량 자료를 이용하는 방법에서는 40,160mt로 각각 추정되었다 이 현상은 이 모델들이 각기 독립된 다른 자료를 이용하여 MSY를 추정하였으나, 추정된 값은 거의 비슷한 결과를 보였다. 참조기자원을 가입당생산량 모델에 적용시킨 결과를 사용하여 자원관리 방안을 모색해 보면, 가능한 최대 가입당 생산량이 43g임에 비하여 현재의 $t_c=0.604, F=1.11$에서의 가입당생산량은 약 20g정도에 불과하다 여기서 $t_c$를 현재 상태로 고정시킨 후. 가입당생산량을 높이는 방안을 생각해 보면, F를 현재의 1.11에서 0.4 정도로 낮추어야 하나, 가입당생산량의 큰 증가는 없다. 즉, 현재의 20g에서 25g밖에 증가되지 않는다. 그러나, 현재의 어획강도(F)를 고정시키는 경우에는 $t_c$를 현재의 0.604세에서 3세 부근으로 조정하면 최대의 가입당생산량(43g)을 얻을 수 있고, 이 $t_c$ 값은 역시 $F_{0.1}$, 방법에서 추정된 적정어획체장을 연령으로 환산한 결과와 거의 일치함을 알 수 있다. Zhang모델을 이용한 자원의 회복 방안에서 참조기 자원의 최대생산가능 자원량$(B^*_{MSY})$를 유지시키려면 F를 약 0.5 수준으로 낮추어야 하고. 이 수준에서 약 8년 뒤에는 자원량이 적정 수준에 거의 접근하게 된다.-저층의 경우, 난류성 종인 E. russelli와 E. plana가 출현하며 수온이 $12^{\circ}C$이상인 제주도 서북방 해역이 난류의 영향을 받는 해역으로 나타났으며, 저온성 종인 C. abdominalis가 출현하는 진도 이북 해역이 황해 냉수괴인 것으로 나타났다. 하계 0-20m층의 진도부관 해역 및 20m- 저층의 진도 이북 해역에서 C. abdominalis가 출현하는 것으로 보아 냉수괴가 존재하는 것으로 나타났다.H와 온도에 대해서 복상어의 trypsin은 고등어의 두 trypsin보다 알칼리성측과 고온에 대해 안정하였으며, 저해제에 의하여서는 복상어 trypsin이 보다 예민하게 나타났다. 또한 BA-p-NA 합성기질에 대한 친화성에 있어서는 고등어의 두 trypsin이 복상어의 trypsin보다 높은 것을 알 수 있었다. 5. 아미노산 조성은 세 효소 모두 비슷하였으나, 고등어 trypsin B의 경우 arginine의 함량이 높은 특징을 보였다. 산성아미노산과 염기성아미노산의 비는 복상어 trypsin이 3.57, 고등어 trypsin A는 3.36, 그리고 고등어 trypsin B는 2.23이었다./TEX>에 의하여 저해를 받았으며, 그 저해의 정도는 고등어 trypsin-A와 B가 보다 심하게 받았다. 또 이들 효소들은 antipain, leupeptin, TLCK(to-syllysine chloromethyl ketone) 및 SBTI(soybean trypsin inhibitor)에 의하여 현저한 저해를 받았고, PMSF(phenylmethane sulfonylfluoride), DFP(diisopropyl fluorophosphate) 및 benzamidine에 의하여 어느정도 저해를 보여 모두 serine-계의

• 농업과학연구
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• 제14권1호
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• pp.98-133
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• 1987

The mechanical and rheological properties of agricultural materials are important for engineering design and analysis of their mechanical harvesting, handling, transporting and processing systems. Agricultural materials, which composed of structural members and fluids do not react in a purely elastic manner, and their response when subjected to stress and strain is a combination of elastic and viscous behavior so called viscoelastic behavior. Many researchers have conducted studies on the mechanical and rheological properties of the various agricultural products, but a few researcher has studied those properties of rice plant, and also those data are available only for foreign varieties of rice plant. This study are conducted to experimentally determine the mechanical and the rheological properties such as axial compressive strength, tensile strength, bending and shear strength, stress relaxation and creep behavior of rice stems, and grain detachment strength. The rheological models for the rice stem were developed from the test data. The shearing characteristics were examined at some different levels of portion, cross-sectional area, moisture content of rice stem and shearing angle. The results obtained from this study were summarized as follows 1. The mechanical properties of the stems of the J aponica types were greater than those of the Indica ${\times}$ Japonica hybrid in compression, tension, bendingand shearing. 2. The mean value of the compressive force was 80.5 N in the Japonica types and 55.5 N in the Indica ${\times}$ Japonica hybrid which was about 70 percent to that of the Japonica types, and then the value increased progressively at the lower portion of the stems generally. 3. The average tensile force was about 226.6 N in the Japonica types and 123.6 N in the Indica ${\times}$ Japonica hybrid which was about 55 percent to that of the Japonica types. 4. The bending moment was $0.19N{\cdot}m$ in the Japonica types and $0.13N{\cdot}m$ in the Indica ${\times}$ Japonica hybrid which was 68 percent to that of the Japonica types and the bending strength was 7.7 MPa in the Japonica types and 6.5 MPa in the Indica ${\times}$ Japonica hybrid respectively. 5. The shearing force was 141.1 N in Jinju, the Japonica type and 101.4 N in Taebaeg, the Indica ${\times}$ Japonica hybrid which was 72 percent to that of Jinju, and the shearing strength of Taebaeg was 63 percent to that of Jinju. 6. The shearing force and the shearing energy along the stem portion in Jinju increased progressively together at the lower portions, meanwhile in Taebaeg the shearing force showed the maximum value at the intermediate portion and the shearing energy was the greatest at the portion of 21 cm from the ground level, and also the shearing strength and the shearing energy per unit cross-sectional area of the stem were the greater values at the intermediate portion than at any other portions. 7. The shearing force and the shearing energy increased with increase of the cross-sectional area of the rice stem and with decrease of the shearing angie from $90^{\circ}$ to $50^{\circ}$. 8. The shearing forces showed the minimum values of 110 N at Jinju and of 60 N at Taebaeg, the shearing energy at the moisture content decreased about 15 percent point from initial moisture content showed value of 50 mJ in Jinju and of 30 mJ in Taebaeg, respectively. 9. The stress relaxation behavior could be described by the generalized Maxwell model and also the compression creep behavior by Burger's model, respectively in the rice stem. 10. With increase of loading rate, the stress relaxation intensity increased, meanwhile the relaxation time and residual stress decreased. 11. In the compression creep test, the logarithmic creep occured at the stress less than 2.0 MPa and the steady-state creep at the stress larger than 2.0 MPa. 12. The stress level had not a significant effect on the relaxation time, while the relaxation intensity and residual stress increased with increase of the stress level. 13. In the compression creep test of the rice stem, the instantaneous elastic modulus of Burger's model showed the range of 60 to 80 MPa and the viscosities of the free dashpot were very large numerical value which was well explained that the rice stem was viscoelastic material. 14. The tensile detachment forces were about 1.7 to 2.3 N in the Japonica types while about 1.0 to 1.3 N in Indica ${\times}$ Japonica hybrid corresponding to 58 percent of Japonica types, and the bending detachment forces were about 0.6 to 1.1 N corresponding to 30 to 50 percent of the tensile detachment forces, and the bending detachment of the Indica ${\times}$ Japonica hybrid was 0.1 to 0.3 N which was 7 to 21 percent of Japonica types. 15. The detachment force of the lower portion was little bigger than that of the upper portion in a penicle and was not significantly affected by the harvesting period from September 28 to October 20. 16. The tensile and bending detachment forces decreased with decrease of the moisture content from 23 to 13 percent (w.b.) by the natural drying, and the decreasing rate of detachment forces along the moisture content was the greater in the bending detachment force than the tensile detachment force.

• 생태와환경
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• 제44권2호
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• pp.172-177
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• 2011

본 연구는 최적화된 자원량을 기반으로 최대 생산성을 얻을 수 있는 잠재생산량 추정을 통한 어족자원(꺽지)의 효율적 관리방안을 모색하고자 하였다. 이를 위해 섬진강 중 상류 수계에서 2008년 8월부터 2009년 4월까지 계절별로 총 4회 조사를 실시하였다. 자원량 추정은 소해면 적법(Swept Area method)을 이용하였으며, 잠재생산량은 생물학적 허용어획량(Allowable Biological Catch, ABC)에 기초한 어족자원 잠재력 추정시스템을 수정 보완하여 사용하였다. 또한, 꺽지 자원의 효율적인 관리 방안을 검토하기 위해 가입당생산량모델(Beverton and Holt)을 사용하였다. 연구결과, 어획개시연령($t_c$)은 1.464 age로 나타났으며, 이를 체장으로 환산한 결과 7.8 cm(BL)로 확인되었다. 현재 어획강도를 나타내는 순간어획사망계수(F)는 0.061 $year^{-1}$이었으며, 이를 기준으로 한가입당 생산량(Y/R)은 4.124 g로 추정되었다. 어획개시연령($t_c$)과 순간어획사망계수(F)를 기준으로 한 적정어획사망계수($F_{ABC}$)는 0.401 $year^{-1}$로 추정되었는데 이는 현재 꺽지 자원에 대한 어획강도가 매우 낮은 상태임을 시사한다. 꺽지의 연간 자원량은 3,048 kg으로 나타났으며, 현재 어획개시연령과 적정어획사망계수를($F_{ABC}$)를 바탕으로 한 잠재생산량은 861 kg으로 추정되었다. 가입당 생산량 모델을 사용하여 어획개시연령을 3 age로 어획사망계수는 0.643 $year^{-1}$로 가정할 경우, 가입당 생산량은 현재의 4.12 g에서 13.84 g로 약 3.4배 증가될 것으로 예상되었다.

• 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.